Fix clang-tidy check readability-implicit-bool-cast.

186 files changed, 2442 insertions, 2320 deletions

diff --git a/src/gui/dialogsmanager.cpp b/src/gui/dialogsmanager.cpp
index b4a3cc6ea..9b2335736 100644
--- a/src/gui/dialogsmanager.cpp
+++ b/src/gui/dialogsmanager.cpp
@@ -82,11 +82,11 @@ void DialogsManager::closeDialogs()
     BuySellDialog::closeAll();
     NpcDialog::closeAll();
     SellDialog::closeAll();
-    if (inventoryHandler)
+    if (inventoryHandler != nullptr)
         inventoryHandler->destroyStorage();
 #endif  // DYECMD
 
-    if (deathNotice)
+    if (deathNotice != nullptr)
     {
         deathNotice->scheduleDelete();
         deathNotice = nullptr;
@@ -139,7 +139,7 @@ Window *DialogsManager::openErrorDialog(const std::string &header,
 void DialogsManager::playerDeath()
 {
 #ifndef DYECMD
-    if (!deathNotice)
+    if (deathNotice == nullptr)
     {
         CREATEWIDGETV(deathNotice, OkDialog,
             // TRANSLATORS: message header
@@ -164,7 +164,7 @@ void DialogsManager::attributeChanged(const AttributesT id,
 {
     if (id == Attributes::TOTAL_WEIGHT)
     {
-        if (!weightNotice && config.getBoolValue("weightMsg"))
+        if ((weightNotice == nullptr) && config.getBoolValue("weightMsg"))
         {
             int percent = settings.overweightPercent;
             if (percent < 1)
diff --git a/src/gui/focushandler.cpp b/src/gui/focushandler.cpp
index 1c6b86954..21b80d9bf 100644
--- a/src/gui/focushandler.cpp
+++ b/src/gui/focushandler.cpp
@@ -92,14 +92,14 @@ void FocusHandler::requestModalFocus(Widget *const widget)
     /* If there is another widget with modal focus, remove its modal focus
      * and put it on the modal widget stack.
      */
-    if (mModalFocusedWidget && mModalFocusedWidget != widget)
+    if ((mModalFocusedWidget != nullptr) && mModalFocusedWidget != widget)
     {
         mModalStack.push_front(mModalFocusedWidget);
         mModalFocusedWidget = nullptr;
     }
 
     mModalFocusedWidget = widget;
-    if (mFocusedWidget && !mFocusedWidget->isModalFocused())
+    if ((mFocusedWidget != nullptr) && !mFocusedWidget->isModalFocused())
         focusNone();
 }
 
@@ -171,7 +171,7 @@ void FocusHandler::remove(Widget *const widget)
 
 void FocusHandler::tabNext()
 {
-    if (mFocusedWidget)
+    if (mFocusedWidget != nullptr)
     {
         if (!mFocusedWidget->isTabOutEnabled())
             return;
@@ -217,7 +217,7 @@ void FocusHandler::tabNext()
 
         const Widget *const widget = mWidgets.at(focusedWidget);
         if (widget->isFocusable() && widget->isTabInEnabled() &&
-            (!mModalFocusedWidget || widget->isModalFocused()))
+            ((mModalFocusedWidget == nullptr) || widget->isModalFocused()))
         {
             done = true;
         }
@@ -242,7 +242,7 @@ void FocusHandler::tabNext()
 
 void FocusHandler::tabPrevious()
 {
-    if (mFocusedWidget)
+    if (mFocusedWidget != nullptr)
     {
         if (!mFocusedWidget->isTabOutEnabled())
             return;
@@ -288,7 +288,7 @@ void FocusHandler::tabPrevious()
 
         const Widget *const widget = mWidgets.at(focusedWidget);
         if (widget->isFocusable() && widget->isTabInEnabled() &&
-            (!mModalFocusedWidget || widget->isModalFocused()))
+            ((mModalFocusedWidget == nullptr) || widget->isModalFocused()))
         {
             done = true;
         }
@@ -313,15 +313,15 @@ void FocusHandler::tabPrevious()
 
 void FocusHandler::checkForWindow() const
 {
-    if (mFocusedWidget)
+    if (mFocusedWidget != nullptr)
     {
         Widget *widget = mFocusedWidget->getParent();
 
-        while (widget)
+        while (widget != nullptr)
         {
             Window *const window = dynamic_cast<Window*>(widget);
 
-            if (window)
+            if (window != nullptr)
             {
                 window->requestMoveToTop();
                 break;
@@ -334,12 +334,12 @@ void FocusHandler::checkForWindow() const
 
 void FocusHandler::distributeFocusGainedEvent(const Event &focusEvent)
 {
-    if (gui)
+    if (gui != nullptr)
         gui->distributeGlobalFocusGainedEvent(focusEvent);
 
     const Widget *const sourceWidget = focusEvent.getSource();
 
-    if (!sourceWidget)
+    if (sourceWidget == nullptr)
         return;
     std::list<FocusListener*> focusListeners
         = sourceWidget->getFocusListeners();
@@ -356,7 +356,7 @@ void FocusHandler::distributeFocusGainedEvent(const Event &focusEvent)
 
 void FocusHandler::requestFocus(const Widget *const widget)
 {
-    if (!widget || widget == mFocusedWidget)
+    if ((widget == nullptr) || widget == mFocusedWidget)
         return;
 
     int toBeFocusedIndex = -1;
@@ -379,7 +379,7 @@ void FocusHandler::requestFocus(const Widget *const widget)
     {
         mFocusedWidget = mWidgets.at(toBeFocusedIndex);
 
-        if (oldFocused)
+        if (oldFocused != nullptr)
         {
             Event focusEvent(oldFocused);
             distributeFocusLostEvent(focusEvent);
@@ -392,7 +392,7 @@ void FocusHandler::requestFocus(const Widget *const widget)
 
 void FocusHandler::requestModalMouseInputFocus(Widget *const widget)
 {
-    if (mModalMouseInputFocusedWidget
+    if ((mModalMouseInputFocusedWidget != nullptr)
         && mModalMouseInputFocusedWidget != widget)
     {
         return;
@@ -539,7 +539,7 @@ void FocusHandler::add(Widget *const widget)
 
 void FocusHandler::focusNone()
 {
-    if (mFocusedWidget)
+    if (mFocusedWidget != nullptr)
     {
         Widget *const focused = mFocusedWidget;
         mFocusedWidget = nullptr;
@@ -552,7 +552,7 @@ void FocusHandler::focusNone()
 void FocusHandler::distributeFocusLostEvent(const Event& focusEvent)
 {
     const Widget *const sourceWidget = focusEvent.getSource();
-    if (!sourceWidget)
+    if (sourceWidget == nullptr)
         return;
 
     std::list<FocusListener*> focusListeners
diff --git a/src/gui/fonts/font.cpp b/src/gui/fonts/font.cpp
index fc752c2eb..78c243a70 100644
--- a/src/gui/fonts/font.cpp
+++ b/src/gui/fonts/font.cpp
@@ -128,7 +128,7 @@ Font::Font(std::string filename,
         size = 4;
     }
 
-    if (!fontCounter)
+    if (fontCounter == 0)
     {
         strBuf = new char[65535];
         memset(strBuf, 0, 65535);
@@ -141,13 +141,13 @@ Font::Font(std::string filename,
         filename.c_str());
     mFont = openFont(filename.c_str(), size);
 
-    if (!mFont)
+    if (mFont == nullptr)
     {
         logger->log("Error normal loading font " + filename);
 
         filename = "fonts/dejavusans.ttf";
         mFont = openFont(fixDirSeparators(filename).c_str(), size);
-        if (!mFont)
+        if (mFont == nullptr)
         {
 #ifdef UNITTESTS
             reportAlways("Font load failed %s",
@@ -229,14 +229,14 @@ void Font::loadFont(std::string filename,
     fixDirSeparators(filename);
     TTF_Font *const font = openFont(filename.c_str(), size);
 
-    if (!font)
+    if (font == nullptr)
     {
         logger->log("Font::Font: " +
                     std::string(TTF_GetError()));
         return;
     }
 
-    if (mFont)
+    if (mFont != nullptr)
         TTF_CloseFont(mFont);
 
     mFont = font;
@@ -283,7 +283,7 @@ void Font::drawString(Graphics *const graphics,
         TextChunk *const chunk2 = (*i).second;
         cache->moveToFirst(chunk2);
         Image *const image = chunk2->img;
-        if (image)
+        if (image != nullptr)
         {
             image->setAlpha(alpha);
             graphics->drawImage(image, x, y);
@@ -309,7 +309,7 @@ void Font::drawString(Graphics *const graphics,
         cache->insertFirst(chunk2);
 
         const Image *const image = chunk2->img;
-        if (image)
+        if (image != nullptr)
             graphics->drawImage(image, x, y);
     }
     BLOCK_END("Font::drawString")
@@ -318,7 +318,7 @@ void Font::drawString(Graphics *const graphics,
 void Font::slowLogic(const int rnd)
 {
     BLOCK_START("Font::slowLogic")
-    if (!mCleanTime)
+    if (mCleanTime == 0)
     {
         mCleanTime = cur_time + CLEAN_TIME + rnd;
     }
@@ -345,7 +345,7 @@ int Font::getWidth(const std::string &text) const
         TextChunk *const chunk = (*i).second;
         cache->moveToFirst(chunk);
         const Image *const image = chunk->img;
-        if (image)
+        if (image != nullptr)
             return image->getWidth();
         else
             return 0;
@@ -476,7 +476,7 @@ void Font::generate(TextChunk &chunk)
 
 void Font::insertChunk(TextChunk *const chunk)
 {
-    if (!chunk || chunk->text.empty() || !chunk->img)
+    if ((chunk == nullptr) || chunk->text.empty() || (chunk->img == nullptr))
         return;
 //    logger->log("insert chunk: text=%s, color: %d,%d,%d",
 //        chunk->text.c_str(), chunk->color.r, chunk->color.g, chunk->color.b);
diff --git a/src/gui/fonts/textchunk.cpp b/src/gui/fonts/textchunk.cpp
index de2c58084..694790881 100644
--- a/src/gui/fonts/textchunk.cpp
+++ b/src/gui/fonts/textchunk.cpp
@@ -113,7 +113,7 @@ void TextChunk::generate(TTF_Font *restrict const font,
     SDL_Surface *surface = MTTF_RenderUTF8_Blended(
         font, strBuf, sdlCol);
 
-    if (!surface)
+    if (surface == nullptr)
     {
         img = nullptr;
         BLOCK_END("TextChunk::generate")
@@ -129,7 +129,7 @@ void TextChunk::generate(TTF_Font *restrict const font,
         SDL_Color sdlCol2;
         SDL_Surface *const background = imageHelper->create32BitSurface(
             width, height);
-        if (!background)
+        if (background == nullptr)
         {
             img = nullptr;
             MSDL_FreeSurface(surface);
@@ -148,7 +148,7 @@ void TextChunk::generate(TTF_Font *restrict const font,
 
         SDL_Surface *const surface2 = MTTF_RenderUTF8_Blended(
             font, strBuf, sdlCol2);
-        if (!surface2)
+        if (surface2 == nullptr)
         {
             img = nullptr;
             MSDL_FreeSurface(surface);
@@ -191,7 +191,7 @@ void TextChunk::generate(TTF_Font *restrict const font,
 
 void TextChunk::deleteImage()
 {
-    if (textFont)
+    if (textFont != nullptr)
     {
         textFont->insertChunk(this);
         img = nullptr;
diff --git a/src/gui/fonts/textchunklist.cpp b/src/gui/fonts/textchunklist.cpp
index df791f5f9..4ce39406b 100644
--- a/src/gui/fonts/textchunklist.cpp
+++ b/src/gui/fonts/textchunklist.cpp
@@ -36,10 +36,10 @@ TextChunkList::TextChunkList() :
 void TextChunkList::insertFirst(TextChunk *restrict const item)
 {
     TextChunk *restrict const oldFirst = start;
-    if (start)
+    if (start != nullptr)
         start->prev = item;
     item->prev = nullptr;
-    if (oldFirst)
+    if (oldFirst != nullptr)
         item->next = oldFirst;
     else
         end = item;
@@ -55,15 +55,15 @@ void TextChunkList::moveToFirst(TextChunk *restrict const item)
         return;
 
     TextChunk *restrict const oldPrev = item->prev;
-    if (oldPrev)
+    if (oldPrev != nullptr)
         oldPrev->next = item->next;
     TextChunk *restrict const oldNext = item->next;
-    if (oldNext)
+    if (oldNext != nullptr)
         oldNext->prev = item->prev;
     else
         end = oldPrev;
     TextChunk *restrict const oldFirst = start;
-    if (start)
+    if (start != nullptr)
         start->prev = item;
     item->prev = nullptr;
     item->next = oldFirst;
@@ -72,16 +72,16 @@ void TextChunkList::moveToFirst(TextChunk *restrict const item)
 
 void TextChunkList::remove(const TextChunk *restrict const item)
 {
-    if (!item)
+    if (item == nullptr)
         return;
 
     TextChunk *restrict const oldPrev = item->prev;
     TextChunk *restrict const oldNext = item->next;
-    if (oldPrev)
+    if (oldPrev != nullptr)
         oldPrev->next = item->next;
     else
         start = oldNext;
-    if (oldNext)
+    if (oldNext != nullptr)
         oldNext->prev = item->prev;
     else
         end = oldPrev;
@@ -95,10 +95,10 @@ void TextChunkList::remove(const TextChunk *restrict const item)
 void TextChunkList::removeBack()
 {
     TextChunk *restrict oldEnd = end;
-    if (oldEnd)
+    if (oldEnd != nullptr)
     {
         end = oldEnd->prev;
-        if (end)
+        if (end != nullptr)
             end->next = nullptr;
         else
             start = nullptr;
@@ -113,7 +113,7 @@ void TextChunkList::removeBack()
 void TextChunkList::removeBack(int n)
 {
     TextChunk *restrict item = end;
-    while (n && item)
+    while ((n != 0) && (item != nullptr))
     {
         n --;
         TextChunk *oldEnd = item;
@@ -124,7 +124,7 @@ void TextChunkList::removeBack(int n)
         delete oldEnd;
         size --;
     }
-    if (item)
+    if (item != nullptr)
     {
         item->next = nullptr;
         end = item;
@@ -141,7 +141,7 @@ void TextChunkList::clear()
     search.clear();
     searchWidth.clear();
     TextChunk *restrict item = start;
-    while (item)
+    while (item != nullptr)
     {
         TextChunk *restrict const item2 = item->next;
         delete item;
diff --git a/src/gui/gui.cpp b/src/gui/gui.cpp
index 04c9e3ada..8063207c6 100644
--- a/src/gui/gui.cpp
+++ b/src/gui/gui.cpp
@@ -269,13 +269,13 @@ Gui::~Gui()
     config.removeListeners(mConfigListener);
     delete2(mConfigListener);
 
-    if (mMouseCursors)
+    if (mMouseCursors != nullptr)
     {
         mMouseCursors->decRef();
         mMouseCursors = nullptr;
     }
 
-    if (windowContainer)
+    if (windowContainer != nullptr)
         windowContainer->slowLogic();
     Widget *top = mTop;
     if (Widget::widgetExists(mTop))
@@ -303,7 +303,7 @@ void Gui::logic()
     BLOCK_START("Gui::logic")
     ResourceManager::clearScheduled();
 
-    if (!mTop)
+    if (mTop == nullptr)
     {
         BLOCK_END("Gui::logic")
         return;
@@ -312,7 +312,7 @@ void Gui::logic()
     handleModalFocus();
     handleModalMouseInputFocus();
 
-    if (guiInput)
+    if (guiInput != nullptr)
         handleMouseInput();
 
     mTop->logic();
@@ -334,26 +334,26 @@ void Gui::slowLogic()
     {
         mMouseCursorAlpha = std::max(0.0F, mMouseCursorAlpha - 0.005F);
     }
-    if (mGuiFont)
+    if (mGuiFont != nullptr)
         mGuiFont->slowLogic(0);
-    if (mInfoParticleFont)
+    if (mInfoParticleFont != nullptr)
         mInfoParticleFont->slowLogic(1);
-    if (mHelpFont)
+    if (mHelpFont != nullptr)
         mHelpFont->slowLogic(2);
-    if (mSecureFont)
+    if (mSecureFont != nullptr)
         mSecureFont->slowLogic(3);
-    if (boldFont)
+    if (boldFont != nullptr)
         boldFont->slowLogic(4);
-    if (mNpcFont)
+    if (mNpcFont != nullptr)
         mNpcFont->slowLogic(5);
-    if (windowContainer)
+    if (windowContainer != nullptr)
         windowContainer->slowLogic();
 
     const time_t time = cur_time;
     if (mTime != time)
     {
         logger->flush();
-        if (ipc)
+        if (ipc != nullptr)
             ipc->flush();
         mTime = time;
 
@@ -369,23 +369,23 @@ void Gui::slowLogic()
 
 void Gui::clearFonts()
 {
-    if (mGuiFont)
+    if (mGuiFont != nullptr)
         mGuiFont->clear();
-    if (mInfoParticleFont)
+    if (mInfoParticleFont != nullptr)
         mInfoParticleFont->clear();
-    if (mHelpFont)
+    if (mHelpFont != nullptr)
         mHelpFont->clear();
-    if (mSecureFont)
+    if (mSecureFont != nullptr)
         mSecureFont->clear();
-    if (boldFont)
+    if (boldFont != nullptr)
         boldFont->clear();
-    if (mNpcFont)
+    if (mNpcFont != nullptr)
         mNpcFont->clear();
 }
 
 bool Gui::handleInput()
 {
-    if (mInput)
+    if (mInput != nullptr)
         return handleKeyInput();
     else
         return false;
@@ -393,7 +393,7 @@ bool Gui::handleInput()
 
 bool Gui::handleKeyInput()
 {
-    if (!guiInput)
+    if (guiInput == nullptr)
         return false;
 
     BLOCK_START("Gui::handleKeyInput")
@@ -423,12 +423,12 @@ bool Gui::handleKeyInput()
             continue;
         }
 
-        if (mFocusHandler)
+        if (mFocusHandler != nullptr)
         {
             bool eventConsumed = false;
 
             // Send key inputs to the focused widgets
-            if (mFocusHandler->getFocused())
+            if (mFocusHandler->getFocused() != nullptr)
             {
                 KeyEvent event(getKeyEventSource(),
                     keyInput.getType(),
@@ -470,7 +470,7 @@ void Gui::draw()
 {
     BLOCK_START("Gui::draw 1")
     Widget *const top = getTop();
-    if (!top)
+    if (top == nullptr)
         return;
     mGraphics->pushClipArea(top->getDimension());
 
@@ -489,25 +489,29 @@ void Gui::draw()
     int mouseY;
     const MouseStateType button = getMouseState(mouseX, mouseY);
 
-    if ((settings.mouseFocused || button & SDL_BUTTON(1))
-        && mMouseCursors && mCustomCursor && mMouseCursorAlpha > 0.0F)
+    if ((settings.mouseFocused ||
+        ((button & SDL_BUTTON(1)) != 0)) &&
+        mMouseCursors != nullptr &&
+        mCustomCursor &&
+        mMouseCursorAlpha > 0.0F)
     {
 #ifndef DYECMD
         const Image *const image = dragDrop.getItemImage();
-        if (mGuiFont)
+        if (mGuiFont != nullptr)
         {
             const std::string &str = dragDrop.getText();
             if (!str.empty())
             {
                 const int posX = mouseX - mGuiFont->getWidth(str) / 2;
-                const int posY = mouseY + (image ? image->mBounds.h / 2 : 0);
+                const int posY = mouseY +
+                    (image != nullptr ? image->mBounds.h / 2 : 0);
                 mGuiFont->drawString(mGraphics,
                     mForegroundColor, mForegroundColor2,
                     str,
                     posX, posY);
             }
         }
-        if (image)
+        if (image != nullptr)
         {
             const int posX = mouseX - (image->mBounds.w / 2);
             const int posY = mouseY - (image->mBounds.h / 2);
@@ -517,7 +521,7 @@ void Gui::draw()
 
         Image *const mouseCursor = mMouseCursors->get(
             CAST_SIZE(mCursorType));
-        if (mouseCursor)
+        if (mouseCursor != nullptr)
         {
             mouseCursor->setAlpha(mMouseCursorAlpha);
             mGraphics->drawImage(mouseCursor, mouseX - 15, mouseY - 17);
@@ -532,7 +536,7 @@ void Gui::videoResized() const
 {
     WindowContainer *const top = static_cast<WindowContainer *>(getTop());
 
-    if (top)
+    if (top != nullptr)
     {
         const int oldWidth = top->getWidth();
         const int oldHeight = top->getHeight();
@@ -541,7 +545,7 @@ void Gui::videoResized() const
         top->adjustAfterResize(oldWidth, oldHeight);
     }
 
-    if (viewport)
+    if (viewport != nullptr)
         viewport->videoResized();
     Widget::distributeWindowResizeEvent();
 }
@@ -558,11 +562,11 @@ void Gui::setUseCustomCursor(const bool customCursor)
             SDL::showCursor(false);
 
             // Load the mouse cursor
-            if (mMouseCursors)
+            if (mMouseCursors != nullptr)
                 mMouseCursors->decRef();
             mMouseCursors = Theme::getImageSetFromTheme("mouse.png", 40, 40);
 
-            if (!mMouseCursors)
+            if (mMouseCursors == nullptr)
                 logger->log("Error: Unable to load mouse cursors.");
         }
         else
@@ -571,7 +575,7 @@ void Gui::setUseCustomCursor(const bool customCursor)
             SDL::showCursor(true);
 
             // Unload the mouse cursor
-            if (mMouseCursors)
+            if (mMouseCursors != nullptr)
             {
                 mMouseCursors->decRef();
                 mMouseCursors = nullptr;
@@ -583,9 +587,12 @@ void Gui::setUseCustomCursor(const bool customCursor)
 void Gui::handleMouseMoved(const MouseInput &mouseInput)
 {
     // Check if the mouse leaves the application window.
-    if (mTop && !mWidgetWithMouseQueue.empty() && (mouseInput.getX() < 0
-        || mouseInput.getY() < 0 || !mTop->getDimension().isPointInRect(
-        mouseInput.getX(), mouseInput.getY())))
+    if (mTop != nullptr &&
+        !mWidgetWithMouseQueue.empty() &&
+        (mouseInput.getX() < 0 ||
+        mouseInput.getY() < 0 ||
+        !mTop->getDimension().isPointInRect(mouseInput.getX(),
+        mouseInput.getY())))
     {
         // Distribute an event to all widgets in the
         // "widget with mouse" queue.
@@ -681,10 +688,10 @@ void Gui::handleMouseMoved(const MouseInput &mouseInput)
     // widget with modal mouse input focus, hence we need to check if
     // that's the case. If it's not we should simply ignore to send any
     // mouse entered events.
-    if (mFocusHandler->getModalMouseInputFocused()
+    if ((mFocusHandler->getModalMouseInputFocused() != nullptr)
         && widget == mFocusHandler->getModalMouseInputFocused()
         && Widget::widgetExists(widget) &&
-        widget)
+        (widget != nullptr))
     {
         int x, y;
         widget->getAbsolutePosition(x, y);
@@ -697,7 +704,7 @@ void Gui::handleMouseMoved(const MouseInput &mouseInput)
         }
     }
 
-    while (parent)
+    while (parent != nullptr)
     {
         parent = widget->getParent();
 
@@ -733,7 +740,7 @@ void Gui::handleMouseMoved(const MouseInput &mouseInput)
         parent = swap->getParent();
     }
 
-    if (mFocusHandler->getDraggedWidget())
+    if (mFocusHandler->getDraggedWidget() != nullptr)
     {
         distributeMouseEvent(mFocusHandler->getDraggedWidget(),
                              MouseEventType::DRAGGED,
@@ -762,18 +769,18 @@ void Gui::handleMousePressed(const MouseInput &mouseInput)
 
     Widget *sourceWidget = getMouseEventSource(x, y);
 
-    if (mFocusHandler->getDraggedWidget())
+    if (mFocusHandler->getDraggedWidget() != nullptr)
         sourceWidget = mFocusHandler->getDraggedWidget();
 
-    if (!sourceWidget)
+    if (sourceWidget == nullptr)
         return;
     int sourceWidgetX;
     int sourceWidgetY;
     sourceWidget->getAbsolutePosition(sourceWidgetX, sourceWidgetY);
 
-    if ((mFocusHandler->getModalFocused()
+    if (((mFocusHandler->getModalFocused() != nullptr)
         && sourceWidget->isModalFocused())
-        || !mFocusHandler->getModalFocused())
+        || (mFocusHandler->getModalFocused() == nullptr))
     {
         sourceWidget->requestFocus();
     }
@@ -834,7 +841,7 @@ void Gui::distributeMouseEvent(Widget *const source,
                                const bool force,
                                const bool toSourceOnly)
 {
-    if (!source || !mFocusHandler)
+    if ((source == nullptr) || (mFocusHandler == nullptr))
         return;
 
     Widget *widget = source;
@@ -858,7 +865,7 @@ void Gui::distributeMouseEvent(Widget *const source,
         x, y, mClickCount);
 
     Widget* parent = source;
-    while (parent)
+    while (parent != nullptr)
     {
         // If the widget has been removed due to input
         // cancel the distribution.
@@ -932,12 +939,12 @@ void Gui::distributeMouseEvent(Widget *const source,
             dragDrop.clear();
 #endif  // DYECMD
 
-        if (!widget || event.isConsumed())
+        if ((widget == nullptr) || event.isConsumed())
             break;
 
         // If a non modal focused widget has been reach
         // and we have modal focus cancel the distribution.
-        if (mFocusHandler->getModalFocused()
+        if ((mFocusHandler->getModalFocused() != nullptr)
             && !widget->isModalFocused())
         {
             break;
@@ -945,7 +952,7 @@ void Gui::distributeMouseEvent(Widget *const source,
 
         // If a non modal mouse input focused widget has been reach
         // and we have modal mouse input focus cancel the distribution.
-        if (mFocusHandler->getModalMouseInputFocused()
+        if ((mFocusHandler->getModalMouseInputFocused() != nullptr)
             && !widget->isModalMouseInputFocused())
         {
             break;
@@ -961,7 +968,7 @@ void Gui::resetClickCount()
 
 MouseEvent *Gui::createMouseEvent(Window *const widget)
 {
-    if (!viewport || !widget)
+    if ((viewport == nullptr) || (widget == nullptr))
         return nullptr;
 
     int x = 0;
@@ -984,11 +991,11 @@ void Gui::getAbsolutePosition(Widget *restrict widget,
                               int &restrict x,
                               int &restrict y)
 {
-    if (!widget)
+    if (widget == nullptr)
         return;
     x = 0;
     y = 0;
-    while (widget->getParent())
+    while (widget->getParent() != nullptr)
     {
         x += widget->getX();
         y += widget->getY();
@@ -1061,14 +1068,14 @@ void Gui::handleMouseReleased(const MouseInput &mouseInput)
 
     int sourceWidgetX;
     int sourceWidgetY;
-    if (mFocusHandler->getDraggedWidget())
+    if (mFocusHandler->getDraggedWidget() != nullptr)
     {
         if (sourceWidget != mFocusHandler->getLastWidgetPressed())
             mFocusHandler->setLastWidgetPressed(nullptr);
 
         Widget *const oldWidget = sourceWidget;
         sourceWidget = mFocusHandler->getDraggedWidget();
-        if (oldWidget && oldWidget != sourceWidget)
+        if ((oldWidget != nullptr) && oldWidget != sourceWidget)
         {
             oldWidget->getAbsolutePosition(sourceWidgetX, sourceWidgetY);
             distributeMouseEvent(oldWidget,
@@ -1079,7 +1086,7 @@ void Gui::handleMouseReleased(const MouseInput &mouseInput)
         }
     }
 
-    if (!sourceWidget)
+    if (sourceWidget == nullptr)
         return;
     sourceWidget->getAbsolutePosition(sourceWidgetX, sourceWidgetY);
     distributeMouseEvent(sourceWidget,
@@ -1105,7 +1112,7 @@ void Gui::handleMouseReleased(const MouseInput &mouseInput)
         mClickCount = 0;
     }
 
-    if (mFocusHandler->getDraggedWidget())
+    if (mFocusHandler->getDraggedWidget() != nullptr)
         mFocusHandler->setDraggedWidget(nullptr);
 }
 
@@ -1131,7 +1138,7 @@ void Gui::distributeGlobalFocusGainedEvent(const Event &focusEvent)
 
 void Gui::removeDragged(const Widget *const widget)
 {
-    if (!mFocusHandler)
+    if (mFocusHandler == nullptr)
         return;
 
     if (mFocusHandler->getDraggedWidget() == widget)
@@ -1149,9 +1156,9 @@ MouseStateType Gui::getMouseState(int &x, int &y)
 
 void Gui::setTop(Widget *const top)
 {
-    if (mTop)
+    if (mTop != nullptr)
         mTop->setFocusHandler(nullptr);
-    if (top)
+    if (top != nullptr)
         top->setFocusHandler(mFocusHandler);
 
     mTop = top;
@@ -1192,10 +1199,10 @@ void Gui::handleMouseWheelMovedDown(const MouseInput& mouseInput)
     Widget* sourceWidget = getMouseEventSource(
         mouseInput.getX(), mouseInput.getY());
 
-    if (mFocusHandler->getDraggedWidget())
+    if (mFocusHandler->getDraggedWidget() != nullptr)
         sourceWidget = mFocusHandler->getDraggedWidget();
 
-    if (sourceWidget)
+    if (sourceWidget != nullptr)
     {
         int sourceWidgetX = 0;
         int sourceWidgetY = 0;
@@ -1214,10 +1221,10 @@ void Gui::handleMouseWheelMovedUp(const MouseInput& mouseInput)
     Widget* sourceWidget = getMouseEventSource(
         mouseInput.getX(), mouseInput.getY());
 
-    if (mFocusHandler->getDraggedWidget())
+    if (mFocusHandler->getDraggedWidget() != nullptr)
         sourceWidget = mFocusHandler->getDraggedWidget();
 
-    if (sourceWidget)
+    if (sourceWidget != nullptr)
     {
         int sourceWidgetX;
         int sourceWidgetY;
@@ -1238,14 +1245,14 @@ Widget* Gui::getWidgetAt(const int x, const int y) const
     Widget* child = mTop;
     Widget* selectable = mTop;
 
-    while (child)
+    while (child != nullptr)
     {
         Widget *const swap = child;
         int parentX, parentY;
         parent->getAbsolutePosition(parentX, parentY);
         child = parent->getWidgetAt(x - parentX, y - parentY);
         parent = swap;
-        if (parent && parent->isSelectable())
+        if ((parent != nullptr) && parent->isSelectable())
             selectable = parent;
     }
 
@@ -1255,11 +1262,12 @@ Widget* Gui::getWidgetAt(const int x, const int y) const
 Widget* Gui::getMouseEventSource(const int x, const int y) const
 {
     Widget *const widget = getWidgetAt(x, y);
-    if (!widget)
+    if (widget == nullptr)
         return nullptr;
 
-    if (mFocusHandler && mFocusHandler->getModalMouseInputFocused()
-        && !widget->isModalMouseInputFocused())
+    if (mFocusHandler != nullptr &&
+        mFocusHandler->getModalMouseInputFocused() != nullptr &&
+        !widget->isModalMouseInputFocused())
     {
         return mFocusHandler->getModalMouseInputFocused();
     }
@@ -1271,8 +1279,9 @@ Widget* Gui::getKeyEventSource() const
 {
     Widget* widget = mFocusHandler->getFocused();
 
-    while (widget && widget->getInternalFocusHandler()
-           && widget->getInternalFocusHandler()->getFocused())
+    while (widget != nullptr &&
+           widget->getInternalFocusHandler() != nullptr &&
+           widget->getInternalFocusHandler()->getFocused() != nullptr)
     {
         widget = widget->getInternalFocusHandler()->getFocused();
     }
@@ -1285,17 +1294,20 @@ void Gui::distributeKeyEvent(KeyEvent &event) const
     Widget* parent = event.getSource();
     Widget* widget = parent;
 
-    if (!parent)
+    if (parent == nullptr)
         return;
-    if (mFocusHandler->getModalFocused() && !widget->isModalFocused())
+    if (mFocusHandler->getModalFocused() != nullptr &&
+        !widget->isModalFocused())
+    {
         return;
-    if (mFocusHandler->getModalMouseInputFocused()
-        && !widget->isModalMouseInputFocused())
+    }
+    if (mFocusHandler->getModalMouseInputFocused() != nullptr &&
+        !widget->isModalMouseInputFocused())
     {
         return;
     }
 
-    while (parent)
+    while (parent != nullptr)
     {
         // If the widget has been removed due to input
         // cancel the distribution.
@@ -1334,8 +1346,8 @@ void Gui::distributeKeyEvent(KeyEvent &event) const
 
         // If a non modal focused widget has been reach
         // and we have modal focus cancel the distribution.
-        if (widget &&
-            mFocusHandler->getModalFocused() &&
+        if ((widget != nullptr) &&
+            (mFocusHandler->getModalFocused() != nullptr) &&
             !widget->isModalFocused())
         {
             break;
@@ -1376,7 +1388,7 @@ void Gui::handleModalMouseInputFocus()
     if (lastModalWidget != modalWidget)
     {
         // Check if modal mouse input focus has been gained by a widget.
-        if (!lastModalWidget)
+        if (lastModalWidget == nullptr)
         {
             handleModalFocusGained();
             mFocusHandler->setLastWidgetWithModalMouseInputFocus(modalWidget);
@@ -1401,7 +1413,7 @@ void Gui::handleModalFocus()
     if (lastModalWidget != modalWidget)
     {
         // Check if modal focus has been gained by a widget.
-        if (!lastModalWidget)
+        if (lastModalWidget == nullptr)
         {
             handleModalFocusGained();
             mFocusHandler->setLastWidgetWithModalFocus(modalWidget);
@@ -1450,7 +1462,7 @@ void Gui::handleModalFocusReleased()
     Widget* widget = getMouseEventSource(mLastMouseX, mLastMouseY);
     Widget* parent = widget;
 
-    while (parent)
+    while (parent != nullptr)
     {
         parent = widget->getParent();
 
@@ -1488,7 +1500,7 @@ void Gui::handleModalFocusReleased()
 
 int Gui::getMousePressLength() const
 {
-    if (!mLastMousePressTimeStamp)
+    if (mLastMousePressTimeStamp == 0u)
         return 0;
     unsigned int ticks = SDL_GetTicks();
     if (ticks > mLastMousePressTimeStamp)
diff --git a/src/gui/models/colormodel.cpp b/src/gui/models/colormodel.cpp
index 76a7da8fa..3bbded2e2 100644
--- a/src/gui/models/colormodel.cpp
+++ b/src/gui/models/colormodel.cpp
@@ -71,7 +71,7 @@ void ColorModel::add(const std::string &name, const Color *const color1,
 ColorModel *ColorModel::createDefault(const Widget2 *const widget)
 {
     ColorModel *const model = new ColorModel;
-    if (!widget)
+    if (widget == nullptr)
         return model;
     // TRANSLATORS: color name
     addColor(_("black"), BLACK);
diff --git a/src/gui/models/extendednamesmodel.cpp b/src/gui/models/extendednamesmodel.cpp
index 2b185d9b3..2c8d7167a 100644
--- a/src/gui/models/extendednamesmodel.cpp
+++ b/src/gui/models/extendednamesmodel.cpp
@@ -58,7 +58,7 @@ void ExtendedNamesModel::clear()
     mNames.clear();
     FOR_EACH (std::vector<Image*>::iterator, it, mImages)
     {
-        if (*it)
+        if (*it != nullptr)
             (*it)->decRef();
     }
     mImages.clear();
diff --git a/src/gui/models/langlistmodel.h b/src/gui/models/langlistmodel.h
index 839a836e7..f8c67ad30 100644
--- a/src/gui/models/langlistmodel.h
+++ b/src/gui/models/langlistmodel.h
@@ -116,7 +116,7 @@ class LangListModel final : public ExtendedListModel
             for (int f = 0; f < langs_count; f ++)
             {
                 Image *const img = mIcons[f];
-                if (img)
+                if (img != nullptr)
                     img->decRef();
             }
         }
diff --git a/src/gui/models/modelistmodel.cpp b/src/gui/models/modelistmodel.cpp
index 60974bb7e..3c39921ad 100644
--- a/src/gui/models/modelistmodel.cpp
+++ b/src/gui/models/modelistmodel.cpp
@@ -36,12 +36,12 @@ static bool modeSorter(const std::string &mode1, const std::string &mode2)
 {
     const int width1 = atoi(mode1.substr(0, mode1.find('x')).c_str());
     const int height1 = atoi(mode1.substr(mode1.find('x') + 1).c_str());
-    if (!width1 || !height1)
+    if ((width1 == 0) || (height1 == 0))
         return false;
 
     const int width2 = atoi(mode2.substr(0, mode2.find('x')).c_str());
     const int height2 = atoi(mode2.substr(mode2.find('x') + 1).c_str());
-    if (!width2 || !height2)
+    if ((width2 == 0) || (height2 == 0))
         return false;
     if (width1 != width2)
         return width1 < width2;
diff --git a/src/gui/models/namesmodel.cpp b/src/gui/models/namesmodel.cpp
index 9c90ff4c0..5a351f471 100644
--- a/src/gui/models/namesmodel.cpp
+++ b/src/gui/models/namesmodel.cpp
@@ -49,7 +49,7 @@ std::string NamesModel::getElementAt(int i)
 void NamesModel::fillFromArray(const char *const *const arr,
                                const std::size_t sz)
 {
-    if (!arr)
+    if (arr == nullptr)
         return;
     for (size_t f = 0; f < sz; f ++)
         mNames.push_back(gettext(arr[f]));
diff --git a/src/gui/models/playertablemodel.cpp b/src/gui/models/playertablemodel.cpp
index 29e08578d..9c8526e0d 100644
--- a/src/gui/models/playertablemodel.cpp
+++ b/src/gui/models/playertablemodel.cpp
@@ -66,7 +66,7 @@ PlayerTableModel::~PlayerTableModel()
 
 int PlayerTableModel::getRows() const
 {
-    if (mPlayers)
+    if (mPlayers != nullptr)
         return CAST_S32(mPlayers->size());
     else
         return 0;
@@ -120,7 +120,7 @@ void PlayerTableModel::updateModelInRow(const int row) const
 {
     const DropDown *const choicebox = static_cast<DropDown *>(
         getElementAt(row, RELATION_CHOICE_COLUMN));
-    if (!choicebox)
+    if (choicebox == nullptr)
         return;
     player_relations.setRelation(getPlayerAt(row),
         static_cast<RelationT>(
@@ -141,7 +141,7 @@ void PlayerTableModel::freeWidgets()
 
 std::string PlayerTableModel::getPlayerAt(const int index) const
 {
-    if (!mPlayers || index < 0
+    if ((mPlayers == nullptr) || index < 0
         || index >= CAST_S32(mPlayers->size()))
     {
         return std::string();
diff --git a/src/gui/models/serverslistmodel.h b/src/gui/models/serverslistmodel.h
index 453c1fa09..935fd3422 100644
--- a/src/gui/models/serverslistmodel.h
+++ b/src/gui/models/serverslistmodel.h
@@ -42,7 +42,7 @@ class ServersListModel final : public ListModel
         ServersListModel(ServerInfos *const servers,
                          ServerDialog *const parent) :
             mServers(servers),
-            mVersionStrings(servers ? servers->size() : 0,
+            mVersionStrings(servers != nullptr ? servers->size() : 0,
                 VersionString(0, "")),
             mParent(parent)
         {
@@ -83,7 +83,7 @@ class ServersListModel final : public ListModel
             if (index < 0 || index >= CAST_S32(mVersionStrings.size()))
             return;
 
-            if (version.empty() || !gui)
+            if (version.empty() || (gui == nullptr))
             {
                 mVersionStrings[index] = VersionString(0, "");
             }
diff --git a/src/gui/models/shopitems.cpp b/src/gui/models/shopitems.cpp
index 94bba3be4..a5c05388b 100644
--- a/src/gui/models/shopitems.cpp
+++ b/src/gui/models/shopitems.cpp
@@ -46,7 +46,7 @@ ShopItems::~ShopItems()
 std::string ShopItems::getElementAt(int i)
 {
     if (i < 0 || CAST_U32(i)
-        >= CAST_U32(mShopItems.size()) || !mShopItems.at(i))
+        >= CAST_U32(mShopItems.size()) || (mShopItems.at(i) == nullptr))
     {
         return "";
     }
@@ -79,7 +79,7 @@ ShopItem *ShopItems::addItemNoDup(const int id,
                                   const int price)
 {
     ShopItem *item = findItem(id, color);
-    if (!item)
+    if (item == nullptr)
     {
         item = new ShopItem(-1,
             id,
@@ -105,7 +105,7 @@ ShopItem *ShopItems::addItem2(const int inventoryIndex,
     if (mMergeDuplicates)
         item = findItem(id, color);
 
-    if (item)
+    if (item != nullptr)
     {
         item->addDuplicate(inventoryIndex, quantity);
     }
@@ -199,7 +199,7 @@ void ShopItems::updateList()
     FOR_EACH (std::vector<ShopItem*>::iterator, it, mAllShopItems)
     {
         ShopItem *const item = *it;
-        if (item && item->isVisible())
+        if ((item != nullptr) && item->isVisible())
             mShopItems.push_back(item);
     }
 }
diff --git a/src/gui/models/skillmodel.cpp b/src/gui/models/skillmodel.cpp
index 13d2bb547..102956897 100644
--- a/src/gui/models/skillmodel.cpp
+++ b/src/gui/models/skillmodel.cpp
@@ -43,7 +43,7 @@ SkillInfo *SkillModel::getSkillAt(const int i) const
 std::string SkillModel::getElementAt(int i)
 {
     const SkillInfo *const info = getSkillAt(i);
-    if (info)
+    if (info != nullptr)
         return info->data->name;
     else
         return std::string();
@@ -55,7 +55,7 @@ void SkillModel::updateVisibilities()
 
     FOR_EACH (SkillList::const_iterator, it, mSkills)
     {
-        if ((*it) && (*it)->visible == Visible_true)
+        if (((*it) != nullptr) && (*it)->visible == Visible_true)
             mVisibleSkills.push_back((*it));
     }
 }
diff --git a/src/gui/models/tablemodel.cpp b/src/gui/models/tablemodel.cpp
index fe60ccc95..08cfb6d83 100644
--- a/src/gui/models/tablemodel.cpp
+++ b/src/gui/models/tablemodel.cpp
@@ -32,13 +32,13 @@
 
 void TableModel::installListener(TableModelListener *const listener)
 {
-    if (listener)
+    if (listener != nullptr)
         listeners.insert(listener);
 }
 
 void TableModel::removeListener(TableModelListener *const listener)
 {
-    if (listener)
+    if (listener != nullptr)
         listeners.erase(listener);
 }
 
@@ -56,7 +56,7 @@ void TableModel::signalAfterUpdate()
     for (std::set<TableModelListener *>::const_iterator it = listeners.begin();
          it != listeners.end(); ++it)
     {
-        if (*it)
+        if (*it != nullptr)
             (*it)->modelUpdated(true);
     }
 }
@@ -93,7 +93,7 @@ void StaticTableModel::resize()
 void StaticTableModel::set(const int row, const int column,
                            Widget *const widget)
 {
-    if (!widget || row >= mRows || row < 0
+    if ((widget == nullptr) || row >= mRows || row < 0
         || column >= mColumns || column < 0)
     {
         // raise exn?
diff --git a/src/gui/models/touchactionmodel.cpp b/src/gui/models/touchactionmodel.cpp
index 6238797e6..983fc7065 100644
--- a/src/gui/models/touchactionmodel.cpp
+++ b/src/gui/models/touchactionmodel.cpp
@@ -37,7 +37,7 @@ static class SortTouchActionFunctor final
         bool operator() (const SetupActionData *const data1,
                          const SetupActionData *const data2) const
         {
-            if (!data1 || !data2)
+            if ((data1 == nullptr) || (data2 == nullptr))
                 return false;
             return data1->name < data2->name;
         }
diff --git a/src/gui/models/worldlistmodel.h b/src/gui/models/worldlistmodel.h
index 4fe0a812e..4436f848c 100644
--- a/src/gui/models/worldlistmodel.h
+++ b/src/gui/models/worldlistmodel.h
@@ -53,7 +53,7 @@ class WorldListModel final : public ListModel
         std::string getElementAt(int i) override final
         {
             const WorldInfo *const si = mWorlds[i];
-            if (si)
+            if (si != nullptr)
             {
                 return std::string(si->name).append(" (").append(
                     toString(si->online_users)).append(")");
diff --git a/src/gui/palette.cpp b/src/gui/palette.cpp
index c3e3a6fa8..25f8084e9 100644
--- a/src/gui/palette.cpp
+++ b/src/gui/palette.cpp
@@ -93,7 +93,7 @@ void Palette::advanceGradient()
         for (size_t i = 0, sz = mGradVector.size(); i < sz; i++)
         {
             ColorElem *const elem A_NONNULLPOINTER = mGradVector[i];
-            if (!elem)
+            if (elem == nullptr)
                 continue;
 
             int delay = elem->delay;
@@ -110,9 +110,9 @@ void Palette::advanceGradient()
                 % (delay * numOfColors);
 
             const int gradIndex = elem->gradientIndex;
-            const int pos = delay ? (gradIndex % delay) : gradIndex;
+            const int pos = delay != 0 ? (gradIndex % delay) : gradIndex;
             int colIndex;
-            if (delay)
+            if (delay != 0)
                 colIndex = gradIndex / delay;
             else
                 colIndex = gradIndex;
@@ -133,9 +133,9 @@ void Palette::advanceGradient()
             }
             else if (grad == GradientType::SPECTRUM)
             {
-                if (colIndex % 2)
+                if ((colIndex % 2) != 0)
                 {   // falling curve
-                    if (delay)
+                    if (delay != 0)
                     {
                         colVal = CAST_S32(255.0 *
                              (cos(M_PI * pos / delay) + 1) / 2);
@@ -148,7 +148,7 @@ void Palette::advanceGradient()
                 }
                 else
                 {   // ascending curve
-                    if (delay)
+                    if (delay != 0)
                     {
                         colVal = CAST_S32(255.0 * (cos(M_PI *
                             (delay - pos) / delay) + 1) / 2);
@@ -175,7 +175,7 @@ void Palette::advanceGradient()
                 double startColVal;
                 double destColVal;
 
-                if (delay)
+                if (delay != 0)
                     startColVal = (cos(M_PI * pos / delay) + 1) / 2;
                 else
                     startColVal = 0;
@@ -193,7 +193,7 @@ void Palette::advanceGradient()
             }
         }
 
-        if (advance)
+        if (advance != 0)
             mRainbowTime = tick_time;
     }
 }
diff --git a/src/gui/popupmanager.cpp b/src/gui/popupmanager.cpp
index 5a9c2809b..c415956ce 100644
--- a/src/gui/popupmanager.cpp
+++ b/src/gui/popupmanager.cpp
@@ -43,7 +43,7 @@ PopupManager::~PopupManager()
 void PopupManager::closePopupMenu()
 {
 #ifndef DYECMD
-    if (popupMenu)
+    if (popupMenu != nullptr)
         popupMenu->handleLink("cancel", nullptr);
 #endif  // DYECMD
 }
@@ -51,21 +51,21 @@ void PopupManager::closePopupMenu()
 void PopupManager::hideBeingPopup()
 {
 #ifndef DYECMD
-    if (beingPopup)
+    if (beingPopup != nullptr)
         beingPopup->setVisible(Visible_false);
 #endif  // DYECMD
 }
 
 void PopupManager::hideTextPopup()
 {
-    if (textPopup)
+    if (textPopup != nullptr)
         textPopup->setVisible(Visible_false);
 }
 
 void PopupManager::hidePopupMenu()
 {
 #ifndef DYECMD
-    if (popupMenu)
+    if (popupMenu != nullptr)
         popupMenu->setVisible(Visible_false);
 #endif  // DYECMD
 }
@@ -73,7 +73,7 @@ void PopupManager::hidePopupMenu()
 bool PopupManager::isPopupMenuVisible()
 {
 #ifndef DYECMD
-    return popupMenu ? popupMenu->isPopupVisible() : false;
+    return popupMenu != nullptr ? popupMenu->isPopupVisible() : false;
 #else
     return false;
 #endif  // DYECMD
@@ -82,20 +82,20 @@ bool PopupManager::isPopupMenuVisible()
 void PopupManager::clearPopup()
 {
 #ifndef DYECMD
-    if (popupMenu)
+    if (popupMenu != nullptr)
         popupMenu->clear();
 #endif  // DYECMD
 }
 
 bool PopupManager::isTextPopupVisible()
 {
-    return textPopup ? textPopup->isPopupVisible() : false;
+    return textPopup != nullptr ? textPopup->isPopupVisible() : false;
 }
 
 bool PopupManager::isBeingPopupVisible()
 {
 #ifndef DYECMD
-    return beingPopup ? beingPopup->isPopupVisible() : false;
+    return beingPopup != nullptr ? beingPopup->isPopupVisible() : false;
 #else  // DYECMD
     return false;
 #endif  // DYECMD
diff --git a/src/gui/popups/beingpopup.cpp b/src/gui/popups/beingpopup.cpp
index 5a800871b..c18ac3871 100644
--- a/src/gui/popups/beingpopup.cpp
+++ b/src/gui/popups/beingpopup.cpp
@@ -84,7 +84,7 @@ void BeingPopup::addLabels(const int fontHeight)
 
 void BeingPopup::show(const int x, const int y, Being *const b)
 {
-    if (!b)
+    if (b == nullptr)
     {
         setVisible(Visible_false);
         return;
@@ -101,7 +101,7 @@ void BeingPopup::show(const int x, const int y, Being *const b)
     }
 
     mBeingName->setCaption(b->getName() + b->getGenderSignWithSpace());
-    if (gui)
+    if (gui != nullptr)
     {
         if (player_relations.isGoodName(b))
             mBeingName->setFont(boldFont);
@@ -130,7 +130,7 @@ void BeingPopup::show(const int x, const int y, Being *const b)
     if (type == ActorType::Pet)
     {
         const PetInfo *const info = PlayerInfo::getPet();
-        if (info && info->id == b->getId())
+        if ((info != nullptr) && info->id == b->getId())
         {
             ptr = mLabels[num];
             // TRANSLATORS: being popup label
@@ -149,7 +149,7 @@ void BeingPopup::show(const int x, const int y, Being *const b)
     else if (type == ActorType::Homunculus)
     {
         const HomunculusInfo *const info = PlayerInfo::getHomunculus();
-        if (info && info->id == b->getId())
+        if ((info != nullptr) && info->id == b->getId())
         {
             ptr = mLabels[num];
             // TRANSLATORS: being popup label
@@ -239,7 +239,7 @@ void BeingPopup::show(const int x, const int y, Being *const b)
         }
 
         const ChatObject *const chat = b->getChat();
-        if (chat)
+        if (chat != nullptr)
         {
             ptr = mLabels[num];
             // TRANSLATORS: being popup label
@@ -298,7 +298,7 @@ void BeingPopup::show(const int x, const int y, Being *const b)
     FOR_EACH (std::vector<Label*>::iterator, it, mLabels)
     {
         const Label *const label = *it;
-        if (label)
+        if (label != nullptr)
         {
             if (label->getWidth() > minWidth)
                 minWidth = label->getWidth();
diff --git a/src/gui/popups/itempopup.cpp b/src/gui/popups/itempopup.cpp
index 17f955da0..3fc546cf0 100644
--- a/src/gui/popups/itempopup.cpp
+++ b/src/gui/popups/itempopup.cpp
@@ -125,10 +125,10 @@ void ItemPopup::postInit()
 
 ItemPopup::~ItemPopup()
 {
-    if (mIcon)
+    if (mIcon != nullptr)
     {
         Image *const image = mIcon->getImage();
-        if (image)
+        if (image != nullptr)
             image->decRef();
     }
 }
@@ -136,7 +136,7 @@ ItemPopup::~ItemPopup()
 void ItemPopup::setItem(const Item *const item,
                         const bool showImage)
 {
-    if (!item)
+    if (item == nullptr)
         return;
 
     const ItemInfo &ii = item->getInfo();
@@ -181,8 +181,8 @@ void ItemPopup::setItem(const ItemInfo &item,
                         const int *const cards,
                         const ItemOptionsList *const options)
 {
-    if (!mIcon || (item.getName() == mLastName && color == mLastColor
-        && id == mLastId))
+    if (mIcon == nullptr ||
+        (item.getName() == mLastName && color == mLastColor && id == mLastId))
     {
         return;
     }
@@ -193,7 +193,7 @@ void ItemPopup::setItem(const ItemInfo &item,
     int space = 0;
 
     Image *const oldImage = mIcon->getImage();
-    if (oldImage)
+    if (oldImage != nullptr)
         oldImage->decRef();
 
     if (showImage)
@@ -204,7 +204,7 @@ void ItemPopup::setItem(const ItemInfo &item,
             item.getDyeIconColorsString(color)));
 
         mIcon->setImage(image);
-        if (image)
+        if (image != nullptr)
         {
             mIcon->setPosition(0, 0);
             space = mIcon->getWidth();
@@ -297,7 +297,7 @@ void ItemPopup::setItem(const ItemInfo &item,
 
 std::string ItemPopup::getCardsString(const int *const cards)
 {
-    if (!cards)
+    if (cards == nullptr)
         return std::string();
 
     std::string label;
@@ -331,7 +331,7 @@ std::string ItemPopup::getCardsString(const int *const cards)
             for (int f = 0; f < maxCards; f ++)
             {
                 const int id = cards[f];
-                if (id)
+                if (id != 0)
                 {
                     if (!label.empty())
                         label.append(" / ");
diff --git a/src/gui/popups/popupmenu.cpp b/src/gui/popups/popupmenu.cpp
index 69fd7d879..b5a337b1c 100644
--- a/src/gui/popups/popupmenu.cpp
+++ b/src/gui/popups/popupmenu.cpp
@@ -145,7 +145,7 @@ void PopupMenu::postInit()
 
 void PopupMenu::showPopup(const int x, const int y, const Being *const being)
 {
-    if (!being || !localPlayer || !actorManager)
+    if ((being == nullptr) || (localPlayer == nullptr) || (actorManager == nullptr))
         return;
 
     mBeingId = being->getId();
@@ -193,9 +193,9 @@ void PopupMenu::showPopup(const int x, const int y, const Being *const being)
 
             const Guild *const guild1 = being->getGuild();
             const Guild *const guild2 = localPlayer->getGuild();
-            if (guild2)
+            if (guild2 != nullptr)
             {
-                if (guild1)
+                if (guild1 != nullptr)
                 {
                     if (guild1->getId() == guild2->getId())
                     {
@@ -213,7 +213,7 @@ void PopupMenu::showPopup(const int x, const int y, const Being *const being)
                         }
                     }
                 }
-                else if (guild2->getMember(mName))
+                else if (guild2->getMember(mName) != nullptr)
                 {
                     mBrowserBox->addRow("/kickguild 'NAME'",
                         // TRANSLATORS: popup menu item
@@ -231,8 +231,8 @@ void PopupMenu::showPopup(const int x, const int y, const Being *const being)
                 else
                 {
 #ifdef TMWA_SUPPORT
-                    if (guild2->getServerGuild()
-                        || (guildManager && guildManager->havePower()))
+                    if (guild2->getServerGuild() ||
+                        (guildManager != nullptr && guildManager->havePower()))
 #endif  // TMWA_SUPPORT
                     {
                         mBrowserBox->addRow("/guild 'NAME'",
@@ -345,7 +345,7 @@ void PopupMenu::showPopup(const int x, const int y, const Being *const being)
         case ActorType::Homunculus:
         {
             const HomunculusInfo *const info = PlayerInfo::getHomunculus();
-            if (info)
+            if (info != nullptr)
             {
                 mBrowserBox->addRow("homunculus to master",
                     // TRANSLATORS: popup menu item
@@ -387,7 +387,7 @@ void PopupMenu::showPopup(const int x, const int y, const Being *const being)
                 mBrowserBox->addRow("##3---");
                 const BeingInfo *const info = being->getInfo();
                 std::string msg;
-                if (info)
+                if (info != nullptr)
                     msg = info->getString(0);
                 if (!msg.empty())
                 {
@@ -411,7 +411,7 @@ void PopupMenu::showPopup(const int x, const int y, const Being *const being)
             const BeingId id = being->getCreatorId();
             std::string creatorName;
             Being *const creator = actorManager->findBeing(id);
-            if (creator)
+            if (creator != nullptr)
                 creatorName = creator->getName();
             else
                 creatorName = actorManager->getSeenPlayerById(id);
@@ -448,12 +448,12 @@ void PopupMenu::showPopup(const int x, const int y, const Being *const being)
 bool PopupMenu::addBeingMenu()
 {
     Being *being = actorManager->findBeing(mBeingId);
-    if (!being)
+    if (being == nullptr)
         return false;
 
     BeingInfo *const info = NPCDB::get(fromInt(
         being->getSubType(), BeingTypeId));
-    if (!info)
+    if (info == nullptr)
         return false;
 
     const std::vector<BeingMenuItem> &menu = info->getMenu();
@@ -467,7 +467,7 @@ bool PopupMenu::addBeingMenu()
 
 void PopupMenu::setMousePos()
 {
-    if (viewport)
+    if (viewport != nullptr)
     {
         mX = viewport->mMouseX;
         mY = viewport->mMouseY;
@@ -482,7 +482,7 @@ void PopupMenu::setMousePos2()
 {
     if (mX == 0 && mY == 0)
     {
-        if (viewport)
+        if (viewport != nullptr)
         {
             mX = viewport->mMouseX;
             mY = viewport->mMouseY;
@@ -506,7 +506,7 @@ void PopupMenu::showPopup(const int x, const int y,
     {
         const Being *const being = dynamic_cast<const Being*>(*it);
         const ActorSprite *const actor = *it;
-        if (being && !being->getName().empty())
+        if ((being != nullptr) && !being->getName().empty())
         {
             mBrowserBox->addRow(strprintf("@@player_%u|%s >@@",
                 CAST_U32(being->getId()), (being->getName()
@@ -530,7 +530,7 @@ void PopupMenu::showPopup(const int x, const int y,
 
 void PopupMenu::showPlayerPopup(const std::string &nick)
 {
-    if (nick.empty() || !localPlayer)
+    if (nick.empty() || (localPlayer == nullptr))
         return;
 
     setMousePos();
@@ -563,10 +563,10 @@ void PopupMenu::showPlayerPopup(const std::string &nick)
     if (localPlayer->isInParty())
     {
         const Party *const party = localPlayer->getParty();
-        if (party)
+        if (party != nullptr)
         {
             const PartyMember *const member = party->getMember(mName);
-            if (member)
+            if (member != nullptr)
             {
                 // TRANSLATORS: popup menu item
                 // TRANSLATORS: kick player from party
@@ -575,7 +575,7 @@ void PopupMenu::showPlayerPopup(const std::string &nick)
                 const PartyMember *const o = party->getMember(
                     localPlayer->getName());
                 showAdoptCommands();
-                if (o && member->getMap() == o->getMap())
+                if ((o != nullptr) && member->getMap() == o->getMap())
                 {
                     // TRANSLATORS: popup menu item
                     // TRANSLATORS: move to player position
@@ -586,12 +586,12 @@ void PopupMenu::showPlayerPopup(const std::string &nick)
     }
 
     const Guild *const guild2 = localPlayer->getGuild();
-    if (guild2)
+    if (guild2 != nullptr)
     {
-        if (guild2->getMember(mName))
+        if (guild2->getMember(mName) != nullptr)
         {
 #ifdef TMWA_SUPPORT
-            if (guild2->getServerGuild() || (guildManager
+            if (guild2->getServerGuild() || (guildManager != nullptr
                 && guildManager->havePower()))
 #endif  // TMWA_SUPPORT
             {
@@ -611,7 +611,7 @@ void PopupMenu::showPlayerPopup(const std::string &nick)
         else
         {
 #ifdef TMWA_SUPPORT
-            if (guild2->getServerGuild() || (guildManager
+            if (guild2->getServerGuild() || (guildManager != nullptr
                 && guildManager->havePower()))
 #endif  // TMWA_SUPPORT
             {
@@ -637,7 +637,7 @@ void PopupMenu::showPlayerPopup(const std::string &nick)
 void PopupMenu::showPopup(const int x, const int y,
                           const FloorItem *const floorItem)
 {
-    if (!floorItem)
+    if (floorItem == nullptr)
         return;
 
     mX = x;
@@ -690,7 +690,7 @@ void PopupMenu::showPopup(const int x, const int y,
 
 void PopupMenu::showPopup(const int x, const int y, MapItem *const mapItem)
 {
-    if (!mapItem)
+    if (mapItem == nullptr)
         return;
 
     mMapItem = mapItem;
@@ -708,7 +708,7 @@ void PopupMenu::showPopup(const int x, const int y, MapItem *const mapItem)
     // TRANSLATORS: remove map item
     mBrowserBox->addRow("remove map", _("Remove"));
 
-    if (localPlayer && localPlayer->isGM())
+    if ((localPlayer != nullptr) && localPlayer->isGM())
     {
         mBrowserBox->addRow("##3---");
         // TRANSLATORS: popup menu item
@@ -738,7 +738,7 @@ void PopupMenu::showMapPopup(const int x, const int y,
     // TRANSLATORS: popup menu header
     mBrowserBox->addRow(_("Map Item"));
 
-    if (localPlayer && localPlayer->isGM())
+    if ((localPlayer != nullptr) && localPlayer->isGM())
     {
         // TRANSLATORS: popup menu item
         // TRANSLATORS: warp to map item
@@ -806,7 +806,7 @@ void PopupMenu::showOutfitsWindowPopup(const int x, const int y)
 void PopupMenu::showSpellPopup(const int x, const int y,
                                TextCommand *const cmd)
 {
-    if (!cmd)
+    if (cmd == nullptr)
         return;
 
     mBrowserBox->clearRows();
@@ -830,7 +830,7 @@ void PopupMenu::showSpellPopup(const int x, const int y,
 
 void PopupMenu::showChatPopup(const int x, const int y, ChatTab *const tab)
 {
-    if (!tab || !actorManager || !localPlayer)
+    if ((tab == nullptr) || (actorManager == nullptr) || (localPlayer == nullptr))
         return;
 
     mTab = tab;
@@ -911,7 +911,7 @@ void PopupMenu::showChatPopup(const int x, const int y, ChatTab *const tab)
             name, ActorType::Player);
 
         addGmCommands();
-        if (being)
+        if (being != nullptr)
         {
             mBeingId = being->getId();
             mName = being->getName();
@@ -943,15 +943,16 @@ void PopupMenu::showChatPopup(const int x, const int y, ChatTab *const tab)
             addParty(wTab->getNick());
             const Guild *const guild1 = being->getGuild();
             const Guild *const guild2 = localPlayer->getGuild();
-            if (guild2)
+            if (guild2 != nullptr)
             {
-                if (guild1)
+                if (guild1 != nullptr)
                 {
                     if (guild1->getId() == guild2->getId())
                     {
 #ifdef TMWA_SUPPORT
-                        if (guild2->getServerGuild() || (guildManager
-                            && guildManager->havePower()))
+                        if (guild2->getServerGuild() ||
+                            (guildManager != nullptr &&
+                            guildManager->havePower()))
 #endif  // TMWA_SUPPORT
                         {
                             mBrowserBox->addRow("/kickguild 'NAME'",
@@ -971,7 +972,7 @@ void PopupMenu::showChatPopup(const int x, const int y, ChatTab *const tab)
                 else
                 {
 #ifdef TMWA_SUPPORT
-                    if (guild2->getServerGuild() || (guildManager
+                    if (guild2->getServerGuild() || (guildManager != nullptr
                         && guildManager->havePower()))
 #endif  // TMWA_SUPPORT
                     {
@@ -998,10 +999,10 @@ void PopupMenu::showChatPopup(const int x, const int y, ChatTab *const tab)
             if (localPlayer->isInParty())
             {
                 const Party *const party = localPlayer->getParty();
-                if (party)
+                if (party != nullptr)
                 {
                     const PartyMember *const m = party->getMember(mName);
-                    if (m)
+                    if (m != nullptr)
                     {
                         // TRANSLATORS: popup menu item
                         // TRANSLATORS: move to player location
@@ -1031,13 +1032,13 @@ void PopupMenu::showChangePos(const int x, const int y)
     // TRANSLATORS: popup menu header
     mBrowserBox->addRow(_("Change guild position"));
 
-    if (!localPlayer)
+    if (localPlayer == nullptr)
         return;
 
     mX = x;
     mY = y;
     const Guild *const guild = localPlayer->getGuild();
-    if (guild)
+    if (guild != nullptr)
     {
         const PositionsMap &map = guild->getPositions();
         FOR_EACH (PositionsMap::const_iterator, itr, map)
@@ -1072,7 +1073,7 @@ void PopupMenu::showChangePos(const int x, const int y)
 
 void PopupMenu::showWindowPopup(Window *const window)
 {
-    if (!window)
+    if (window == nullptr)
         return;
 
     setMousePos();
@@ -1092,7 +1093,7 @@ void PopupMenu::showWindowPopup(Window *const window)
 
 void PopupMenu::addWindowMenu(const Window *const window)
 {
-    if (!window)
+    if (window == nullptr)
         return;
 
     if (window->getAlowClose())
@@ -1158,20 +1159,20 @@ void PopupMenu::handleLink(const std::string &link,
                            MouseEvent *event A_UNUSED)
 {
     Being *being = nullptr;
-    if (actorManager)
+    if (actorManager != nullptr)
         being = actorManager->findBeing(mBeingId);
 
     mAllowCleanMenu = true;
 
-    if (link == "remove map" && mMapItem)
+    if (link == "remove map" && (mMapItem != nullptr))
     {
-        if (viewport)
+        if (viewport != nullptr)
         {
             const Map *const map = viewport->getMap();
-            if (map)
+            if (map != nullptr)
             {
                 SpecialLayer *const specialLayer = map->getSpecialLayer();
-                if (specialLayer)
+                if (specialLayer != nullptr)
                 {
                     const bool isHome = (mMapItem->getType()
                         == CAST_S32(MapItemType::HOME));
@@ -1180,9 +1181,9 @@ void PopupMenu::handleLink(const std::string &link,
                     specialLayer->setTile(x, y,
                         CAST_S32(MapItemType::EMPTY));
                     specialLayer->updateCache();
-                    if (socialWindow)
+                    if (socialWindow != nullptr)
                         socialWindow->removePortal(x, y);
-                    if (isHome && localPlayer)
+                    if (isHome && (localPlayer != nullptr))
                     {
                         localPlayer->removeHome();
                         localPlayer->saveHomes();
@@ -1191,7 +1192,7 @@ void PopupMenu::handleLink(const std::string &link,
             }
         }
     }
-    else if (link == "rename map" && mMapItem)
+    else if (link == "rename map" && (mMapItem != nullptr))
     {
         mRenameListener.setMapItem(mMapItem);
         CREATEWIDGETV(mDialog, TextDialog,
@@ -1206,7 +1207,7 @@ void PopupMenu::handleLink(const std::string &link,
         mDialog->setActionEventId("ok");
         mDialog->addActionListener(&mRenameListener);
     }
-    else if (link == "edit spell" && mSpell)
+    else if (link == "edit spell" && (mSpell != nullptr))
     {
         CREATEWIDGET(TextCommandEditor, mSpell);
     }
@@ -1223,7 +1224,7 @@ void PopupMenu::handleLink(const std::string &link,
         mPlayerListener.setNick(mName);
         mPlayerListener.setType(mType);
 
-        if (being)
+        if (being != nullptr)
         {
             being->updateComment();
             dialog->setText(being->getComment());
@@ -1243,12 +1244,12 @@ void PopupMenu::handleLink(const std::string &link,
     }
     else if (link == "clipboard copy")
     {
-        if (mTextField)
+        if (mTextField != nullptr)
             mTextField->handleCopy();
     }
     else if (link == "clipboard paste")
     {
-        if (mTextField)
+        if (mTextField != nullptr)
             mTextField->handlePaste();
     }
     else if (link == "gm" && !mName.empty())
@@ -1266,25 +1267,25 @@ void PopupMenu::handleLink(const std::string &link,
         showPlayerMenu();
         return;
     }
-    else if (link == "window close" && mCallerWindow)
+    else if (link == "window close" && (mCallerWindow != nullptr))
     {
         if (Widget::widgetExists(mCallerWindow))
             mCallerWindow->close();
     }
-    else if (link == "window unlock" && mCallerWindow)
+    else if (link == "window unlock" && (mCallerWindow != nullptr))
     {
         if (Widget::widgetExists(mCallerWindow))
             mCallerWindow->setSticky(false);
     }
-    else if (link == "window lock" && mCallerWindow)
+    else if (link == "window lock" && (mCallerWindow != nullptr))
     {
         if (Widget::widgetExists(mCallerWindow))
             mCallerWindow->setSticky(true);
     }
-    else if (link == "join chat" && being)
+    else if (link == "join chat" && (being != nullptr))
     {
         const ChatObject *const chat = being->getChat();
-        if (chat)
+        if (chat != nullptr)
             chatHandler->joinChat(chat, "");
     }
     else if (link == "fire mercenary")
@@ -1328,42 +1329,42 @@ void PopupMenu::handleLink(const std::string &link,
     {
         petHandler->unequip();
     }
-    else if (!link.compare(0, 10, "guild-pos-"))
+    else if (link.compare(0, 10, "guild-pos-") == 0)
     {
-        if (localPlayer)
+        if (localPlayer != nullptr)
         {
             const int num = atoi(link.substr(10).c_str());
             const Guild *const guild = localPlayer->getGuild();
-            if (guild)
+            if (guild != nullptr)
             {
                 guildHandler->changeMemberPostion(
                     guild->getMember(mName), num);
             }
         }
     }
-    else if (!link.compare(0, 7, "player_"))
+    else if (link.compare(0, 7, "player_") == 0)
     {
-        if (actorManager)
+        if (actorManager != nullptr)
         {
             mBeingId = fromInt(atoi(link.substr(7).c_str()), BeingId);
             being = actorManager->findBeing(mBeingId);
-            if (being)
+            if (being != nullptr)
             {
                 showPopup(getX(), getY(), being);
                 return;
             }
         }
     }
-    else if (!link.compare(0, 10, "flooritem_"))
+    else if (link.compare(0, 10, "flooritem_") == 0)
     {
-        if (actorManager)
+        if (actorManager != nullptr)
         {
             const BeingId id = fromInt(atoi(
                 link.substr(10).c_str()), BeingId);
             if (id != BeingId_zero)
             {
                 const FloorItem *const item = actorManager->findItem(id);
-                if (item)
+                if (item != nullptr)
                 {
                     mFloorItemId = item->getId();
                     mItemId = item->getItemId();
@@ -1375,43 +1376,43 @@ void PopupMenu::handleLink(const std::string &link,
             }
         }
     }
-    else if (!link.compare(0, 12, "hide button_"))
+    else if (link.compare(0, 12, "hide button_") == 0)
     {
-        if (windowMenu)
+        if (windowMenu != nullptr)
             windowMenu->showButton(link.substr(12), Visible_false);
     }
-    else if (!link.compare(0, 12, "show button_"))
+    else if (link.compare(0, 12, "show button_") == 0)
     {
-        if (windowMenu)
+        if (windowMenu != nullptr)
             windowMenu->showButton(link.substr(12), Visible_true);
     }
-    else if (!link.compare(0, 9, "hide bar_"))
+    else if (link.compare(0, 9, "hide bar_") == 0)
     {
-        if (miniStatusWindow)
+        if (miniStatusWindow != nullptr)
             miniStatusWindow->showBar(link.substr(9), Visible_false);
     }
-    else if (!link.compare(0, 9, "show bar_"))
+    else if (link.compare(0, 9, "show bar_") == 0)
     {
-        if (miniStatusWindow)
+        if (miniStatusWindow != nullptr)
             miniStatusWindow->showBar(link.substr(9), Visible_true);
     }
-    else if (!link.compare(0, 12, "show window_"))
+    else if (link.compare(0, 12, "show window_") == 0)
     {
         const int id = atoi(link.substr(12).c_str());
         if (id >= 0)
             inputManager.executeAction(static_cast<InputActionT>(id));
     }
-    else if (!link.compare(0, 6, "mute_+"))
+    else if (link.compare(0, 6, "mute_+") == 0)
     {
-        if (being)
+        if (being != nullptr)
         {
             const int time = atoi(link.substr(6).c_str());
             adminHandler->mute(being, 1, time);
         }
     }
-    else if (!link.compare(0, 6, "mute_-"))
+    else if (link.compare(0, 6, "mute_-") == 0)
     {
-        if (being)
+        if (being != nullptr)
         {
             const int time = atoi(link.substr(6).c_str());
             adminHandler->mute(being, 0, time);
@@ -1440,7 +1441,7 @@ void PopupMenu::handleLink(const std::string &link,
             replaceAll(cmd, "'INVINDEX'", toString(mItemIndex));
         else
             replaceAll(cmd, "'INVINDEX'", "0");
-        if (mMapItem)
+        if (mMapItem != nullptr)
         {
             replaceAll(cmd, "'MAPX'", toString(mMapItem->getX()));
             replaceAll(cmd, "'MAPY'", toString(mMapItem->getY()));
@@ -1455,7 +1456,7 @@ void PopupMenu::handleLink(const std::string &link,
         for (int f = 0; f < maxCards; f ++)
         {
             const int id = mItemCards[f];
-            if (id)
+            if (id != 0)
             {
                 cards.append(",");
                 cards.append(toString(id));
@@ -1463,15 +1464,15 @@ void PopupMenu::handleLink(const std::string &link,
         }
         replaceAll(cmd, "'CARDS'", cards);
         replaceAll(cmd, "'ECARDS'", escapeString(cards));
-        if (actorManager)
+        if (actorManager != nullptr)
         {
-            if (!being)
+            if (being == nullptr)
             {
                 being = actorManager->findBeingByName(mName,
                     ActorType::Player);
             }
         }
-        if (being)
+        if (being != nullptr)
             replaceAll(cmd, "'PARTY'", being->getPartyName());
         else
             replaceAll(cmd, "'PARTY'", "");
@@ -1520,7 +1521,7 @@ void PopupMenu::showPopup(Window *const parent,
                           const Item *const item,
                           const InventoryTypeT type)
 {
-    if (!item)
+    if (item == nullptr)
         return;
 
     mItemId = item->getId();
@@ -1541,7 +1542,9 @@ void PopupMenu::showPopup(Window *const parent,
     switch (type)
     {
         case InventoryType::Inventory:
-            if (tradeWindow && tradeWindow->isWindowVisible() && !isProtected)
+            if (tradeWindow != nullptr &&
+                tradeWindow->isWindowVisible() &&
+                !isProtected)
             {
                 // TRANSLATORS: popup menu item
                 // TRANSLATORS: add item to trade
@@ -1599,10 +1602,10 @@ void PopupMenu::showPopup(Window *const parent,
                 }
                 mBrowserBox->addRow("##3---");
             }
-            if (npcHandler)
+            if (npcHandler != nullptr)
             {
                 NpcDialog *const dialog = npcHandler->getCurrentNpcDialog();
-                if (dialog &&
+                if ((dialog != nullptr) &&
                     dialog->getInputState() == NpcInputState::ITEM_CRAFT)
                 {
                     mBrowserBox->addRow("craftmenu",
@@ -1679,11 +1682,11 @@ void PopupMenu::showItemPopup(const int x, const int y,
                               const ItemColor color)
 {
     const Inventory *const inv = PlayerInfo::getInventory();
-    if (!inv)
+    if (inv == nullptr)
         return;
 
     Item *const item = inv->findItem(itemId, color);
-    if (item)
+    if (item != nullptr)
     {
         showItemPopup(x, y, item);
     }
@@ -1720,7 +1723,7 @@ void PopupMenu::showItemPopup(const int x, const int y,
 {
     mX = x;
     mY = y;
-    if (item)
+    if (item != nullptr)
     {
         mItemId = item->getId();
         mItemColor = item->getColor();
@@ -1740,7 +1743,7 @@ void PopupMenu::showItemPopup(const int x, const int y,
     mExtName.clear();
     mBrowserBox->clearRows();
 
-    if (item)
+    if (item != nullptr)
     {
         const bool isProtected = PlayerInfo::isItemProtected(mItemId);
         addUseDrop(item, isProtected);
@@ -1782,7 +1785,7 @@ void PopupMenu::showDropPopup(const int x,
     mExtName.clear();
     mBrowserBox->clearRows();
 
-    if (item)
+    if (item != nullptr)
     {
         mItemId = item->getId();
         mItemColor = item->getColor();
@@ -1823,7 +1826,7 @@ void PopupMenu::showDropPopup(const int x,
 
 void PopupMenu::showPopup(const int x, const int y, Button *const button)
 {
-    if (!button || !windowMenu)
+    if ((button == nullptr) || (windowMenu == nullptr))
         return;
 
     mButton = button;
@@ -1836,7 +1839,7 @@ void PopupMenu::showPopup(const int x, const int y, Button *const button)
          it_end = names.end(); it != it_end; ++ it)
     {
         const Button *const btn = *it;
-        if (!btn || btn->getActionEventId() == "SET")
+        if ((btn == nullptr) || btn->getActionEventId() == "SET")
             continue;
 
         if (btn->mVisible == Visible_true)
@@ -1864,7 +1867,7 @@ void PopupMenu::showPopup(const int x, const int y, Button *const button)
 
 void PopupMenu::showPopup(const int x, const int y, const ProgressBar *const b)
 {
-    if (!b || !miniStatusWindow)
+    if ((b == nullptr) || (miniStatusWindow == nullptr))
         return;
 
     mName = b->text();
@@ -1882,7 +1885,7 @@ void PopupMenu::showPopup(const int x, const int y, const ProgressBar *const b)
          it_end = bars.end(); it != it_end; ++it)
     {
         ProgressBar *const bar = *it;
-        if (!bar)
+        if (bar == nullptr)
             continue;
 
         if (bar->mVisible == Visible_true)
@@ -1898,7 +1901,7 @@ void PopupMenu::showPopup(const int x, const int y, const ProgressBar *const b)
          it_end = bars.end(); it != it_end; ++it)
     {
         ProgressBar *const bar = *it;
-        if (!bar || bar == onlyBar)
+        if ((bar == nullptr) || bar == onlyBar)
             continue;
 
         if (bar->mVisible == Visible_true)
@@ -1937,7 +1940,7 @@ void PopupMenu::showAttackMonsterPopup(const int x, const int y,
                                        const std::string &name,
                                        const int type)
 {
-    if (!localPlayer || !actorManager)
+    if ((localPlayer == nullptr) || (actorManager == nullptr))
         return;
 
     mName = name;
@@ -2019,7 +2022,7 @@ void PopupMenu::showAttackMonsterPopup(const int x, const int y,
 void PopupMenu::showPickupItemPopup(const int x, const int y,
                                     const std::string &name)
 {
-    if (!localPlayer || !actorManager)
+    if ((localPlayer == nullptr) || (actorManager == nullptr))
         return;
 
     mName = name;
@@ -2056,7 +2059,7 @@ void PopupMenu::showUndressPopup(const int x, const int y,
                                  const Being *const being,
                                  const Item *const item)
 {
-    if (!being || !item)
+    if ((being == nullptr) || (item == nullptr))
         return;
 
     mBeingId = being->getId();
@@ -2139,7 +2142,7 @@ void PopupMenu::showWindowsPopup()
     FOR_EACH (std::vector<ButtonText*>::const_iterator, it, names)
     {
         const ButtonText *const btn = *it;
-        if (!btn)
+        if (btn == nullptr)
             continue;
 
         mBrowserBox->addRow(strprintf("show window_%d",
@@ -2174,7 +2177,7 @@ void PopupMenu::showNpcDialogPopup(const BeingId npcId,
 
 void PopupMenu::showSkillPopup(const SkillInfo *const info)
 {
-    if (!info)
+    if (info == nullptr)
         return;
     setMousePos();
 
@@ -2212,7 +2215,7 @@ void PopupMenu::showSkillPopup(const SkillInfo *const info)
 void PopupMenu::showSkillOffsetPopup(const SkillInfo *const info,
                                      const bool isOffsetX)
 {
-    if (!info)
+    if (info == nullptr)
         return;
     setMousePos2();
 
@@ -2258,7 +2261,7 @@ void PopupMenu::showSkillOffsetPopup(const SkillInfo *const info,
 
 void PopupMenu::showSkillLevelPopup(const SkillInfo *const info)
 {
-    if (!info)
+    if (info == nullptr)
         return;
     setMousePos2();
 
@@ -2294,7 +2297,7 @@ void PopupMenu::showSkillLevelPopup(const SkillInfo *const info)
 
 void PopupMenu::showSkillTypePopup(const SkillInfo *const info)
 {
-    if (!info)
+    if (info == nullptr)
         return;
     setMousePos2();
 
@@ -2490,7 +2493,7 @@ void PopupMenu::addFollow()
 
 void PopupMenu::addBuySell(const Being *const being)
 {
-    if (player_relations.getDefault() & PlayerRelation::TRADE)
+    if ((player_relations.getDefault() & PlayerRelation::TRADE) != 0u)
     {
         mBrowserBox->addRow("##3---");
         const bool haveVending =
@@ -2524,7 +2527,7 @@ void PopupMenu::addBuySell(const Being *const being)
 
 void PopupMenu::addBuySellDefault()
 {
-    if (player_relations.getDefault() & PlayerRelation::TRADE)
+    if ((player_relations.getDefault() & PlayerRelation::TRADE) != 0u)
     {
         mBrowserBox->addRow("##3---");
         // TRANSLATORS: popup menu item
@@ -2540,7 +2543,7 @@ void PopupMenu::addPartyName(const std::string &partyName)
 {
     if (localPlayer->isInParty())
     {
-        if (localPlayer->getParty())
+        if (localPlayer->getParty() != nullptr)
         {
             if (localPlayer->getParty()->getName() != partyName)
             {
@@ -2565,7 +2568,7 @@ void PopupMenu::addParty(const std::string &nick)
     if (localPlayer->isInParty())
     {
         const Party *const party = localPlayer->getParty();
-        if (party)
+        if (party != nullptr)
         {
             if (!party->isMember(nick))
             {
@@ -2587,10 +2590,10 @@ void PopupMenu::addParty(const std::string &nick)
 
 void PopupMenu::addChat(const Being *const being)
 {
-    if (!being)
+    if (being == nullptr)
         return;
     const ChatObject *const chat = being->getChat();
-    if (chat)
+    if (chat != nullptr)
     {
         mBrowserBox->addRow("join chat",
             // TRANSLATORS: popup menu item
@@ -2638,7 +2641,7 @@ void PopupMenu::addPickupFilter(const std::string &name)
 void PopupMenu::showPopup(const int x, const int y,
                           ListModel *const model)
 {
-    if (!model)
+    if (model == nullptr)
         return;
 
     mBrowserBox->clearRows();
@@ -2655,7 +2658,7 @@ void PopupMenu::showPopup(const int x, const int y,
 
 void PopupMenu::clear()
 {
-    if (mDialog)
+    if (mDialog != nullptr)
     {
         mDialog->close();
         mDialog = nullptr;
@@ -2809,7 +2812,7 @@ void PopupMenu::showPlayerGMCommands(const std::string &name)
     {
         Being *const being = actorManager->findBeingByName(name,
             ActorType::Player);
-        if (being)
+        if (being != nullptr)
         {
             if (!being->getPartyName().empty())
             {
@@ -2826,10 +2829,10 @@ void PopupMenu::showPlayerGMCommands(const std::string &name)
                     _("Recall guild"));
             }
         }
-        if (localPlayer && localPlayer->isInParty())
+        if ((localPlayer != nullptr) && localPlayer->isInParty())
         {
             const Party *const party = localPlayer->getParty();
-            if (party && party->isMember(name))
+            if ((party != nullptr) && party->isMember(name))
             {
                 mBrowserBox->addRow("/gmpartyleader 'NAME'",
                     // TRANSLATORS: popup menu item
@@ -3208,7 +3211,7 @@ void PopupMenu::addSocialMenu()
     mBrowserBox->clearRows();
     setMousePos();
     const Party *const party = localPlayer->getParty();
-    if (party)
+    if (party != nullptr)
     {
         // TRANSLATORS: popup menu item
         // TRANSLATORS: leave party
@@ -3224,7 +3227,7 @@ void PopupMenu::addSocialMenu()
     if (Net::getNetworkType() != ServerType::TMWATHENA)
     {
         const Guild *const guild = localPlayer->getGuild();
-        if (guild)
+        if (guild != nullptr)
         {
             // TRANSLATORS: popup menu item
             // TRANSLATORS: leave guild
diff --git a/src/gui/popups/skillpopup.cpp b/src/gui/popups/skillpopup.cpp
index ab66dba81..91ea03feb 100644
--- a/src/gui/popups/skillpopup.cpp
+++ b/src/gui/popups/skillpopup.cpp
@@ -101,8 +101,8 @@ void SkillPopup::show(const SkillInfo *const skill,
                       const int offsetX,
                       const int offsetY)
 {
-    if (!skill ||
-        !skill->data ||
+    if ((skill == nullptr) ||
+        (skill->data == nullptr) ||
         (skill->id == mLastId &&
         level == mLastLevel &&
         castType == mCastType &&
diff --git a/src/gui/popups/speechbubble.cpp b/src/gui/popups/speechbubble.cpp
index a76f8694c..50d54e692 100644
--- a/src/gui/popups/speechbubble.cpp
+++ b/src/gui/popups/speechbubble.cpp
@@ -37,7 +37,7 @@
 SpeechBubble::SpeechBubble() :
     Popup("Speech", "speechbubble.xml"),
     mText(),
-    mSpacing(mSkin ? mSkin->getOption("spacing") : 2),
+    mSpacing(mSkin != nullptr ? mSkin->getOption("spacing") : 2),
     mCaption(new Label(this)),
     mSpeechBox(new BrowserBox(this, BrowserBoxMode::AUTO_SIZE, Opaque_true,
         "speechbrowserbox.xml"))
diff --git a/src/gui/popups/spellpopup.cpp b/src/gui/popups/spellpopup.cpp
index fcfe837d5..16169d81e 100644
--- a/src/gui/popups/spellpopup.cpp
+++ b/src/gui/popups/spellpopup.cpp
@@ -60,7 +60,7 @@ SpellPopup::~SpellPopup()
 
 void SpellPopup::setItem(const TextCommand *const spell)
 {
-    if (spell)
+    if (spell != nullptr)
     {
         mItemName->setCaption(spell->getName());
         mItemComment->setCaption(spell->getComment());
diff --git a/src/gui/sdlinput.cpp b/src/gui/sdlinput.cpp
index ead88bf6a..a6a3b831c 100644
--- a/src/gui/sdlinput.cpp
+++ b/src/gui/sdlinput.cpp
@@ -270,7 +270,8 @@ void SDLInput::pushInput(const SDL_Event &event)
              * This occurs when the mouse leaves the window and the Gui-chan
              * application loses its mousefocus.
              */
-            if ((event.active.state & SDL_APPMOUSEFOCUS) && !event.active.gain)
+            if ((event.active.state & SDL_APPMOUSEFOCUS) != 0 &&
+                event.active.gain == 0u)
             {
                 mMouseInWindow = false;
 
@@ -284,8 +285,11 @@ void SDLInput::pushInput(const SDL_Event &event)
                 }
             }
 
-            if ((event.active.state & SDL_APPMOUSEFOCUS) && event.active.gain)
+            if ((event.active.state & SDL_APPMOUSEFOCUS) != 0 &&
+                event.active.gain != 0u)
+            {
                 mMouseInWindow = true;
+            }
             break;
 #endif  // USE_SDL2
 
@@ -344,7 +348,7 @@ void SDLInput::simulateMouseClick(const int x, const int y,
 
 void SDLInput::simulateMouseMove()
 {
-    if (!gui)
+    if (gui == nullptr)
         return;
 
     int x, y;
diff --git a/src/gui/sdlinput.h b/src/gui/sdlinput.h
index 142a942aa..573dc3fd2 100644
--- a/src/gui/sdlinput.h
+++ b/src/gui/sdlinput.h
@@ -326,7 +326,7 @@ class SDLInput final
             }
             PRAGMA45(GCC diagnostic pop)
 
-            if (!(CAST_U32(keysym.mod) & KMOD_NUM))
+            if ((CAST_U32(keysym.mod) & KMOD_NUM) == 0u)
             {
                 PRAGMA45(GCC diagnostic push)
                 PRAGMA45(GCC diagnostic ignored "-Wswitch-enum")
diff --git a/src/gui/shortcut/dropshortcut.cpp b/src/gui/shortcut/dropshortcut.cpp
index 1afea70ec..f9876ebee 100644
--- a/src/gui/shortcut/dropshortcut.cpp
+++ b/src/gui/shortcut/dropshortcut.cpp
@@ -53,7 +53,7 @@ DropShortcut::~DropShortcut()
 
 void DropShortcut::dropFirst() const
 {
-    if (!localPlayer)
+    if (localPlayer == nullptr)
         return;
 
     if (!PacketLimiter::limitPackets(PacketType::PACKET_DROP))
@@ -68,7 +68,7 @@ void DropShortcut::dropFirst() const
     {
         const Item *const item = PlayerInfo::getInventory()
             ->findItem(itemId, itemColor);
-        if (item && item->getQuantity())
+        if ((item != nullptr) && (item->getQuantity() != 0))
         {
             const int cnt = settings.quickDropCounter;
             if (localPlayer->isServerBuggy())
@@ -86,7 +86,7 @@ void DropShortcut::dropFirst() const
 
 void DropShortcut::dropItems(const int cnt)
 {
-    if (!localPlayer)
+    if (localPlayer == nullptr)
         return;
 
     if (localPlayer->isServerBuggy())
@@ -114,7 +114,7 @@ void DropShortcut::dropItems(const int cnt)
 bool DropShortcut::dropItem(const int cnt)
 {
     const Inventory *const inv = PlayerInfo::getInventory();
-    if (!inv)
+    if (inv == nullptr)
         return false;
 
     int itemId = 0;
@@ -133,7 +133,7 @@ bool DropShortcut::dropItem(const int cnt)
     if (itemId > 0)
     {
         const Item *const item = inv->findItem(itemId, itemColor);
-        if (item &&
+        if ((item != nullptr) &&
             item->getQuantity() > 0)
         {
             PlayerInfo::dropItem(item, cnt, Sfx_true);
@@ -158,7 +158,7 @@ bool DropShortcut::dropItem(const int cnt)
         if (itemId > 0)
         {
             const Item *const item = inv->findItem(itemId, itemColor);
-            if (item && item->getQuantity() > 0)
+            if ((item != nullptr) && item->getQuantity() > 0)
             {
                 PlayerInfo::dropItem(item, cnt, Sfx_true);
                 return true;
diff --git a/src/gui/shortcut/emoteshortcut.cpp b/src/gui/shortcut/emoteshortcut.cpp
index ac9581fa3..0fcf4abaf 100644
--- a/src/gui/shortcut/emoteshortcut.cpp
+++ b/src/gui/shortcut/emoteshortcut.cpp
@@ -56,7 +56,7 @@ void EmoteShortcut::load()
          i++)
     {
         const EmoteSprite *const sprite = EmoteDB::getSprite(i, true);
-        if (sprite)
+        if (sprite != nullptr)
         {
             mEmotes[j] = CAST_U8(i + 1);
             j ++;
@@ -68,7 +68,7 @@ void EmoteShortcut::save() const
 {
     for (int i = 0; i < SHORTCUT_EMOTES; i++)
     {
-        const unsigned char emoteId = mEmotes[i] ? mEmotes[i]
+        const unsigned char emoteId = mEmotes[i] != 0u ? mEmotes[i]
             : CAST_U8(0);
         serverConfig.setValue("emoteshortcut" + toString(i),
             CAST_U32(emoteId));
@@ -77,7 +77,7 @@ void EmoteShortcut::save() const
 
 void EmoteShortcut::useEmotePlayer(const int index) const
 {
-    if (!localPlayer)
+    if (localPlayer == nullptr)
         return;
 
     if (index > 0 &&
@@ -90,7 +90,7 @@ void EmoteShortcut::useEmotePlayer(const int index) const
 
 void EmoteShortcut::useEmote(const int index) const
 {
-    if (!localPlayer)
+    if (localPlayer == nullptr)
         return;
 
     if (index > 0 &&
diff --git a/src/gui/shortcut/emoteshortcut.h b/src/gui/shortcut/emoteshortcut.h
index b9bbb920e..14d68fbc6 100644
--- a/src/gui/shortcut/emoteshortcut.h
+++ b/src/gui/shortcut/emoteshortcut.h
@@ -98,7 +98,7 @@ class EmoteShortcut final
          * A flag to check if the Emote is selected.
          */
         bool isEmoteSelected() const noexcept2 A_WARN_UNUSED
-        { return mEmoteSelected; }
+        { return mEmoteSelected != 0u; }
 
         /**
          * Remove a Emote from the shortcut.
diff --git a/src/gui/shortcut/itemshortcut.cpp b/src/gui/shortcut/itemshortcut.cpp
index 9f1c0705c..5828ae4e7 100644
--- a/src/gui/shortcut/itemshortcut.cpp
+++ b/src/gui/shortcut/itemshortcut.cpp
@@ -64,7 +64,7 @@ void ItemShortcut::load()
     std::string data;
     const Configuration *cfg = &serverConfig;
 
-    if (mNumber)
+    if (mNumber != 0)
     {
         name = std::string("shortcut").append(toString(mNumber)).append("_");
         color = std::string("shortcutColor").append(
@@ -96,7 +96,7 @@ void ItemShortcut::save() const
     std::string name;
     std::string color;
     std::string data;
-    if (mNumber)
+    if (mNumber != 0)
     {
         name = std::string("shortcut").append(toString(mNumber)).append("_");
         color = std::string("shortcutColor").append(
@@ -113,7 +113,7 @@ void ItemShortcut::save() const
 
     for (unsigned int i = 0; i < SHORTCUT_ITEMS; i++)
     {
-        const int itemId = mItems[i] ? mItems[i] : -1;
+        const int itemId = mItems[i] != 0 ? mItems[i] : -1;
         const int itemColor = toInt(mItemColors[i], int);
         const std::string itemData = mItemData[i];
         if (itemId != -1)
@@ -134,7 +134,7 @@ void ItemShortcut::save() const
 void ItemShortcut::useItem(const int index) const
 {
     const Inventory *const inv = PlayerInfo::getInventory();
-    if (!inv)
+    if (inv == nullptr)
         return;
 
     const int itemId = mItems[index];
@@ -144,14 +144,14 @@ void ItemShortcut::useItem(const int index) const
         if (itemId < SPELL_MIN_ID)
         {
             const Item *const item = inv->findItem(itemId, itemColor);
-            if (item && item->getQuantity())
+            if ((item != nullptr) && (item->getQuantity() != 0))
                 PlayerInfo::useEquipItem(item, Sfx_true);
         }
-        else if (itemId < SKILL_MIN_ID && spellManager)
+        else if (itemId < SKILL_MIN_ID && (spellManager != nullptr))
         {
             spellManager->useItem(itemId);
         }
-        else if (skillDialog)
+        else if (skillDialog != nullptr)
         {
             skillDialog->useItem(itemId,
                 fromBool(config.getBoolValue("skillAutotarget"), AutoTarget),
@@ -164,14 +164,14 @@ void ItemShortcut::useItem(const int index) const
 void ItemShortcut::equipItem(const int index) const
 {
     const Inventory *const inv = PlayerInfo::getInventory();
-    if (!inv)
+    if (inv == nullptr)
         return;
 
     const int itemId = mItems[index];
-    if (itemId)
+    if (itemId != 0)
     {
         const Item *const item = inv->findItem(itemId, mItemColors[index]);
-        if (item && item->getQuantity())
+        if ((item != nullptr) && (item->getQuantity() != 0))
         {
             if (item->isEquipment() == Equipm_true)
             {
@@ -184,14 +184,14 @@ void ItemShortcut::equipItem(const int index) const
 void ItemShortcut::unequipItem(const int index) const
 {
     const Inventory *const inv = PlayerInfo::getInventory();
-    if (!inv)
+    if (inv == nullptr)
         return;
 
     const int itemId = mItems[index];
-    if (itemId)
+    if (itemId != 0)
     {
         const Item *const item = inv->findItem(itemId, mItemColors[index]);
-        if (item && item->getQuantity())
+        if ((item != nullptr) && (item->getQuantity() != 0))
         {
             if (item->isEquipment() == Equipm_true)
             {
@@ -204,7 +204,7 @@ void ItemShortcut::unequipItem(const int index) const
 
 void ItemShortcut::setItemSelected(const Item *const item)
 {
-    if (item)
+    if (item != nullptr)
     {
         mItemSelected = item->getId();
         mItemColorSelected = item->getColor();
diff --git a/src/gui/shortcut/shortcutbase.cpp b/src/gui/shortcut/shortcutbase.cpp
index 0b3121ee0..8b7bf80c3 100644
--- a/src/gui/shortcut/shortcutbase.cpp
+++ b/src/gui/shortcut/shortcutbase.cpp
@@ -74,7 +74,7 @@ void ShortcutBase::save() const
 {
     for (int i = 0; i < mMaxSize; i++)
     {
-        const int itemId = mItems[i] ? mItems[i] : -1;
+        const int itemId = mItems[i] != 0 ? mItems[i] : -1;
         const int itemColor = (mItemColors[i] != ItemColor_zero)
             ? toInt(mItemColors[i], int) : 1;
         if (itemId != -1)
@@ -92,7 +92,7 @@ void ShortcutBase::save() const
 
 void ShortcutBase::setItemSelected(const Item *const item)
 {
-    if (item)
+    if (item != nullptr)
     {
         mItemSelected = item->getId();
         mItemColorSelected = item->getColor();
diff --git a/src/gui/shortcut/spellshortcut.cpp b/src/gui/shortcut/spellshortcut.cpp
index 9cec4cd9a..ef6815a2c 100644
--- a/src/gui/shortcut/spellshortcut.cpp
+++ b/src/gui/shortcut/spellshortcut.cpp
@@ -44,7 +44,7 @@ void SpellShortcut::load()
     for (unsigned f = 0; f < SPELLS_SIZE; f ++)
         mItems[f] = -1;
 
-    if (!spellManager)
+    if (spellManager == nullptr)
         return;
 
     const std::vector<TextCommand*> &spells = spellManager->getAll();
diff --git a/src/gui/skin.cpp b/src/gui/skin.cpp
index d3c2a048e..45317fa0d 100644
--- a/src/gui/skin.cpp
+++ b/src/gui/skin.cpp
@@ -45,18 +45,18 @@ Skin::Skin(ImageRect *const restrict skin,
     mFilePath(filePath),
     mName(name),
     mBorder(skin),
-    mCloseImage(images ? images->grid[0] : nullptr),
-    mCloseImageHighlighted(images ? images->grid[1] : nullptr),
-    mStickyImageUp(images ? images->grid[2] : nullptr),
-    mStickyImageDown(images ? images->grid[3] : nullptr),
+    mCloseImage(images != nullptr ? images->grid[0] : nullptr),
+    mCloseImageHighlighted(images != nullptr ? images->grid[1] : nullptr),
+    mStickyImageUp(images != nullptr ? images->grid[2] : nullptr),
+    mStickyImageDown(images != nullptr ? images->grid[3] : nullptr),
     mPadding(padding),
     mTitlePadding(titlePadding),
     mOptions(options)
 {
-    if (!mCloseImageHighlighted)
+    if (mCloseImageHighlighted == nullptr)
     {
         mCloseImageHighlighted = mCloseImage;
-        if (mCloseImageHighlighted)
+        if (mCloseImageHighlighted != nullptr)
             mCloseImageHighlighted->incRef();
     }
 }
@@ -65,32 +65,32 @@ Skin::~Skin()
 {
     for (int i = 0; i < 9; i++)
     {
-        if (mBorder && mBorder->grid[i])
+        if ((mBorder != nullptr) && (mBorder->grid[i] != nullptr))
         {
             mBorder->grid[i]->decRef();
             mBorder->grid[i] = nullptr;
         }
     }
 
-    if (mCloseImage)
+    if (mCloseImage != nullptr)
     {
         mCloseImage->decRef();
         mCloseImage = nullptr;
     }
 
-    if (mCloseImageHighlighted)
+    if (mCloseImageHighlighted != nullptr)
     {
         mCloseImageHighlighted->decRef();
         mCloseImageHighlighted = nullptr;
     }
 
-    if (mStickyImageUp)
+    if (mStickyImageUp != nullptr)
     {
         mStickyImageUp->decRef();
         mStickyImageUp = nullptr;
     }
 
-    if (mStickyImageDown)
+    if (mStickyImageDown != nullptr)
     {
         mStickyImageDown->decRef();
         mStickyImageDown = nullptr;
@@ -106,30 +106,30 @@ void Skin::updateAlpha(const float minimumOpacityAllowed)
         std::max(static_cast<double>(minimumOpacityAllowed),
         static_cast<double>(settings.guiAlpha)));
 
-    if (mBorder)
+    if (mBorder != nullptr)
     {
         for (int i = 0; i < 9; i++)
         {
-            if (mBorder->grid[i])
+            if (mBorder->grid[i] != nullptr)
                 mBorder->grid[i]->setAlpha(alpha);
         }
     }
 
-    if (mCloseImage)
+    if (mCloseImage != nullptr)
         mCloseImage->setAlpha(alpha);
-    if (mCloseImageHighlighted)
+    if (mCloseImageHighlighted != nullptr)
         mCloseImageHighlighted->setAlpha(alpha);
-    if (mStickyImageUp)
+    if (mStickyImageUp != nullptr)
         mStickyImageUp->setAlpha(alpha);
-    if (mStickyImageDown)
+    if (mStickyImageDown != nullptr)
         mStickyImageDown->setAlpha(alpha);
 }
 
 int Skin::getMinWidth() const
 {
-    if (!mBorder ||
-        !mBorder->grid[ImagePosition::UPPER_LEFT] ||
-        !mBorder->grid[ImagePosition::UPPER_RIGHT])
+    if ((mBorder == nullptr) ||
+        (mBorder->grid[ImagePosition::UPPER_LEFT] == nullptr) ||
+        (mBorder->grid[ImagePosition::UPPER_RIGHT] == nullptr))
     {
         return 1;
     }
@@ -140,9 +140,9 @@ int Skin::getMinWidth() const
 
 int Skin::getMinHeight() const
 {
-    if (!mBorder ||
-        !mBorder->grid[ImagePosition::UPPER_LEFT] ||
-        !mBorder->grid[ImagePosition::LOWER_LEFT])
+    if ((mBorder == nullptr) ||
+        (mBorder->grid[ImagePosition::UPPER_LEFT] == nullptr) ||
+        (mBorder->grid[ImagePosition::LOWER_LEFT] == nullptr))
     {
         return 1;
     }
diff --git a/src/gui/theme.cpp b/src/gui/theme.cpp
index 5eda09a36..6d16dfd4e 100644
--- a/src/gui/theme.cpp
+++ b/src/gui/theme.cpp
@@ -158,12 +158,12 @@ Color Theme::getProgressColor(const ProgressColorIdT type,
 {
     int color[3] = {0, 0, 0};
 
-    if (theme)
+    if (theme != nullptr)
     {
         const DyePalette *const dye
             = theme->mProgressColors[CAST_SIZE(type)];
 
-        if (dye)
+        if (dye != nullptr)
         {
             dye->getColor(progress, color);
         }
@@ -187,7 +187,7 @@ Skin *Theme::load(const std::string &filename,
     const SkinIterator skinIterator = mSkins.find(filename);
     if (mSkins.end() != skinIterator)
     {
-        if (skinIterator->second)
+        if (skinIterator->second != nullptr)
             skinIterator->second->instances++;
         return skinIterator->second;
     }
@@ -196,9 +196,9 @@ Skin *Theme::load(const std::string &filename,
     if (mScreenDensity.empty())
     {   // if no density detected
         skin = readSkin(filename, full);
-        if (!skin && !filename2.empty() && filename2 != filename)
+        if ((skin == nullptr) && !filename2.empty() && filename2 != filename)
             skin = readSkin(filename2, full);
-        if (!skin && filename2 != "window.xml")
+        if ((skin == nullptr) && filename2 != "window.xml")
             skin = readSkin("window.xml", full);
     }
     else
@@ -207,25 +207,25 @@ Skin *Theme::load(const std::string &filename,
         std::string name = filename;
         if (findCutLast(name, ".xml"))
             skin = readSkin(name + endStr, full);
-        if (!skin)
+        if (skin == nullptr)
             skin = readSkin(filename, full);
-        if (!skin && !filename2.empty() && filename2 != filename)
+        if ((skin == nullptr) && !filename2.empty() && filename2 != filename)
         {
             name = filename2;
             if (findCutLast(name, ".xml"))
                 skin = readSkin(name + endStr, full);
-            if (!skin)
+            if (skin == nullptr)
                 skin = readSkin(filename2, full);
         }
-        if (!skin && filename2 != "window.xml")
+        if ((skin == nullptr) && filename2 != "window.xml")
         {
             skin = readSkin("window" + endStr, full);
-            if (!skin)
+            if (skin == nullptr)
                 skin = readSkin("window.xml", full);
         }
     }
 
-    if (!skin)
+    if (skin == nullptr)
     {
         // Try falling back on the defaultPath if this makes sense
         if (filename != defaultPath)
@@ -236,7 +236,7 @@ Skin *Theme::load(const std::string &filename,
             skin = readSkin(defaultPath, full);
         }
 
-        if (!skin)
+        if (skin == nullptr)
         {
             logger->log(strprintf("Error: Loading default skin '%s' failed. "
                                   "Make sure the skin file is valid.",
@@ -250,10 +250,10 @@ Skin *Theme::load(const std::string &filename,
 
 void Theme::unload(Skin *const skin)
 {
-    if (!skin)
+    if (skin == nullptr)
         return;
     skin->instances --;
-    if (!skin->instances)
+    if (skin->instances == 0)
     {
         SkinIterator it = mSkins.begin();
         const SkinIterator it_end = mSkins.end();
@@ -284,7 +284,7 @@ void Theme::updateAlpha()
     FOR_EACH (SkinIterator, iter, mSkins)
     {
         Skin *const skin = iter->second;
-        if (skin)
+        if (skin != nullptr)
             skin->updateAlpha(mMinimumOpacity);
     }
 }
@@ -403,10 +403,10 @@ Skin *Theme::readSkin(const std::string &filename, const bool full)
     XML::Document *const doc = Loader::getXml(path,
         UseVirtFs_true,
         SkipError_true);
-    if (!doc)
+    if (doc == nullptr)
         return nullptr;
     XmlNodeConstPtr rootNode = doc->rootNode();
-    if (!rootNode || !xmlNameEqual(rootNode, "skinset"))
+    if ((rootNode == nullptr) || !xmlNameEqual(rootNode, "skinset"))
     {
         doc->decRef();
         return nullptr;
@@ -461,7 +461,7 @@ Skin *Theme::readSkin(const std::string &filename, const bool full)
                         partNode, "ypos", 0) + globalYPos;
                     helper.width = XML::getProperty(partNode, "width", 0);
                     helper.height = XML::getProperty(partNode, "height", 0);
-                    if (!helper.width || !helper.height)
+                    if ((helper.width == 0) || (helper.height == 0))
                         continue;
                     helper.image = dBorders;
 
@@ -528,7 +528,7 @@ Skin *Theme::readSkin(const std::string &filename, const bool full)
         }
     }
 
-    if (dBorders)
+    if (dBorders != nullptr)
         dBorders->decRef();
 
     (*mOptions)["closePadding"] = closePadding;
@@ -555,7 +555,7 @@ bool Theme::tryThemePath(const std::string &themeName)
         {
             mThemePath = path;
             mThemeName = themeName;
-            if (theme)
+            if (theme != nullptr)
                 theme->loadColors("");
             return true;
         }
@@ -960,7 +960,7 @@ static GradientTypeT readColorGradient(const std::string &grad)
 
     for (int i = 0; i < 4; i++)
     {
-        if (compareStrI(grad, grads[i]))
+        if (compareStrI(grad, grads[i]) != 0)
             return static_cast<GradientTypeT>(i);
     }
 
@@ -1008,11 +1008,11 @@ void Theme::loadColors(std::string file)
     XML::Document *const doc = Loader::getXml(resolveThemePath(file),
         UseVirtFs_true,
         SkipError_false);
-    if (!doc)
+    if (doc == nullptr)
         return;
     XmlNodeConstPtrConst root = doc->rootNode();
 
-    if (!root || !xmlNameEqual(root, "colors"))
+    if ((root == nullptr) || !xmlNameEqual(root, "colors"))
     {
         logger->log("Error loading colors file: %s", file.c_str());
         doc->decRef();
@@ -1097,7 +1097,7 @@ void Theme::loadRect(ImageRect &image,
                      const int end)
 {
     Skin *const skin = load(name, name2, false);
-    if (skin)
+    if (skin != nullptr)
     {
         loadGrid();
         unload(skin);
@@ -1111,7 +1111,7 @@ Skin *Theme::loadSkinRect(ImageRect &image,
                           const int end)
 {
     Skin *const skin = load(name, name2);
-    if (skin)
+    if (skin != nullptr)
         loadGrid();
     return skin;
 }
@@ -1122,7 +1122,7 @@ void Theme::unloadRect(const ImageRect &rect,
 {
     for (int f = start; f <= end; f ++)
     {
-        if (rect.grid[f])
+        if (rect.grid[f] != nullptr)
             rect.grid[f]->decRef();
     }
 }
@@ -1130,14 +1130,14 @@ void Theme::unloadRect(const ImageRect &rect,
 Image *Theme::getImageFromThemeXml(const std::string &name,
                                    const std::string &name2)
 {
-    if (!theme)
+    if (theme == nullptr)
         return nullptr;
 
     Skin *const skin = theme->load(name, name2, false);
-    if (skin)
+    if (skin != nullptr)
     {
         const ImageRect &rect = skin->getBorder();
-        if (rect.grid[0])
+        if (rect.grid[0] != nullptr)
         {
             Image *const image = rect.grid[0];
             image->incRef();
@@ -1153,18 +1153,18 @@ ImageSet *Theme::getImageSetFromThemeXml(const std::string &name,
                                          const std::string &name2,
                                          const int w, const int h)
 {
-    if (!theme)
+    if (theme == nullptr)
         return nullptr;
 
     Skin *const skin = theme->load(name, name2, false);
-    if (skin)
+    if (skin != nullptr)
     {
         const ImageRect &rect = skin->getBorder();
-        if (rect.grid[0])
+        if (rect.grid[0] != nullptr)
         {
             Image *const image = rect.grid[0];
             const SDL_Rect &rect2 = image->mBounds;
-            if (rect2.w && rect2.h)
+            if ((rect2.w != 0u) && (rect2.h != 0u))
             {
                 ImageSet *const imageSet = Loader::getSubImageSet(
                     image, w, h);
@@ -1218,11 +1218,11 @@ ThemeInfo *Theme::loadInfo(const std::string &themeName)
     XML::Document *const doc = Loader::getXml(path,
         UseVirtFs_true,
         SkipError_false);
-    if (!doc)
+    if (doc == nullptr)
         return nullptr;
     XmlNodeConstPtrConst rootNode = doc->rootNode();
 
-    if (!rootNode || !xmlNameEqual(rootNode, "info"))
+    if ((rootNode == nullptr) || !xmlNameEqual(rootNode, "info"))
     {
         doc->decRef();
         return nullptr;
diff --git a/src/gui/viewport.cpp b/src/gui/viewport.cpp
index df9b9ae9b..3fb80fd33 100644
--- a/src/gui/viewport.cpp
+++ b/src/gui/viewport.cpp
@@ -121,7 +121,7 @@ Viewport::~Viewport()
 
 void Viewport::setMap(Map *const map)
 {
-    if (mMap && map)
+    if ((mMap != nullptr) && (map != nullptr))
         map->setDrawLayersFlags(mMap->getDrawLayersFlags());
     mMap = map;
     updateMaxVars();
@@ -132,7 +132,7 @@ void Viewport::draw(Graphics *const graphics)
     BLOCK_START("Viewport::draw 1")
     static int lastTick = tick_time;
 
-    if (!mMap || !localPlayer)
+    if ((mMap == nullptr) || (localPlayer == nullptr))
     {
         graphics->setColor(Color(64, 64, 64));
         graphics->fillRectangle(
@@ -247,7 +247,7 @@ void Viewport::draw(Graphics *const graphics)
     }
 
     // Draw text
-    if (textManager)
+    if (textManager != nullptr)
         textManager->draw(graphics, mPixelViewX, mPixelViewY);
 
     // Draw player names, speech, and emotion sprite as needed
@@ -261,7 +261,7 @@ void Viewport::draw(Graphics *const graphics)
         b->drawEmotion(graphics, mPixelViewX, mPixelViewY);
     }
 
-    if (miniStatusWindow)
+    if (miniStatusWindow != nullptr)
         miniStatusWindow->drawIcons(graphics);
 
     // Draw contained widgets
@@ -285,11 +285,11 @@ void Viewport::logic()
 
 void Viewport::followMouse()
 {
-    if (!gui)
+    if (gui == nullptr)
         return;
     const MouseStateType button = Gui::getMouseState(mMouseX, mMouseY);
     // If the left button is dragged
-    if (mPlayerFollowMouse && (button & SDL_BUTTON(1)))
+    if (mPlayerFollowMouse && ((button & SDL_BUTTON(1)) != 0))
     {
         // We create a mouse event and send it to mouseDragged.
         const MouseEvent event(nullptr,
@@ -305,8 +305,14 @@ void Viewport::followMouse()
 
 void Viewport::drawDebugPath(Graphics *const graphics)
 {
-    if (!localPlayer || !userPalette || !actorManager || !mMap || !gui)
+    if (localPlayer == nullptr ||
+        userPalette == nullptr ||
+        actorManager == nullptr ||
+        mMap == nullptr ||
+        gui == nullptr)
+    {
         return;
+    }
 
     Gui::getMouseState(mMouseX, mMouseY);
 
@@ -335,7 +341,7 @@ void Viewport::drawDebugPath(Graphics *const graphics)
     FOR_EACH (ActorSpritesConstIterator, it, actors)
     {
         const Being *const being = dynamic_cast<const Being*>(*it);
-        if (being && being != localPlayer)
+        if ((being != nullptr) && being != localPlayer)
         {
             const Path &beingPath = being->getPath();
             drawPath(graphics, beingPath, userPalette->getColorWithAlpha(
@@ -358,7 +364,7 @@ void Viewport::drawPath(Graphics *const graphics,
         const int squareY = i->y * mapTileSize - mPixelViewY + 12;
 
         graphics->fillRectangle(Rect(squareX, squareY, 8, 8));
-        if (mMap)
+        if (mMap != nullptr)
         {
             const std::string str = toString(cnt);
             font->drawString(graphics,
@@ -376,12 +382,12 @@ bool Viewport::openContextMenu(const MouseEvent &event)
     mPlayerFollowMouse = false;
     const int eventX = event.getX();
     const int eventY = event.getY();
-    if (!popupMenu)
+    if (popupMenu == nullptr)
         return false;
-    if (mHoverBeing)
+    if (mHoverBeing != nullptr)
     {
         validateSpeed();
-        if (actorManager)
+        if (actorManager != nullptr)
         {
             std::vector<ActorSprite*> beings;
             const int x = mMouseX + mPixelViewX;
@@ -394,21 +400,21 @@ bool Viewport::openContextMenu(const MouseEvent &event)
             return true;
         }
     }
-    else if (mHoverItem)
+    else if (mHoverItem != nullptr)
     {
         validateSpeed();
         popupMenu->showPopup(eventX, eventY, mHoverItem);
         return true;
     }
-    else if (mHoverSign)
+    else if (mHoverSign != nullptr)
     {
         validateSpeed();
         popupMenu->showPopup(eventX, eventY, mHoverSign);
         return true;
     }
-    else if (settings.cameraMode)
+    else if (settings.cameraMode != 0u)
     {
-        if (!mMap)
+        if (mMap == nullptr)
             return false;
         popupMenu->showMapPopup(eventX, eventY,
             (mMouseX + mPixelViewX) / mMap->getTileWidth(),
@@ -424,7 +430,7 @@ bool Viewport::leftMouseAction()
     const bool stopAttack = inputManager.isActionActive(
         InputAction::STOP_ATTACK);
     // Interact with some being
-    if (mHoverBeing)
+    if (mHoverBeing != nullptr)
     {
         if (!mHoverBeing->isAlive())
             return true;
@@ -442,14 +448,14 @@ bool Viewport::leftMouseAction()
             {
                 case ActorType::Player:
                     validateSpeed();
-                    if (actorManager)
+                    if (actorManager != nullptr)
                     {
 #ifdef TMWA_SUPPORT
                         if (localPlayer != mHoverBeing || mSelfMouseHeal)
                             actorManager->heal(mHoverBeing);
 #endif  // TMWA_SUPPORT
 
-                        if (localPlayer == mHoverBeing && mHoverItem)
+                        if (localPlayer == mHoverBeing && (mHoverItem != nullptr))
                             localPlayer->pickUp(mHoverItem);
                         return true;
                     }
@@ -500,14 +506,14 @@ bool Viewport::leftMouseAction()
         }
     }
     // Picks up a item if we clicked on one
-    if (mHoverItem)
+    if (mHoverItem != nullptr)
     {
         validateSpeed();
         localPlayer->pickUp(mHoverItem);
     }
     else if (stopAttack)
     {
-        if (mMap)
+        if (mMap != nullptr)
         {
             const int mouseTileX = (mMouseX + mPixelViewX)
                 / mMap->getTileWidth();
@@ -542,7 +548,7 @@ void Viewport::mousePressed(MouseEvent &event)
         return;
 
     // Check if we are alive and kickin'
-    if (!mMap || !localPlayer)
+    if ((mMap == nullptr) || (localPlayer == nullptr))
         return;
 
     // Check if we are busy
@@ -590,12 +596,12 @@ void Viewport::mousePressed(MouseEvent &event)
         mPlayerFollowMouse = false;
         validateSpeed();
         // Find the being nearest to the clicked position
-        if (actorManager)
+        if (actorManager != nullptr)
         {
             Being *const target = actorManager->findNearestLivingBeing(
                 pixelX, pixelY, 20, ActorType::Monster, nullptr);
 
-            if (target)
+            if (target != nullptr)
                 localPlayer->setTarget(target);
         }
     }
@@ -609,7 +615,7 @@ void Viewport::getMouseTile(int &destX, int &destY) const
 void Viewport::getMouseTile(const int x, const int y,
                             int &destX, int &destY) const
 {
-    if (!mMap)
+    if (mMap == nullptr)
         return;
     const int tw = mMap->getTileWidth();
     const int th = mMap->getTileHeight();
@@ -656,7 +662,7 @@ void Viewport::getMouseTile(const int x, const int y,
 
 void Viewport::walkByMouse(const MouseEvent &event)
 {
-    if (!mMap || !localPlayer)
+    if ((mMap == nullptr) || (localPlayer == nullptr))
         return;
     if (mPlayerFollowMouse
         && !inputManager.isActionActive(InputAction::STOP_ATTACK)
@@ -678,7 +684,7 @@ void Viewport::walkByMouse(const MouseEvent &event)
                     / static_cast<float>(height);
                 int x = event.getX() - width;
                 int y = event.getY() - height;
-                if (!x && !y)
+                if ((x == 0) && (y == 0))
                     return;
                 const int x2 = abs(x);
                 const int y2 = abs(y);
@@ -687,7 +693,7 @@ void Viewport::walkByMouse(const MouseEvent &event)
                 int dy = 0;
                 if (x2 > y2)
                 {
-                    if (y2 && static_cast<float>(x2) / static_cast<float>(y2)
+                    if ((y2 != 0) && static_cast<float>(x2) / static_cast<float>(y2)
                         / wh > diff)
                     {
                         y = 0;
@@ -695,7 +701,7 @@ void Viewport::walkByMouse(const MouseEvent &event)
                 }
                 else
                 {
-                    if (x2 && y2 * wh / x2 > diff)
+                    if ((x2 != 0) && y2 * wh / x2 > diff)
                         x = 0;
                 }
                 if (x > 0)
@@ -718,7 +724,7 @@ void Viewport::walkByMouse(const MouseEvent &event)
                 }
                 else
                 {
-                    if (dx && dy)
+                    if ((dx != 0) && (dy != 0))
                     {
                         // try avoid diagonal collision
                         if (x2 > y2)
@@ -757,7 +763,7 @@ void Viewport::walkByMouse(const MouseEvent &event)
                     else
                     {
                         // try avoid vertical or horisontal collision
-                        if (!dx)
+                        if (dx == 0)
                         {
                             if (mMap->getWalk(playerX + 1,
                                 playerY + dy,
@@ -778,7 +784,7 @@ void Viewport::walkByMouse(const MouseEvent &event)
                                 dx = -1;
                             }
                         }
-                        if (!dy)
+                        if (dy == 0)
                         {
                             if (mMap->getWalk(playerX + dx,
                                 playerY + 1,
@@ -839,7 +845,7 @@ void Viewport::mouseDragged(MouseEvent &event)
     }
     if (mAllowMoveByMouse &&
         mMouseClicked &&
-        localPlayer &&
+        (localPlayer != nullptr) &&
         localPlayer->canMove())
     {
         if (abs(event.getX() - mMousePressX) > 32
@@ -865,7 +871,7 @@ void Viewport::mouseReleased(MouseEvent &event)
         if (eventButton == MouseButton::LEFT)
         {
             // long button press
-            if (gui && gui->isLongPress())
+            if ((gui != nullptr) && gui->isLongPress())
             {
                 if (openContextMenu(event))
                 {
@@ -906,7 +912,7 @@ void Viewport::optionChanged(const std::string &name)
 void Viewport::mouseMoved(MouseEvent &event)
 {
     // Check if we are on the map
-    if (!mMap || !localPlayer || !actorManager)
+    if ((mMap == nullptr) || (localPlayer == nullptr) || (actorManager == nullptr))
         return;
 
     if (mMouseDirectionMove)
@@ -917,9 +923,9 @@ void Viewport::mouseMoved(MouseEvent &event)
 
     ActorTypeT type = ActorType::Unknown;
     mHoverBeing = actorManager->findBeingByPixel(x, y, AllPlayers_true);
-    if (mHoverBeing)
+    if (mHoverBeing != nullptr)
         type = mHoverBeing->getType();
-    if (mHoverBeing
+    if ((mHoverBeing != nullptr)
         && (type == ActorType::Player
         || type == ActorType::Npc
         || type == ActorType::Homunculus
@@ -927,7 +933,7 @@ void Viewport::mouseMoved(MouseEvent &event)
         || type == ActorType::Pet))
     {
         popupManager->hideTextPopup();
-        if (mShowBeingPopup && beingPopup)
+        if (mShowBeingPopup && (beingPopup != nullptr))
             beingPopup->show(mMouseX, mMouseY, mHoverBeing);
     }
     else
@@ -938,10 +944,10 @@ void Viewport::mouseMoved(MouseEvent &event)
     mHoverItem = actorManager->findItem(x / mMap->getTileWidth(),
         y / mMap->getTileHeight());
 
-    if (!mHoverBeing && !mHoverItem)
+    if ((mHoverBeing == nullptr) && (mHoverItem == nullptr))
     {
         const SpecialLayer *const specialLayer = mMap->getSpecialLayer();
-        if (specialLayer)
+        if (specialLayer != nullptr)
         {
             const int mouseTileX = (mMouseX + mPixelViewX)
                 / mMap->getTileWidth();
@@ -949,12 +955,12 @@ void Viewport::mouseMoved(MouseEvent &event)
                 / mMap->getTileHeight();
 
             mHoverSign = specialLayer->getTile(mouseTileX, mouseTileY);
-            if (mHoverSign && mHoverSign->getType() != MapItemType::EMPTY)
+            if ((mHoverSign != nullptr) && mHoverSign->getType() != MapItemType::EMPTY)
             {
                 if (!mHoverSign->getComment().empty())
                 {
                     popupManager->hideBeingPopup();
-                    if (textPopup)
+                    if (textPopup != nullptr)
                     {
                         textPopup->show(mMouseX, mMouseY,
                             mHoverSign->getComment());
@@ -973,7 +979,7 @@ void Viewport::mouseMoved(MouseEvent &event)
     if (!event.isConsumed() && popupManager->isTextPopupVisible())
         popupManager->hideTextPopup();
 
-    if (mHoverBeing)
+    if (mHoverBeing != nullptr)
     {
         switch (type)
         {
@@ -998,7 +1004,7 @@ void Viewport::mouseMoved(MouseEvent &event)
         }
     }
     // Item mouseover
-    else if (mHoverItem)
+    else if (mHoverItem != nullptr)
     {
         gui->setCursorType(mHoverItem->getHoverCursor());
     }
@@ -1014,7 +1020,7 @@ void Viewport::toggleMapDrawType()
         CAST_S32(settings.mapDrawType) + 1);
     if (settings.mapDrawType > MapType::BLACKWHITE)
         settings.mapDrawType = MapType::NORMAL;
-    if (mMap)
+    if (mMap != nullptr)
         mMap->setDrawLayersFlags(settings.mapDrawType);
 }
 
@@ -1023,7 +1029,7 @@ void Viewport::toggleCameraMode()
     settings.cameraMode ++;
     if (settings.cameraMode > 1)
         settings.cameraMode = 0;
-    if (!settings.cameraMode)
+    if (settings.cameraMode == 0u)
     {
         mCameraRelativeX = 0;
         mCameraRelativeY = 0;
@@ -1058,11 +1064,11 @@ void Viewport::moveCamera(const int dx, const int dy)
 void Viewport::moveCameraToActor(const BeingId actorId,
                                  const int x, const int y)
 {
-    if (!localPlayer || !actorManager)
+    if ((localPlayer == nullptr) || (actorManager == nullptr))
         return;
 
     const Actor *const actor = actorManager->findBeing(actorId);
-    if (!actor)
+    if (actor == nullptr)
         return;
     settings.cameraMode = 1;
     mCameraRelativeX = actor->mPixelX - localPlayer->mPixelX + x;
@@ -1072,7 +1078,7 @@ void Viewport::moveCameraToActor(const BeingId actorId,
 
 void Viewport::moveCameraToPosition(const int x, const int y)
 {
-    if (!localPlayer)
+    if (localPlayer == nullptr)
         return;
 
     settings.cameraMode = 1;
@@ -1102,7 +1108,7 @@ void Viewport::validateSpeed()
     if (!inputManager.isActionActive(InputAction::TARGET_ATTACK) &&
         !inputManager.isActionActive(InputAction::ATTACK))
     {
-        if (Game::instance())
+        if (Game::instance() != nullptr)
             Game::instance()->setValidSpeed();
     }
 }
@@ -1117,7 +1123,7 @@ void Viewport::updateMidVars()
 
 void Viewport::updateMaxVars()
 {
-    if (!mMap)
+    if (mMap == nullptr)
         return;
     mViewXmax = mMap->getWidth() * mMap->getTileWidth()
         - mainGraphics->mWidth;
diff --git a/src/gui/widgets/attrs/attrdisplay.cpp b/src/gui/widgets/attrs/attrdisplay.cpp
index 503444e7f..3b91fef9d 100644
--- a/src/gui/widgets/attrs/attrdisplay.cpp
+++ b/src/gui/widgets/attrs/attrdisplay.cpp
@@ -60,7 +60,7 @@ std::string AttrDisplay::update()
     const int base = PlayerInfo::getStatBase(mId);
     const int bonus = PlayerInfo::getStatMod(mId);
     std::string value = toString(base + bonus);
-    if (bonus)
+    if (bonus != 0)
         value.append(strprintf("=%d%+d", base, bonus));
     mValue->setCaption(value);
     return mName;
diff --git a/src/gui/widgets/attrs/attrdisplay.h b/src/gui/widgets/attrs/attrdisplay.h
index c4f23339f..1641bac9f 100644
--- a/src/gui/widgets/attrs/attrdisplay.h
+++ b/src/gui/widgets/attrs/attrdisplay.h
@@ -54,7 +54,7 @@ class AttrDisplay notfinal : public Container
 
         std::string getValue() const
         {
-            if (!mValue)
+            if (mValue == nullptr)
                 return "-";
             else
                 return mValue->getCaption();
diff --git a/src/gui/widgets/avatarlistbox.cpp b/src/gui/widgets/avatarlistbox.cpp
index c81798e29..383efb397 100644
--- a/src/gui/widgets/avatarlistbox.cpp
+++ b/src/gui/widgets/avatarlistbox.cpp
@@ -56,7 +56,7 @@ Image *AvatarListBox::offlineIcon = nullptr;
 AvatarListBox::AvatarListBox(const Widget2 *const widget,
                              AvatarListModel *const model) :
     ListBox(widget, model, "avatarlistbox.xml"),
-    mImagePadding(mSkin ? mSkin->getOption("imagePadding") : 0),
+    mImagePadding(mSkin != nullptr ? mSkin->getOption("imagePadding") : 0),
     mShowGender(config.getBoolValue("showgender")),
     mShowLevel(config.getBoolValue("showlevel"))
 {
@@ -86,12 +86,12 @@ AvatarListBox::~AvatarListBox()
 
     if (instances == 0)
     {
-        if (onlineIcon)
+        if (onlineIcon != nullptr)
         {
             onlineIcon->decRef();
             onlineIcon = nullptr;
         }
-        if (offlineIcon)
+        if (offlineIcon != nullptr)
         {
             offlineIcon->decRef();
             offlineIcon = nullptr;
@@ -102,14 +102,14 @@ AvatarListBox::~AvatarListBox()
 void AvatarListBox::draw(Graphics *const graphics)
 {
     BLOCK_START("AvatarListBox::draw")
-    if (!mListModel || !localPlayer)
+    if ((mListModel == nullptr) || (localPlayer == nullptr))
     {
         BLOCK_END("AvatarListBox::draw")
         return;
     }
 
     const Widget *const parent = mParent;
-    if (!parent)
+    if (parent == nullptr)
         return;
 
     AvatarListModel *const model = static_cast<AvatarListModel *>(
@@ -129,7 +129,7 @@ void AvatarListBox::draw(Graphics *const graphics)
          ++i, y += fontHeight)
     {
         const Avatar *const a = model->getAvatarAt(i);
-        if (!a)
+        if (a == nullptr)
             continue;
 
         const MapItemType::Type type = static_cast<MapItemType::Type>(
@@ -139,7 +139,7 @@ void AvatarListBox::draw(Graphics *const graphics)
             // Draw online status
             const Image *const icon = a->getOnline()
                 ? onlineIcon : offlineIcon;
-            if (icon)
+            if (icon != nullptr)
             {
                 graphics->calcTileCollection(&vertexes, icon,
                     mImagePadding, y + mPadding);
@@ -155,7 +155,7 @@ void AvatarListBox::draw(Graphics *const graphics)
          ++i, y += fontHeight)
     {
         const Avatar *const a = model->getAvatarAt(i);
-        if (!a)
+        if (a == nullptr)
             continue;
 
         const MapItemType::Type type = static_cast<MapItemType::Type>(
@@ -175,7 +175,7 @@ void AvatarListBox::draw(Graphics *const graphics)
                                  a->getHp(), a->getMaxHp());
             }
             const bool isPoison = a->getPoison();
-            if (a->getMaxHp())
+            if (a->getMaxHp() != 0)
             {
                 const ProgressColorIdT themeColor = (isPoison
                     ? ProgressColorId::PROG_HP_POISON
@@ -347,14 +347,14 @@ void AvatarListBox::draw(Graphics *const graphics)
 void AvatarListBox::safeDraw(Graphics *const graphics)
 {
     BLOCK_START("AvatarListBox::draw")
-    if (!mListModel || !localPlayer)
+    if ((mListModel == nullptr) || (localPlayer == nullptr))
     {
         BLOCK_END("AvatarListBox::draw")
         return;
     }
 
     const Widget *const parent = mParent;
-    if (!parent)
+    if (parent == nullptr)
         return;
 
     AvatarListModel *const model = static_cast<AvatarListModel *>(
@@ -373,7 +373,7 @@ void AvatarListBox::safeDraw(Graphics *const graphics)
          ++i, y += fontHeight)
     {
         const Avatar *const a = model->getAvatarAt(i);
-        if (!a)
+        if (a == nullptr)
             continue;
 
         const MapItemType::Type type = static_cast<MapItemType::Type>(
@@ -383,7 +383,7 @@ void AvatarListBox::safeDraw(Graphics *const graphics)
             // Draw online status
             const Image *const icon = a->getOnline()
                 ? onlineIcon : offlineIcon;
-            if (icon)
+            if (icon != nullptr)
                 graphics->drawImage(icon, mImagePadding, y + mPadding);
         }
     }
@@ -393,7 +393,7 @@ void AvatarListBox::safeDraw(Graphics *const graphics)
          ++i, y += fontHeight)
     {
         const Avatar *const a = model->getAvatarAt(i);
-        if (!a)
+        if (a == nullptr)
             continue;
 
         const MapItemType::Type type = static_cast<MapItemType::Type>(
@@ -413,7 +413,7 @@ void AvatarListBox::safeDraw(Graphics *const graphics)
                                  a->getHp(), a->getMaxHp());
             }
             const bool isPoison = a->getPoison();
-            if (a->getMaxHp())
+            if (a->getMaxHp() != 0)
             {
                 const ProgressColorIdT themeColor = (isPoison
                     ? ProgressColorId::PROG_HP_POISON
@@ -584,15 +584,19 @@ void AvatarListBox::safeDraw(Graphics *const graphics)
 
 void AvatarListBox::mousePressed(MouseEvent &event)
 {
-    if (!actorManager || !localPlayer || !popupManager)
+    if (actorManager == nullptr ||
+        localPlayer == nullptr ||
+        popupManager == nullptr)
+    {
         return;
+    }
 
     const int height = getFont()->getHeight();
-    if (!height)
+    if (height == 0)
         return;
 
     const int y = (event.getY() - mPadding) / height;
-    if (!mListModel || y > mListModel->getNumberOfElements())
+    if ((mListModel == nullptr) || y > mListModel->getNumberOfElements())
         return;
 
     setSelected(y);
@@ -600,10 +604,10 @@ void AvatarListBox::mousePressed(MouseEvent &event)
     const int selected = getSelected();
     AvatarListModel *const model = static_cast<AvatarListModel *>(
         mListModel);
-    if (!model)
+    if (model == nullptr)
         return;
     const Avatar *ava = model->getAvatarAt(selected);
-    if (!ava)
+    if (ava == nullptr)
         return;
 
     const MapItemType::Type type = static_cast<MapItemType::Type>(
@@ -618,7 +622,7 @@ void AvatarListBox::mousePressed(MouseEvent &event)
         {
             const Being *const being = actorManager->findBeingByName(
                 ava->getName(), ActorType::Player);
-            if (being)
+            if (being != nullptr)
                 actorManager->heal(being);
         }
         else
@@ -634,11 +638,11 @@ void AvatarListBox::mousePressed(MouseEvent &event)
             case MapItemType::EMPTY:
             {
                 const Avatar *const avatar = model->getAvatarAt(selected);
-                if (avatar)
+                if (avatar != nullptr)
                 {
                     const Being *const being = actorManager->findBeingByName(
                         avatar->getName(), ActorType::Player);
-                    if (being)
+                    if (being != nullptr)
                     {
                         popupMenu->showPopup(viewport->mMouseX,
                             viewport->mMouseY,
@@ -698,7 +702,7 @@ void AvatarListBox::mousePressed(MouseEvent &event)
             {
                 const Map *const map = viewport->getMap();
                 ava = model->getAvatarAt(selected);
-                if (map && ava)
+                if ((map != nullptr) && (ava != nullptr))
                 {
                     MapItem *const mapItem = map->findPortalXY(
                         ava->getX(), ava->getY());
@@ -712,12 +716,12 @@ void AvatarListBox::mousePressed(MouseEvent &event)
     }
     else if (eventButton == MouseButton::MIDDLE)
     {
-        if (type == MapItemType::EMPTY && chatWindow)
+        if (type == MapItemType::EMPTY && (chatWindow != nullptr))
         {
             const std::string &name = model->getAvatarAt(selected)->getName();
             const WhisperTab *const tab = chatWindow->addWhisperTab(
                 name, name, true);
-            if (tab)
+            if (tab != nullptr)
                 chatWindow->saveState();
         }
     }
diff --git a/src/gui/widgets/basiccontainer.cpp b/src/gui/widgets/basiccontainer.cpp
index 68f440fcf..771ba83f4 100644
--- a/src/gui/widgets/basiccontainer.cpp
+++ b/src/gui/widgets/basiccontainer.cpp
@@ -234,7 +234,7 @@ void BasicContainer::setFocusHandler(FocusHandler *restrict2 const
 {
     Widget::setFocusHandler(focusHandler);
 
-    if (mInternalFocusHandler)
+    if (mInternalFocusHandler != nullptr)
         return;
 
     FOR_EACH (WidgetListConstIterator, iter, mWidgets)
@@ -243,13 +243,13 @@ void BasicContainer::setFocusHandler(FocusHandler *restrict2 const
 
 void BasicContainer::add(Widget *const widget) restrict2
 {
-    if (!widget)
+    if (widget == nullptr)
         return;
     mWidgets.push_back(widget);
     if (widget->isAllowLogic())
         mLogicWidgets.push_back(widget);
 
-    if (!mInternalFocusHandler)
+    if (mInternalFocusHandler == nullptr)
         widget->setFocusHandler(getFocusHandler());
     else
         widget->setFocusHandler(mInternalFocusHandler);
@@ -260,7 +260,7 @@ void BasicContainer::add(Widget *const widget) restrict2
 
 void BasicContainer::remove(Widget *const restrict widget) restrict2
 {
-    if (!widget)
+    if (widget == nullptr)
         return;
     FOR_EACH (WidgetListIterator, iter, mWidgets)
     {
@@ -391,7 +391,7 @@ void BasicContainer::logicChildren() restrict2
 void BasicContainer::showWidgetPart(Widget *restrict const widget,
                                     const Rect &restrict area) restrict2
 {
-    if (!widget)
+    if (widget == nullptr)
         return;
 
     const Rect widgetArea = getChildrenArea();
@@ -417,7 +417,7 @@ void BasicContainer::setInternalFocusHandler(FocusHandler *const restrict
 {
     Widget::setInternalFocusHandler(focusHandler);
 
-    FocusHandler *const restrict handler = mInternalFocusHandler ?
+    FocusHandler *const restrict handler = mInternalFocusHandler != nullptr ?
         mInternalFocusHandler : getFocusHandler();
     FOR_EACH (WidgetListConstIterator, iter, mWidgets)
     {
diff --git a/src/gui/widgets/basiccontainer2.cpp b/src/gui/widgets/basiccontainer2.cpp
index c89cf1962..ad143010d 100644
--- a/src/gui/widgets/basiccontainer2.cpp
+++ b/src/gui/widgets/basiccontainer2.cpp
@@ -121,7 +121,7 @@ void BasicContainer2::addXY(Widget *const widget,
                             const int x,
                             const int y)
 {
-    if (!widget)
+    if (widget == nullptr)
         return;
     widget->setPosition(x, y);
     BasicContainer::add(widget);
diff --git a/src/gui/widgets/browserbox.cpp b/src/gui/widgets/browserbox.cpp
index 0c35b63d4..22a6cec9d 100644
--- a/src/gui/widgets/browserbox.cpp
+++ b/src/gui/widgets/browserbox.cpp
@@ -123,7 +123,7 @@ BrowserBox::BrowserBox(const Widget2 *const widget,
 
     mBackgroundColor = getThemeColor(ThemeColorId::BACKGROUND);
 
-    if (theme)
+    if (theme != nullptr)
         mSkin = theme->load(skin, "browserbox.xml");
     if (mInstances == 0)
     {
@@ -132,15 +132,15 @@ BrowserBox::BrowserBox(const Widget2 *const widget,
     }
     mInstances ++;
 
-    if (mSkin)
+    if (mSkin != nullptr)
     {
         mPadding = mSkin->getPadding();
         mNewLinePadding = CAST_U32(
             mSkin->getOption("newLinePadding", 15));
         mItemPadding = mSkin->getOption("itemPadding");
-        if (mSkin->getOption("highlightBackground"))
+        if (mSkin->getOption("highlightBackground") != 0)
             mHighlightMode |= LinkHighlightMode::BACKGROUND;
-        if (mSkin->getOption("highlightUnderline"))
+        if (mSkin->getOption("highlightUnderline") != 0)
             mHighlightMode |= LinkHighlightMode::UNDERLINE;
     }
 
@@ -161,10 +161,10 @@ BrowserBox::BrowserBox(const Widget2 *const widget,
 
 BrowserBox::~BrowserBox()
 {
-    if (gui)
+    if (gui != nullptr)
         gui->removeDragged(this);
 
-    if (theme)
+    if (theme != nullptr)
     {
         theme->unload(mSkin);
         mSkin = nullptr;
@@ -173,7 +173,7 @@ BrowserBox::~BrowserBox()
     mInstances --;
     if (mInstances == 0)
     {
-        if (mEmotes)
+        if (mEmotes != nullptr)
         {
             mEmotes->decRef();
             mEmotes = nullptr;
@@ -231,7 +231,7 @@ void BrowserBox::addRow(const std::string &row, const bool atTop)
             {
                 bLink.caption = BrowserBoxTools::replaceLinkCommands(
                     bLink.link);
-                if (translator)
+                if (translator != nullptr)
                     bLink.caption = translator->getStr(bLink.caption);
             }
 
@@ -295,7 +295,7 @@ void BrowserBox::addRow(const std::string &row, const bool atTop)
             int cnt = mTextRowLinksCount.front();
             mTextRowLinksCount.pop_front();
 
-            while (cnt && !mLinks.empty())
+            while ((cnt != 0) && !mLinks.empty())
             {
                 mLinks.erase(mLinks.begin());
                 cnt --;
@@ -413,7 +413,7 @@ void BrowserBox::clearRows()
 
 void BrowserBox::mousePressed(MouseEvent &event)
 {
-    if (!mLinkHandler)
+    if (mLinkHandler == nullptr)
         return;
 
     const LinkIterator i = std::find_if(mLinks.begin(), mLinks.end(),
@@ -462,7 +462,7 @@ void BrowserBox::draw(Graphics *const graphics)
     if (mSelectedLink >= 0 &&
         mSelectedLink < CAST_S32(mLinks.size()))
     {
-        if ((mHighlightMode & LinkHighlightMode::BACKGROUND))
+        if ((mHighlightMode & LinkHighlightMode::BACKGROUND) != 0u)
         {
             BrowserLink &link = mLinks[CAST_SIZE(mSelectedLink)];
             graphics->setColor(mHighlightColor);
@@ -473,7 +473,7 @@ void BrowserBox::draw(Graphics *const graphics)
                 link.y2 - link.y1));
         }
 
-        if ((mHighlightMode & LinkHighlightMode::UNDERLINE))
+        if ((mHighlightMode & LinkHighlightMode::UNDERLINE) != 0u)
         {
             BrowserLink &link = mLinks[CAST_SIZE(mSelectedLink)];
             graphics->setColor(mHyperLinkColor);
@@ -494,7 +494,7 @@ void BrowserBox::draw(Graphics *const graphics)
             continue;
         if (part.mY > yEnd)
             break;
-        if (!part.mType)
+        if (part.mType == 0u)
         {
             if (part.mBold)
             {
@@ -513,7 +513,7 @@ void BrowserBox::draw(Graphics *const graphics)
                     part.mX, part.mY);
             }
         }
-        else if (part.mImage)
+        else if (part.mImage != nullptr)
         {
             graphics->drawImage(part.mImage, part.mX, part.mY);
         }
@@ -580,7 +580,7 @@ int BrowserBox::calcHeight()
             if (sz > 2 && str.substr(sz - 1) == "~")
                 str = str.substr(0, sz - 1);
             Image *const img = Loader::getImage(str);
-            if (img)
+            if (img != nullptr)
             {
                 img->incRef();
                 mLineParts.push_back(LinePart(CAST_S32(x),
@@ -757,14 +757,14 @@ int BrowserBox::calcHeight()
                         const int cid = row.at(start + 2) - '0';
                         if (cid >= 0)
                         {
-                            if (mEmotes)
+                            if (mEmotes != nullptr)
                             {
                                 const size_t sz = mEmotes->size();
                                 if (CAST_SIZE(cid) < sz)
                                 {
                                     Image *const img = mEmotes->get(
                                         CAST_SIZE(cid));
-                                    if (img)
+                                    if (img != nullptr)
                                     {
                                         mLineParts.push_back(LinePart(
                                             CAST_S32(x),
@@ -890,7 +890,7 @@ int BrowserBox::calcHeight()
 void BrowserBox::updateHeight()
 {
     if (mAlwaysUpdate || mUpdateTime != cur_time
-        || mTextRows.size() < 3 || !mUpdateTime)
+        || mTextRows.size() < 3 || (mUpdateTime == 0))
     {
         mWidth = mDimension.width;
         mHeight = calcHeight();
@@ -958,7 +958,7 @@ void BrowserBox::moveSelectionDown()
 
 void BrowserBox::selectSelection()
 {
-    if (!mLinkHandler ||
+    if ((mLinkHandler == nullptr) ||
         mSelectedLink < 0 ||
         mSelectedLink >= static_cast<signed int>(mLinks.size()))
     {
diff --git a/src/gui/widgets/button.cpp b/src/gui/widgets/button.cpp
index f24d5c9a0..3509b927c 100644
--- a/src/gui/widgets/button.cpp
+++ b/src/gui/widgets/button.cpp
@@ -183,7 +183,7 @@ Button::Button(const Widget2 *const widget,
     adjustSize();
     setActionEventId(actionEventId);
 
-    if (listener)
+    if (listener != nullptr)
         addActionListener(listener);
 }
 
@@ -234,7 +234,7 @@ Button::Button(const Widget2 *const widget,
     adjustSize();
     setActionEventId(actionEventId);
 
-    if (listener)
+    if (listener != nullptr)
         addActionListener(listener);
 }
 
@@ -284,7 +284,7 @@ Button::Button(const Widget2 *const widget,
     adjustSize();
     setActionEventId(actionEventId);
 
-    if (listener)
+    if (listener != nullptr)
         addActionListener(listener);
 }
 
@@ -334,7 +334,7 @@ Button::Button(const Widget2 *const widget,
     adjustSize();
     setActionEventId(actionEventId);
 
-    if (listener)
+    if (listener != nullptr)
         addActionListener(listener);
 }
 
@@ -351,12 +351,12 @@ void Button::init()
 
     if (mInstances == 0)
     {
-        if (theme)
+        if (theme != nullptr)
         {
             for (int mode = 0; mode < BUTTON_COUNT; mode ++)
             {
                 Skin *const skin = theme->load(data[mode], "button.xml");
-                if (skin)
+                if (skin != nullptr)
                 {
                     button[mode] = skin;
                     mSpacing[mode] = skin->getOption("spacing");
@@ -372,26 +372,26 @@ void Button::init()
 
 Button::~Button()
 {
-    if (mWindow)
+    if (mWindow != nullptr)
         mWindow->removeWidgetListener(this);
 
-    if (gui)
+    if (gui != nullptr)
         gui->removeDragged(this);
 
     mInstances--;
 
-    if (mInstances == 0 && theme)
+    if (mInstances == 0 && (theme != nullptr))
     {
         for (int mode = 0; mode < BUTTON_COUNT; mode ++)
             theme->unload(button[mode]);
     }
     delete2(mVertexes2);
-    if (mImageSet)
+    if (mImageSet != nullptr)
     {
         mImageSet->decRef();
         mImageSet = nullptr;
     }
-    if (mImages)
+    if (mImages != nullptr)
     {
         for (int f = 0; f < BUTTON_COUNT; f ++)
             mImages[f] = nullptr;
@@ -403,7 +403,7 @@ Button::~Button()
 
 void Button::loadImage(const std::string &imageName)
 {
-    if (mImageSet)
+    if (mImageSet != nullptr)
     {
         mImageSet->decRef();
         mImageSet = nullptr;
@@ -416,21 +416,21 @@ void Button::loadImage(const std::string &imageName)
 
 void Button::loadImageSet(const std::string &imageName)
 {
-    if (mImageSet)
+    if (mImageSet != nullptr)
     {
         mImageSet->decRef();
         mImageSet = nullptr;
     }
     mImageSet = Theme::getImageSetFromTheme(imageName,
         mImageWidth, mImageHeight);
-    if (!mImageSet)
+    if (mImageSet == nullptr)
         return;
     mImages = new Image*[BUTTON_COUNT];
     mImages[0] = nullptr;
     for (size_t f = 0; f < BUTTON_COUNT; f ++)
     {
         Image *const img = mImageSet->get(f);
-        if (img)
+        if (img != nullptr)
             mImages[f] = img;
         else
             mImages[f] = mImages[0];
@@ -450,11 +450,11 @@ void Button::updateAlpha()
             for (int a = 0; a < 9; a ++)
             {
                 Skin *const skin = button[mode];
-                if (skin)
+                if (skin != nullptr)
                 {
                     const ImageRect &rect = skin->getBorder();
                     Image *const image = rect.grid[a];
-                    if (image)
+                    if (image != nullptr)
                         image->setAlpha(mAlpha);
                 }
             }
@@ -477,7 +477,7 @@ void Button::draw(Graphics *const graphics)
         mode = BUTTON_STANDARD;
 
     const Skin *const skin = button[mode];
-    if (!skin)
+    if (skin == nullptr)
     {
         BLOCK_END("Button::draw")
         return;
@@ -526,7 +526,7 @@ void Button::draw(Graphics *const graphics)
     const int height = rect.height;
     Font *const font = getFont();
     int textY = height / 2 - font->getHeight() / 2;
-    if (mImages)
+    if (mImages != nullptr)
         imageY = height / 2 - mImageHeight / 2;
 
 // need move calculation from draw!!!
@@ -536,7 +536,7 @@ void Button::draw(Graphics *const graphics)
         default:
         case Graphics::LEFT:
         {
-            if (mImages)
+            if (mImages != nullptr)
             {
                 imageX = padding;
                 textX = padding + mImageWidth + spacing;
@@ -550,7 +550,7 @@ void Button::draw(Graphics *const graphics)
         case Graphics::CENTER:
         {
             const int width1 = font->getWidth(mCaption);
-            if (mImages)
+            if (mImages != nullptr)
             {
                 const int w = width1 + mImageWidth + spacing;
                 imageX = (width - w) / 2;
@@ -581,7 +581,7 @@ void Button::draw(Graphics *const graphics)
             width, height,
             skin->getBorder());
 
-        if (mImages)
+        if (mImages != nullptr)
         {
             if (isPressed())
             {
@@ -635,7 +635,7 @@ void Button::draw(Graphics *const graphics)
     }
 
     const Image *const image = mTextChunk.img;
-    if (image)
+    if (image != nullptr)
         graphics->drawImage(image, textX, textY);
 
     BLOCK_END("Button::draw")
@@ -656,7 +656,7 @@ void Button::safeDraw(Graphics *const graphics)
         mode = BUTTON_STANDARD;
 
     const Skin *const skin = button[mode];
-    if (!skin)
+    if (skin == nullptr)
     {
         BLOCK_END("Button::safeDraw")
         return;
@@ -681,7 +681,7 @@ void Button::safeDraw(Graphics *const graphics)
     const int height = rect.height;
     Font *const font = getFont();
     int textY = height / 2 - font->getHeight() / 2;
-    if (mImages)
+    if (mImages != nullptr)
         imageY = height / 2 - mImageHeight / 2;
 
 // need move calculation from draw!!!
@@ -691,7 +691,7 @@ void Button::safeDraw(Graphics *const graphics)
         default:
         case Graphics::LEFT:
         {
-            if (mImages)
+            if (mImages != nullptr)
             {
                 imageX = padding;
                 textX = padding + mImageWidth + spacing;
@@ -705,7 +705,7 @@ void Button::safeDraw(Graphics *const graphics)
         case Graphics::CENTER:
         {
             const int width1 = font->getWidth(mCaption);
-            if (mImages)
+            if (mImages != nullptr)
             {
                 const int w = width1 + mImageWidth + spacing;
                 imageX = (width - w) / 2;
@@ -728,7 +728,7 @@ void Button::safeDraw(Graphics *const graphics)
 
     graphics->drawImageRect(0, 0, width, height, skin->getBorder());
 
-    if (mImages)
+    if (mImages != nullptr)
     {
         if (isPressed())
             graphics->drawImage(mImages[mode], imageX + 1, imageY + 1);
@@ -771,7 +771,7 @@ void Button::safeDraw(Graphics *const graphics)
     }
 
     const Image *const image = mTextChunk.img;
-    if (image)
+    if (image != nullptr)
         graphics->drawImage(image, textX, textY);
 
     BLOCK_END("Button::safeDraw")
@@ -822,15 +822,15 @@ void Button::adjustSize()
 {
     const Font *const font = getFont();
     const Skin *const skin = button[BUTTON_STANDARD];
-    if (!skin)
+    if (skin == nullptr)
         return;
     const int padding = skin->getPadding();
 
-    if (mImages)
+    if (mImages != nullptr)
     {
         const int spacing = mSpacing[BUTTON_STANDARD];
         const int width = font->getWidth(mCaption);
-        if (width)
+        if (width != 0)
             setWidth(width + mImageWidth + spacing + 2 * padding);
         else
             setWidth(mImageWidth + 2 * padding);
@@ -916,14 +916,14 @@ void Button::mouseDragged(MouseEvent& event)
 
 void Button::setParent(Widget *widget)
 {
-    if (mWindow)
+    if (mWindow != nullptr)
         mWindow->addWidgetListener(this);
     Widget::setParent(widget);
 }
 
 void Button::setWindow(Widget *const widget)
 {
-    if (!widget && mWindow)
+    if ((widget == nullptr) && (mWindow != nullptr))
     {
         mWindow->removeWidgetListener(this);
         mWindow = nullptr;
diff --git a/src/gui/widgets/characterdisplay.cpp b/src/gui/widgets/characterdisplay.cpp
index 696b8c2bf..c3b5ea064 100644
--- a/src/gui/widgets/characterdisplay.cpp
+++ b/src/gui/widgets/characterdisplay.cpp
@@ -85,7 +85,7 @@ void CharacterDisplay::setCharacter(Net::Character *const character)
         return;
 
     mCharacter = character;
-    mPlayerBox->setPlayer(character ? character->dummy : nullptr);
+    mPlayerBox->setPlayer(character != nullptr ? character->dummy : nullptr);
     update();
 }
 
@@ -99,7 +99,7 @@ void CharacterDisplay::setActive(const bool active A_UNUSED)
 
 void CharacterDisplay::update()
 {
-    if (mCharacter)
+    if (mCharacter != nullptr)
         mName->setCaption(mCharacter->dummy->getName());
     else
         mName->setCaption("");
@@ -111,20 +111,24 @@ void CharacterDisplay::update()
 
 void CharacterDisplay::widgetHidden(const Event &event A_UNUSED)
 {
-    if (textPopup)
+    if (textPopup != nullptr)
         textPopup->setVisible(Visible_false);
 }
 
 void CharacterDisplay::mouseExited(MouseEvent &event A_UNUSED)
 {
-    if (textPopup)
+    if (textPopup != nullptr)
         textPopup->setVisible(Visible_false);
 }
 
 void CharacterDisplay::mouseMoved(MouseEvent &event A_UNUSED)
 {
-    if (!gui || !textPopup || !mCharacter)
+    if (gui == nullptr ||
+        textPopup == nullptr ||
+        mCharacter == nullptr)
+    {
         return;
+    }
 
     int mouseX = 0;
     int mouseY = 0;
diff --git a/src/gui/widgets/characterviewnormal.cpp b/src/gui/widgets/characterviewnormal.cpp
index c4bf0d5ef..c92ad7477 100644
--- a/src/gui/widgets/characterviewnormal.cpp
+++ b/src/gui/widgets/characterviewnormal.cpp
@@ -34,7 +34,7 @@ CharacterViewNormal::CharacterViewNormal(CharSelectDialog *const widget,
     mCharacterEntries(entries)
 {
     addKeyListener(widget);
-    if (entries)
+    if (entries != nullptr)
     {
         FOR_EACHP (std::vector<CharacterDisplay*>::iterator,
                     it, entries)
@@ -47,7 +47,7 @@ CharacterViewNormal::CharacterViewNormal(CharSelectDialog *const widget,
         if (mSelected >= 0 && mSelected < CAST_S32(sz))
         {
             CharacterDisplay *const display = (*mCharacterEntries)[mSelected];
-            if (display)
+            if (display != nullptr)
                 display->setSelect(false);
         }
         if (sz > 0)
diff --git a/src/gui/widgets/characterviewsmall.cpp b/src/gui/widgets/characterviewsmall.cpp
index dbb04064f..a861e5033 100644
--- a/src/gui/widgets/characterviewsmall.cpp
+++ b/src/gui/widgets/characterviewsmall.cpp
@@ -40,7 +40,7 @@ CharacterViewSmall::CharacterViewSmall(CharSelectDialog *const widget,
     mCharacterEntries(entries)
 {
     addKeyListener(widget);
-    if (entries)
+    if (entries != nullptr)
     {
         FOR_EACHP (std::vector<CharacterDisplay*>::iterator,
                    it, entries)
@@ -81,7 +81,7 @@ void CharacterViewSmall::show(const int i)
     const int sz = CAST_S32(mCharacterEntries->size());
     if (sz <= 0)
         return;
-    if (mSelectedEntry)
+    if (mSelectedEntry != nullptr)
         mSelectedEntry->setVisible(Visible_false);
     if (i >= sz)
         mSelected = 0;
diff --git a/src/gui/widgets/chatinput.h b/src/gui/widgets/chatinput.h
index 2a6a23a80..92c7dc341 100644
--- a/src/gui/widgets/chatinput.h
+++ b/src/gui/widgets/chatinput.h
@@ -60,7 +60,7 @@ class ChatInput final : public TextField
             if (mFocusGaining || !config.getBoolValue("protectChatFocus"))
             {
                 processVisible(Visible_false);
-                if (chatWindow)
+                if (chatWindow != nullptr)
                     chatWindow->updateVisibility();
                 mFocusGaining = false;
                 return;
@@ -72,7 +72,7 @@ class ChatInput final : public TextField
 
         void processVisible(const Visible n)
         {
-            if (!mWindow || isVisible() == (n == Visible_true))
+            if (mWindow == nullptr || isVisible() == (n == Visible_true))
                 return;
 
             if (n == Visible_false)
@@ -83,7 +83,7 @@ class ChatInput final : public TextField
             {
                 mWindow->adjustTabSize();
             }
-            if (emoteWindow)
+            if (emoteWindow != nullptr)
             {
                 emoteWindow->hide();
             }
diff --git a/src/gui/widgets/checkbox.cpp b/src/gui/widgets/checkbox.cpp
index 03da61a7b..ab1227b08 100644
--- a/src/gui/widgets/checkbox.cpp
+++ b/src/gui/widgets/checkbox.cpp
@@ -115,7 +115,7 @@ CheckBox::CheckBox(const Widget2 *const widget,
     mForegroundColor2 = getThemeColor(ThemeColorId::CHECKBOX_OUTLINE);
     if (instances == 0)
     {
-        if (theme)
+        if (theme != nullptr)
         {
             mSkin = theme->load("checkbox.xml", "");
             updateAlpha();
@@ -127,17 +127,17 @@ CheckBox::CheckBox(const Widget2 *const widget,
     if (!eventId.empty())
         setActionEventId(eventId);
 
-    if (listener)
+    if (listener != nullptr)
         addActionListener(listener);
 
     mForegroundColor = getThemeColor(ThemeColorId::CHECKBOX);
-    if (mSkin)
+    if (mSkin != nullptr)
     {
         mPadding = mSkin->getPadding();
         mImagePadding = mSkin->getOption("imagePadding");
         mImageSize = mSkin->getOption("imageSize");
         mSpacing = mSkin->getOption("spacing");
-        mDrawBox = mSkin->getOption("drawBox", 1);
+        mDrawBox = (mSkin->getOption("drawBox", 1) != 0);
         mTextX = mPadding + mImageSize + mSpacing;
     }
     adjustSize();
@@ -145,17 +145,17 @@ CheckBox::CheckBox(const Widget2 *const widget,
 
 CheckBox::~CheckBox()
 {
-    if (mWindow)
+    if (mWindow != nullptr)
         mWindow->removeWidgetListener(this);
 
-    if (gui)
+    if (gui != nullptr)
         gui->removeDragged(this);
 
     instances--;
 
     if (instances == 0)
     {
-        if (theme)
+        if (theme != nullptr)
             theme->unload(mSkin);
     }
 }
@@ -179,7 +179,7 @@ void CheckBox::draw(Graphics *const graphics)
     }
 
     const Image *const image = mTextChunk.img;
-    if (image)
+    if (image != nullptr)
         graphics->drawImage(image, mTextX, mPadding);
 
     BLOCK_END("CheckBox::draw")
@@ -198,13 +198,13 @@ void CheckBox::updateAlpha()
     if (mAlpha != alpha)
     {
         mAlpha = alpha;
-        if (mSkin)
+        if (mSkin != nullptr)
         {
             const ImageRect &rect = mSkin->getBorder();
             for (int a = 0; a < 6; a ++)
             {
                 Image *const image = rect.grid[a];
-                if (image)
+                if (image != nullptr)
                     image->setAlpha(mAlpha);
             }
         }
@@ -213,7 +213,7 @@ void CheckBox::updateAlpha()
 
 void CheckBox::drawBox(Graphics *const graphics)
 {
-    if (!mSkin || !mDrawBox)
+    if ((mSkin == nullptr) || !mDrawBox)
         return;
 
     const ImageRect &rect = mSkin->getBorder();
@@ -247,7 +247,7 @@ void CheckBox::drawBox(Graphics *const graphics)
 
     updateAlpha();
 
-    if (box)
+    if (box != nullptr)
     {
         graphics->drawImage(box,
             mImagePadding,
@@ -313,7 +313,7 @@ void CheckBox::setCaption(const std::string& caption)
 
 void CheckBox::setParent(Widget *widget)
 {
-    if (mWindow)
+    if (mWindow != nullptr)
         mWindow->addWidgetListener(this);
     Widget::setParent(widget);
 }
@@ -326,7 +326,7 @@ void CheckBox::widgetHidden(const Event &event A_UNUSED)
 
 void CheckBox::setWindow(Widget *const widget)
 {
-    if (!widget && mWindow)
+    if ((widget == nullptr) && (mWindow != nullptr))
     {
         mWindow->removeWidgetListener(this);
         mWindow = nullptr;
diff --git a/src/gui/widgets/colorpage.cpp b/src/gui/widgets/colorpage.cpp
index f29540c0f..fa3099c2c 100644
--- a/src/gui/widgets/colorpage.cpp
+++ b/src/gui/widgets/colorpage.cpp
@@ -35,11 +35,11 @@ ColorPage::ColorPage(const Widget2 *const widget,
                      const std::string &skin) :
     ListBox(widget, listModel, skin)
 {
-    mItemPadding = mSkin ? mSkin->getOption("itemPadding") : 1;
+    mItemPadding = mSkin != nullptr ? mSkin->getOption("itemPadding") : 1;
     const Font *const font = getFont();
     mRowHeight = CAST_U32(font->getHeight() +
         2 * mItemPadding);
-    if (mListModel)
+    if (mListModel != nullptr)
     {
         setHeight(CAST_S32(getRowHeight()) *
             mListModel->getNumberOfElements()
@@ -114,7 +114,7 @@ void ColorPage::resetAction()
 void ColorPage::adjustSize()
 {
     BLOCK_START("ColorPage::adjustSize")
-    if (mListModel)
+    if (mListModel != nullptr)
     {
         setHeight(CAST_S32(getRowHeight()) *
             mListModel->getNumberOfElements() +
diff --git a/src/gui/widgets/container.cpp b/src/gui/widgets/container.cpp
index e6f8ad4f4..2da444728 100644
--- a/src/gui/widgets/container.cpp
+++ b/src/gui/widgets/container.cpp
@@ -34,7 +34,7 @@ Container::Container(const Widget2 *const widget) :
 
 Container::~Container()
 {
-    if (gui)
+    if (gui != nullptr)
         gui->removeDragged(this);
     removeControls();
 }
diff --git a/src/gui/widgets/containerplacer.cpp b/src/gui/widgets/containerplacer.cpp
index 8db3a0e25..634a87fcd 100644
--- a/src/gui/widgets/containerplacer.cpp
+++ b/src/gui/widgets/containerplacer.cpp
@@ -29,15 +29,16 @@
 
 ContainerPlacer ContainerPlacer::at(const int x, const int y)
 {
-    return ContainerPlacer(mContainer, mCell ? &mCell->at(x, y) : nullptr);
+    return ContainerPlacer(mContainer,
+        mCell != nullptr ? &mCell->at(x, y) : nullptr);
 }
 
 LayoutCell &ContainerPlacer::operator()
     (const int x, const int y, Widget *const wg, const int w, const int h)
 {
-    if (mContainer)
+    if (mContainer != nullptr)
         mContainer->add(wg);
-    if (mCell)
+    if (mCell != nullptr)
         return mCell->place(wg, x, y, w, h);
     return LayoutCell::emptyCell;
 }
diff --git a/src/gui/widgets/desktop.cpp b/src/gui/widgets/desktop.cpp
index 83d5bd58e..43248ebe8 100644
--- a/src/gui/widgets/desktop.cpp
+++ b/src/gui/widgets/desktop.cpp
@@ -64,11 +64,11 @@ Desktop::Desktop(const Widget2 *const widget) :
 
     Wallpaper::loadWallpapers();
 
-    if (theme)
+    if (theme != nullptr)
         mSkin = theme->load("desktop.xml", "");
 
-    if (mSkin)
-        mShowBackground = mSkin->getOption("showBackground");
+    if (mSkin != nullptr)
+        mShowBackground = (mSkin->getOption("showBackground") != 0);
 
     const std::string appName = branding.getValue("appName", std::string());
     if (appName.empty())
@@ -87,18 +87,18 @@ Desktop::Desktop(const Widget2 *const widget) :
 
 Desktop::~Desktop()
 {
-    if (mWallpaper)
+    if (mWallpaper != nullptr)
     {
         mWallpaper->decRef();
         mWallpaper = nullptr;
     }
-    if (theme)
+    if (theme != nullptr)
         theme->unload(mSkin);
 }
 
 void Desktop::postInit()
 {
-    if (mSkin)
+    if (mSkin != nullptr)
     {
         addXY(mVersionLabel,
             mSkin->getOption("versionX", 25),
@@ -130,7 +130,7 @@ void Desktop::draw(Graphics *const graphics)
     const Rect &rect = mDimension;
     const int width = rect.width;
     const int height = rect.height;
-    if (mWallpaper)
+    if (mWallpaper != nullptr)
     {
         const int wallpWidth = mWallpaper->getWidth();
         const int wallpHeight = mWallpaper->getHeight();
@@ -178,9 +178,9 @@ void Desktop::setBestFittingWallpaper()
 
     Image *const nWallPaper = Theme::getImageFromTheme(wallpaperName);
 
-    if (nWallPaper)
+    if (nWallPaper != nullptr)
     {
-        if (mWallpaper)
+        if (mWallpaper != nullptr)
         {
             ResourceManager::decRefDelete(mWallpaper);
             mWallpaper = nullptr;
@@ -198,7 +198,7 @@ void Desktop::setBestFittingWallpaper()
             Image *const newRsclWlPpr = Loader::getRescaled(
                 nWallPaper, width, height);
 
-            if (newRsclWlPpr)
+            if (newRsclWlPpr != nullptr)
             {
                 ResourceManager::decRefDelete(nWallPaper);
                 // We replace the resource in the resource manager
diff --git a/src/gui/widgets/dropdown.cpp b/src/gui/widgets/dropdown.cpp
index eb848f4d6..cb9eef73d 100644
--- a/src/gui/widgets/dropdown.cpp
+++ b/src/gui/widgets/dropdown.cpp
@@ -84,20 +84,20 @@ DropDown::DropDown(const Widget2 *const widget,
     mPopup->setHeight(100);
 
     // Initialize graphics
-    if (instances == 0 && theme)
+    if (instances == 0 && (theme != nullptr))
     {
         // Load the background skin
         for (int i = 0; i < 2; i ++)
         {
             Skin *const skin = theme->load(dropdownFiles[i], "dropdown.xml");
-            if (skin)
+            if (skin != nullptr)
             {
-                if (!i)
+                if (i == 0)
                     mSkin = skin;
                 const ImageRect &rect = skin->getBorder();
                 for (int f = 0; f < 2; f ++)
                 {
-                    if (rect.grid[f])
+                    if (rect.grid[f] != nullptr)
                     {
                         rect.grid[f]->incRef();
                         buttons[f][i] = rect.grid[f];
@@ -108,7 +108,7 @@ DropDown::DropDown(const Widget2 *const widget,
                         buttons[f][i] = nullptr;
                     }
                 }
-                if (i)
+                if (i != 0)
                     theme->unload(skin);
             }
             else
@@ -144,12 +144,12 @@ DropDown::DropDown(const Widget2 *const widget,
     if (!eventId.empty())
         setActionEventId(eventId);
 
-    if (listener)
+    if (listener != nullptr)
         addActionListener(listener);
 
     mPopup->adjustSize();
 
-    if (mSkin)
+    if (mSkin != nullptr)
     {
         mSpacing = mSkin->getOption("spacing");
         mFrameSize = CAST_U32(mSkin->getOption("frameSize"));
@@ -161,7 +161,7 @@ DropDown::DropDown(const Widget2 *const widget,
 
 DropDown::~DropDown()
 {
-    if (gui)
+    if (gui != nullptr)
         gui->removeDragged(this);
 
     instances--;
@@ -171,11 +171,11 @@ DropDown::~DropDown()
         {
             for (int i = 0; i < 2; i ++)
             {
-                if (buttons[f][i])
+                if (buttons[f][i] != nullptr)
                     buttons[f][i]->decRef();
             }
         }
-        if (theme)
+        if (theme != nullptr)
         {
             theme->unload(mSkin);
             Theme::unloadRect(skinRect);
@@ -192,18 +192,18 @@ void DropDown::updateAlpha()
     {
         mAlpha = alpha;
 
-        if (buttons[0][0])
+        if (buttons[0][0] != nullptr)
             buttons[0][0]->setAlpha(mAlpha);
-        if (buttons[0][1])
+        if (buttons[0][1] != nullptr)
             buttons[0][1]->setAlpha(mAlpha);
-        if (buttons[1][0])
+        if (buttons[1][0] != nullptr)
             buttons[1][0]->setAlpha(mAlpha);
-        if (buttons[1][1])
+        if (buttons[1][1] != nullptr)
             buttons[1][1]->setAlpha(mAlpha);
 
         for (int a = 0; a < 9; a++)
         {
-            if (skinRect.grid[a])
+            if (skinRect.grid[a] != nullptr)
                 skinRect.grid[a]->setAlpha(mAlpha);
         }
     }
@@ -227,7 +227,7 @@ void DropDown::draw(Graphics *const graphics)
     mShadowColor.a = alpha;
 
     ListModel *const model = mPopup->getListModel();
-    if (model && mPopup->getSelected() >= 0)
+    if ((model != nullptr) && mPopup->getSelected() >= 0)
     {
         Font *const font = getFont();
         if (mExtended)
@@ -236,7 +236,7 @@ void DropDown::draw(Graphics *const graphics)
             ExtendedListModel *const model2
                 = static_cast<ExtendedListModel *>(model);
             const Image *const image = model2->getImageAt(sel);
-            if (!image)
+            if (image == nullptr)
             {
                 font->drawString(graphics,
                     mForegroundColor,
@@ -320,7 +320,7 @@ void DropDown::drawButton(Graphics *const graphics)
     const int height = mDroppedDown ? mFoldedUpHeight : mDimension.height;
 
     Image *image = buttons[mDroppedDown][mPushed];
-    if (image)
+    if (image != nullptr)
     {
         graphics->drawImage(image,
             mDimension.width - image->getWidth() - mImagePadding,
@@ -356,7 +356,7 @@ void DropDown::keyPressed(KeyEvent& event)
             break;
 
         case InputAction::GUI_END:
-            if (mPopup->getListModel())
+            if (mPopup->getListModel() != nullptr)
             {
                 setSelected(mPopup->getListModel()->
                     getNumberOfElements() - 1);
@@ -441,7 +441,7 @@ void DropDown::mouseWheelMovedDown(MouseEvent& event)
 void DropDown::setSelectedString(const std::string &str)
 {
     ListModel *const listModel = mPopup->getListModel();
-    if (!listModel)
+    if (listModel == nullptr)
         return;
 
     for (int f = 0; f < listModel->getNumberOfElements(); f ++)
@@ -457,7 +457,7 @@ void DropDown::setSelectedString(const std::string &str)
 std::string DropDown::getSelectedString() const
 {
     ListModel *const listModel = mPopup->getListModel();
-    if (!listModel)
+    if (listModel == nullptr)
         return "";
 
     return listModel->getElementAt(getSelected());
@@ -472,7 +472,7 @@ void DropDown::dropDown()
 {
     if (!mDroppedDown)
     {
-        if (!mParent)
+        if (mParent == nullptr)
             return;
         mDroppedDown = true;
         mFoldedUpHeight = getHeight();
diff --git a/src/gui/widgets/emotepage.cpp b/src/gui/widgets/emotepage.cpp
index 771813d1b..459e386a4 100644
--- a/src/gui/widgets/emotepage.cpp
+++ b/src/gui/widgets/emotepage.cpp
@@ -54,7 +54,7 @@ EmotePage::EmotePage(const Widget2 *const widget) :
 
 EmotePage::~EmotePage()
 {
-    if (mEmotes)
+    if (mEmotes != nullptr)
     {
         mEmotes->decRef();
         mEmotes = nullptr;
@@ -68,7 +68,7 @@ void EmotePage::draw(Graphics *const graphics)
 
     if (mRedraw)
     {
-        if (!mEmotes)
+        if (mEmotes == nullptr)
             return;
 
         const std::vector<Image*> &images = mEmotes->getImages();
@@ -82,7 +82,7 @@ void EmotePage::draw(Graphics *const graphics)
         FOR_EACH (std::vector<Image*>::const_iterator, it, images)
         {
             const Image *const image = *it;
-            if (image)
+            if (image != nullptr)
             {
                 graphics->calcTileCollection(mVertexes, image, x, y);
                 x += emoteWidth;
@@ -104,7 +104,7 @@ void EmotePage::safeDraw(Graphics *const graphics)
 {
     BLOCK_START("EmotePage::safeDraw")
 
-    if (!mEmotes)
+    if (mEmotes == nullptr)
         return;
 
     const std::vector<Image*> &images = mEmotes->getImages();
@@ -116,7 +116,7 @@ void EmotePage::safeDraw(Graphics *const graphics)
     FOR_EACH (std::vector<Image*>::const_iterator, it, images)
     {
         const Image *const image = *it;
-        if (image)
+        if (image != nullptr)
         {
             graphics->drawImage(image, x, y);
             x += emoteWidth;
diff --git a/src/gui/widgets/emoteshortcutcontainer.cpp b/src/gui/widgets/emoteshortcutcontainer.cpp
index 0d75051eb..37acf7263 100644
--- a/src/gui/widgets/emoteshortcutcontainer.cpp
+++ b/src/gui/widgets/emoteshortcutcontainer.cpp
@@ -57,14 +57,14 @@ EmoteShortcutContainer::EmoteShortcutContainer(Widget2 *restrict const
     mEmoteClicked(false),
     mEmoteMoved(0)
 {
-    if (mBackgroundImg)
+    if (mBackgroundImg != nullptr)
         mBackgroundImg->setAlpha(settings.guiAlpha);
 
     // Setup emote sprites
     for (int i = 0; i <= EmoteDB::getLast(); i++)
     {
         const EmoteSprite *const sprite = EmoteDB::getSprite(i, true);
-        if (sprite && sprite->sprite)
+        if ((sprite != nullptr) && (sprite->sprite != nullptr))
             mEmoteImg.push_back(sprite);
     }
 
@@ -85,13 +85,13 @@ void EmoteShortcutContainer::setWidget2(const Widget2 *restrict const widget)
 
 void EmoteShortcutContainer::draw(Graphics *restrict graphics) restrict2
 {
-    if (!emoteShortcut)
+    if (emoteShortcut == nullptr)
         return;
 
     BLOCK_START("EmoteShortcutContainer::draw")
     if (settings.guiAlpha != mAlpha)
     {
-        if (mBackgroundImg)
+        if (mBackgroundImg != nullptr)
             mBackgroundImg->setAlpha(mAlpha);
         mAlpha = settings.guiAlpha;
     }
@@ -105,10 +105,10 @@ void EmoteShortcutContainer::draw(Graphics *restrict graphics) restrict2
     for (unsigned i = 0; i < sz; i++)
     {
         const EmoteSprite *restrict const emoteImg = mEmoteImg[i];
-        if (emoteImg)
+        if (emoteImg != nullptr)
         {
             const AnimatedSprite *restrict const sprite = emoteImg->sprite;
-            if (sprite)
+            if (sprite != nullptr)
             {
                 sprite->draw(graphics,
                     (i % mGridWidth) * mBoxWidth + 2,
@@ -137,13 +137,13 @@ void EmoteShortcutContainer::draw(Graphics *restrict graphics) restrict2
 
 void EmoteShortcutContainer::safeDraw(Graphics *restrict graphics) restrict2
 {
-    if (!emoteShortcut)
+    if (emoteShortcut == nullptr)
         return;
 
     BLOCK_START("EmoteShortcutContainer::draw")
     if (settings.guiAlpha != mAlpha)
     {
-        if (mBackgroundImg)
+        if (mBackgroundImg != nullptr)
             mBackgroundImg->setAlpha(mAlpha);
         mAlpha = settings.guiAlpha;
     }
@@ -157,10 +157,10 @@ void EmoteShortcutContainer::safeDraw(Graphics *restrict graphics) restrict2
     for (unsigned i = 0; i < sz; i++)
     {
         const EmoteSprite *restrict const emoteImg = mEmoteImg[i];
-        if (emoteImg)
+        if (emoteImg != nullptr)
         {
             const AnimatedSprite *restrict const sprite = emoteImg->sprite;
-            if (sprite)
+            if (sprite != nullptr)
             {
                 sprite->draw(graphics,
                     (i % mGridWidth) * mBoxWidth + 2,
@@ -199,7 +199,7 @@ void EmoteShortcutContainer::mousePressed(MouseEvent &restrict event) restrict2
 
     if (event.getButton() == MouseButton::LEFT)
     {
-        if (!emoteShortcut)
+        if (emoteShortcut == nullptr)
             return;
 
         const int index = getIndexFromGrid(event.getX(), event.getY());
@@ -214,14 +214,14 @@ void EmoteShortcutContainer::mousePressed(MouseEvent &restrict event) restrict2
             emoteShortcut->setEmote(index);
             emoteShortcut->setEmoteSelected(0);
         }
-        else if (emoteShortcut->getEmote(index))
+        else if (emoteShortcut->getEmote(index) != 0u)
         {
             mEmoteClicked = true;
         }
     }
     else if (event.getButton() == MouseButton::RIGHT)
     {
-        if (popupMenu)
+        if (popupMenu != nullptr)
         {
             event.consume();
             popupMenu->showEmoteType();
@@ -232,7 +232,7 @@ void EmoteShortcutContainer::mousePressed(MouseEvent &restrict event) restrict2
 void EmoteShortcutContainer::mouseReleased(MouseEvent &restrict event)
                                            restrict2
 {
-    if (!emoteShortcut)
+    if (emoteShortcut == nullptr)
         return;
 
     if (event.getButton() == MouseButton::LEFT)
@@ -248,12 +248,12 @@ void EmoteShortcutContainer::mouseReleased(MouseEvent &restrict event)
             return;
         }
 
-        if (mEmoteMoved)
+        if (mEmoteMoved != 0u)
         {
             emoteShortcut->setEmotes(index, mEmoteMoved);
             mEmoteMoved = 0;
         }
-        else if (emoteShortcut->getEmote(index) && mEmoteClicked)
+        else if ((emoteShortcut->getEmote(index) != 0u) && mEmoteClicked)
         {
             emoteShortcut->useEmote(index + 1);
         }
@@ -264,7 +264,7 @@ void EmoteShortcutContainer::mouseReleased(MouseEvent &restrict event)
 
 void EmoteShortcutContainer::mouseMoved(MouseEvent &restrict event) restrict2
 {
-    if (!emoteShortcut || !textPopup)
+    if ((emoteShortcut == nullptr) || (textPopup == nullptr))
         return;
 
     const int index = getIndexFromGrid(event.getX(), event.getY());
@@ -274,7 +274,7 @@ void EmoteShortcutContainer::mouseMoved(MouseEvent &restrict event) restrict2
 
     textPopup->setVisible(Visible_false);
 
-    if (CAST_SIZE(index) < mEmoteImg.size() && mEmoteImg[index])
+    if (CAST_SIZE(index) < mEmoteImg.size() && (mEmoteImg[index] != nullptr))
     {
         const EmoteSprite *restrict const sprite = mEmoteImg[index];
         textPopup->show(viewport->mMouseX, viewport->mMouseY,
@@ -285,13 +285,13 @@ void EmoteShortcutContainer::mouseMoved(MouseEvent &restrict event) restrict2
 void EmoteShortcutContainer::mouseExited(MouseEvent &restrict event A_UNUSED)
                                          restrict2
 {
-    if (textPopup)
+    if (textPopup != nullptr)
         textPopup->setVisible(Visible_false);
 }
 
 void EmoteShortcutContainer::widgetHidden(const Event &restrict event A_UNUSED)
                                           restrict2
 {
-    if (textPopup)
+    if (textPopup != nullptr)
         textPopup->setVisible(Visible_false);
 }
diff --git a/src/gui/widgets/extendedlistbox.cpp b/src/gui/widgets/extendedlistbox.cpp
index 921dfee7f..ebbb07bf3 100644
--- a/src/gui/widgets/extendedlistbox.cpp
+++ b/src/gui/widgets/extendedlistbox.cpp
@@ -35,13 +35,13 @@ ExtendedListBox::ExtendedListBox(const Widget2 *const widget,
                                  const std::string &skin,
                                  const unsigned int rowHeight) :
     ListBox(widget, listModel, skin),
-    mImagePadding(mSkin ? mSkin->getOption("imagePadding") : 0),
-    mSpacing(mSkin ? mSkin->getOption("spacing") : 0),
+    mImagePadding(mSkin != nullptr ? mSkin->getOption("imagePadding") : 0),
+    mSpacing(mSkin != nullptr ? mSkin->getOption("spacing") : 0),
     mHeight(0),
     mListItems(),
     mSelectedItems()
 {
-    if (rowHeight)
+    if (rowHeight != 0u)
         mRowHeight = rowHeight;
 }
 
@@ -51,7 +51,7 @@ ExtendedListBox::~ExtendedListBox()
 
 void ExtendedListBox::draw(Graphics *const graphics)
 {
-    if (!mListModel)
+    if (mListModel == nullptr)
         return;
 
     BLOCK_START("ExtendedListBox::draw")
@@ -81,7 +81,7 @@ void ExtendedListBox::draw(Graphics *const graphics)
         int strWidth = font->getWidth(str) + 8;
 
         const Image *const image = model->getImageAt(row);
-        if (image)
+        if (image != nullptr)
             strWidth += image->getWidth() + mImagePadding;
 
         std::vector<ExtendedListBoxItem> &list =
@@ -145,7 +145,7 @@ void ExtendedListBox::draw(Graphics *const graphics)
         if (item.image)
         {
             const Image *const image = model->getImageAt(row1);
-            if (image)
+            if (image != nullptr)
             {
                 graphics->drawImage(image,
                     mImagePadding,
@@ -160,7 +160,7 @@ void ExtendedListBox::draw(Graphics *const graphics)
         const int row1 = item.row;
         const int y1 = item.y;
         const Image *const image = model->getImageAt(row1);
-        if (!image || !item.image)
+        if ((image == nullptr) || !item.image)
         {
             font->drawString(graphics,
                 mForegroundColor, mForegroundColor2,
@@ -182,7 +182,7 @@ void ExtendedListBox::draw(Graphics *const graphics)
         const int row1 = item.row;
         const int y1 = item.y;
         const Image *const image = model->getImageAt(row1);
-        if (!image || !item.image)
+        if ((image == nullptr) || !item.image)
         {
             font->drawString(graphics,
                 mForegroundSelectedColor, mForegroundSelectedColor2,
@@ -205,7 +205,7 @@ void ExtendedListBox::draw(Graphics *const graphics)
         if (item.image)
         {
             const Image *const image = model->getImageAt(row1);
-            if (image)
+            if (image != nullptr)
             {
                 graphics->drawImage(image,
                     mImagePadding,
@@ -224,7 +224,7 @@ void ExtendedListBox::safeDraw(Graphics *const graphics)
 
 void ExtendedListBox::adjustSize()
 {
-    if (mHeight)
+    if (mHeight != 0)
         setHeight(mHeight + 2 * mPadding);
     else
         ListBox::adjustSize();
diff --git a/src/gui/widgets/flowcontainer.cpp b/src/gui/widgets/flowcontainer.cpp
index 7f33208c2..ee3181636 100644
--- a/src/gui/widgets/flowcontainer.cpp
+++ b/src/gui/widgets/flowcontainer.cpp
@@ -34,9 +34,9 @@ FlowContainer::FlowContainer(const Widget2 *const widget,
     mGridHeight(1)
 {
     addWidgetListener(this);
-    if (!mBoxWidth)
+    if (mBoxWidth == 0)
         mBoxWidth = 1;
-    if (!mBoxHeight)
+    if (mBoxHeight == 0)
         mBoxHeight = 1;
 }
 
@@ -50,7 +50,7 @@ void FlowContainer::widgetResized(const Event &event A_UNUSED)
 
     const int itemCount = CAST_S32(mWidgets.size());
 
-    if (!mBoxWidth)
+    if (mBoxWidth == 0)
         mGridWidth = getWidth();
     else
         mGridWidth = getWidth() / mBoxWidth;
@@ -88,7 +88,7 @@ void FlowContainer::widgetResized(const Event &event A_UNUSED)
 
 void FlowContainer::add(Widget *const widget)
 {
-    if (!widget)
+    if (widget == nullptr)
         return;
 
     Container::add(widget);
diff --git a/src/gui/widgets/guitable.cpp b/src/gui/widgets/guitable.cpp
index 3c22dd4b1..392755a20 100644
--- a/src/gui/widgets/guitable.cpp
+++ b/src/gui/widgets/guitable.cpp
@@ -69,7 +69,7 @@ GuiTable::GuiTable(const Widget2 *const widget,
 
 GuiTable::~GuiTable()
 {
-    if (gui)
+    if (gui != nullptr)
         gui->removeDragged(this);
 
     uninstallActionListeners();
@@ -83,7 +83,7 @@ const TableModel *GuiTable::getModel() const
 
 void GuiTable::setModel(TableModel *const new_model)
 {
-    if (mModel)
+    if (mModel != nullptr)
     {
         uninstallActionListeners();
         mModel->removeListener(this);
@@ -98,7 +98,7 @@ void GuiTable::setModel(TableModel *const new_model)
 
 void GuiTable::recomputeDimensions()
 {
-    if (!mModel)
+    if (mModel == nullptr)
         return;
 
     const int rows_nr = mModel->getRows();
@@ -211,7 +211,7 @@ void GuiTable::installActionListeners()
         for (int column = 0; column < columns; ++column)
         {
             Widget *const widget = mModel->getElementAt(row, column);
-            if (widget)
+            if (widget != nullptr)
             {
                 mActionListeners2.push_back(new GuiTableActionListener(
                     this, widget, row, column));
@@ -225,7 +225,7 @@ void GuiTable::installActionListeners()
 // -- widget ops
 void GuiTable::draw(Graphics *const graphics)
 {
-    if (!getRowHeight())
+    if (getRowHeight() == 0)
         return;
 
     BLOCK_START("GuiTable::draw")
@@ -246,7 +246,7 @@ void GuiTable::draw(Graphics *const graphics)
     // First, determine how many rows we need to draw,
     // and where we should start.
     int rHeight = getRowHeight();
-    if (!rHeight)
+    if (rHeight == 0)
         rHeight = 1;
     int first_row = -(y / rHeight);
 
@@ -288,7 +288,7 @@ void GuiTable::draw(Graphics *const graphics)
                 CAST_S32(c));
             const int cWidth = CAST_S32(getColumnWidth(
                 CAST_S32(c)));
-            if (widget)
+            if (widget != nullptr)
             {
                 Rect bounds(x_offset, y_offset, cWidth, rHeight);
 
@@ -331,7 +331,7 @@ void GuiTable::draw(Graphics *const graphics)
         y_offset += rHeight;
     }
 
-    if (mTopWidget)
+    if (mTopWidget != nullptr)
     {
         const Rect &bounds = mTopWidget->getDimension();
         graphics->pushClipArea(bounds);
@@ -343,7 +343,7 @@ void GuiTable::draw(Graphics *const graphics)
 
 void GuiTable::safeDraw(Graphics *const graphics)
 {
-    if (!getRowHeight())
+    if (getRowHeight() == 0)
         return;
 
     BLOCK_START("GuiTable::draw")
@@ -364,7 +364,7 @@ void GuiTable::safeDraw(Graphics *const graphics)
     // First, determine how many rows we need to draw,
     // and where we should start.
     int rHeight = getRowHeight();
-    if (!rHeight)
+    if (rHeight == 0)
         rHeight = 1;
     int first_row = -(y / rHeight);
 
@@ -406,7 +406,7 @@ void GuiTable::safeDraw(Graphics *const graphics)
                 CAST_S32(c));
             const int cWidth = CAST_S32(getColumnWidth(
                 CAST_S32(c)));
-            if (widget)
+            if (widget != nullptr)
             {
                 Rect bounds(x_offset, y_offset, cWidth, rHeight);
 
@@ -449,7 +449,7 @@ void GuiTable::safeDraw(Graphics *const graphics)
         y_offset += rHeight;
     }
 
-    if (mTopWidget)
+    if (mTopWidget != nullptr)
     {
         const Rect &bounds = mTopWidget->getDimension();
         graphics->pushClipArea(bounds);
@@ -513,7 +513,7 @@ void GuiTable::keyPressed(KeyEvent& event)
         setSelectedColumn(0);
         event.consume();
     }
-    else if (action == InputAction::GUI_END && mModel)
+    else if (action == InputAction::GUI_END && (mModel != nullptr))
     {
         setSelectedRow(mModel->getRows() - 1);
         setSelectedColumn(mModel->getColumns() - 1);
@@ -596,13 +596,16 @@ Widget *GuiTable::getWidgetAt(int x, int y)
     const int row = getRowForY(y);
     const int column = getColumnForX(x);
 
-    if (mTopWidget && mTopWidget->getDimension().isPointInRect(x, y))
+    if (mTopWidget != nullptr &&
+        mTopWidget->getDimension().isPointInRect(x, y))
+    {
         return mTopWidget;
+    }
 
-    if (mModel && row > -1 && column > -1)
+    if ((mModel != nullptr) && row > -1 && column > -1)
     {
         Widget *const w = mModel->getElementAt(row, column);
-        if (w && w->isFocusable())
+        if ((w != nullptr) && w->isFocusable())
             return w;
         else
             return nullptr;  // Grab the event locally
@@ -648,7 +651,7 @@ void GuiTable::setFocusHandler(FocusHandler *const focusHandler)
 {
     // add check for focusHandler. may be need remove it?
 
-    if (!focusHandler)
+    if (focusHandler == nullptr)
         return;
 
     Widget::setFocusHandler(focusHandler);
@@ -660,7 +663,7 @@ void GuiTable::setFocusHandler(FocusHandler *const focusHandler)
         for (int c = 0; c < cols ; ++c)
         {
             Widget *const w = mModel->getElementAt(r, c);
-            if (w)
+            if (w != nullptr)
                 w->setFocusHandler(focusHandler);
         }
     }
@@ -668,7 +671,7 @@ void GuiTable::setFocusHandler(FocusHandler *const focusHandler)
 
 void GuiTable::requestFocus()
 {
-    if (!mFocusHandler)
+    if (mFocusHandler == nullptr)
         return;
     Widget::requestFocus();
 }
diff --git a/src/gui/widgets/horizontcontainer.cpp b/src/gui/widgets/horizontcontainer.cpp
index 5b3b08d16..8a026329a 100644
--- a/src/gui/widgets/horizontcontainer.cpp
+++ b/src/gui/widgets/horizontcontainer.cpp
@@ -45,7 +45,7 @@ void HorizontContainer::add(Widget *const widget)
 
 void HorizontContainer::add(Widget *const widget, const int spacing)
 {
-    if (!widget)
+    if (widget == nullptr)
         return;
 
     Container::add(widget);
diff --git a/src/gui/widgets/icon.cpp b/src/gui/widgets/icon.cpp
index 8cb43db6d..dbe46a21a 100644
--- a/src/gui/widgets/icon.cpp
+++ b/src/gui/widgets/icon.cpp
@@ -39,7 +39,7 @@ Icon::Icon(const Widget2 *const widget,
     mImage(Loader::getImage(file)),
     mAutoRelease(autoRelease)
 {
-    if (mImage)
+    if (mImage != nullptr)
     {
         const SDL_Rect &bounds = mImage->mBounds;
         setSize(bounds.w, bounds.h);
@@ -54,7 +54,7 @@ Icon::Icon(const Widget2 *const widget,
     mImage(image),
     mAutoRelease(autoRelease)
 {
-    if (mImage)
+    if (mImage != nullptr)
     {
         const SDL_Rect &bounds = mImage->mBounds;
         setSize(bounds.w, bounds.h);
@@ -64,16 +64,16 @@ Icon::Icon(const Widget2 *const widget,
 
 Icon::~Icon()
 {
-    if (gui)
+    if (gui != nullptr)
         gui->removeDragged(this);
-    if (mImage && mAutoRelease == AutoRelease_true)
+    if ((mImage != nullptr) && mAutoRelease == AutoRelease_true)
         mImage->decRef();
 }
 
 void Icon::setImage(Image *const image)
 {
     mImage = image;
-    if (mImage)
+    if (mImage != nullptr)
     {
         const SDL_Rect &bounds = mImage->mBounds;
         setSize(bounds.w, bounds.h);
@@ -83,7 +83,7 @@ void Icon::setImage(Image *const image)
 void Icon::draw(Graphics *const graphics)
 {
     BLOCK_START("Icon::draw")
-    if (mImage)
+    if (mImage != nullptr)
     {
         graphics->drawImage(mImage,
             (mDimension.width - mImage->mBounds.w) / 2,
@@ -95,7 +95,7 @@ void Icon::draw(Graphics *const graphics)
 void Icon::safeDraw(Graphics *const graphics)
 {
     BLOCK_START("Icon::draw")
-    if (mImage)
+    if (mImage != nullptr)
     {
         graphics->drawImage(mImage,
             (mDimension.width - mImage->mBounds.w) / 2,
diff --git a/src/gui/widgets/itemcontainer.cpp b/src/gui/widgets/itemcontainer.cpp
index 857467f63..15e2df093 100644
--- a/src/gui/widgets/itemcontainer.cpp
+++ b/src/gui/widgets/itemcontainer.cpp
@@ -88,7 +88,7 @@ namespace
             {
                 const Item *const item1 = pair1->mItem;
                 const Item *const item2 = pair2->mItem;
-                if (!item1 || !item2)
+                if ((item1 == nullptr) || (item2 == nullptr))
                     return false;
 
                 const std::string name1 = item1->getInfo().getName(
@@ -112,7 +112,7 @@ namespace
             bool operator() (const ItemIdPair *const pair1,
                              const ItemIdPair *const pair2) const
             {
-                if (!pair1->mItem || !pair2->mItem)
+                if ((pair1->mItem == nullptr) || (pair2->mItem == nullptr))
                     return false;
 
                 const int id1 = pair1->mItem->getId();
@@ -134,7 +134,7 @@ namespace
             bool operator() (const ItemIdPair *const pair1,
                              const ItemIdPair *const pair2) const
             {
-                if (!pair1->mItem || !pair2->mItem)
+                if ((pair1->mItem == nullptr) || (pair2->mItem == nullptr))
                     return false;
 
                 const int w1 = pair1->mItem->getInfo().getWeight();
@@ -164,7 +164,7 @@ namespace
             bool operator() (const ItemIdPair *const pair1,
                              const ItemIdPair *const pair2) const
             {
-                if (!pair1->mItem || !pair2->mItem)
+                if ((pair1->mItem == nullptr) || (pair2->mItem == nullptr))
                     return false;
 
                 const int c1 = pair1->mItem->getQuantity();
@@ -194,7 +194,7 @@ namespace
             bool operator() (const ItemIdPair *const pair1,
                              const ItemIdPair *const pair2) const
             {
-                if (!pair1->mItem || !pair2->mItem)
+                if ((pair1->mItem == nullptr) || (pair2->mItem == nullptr))
                     return false;
 
                 const ItemInfo &info1 = pair1->mItem->getInfo();
@@ -232,7 +232,7 @@ ItemContainer::ItemContainer(const Widget2 *const widget,
     mCellBackgroundImg(Theme::getImageFromThemeXml("inventory_cell.xml", "")),
     mName(),
     mShowMatrix(nullptr),
-    mSkin(theme ? theme->load("itemcontainer.xml", "") : nullptr),
+    mSkin(theme != nullptr ? theme->load("itemcontainer.xml", "") : nullptr),
     mVertexes(new ImageCollection),
     mEquipedColor(getThemeColor(ThemeColorId::ITEM_EQUIPPED)),
     mEquipedColor2(getThemeColor(ThemeColorId::ITEM_EQUIPPED_OUTLINE)),
@@ -246,12 +246,12 @@ ItemContainer::ItemContainer(const Widget2 *const widget,
     mTag(0),
     mSortType(0),
     mClicks(1),
-    mBoxWidth(mSkin ? mSkin->getOption("boxWidth", 35) : 35),
-    mBoxHeight(mSkin ? mSkin->getOption("boxHeight", 43) : 43),
-    mEquippedTextPadding(mSkin ? mSkin->getOption(
+    mBoxWidth(mSkin != nullptr ? mSkin->getOption("boxWidth", 35) : 35),
+    mBoxHeight(mSkin != nullptr ? mSkin->getOption("boxHeight", 43) : 43),
+    mEquippedTextPadding(mSkin != nullptr ? mSkin->getOption(
                          "equippedTextPadding", 29) : 29),
-    mPaddingItemX(mSkin ? mSkin->getOption("paddingItemX", 0) : 0),
-    mPaddingItemY(mSkin ? mSkin->getOption("paddingItemY", 0) : 0),
+    mPaddingItemX(mSkin != nullptr ? mSkin->getOption("paddingItemX", 0) : 0),
+    mPaddingItemY(mSkin != nullptr ? mSkin->getOption("paddingItemY", 0) : 0),
     mMaxColumns(maxColumns),
     mSelectionStatus(SEL_NONE),
     mForceQuantity(forceQuantity),
@@ -267,26 +267,26 @@ ItemContainer::ItemContainer(const Widget2 *const widget,
 
 ItemContainer::~ItemContainer()
 {
-    if (gui)
+    if (gui != nullptr)
         gui->removeDragged(this);
 
-    if (mSelImg)
+    if (mSelImg != nullptr)
     {
         mSelImg->decRef();
         mSelImg = nullptr;
     }
-    if (mProtectedImg)
+    if (mProtectedImg != nullptr)
     {
         mProtectedImg->decRef();
         mProtectedImg = nullptr;
     }
-    if (mCellBackgroundImg)
+    if (mCellBackgroundImg != nullptr)
     {
         mCellBackgroundImg->decRef();
         mCellBackgroundImg = nullptr;
     }
 
-    if (theme)
+    if (theme != nullptr)
         theme->unload(mSkin);
 
     delete []mShowMatrix;
@@ -298,7 +298,7 @@ void ItemContainer::logic()
     BLOCK_START("ItemContainer::logic")
     Widget::logic();
 
-    if (!mInventory)
+    if (mInventory == nullptr)
     {
         BLOCK_END("ItemContainer::logic")
         return;
@@ -316,13 +316,13 @@ void ItemContainer::logic()
 
 void ItemContainer::draw(Graphics *const graphics)
 {
-    if (!mInventory || !mShowMatrix)
+    if ((mInventory == nullptr) || (mShowMatrix == nullptr))
         return;
 
     BLOCK_START("ItemContainer::draw")
     Font *const font = getFont();
 
-    if (mCellBackgroundImg)
+    if (mCellBackgroundImg != nullptr)
     {
         if (mRedraw || graphics->getRedraw())
         {
@@ -367,22 +367,22 @@ void ItemContainer::draw(Graphics *const graphics)
             const Item *const item = mInventory->getItem(
                 mShowMatrix[itemIndex]);
 
-            if (!item || item->getId() == 0)
+            if ((item == nullptr) || item->getId() == 0)
                 continue;
 
             Image *const image = item->getImage();
-            if (image)
+            if (image != nullptr)
             {
                 if (mShowMatrix[itemIndex] == mSelectedIndex)
                 {
-                    if (mSelImg)
+                    if (mSelImg != nullptr)
                         graphics->drawImage(mSelImg, itemX, itemY);
                 }
                 image->setAlpha(1.0F);  // ensure the image if fully drawn...
                 graphics->drawImage(image,
                     itemX + mPaddingItemX,
                     itemY + mPaddingItemY);
-                if (mProtectedImg && PlayerInfo::isItemProtected(
+                if ((mProtectedImg != nullptr) && PlayerInfo::isItemProtected(
                     item->getId()))
                 {
                     graphics->drawImage(mProtectedImg,
@@ -408,7 +408,7 @@ void ItemContainer::draw(Graphics *const graphics)
             const Item *const item = mInventory->getItem(
                 mShowMatrix[itemIndex]);
 
-            if (!item || item->getId() == 0)
+            if ((item == nullptr) || item->getId() == 0)
                 continue;
 
             // Draw item caption
@@ -447,13 +447,13 @@ void ItemContainer::draw(Graphics *const graphics)
 
 void ItemContainer::safeDraw(Graphics *const graphics)
 {
-    if (!mInventory || !mShowMatrix)
+    if ((mInventory == nullptr) || (mShowMatrix == nullptr))
         return;
 
     BLOCK_START("ItemContainer::draw")
     Font *const font = getFont();
 
-    if (mCellBackgroundImg)
+    if (mCellBackgroundImg != nullptr)
     {
         const int invSize = mInventory->getSize();
         const int maxRows = mShowEmptyRows == ShowEmptyRows_true ?
@@ -489,22 +489,22 @@ void ItemContainer::safeDraw(Graphics *const graphics)
             const Item *const item = mInventory->getItem(
                 mShowMatrix[itemIndex]);
 
-            if (!item || item->getId() == 0)
+            if ((item == nullptr) || item->getId() == 0)
                 continue;
 
             Image *const image = item->getImage();
-            if (image)
+            if (image != nullptr)
             {
                 if (mShowMatrix[itemIndex] == mSelectedIndex)
                 {
-                    if (mSelImg)
+                    if (mSelImg != nullptr)
                         graphics->drawImage(mSelImg, itemX, itemY);
                 }
                 image->setAlpha(1.0F);  // ensure the image if fully drawn...
                 graphics->drawImage(image,
                     itemX + mPaddingItemX,
                     itemY + mPaddingItemY);
-                if (mProtectedImg && PlayerInfo::isItemProtected(
+                if ((mProtectedImg != nullptr) && PlayerInfo::isItemProtected(
                     item->getId()))
                 {
                     graphics->drawImage(mProtectedImg,
@@ -530,7 +530,7 @@ void ItemContainer::safeDraw(Graphics *const graphics)
             const Item *const item = mInventory->getItem(
                 mShowMatrix[itemIndex]);
 
-            if (!item || item->getId() == 0)
+            if ((item == nullptr) || item->getId() == 0)
                 continue;
 
             // Draw item caption
@@ -592,7 +592,7 @@ void ItemContainer::setSelectedIndex(const int newIndex)
 
 Item *ItemContainer::getSelectedItem() const
 {
-    if (mInventory)
+    if (mInventory != nullptr)
         return mInventory->getItem(mSelectedIndex);
     else
         return nullptr;
@@ -602,7 +602,7 @@ void ItemContainer::distributeValueChangedEvent()
 {
     FOR_EACH (SelectionListenerIterator, i, mSelectionListeners)
     {
-        if (*i)
+        if (*i != nullptr)
         {
             SelectionEvent event(this);
             (*i)->valueChanged(event);
@@ -620,7 +620,7 @@ void ItemContainer::keyReleased(KeyEvent &event A_UNUSED)
 
 void ItemContainer::mousePressed(MouseEvent &event)
 {
-    if (!mInventory)
+    if (mInventory == nullptr)
         return;
 
     const MouseButtonT button = event.getButton();
@@ -636,7 +636,7 @@ void ItemContainer::mousePressed(MouseEvent &event)
         Item *const item = mInventory->getItem(index);
 
         // put item name into chat window
-        if (item && mDescItems && chatWindow)
+        if ((item != nullptr) && mDescItems && (chatWindow != nullptr))
             chatWindow->addItemText(item->getInfo().getName());
 
         DragDropSourceT src = DragDropSource::Empty;
@@ -674,7 +674,7 @@ void ItemContainer::mousePressed(MouseEvent &event)
             dragDrop.select(item);
             mSelectionStatus = SEL_DESELECTING;
         }
-        else if (item && item->getId())
+        else if ((item != nullptr) && (item->getId() != 0))
         {
             if (index >= 0)
             {
@@ -683,16 +683,16 @@ void ItemContainer::mousePressed(MouseEvent &event)
                 setSelectedIndex(index);
                 mSelectionStatus = SEL_SELECTING;
 
-                if (itemShortcutWindow)
+                if (itemShortcutWindow != nullptr)
                 {
                     const int num = itemShortcutWindow->getTabIndex();
                     if (num >= 0 && num < CAST_S32(SHORTCUT_TABS))
                     {
-                        if (itemShortcut[num])
+                        if (itemShortcut[num] != nullptr)
                             itemShortcut[num]->setItemSelected(item);
                     }
                 }
-                if (shopWindow)
+                if (shopWindow != nullptr)
                     shopWindow->setItemSelected(item->getId());
             }
         }
@@ -712,8 +712,12 @@ void ItemContainer::mouseDragged(MouseEvent &event A_UNUSED)
 
 void ItemContainer::mouseReleased(MouseEvent &event)
 {
-    if (mClicks == 2 || !inventoryHandler || !tradeHandler)
+    if (mClicks == 2 ||
+        inventoryHandler == nullptr ||
+        tradeHandler == nullptr)
+    {
         return;
+    }
 
     switch (mSelectionStatus)
     {
@@ -742,7 +746,7 @@ void ItemContainer::mouseReleased(MouseEvent &event)
         inventoryHandler->moveItem(mSelectedIndex, index);
         selectNone();
     }
-    else if (mInventory)
+    else if (mInventory != nullptr)
     {
         const DragDropSourceT src = dragDrop.getSource();
         DragDropSourceT dst = DragDropSource::Empty;
@@ -809,7 +813,7 @@ void ItemContainer::mouseReleased(MouseEvent &event)
                 return;
             if (index == mSelectedIndex || mSelectedIndex == -1)
                 return;
-            if (inventoryWindow)
+            if (inventoryWindow != nullptr)
                 inventoryWindow->combineItems(index, mSelectedIndex);
             return;
         }
@@ -845,7 +849,7 @@ void ItemContainer::mouseReleased(MouseEvent &event)
                  || dst == DragDropSource::Mail))
         {
             inventory = PlayerInfo::getInventory();
-            if (inventory)
+            if (inventory != nullptr)
             {
                 Item *const item = inventory->getItem(dragDrop.getTag());
                 if (mInventory->addVirtualItem(
@@ -868,7 +872,7 @@ void ItemContainer::mouseReleased(MouseEvent &event)
                 const int index = getSlotByXY(event.getX(), event.getY());
                 if (index == Inventory::NO_SLOT_INDEX)
                 {
-                    if (inventory)
+                    if (inventory != nullptr)
                         inventory->virtualRestore(item, 1);
                     mInventory->removeItemAt(dragDrop.getTag());
                     return;
@@ -886,17 +890,17 @@ void ItemContainer::mouseReleased(MouseEvent &event)
                     Equipm_false,
                     Equipped_false);
                 Item *const item2 = mInventory->getItem(index);
-                if (item2)
+                if (item2 != nullptr)
                     item2->setTag(item->getTag());
                 mInventory->removeItemAt(dragDrop.getTag());
             }
             else
             {
-                if (inventory)
+                if (inventory != nullptr)
                 {
                     const Item *const item = inventory->getItem(
                         dragDrop.getTag());
-                    if (item)
+                    if (item != nullptr)
                     {
                         inventory->virtualRestore(item, 1);
                         mInventory->removeItemAt(dragDrop.getTag());
@@ -909,10 +913,10 @@ void ItemContainer::mouseReleased(MouseEvent &event)
                  dst == DragDropSource::Craft)
         {
             inventory = PlayerInfo::getInventory();
-            if (inventory)
+            if (inventory != nullptr)
             {
                 Item *const item = inventory->getItem(dragDrop.getTag());
-                if (!item || item->isEquipped() == Equipped_true)
+                if ((item == nullptr) || item->isEquipped() == Equipped_true)
                     return;
                 const int slot = getSlotByXY(event.getX(), event.getY());
                 if (item->getQuantity() > 1
@@ -948,7 +952,7 @@ void ItemContainer::mouseReleased(MouseEvent &event)
                 const int index = getSlotByXY(event.getX(), event.getY());
                 if (index == Inventory::NO_SLOT_INDEX)
                 {
-                    if (inventory)
+                    if (inventory != nullptr)
                     {
                         inventory->virtualRestore(item,
                             item->getQuantity());
@@ -960,11 +964,11 @@ void ItemContainer::mouseReleased(MouseEvent &event)
             }
             else
             {
-                if (inventory)
+                if (inventory != nullptr)
                 {
                     const Item *const item = inventory->getItem(
                         dragDrop.getTag());
-                    if (item)
+                    if (item != nullptr)
                     {
                         inventory->virtualRestore(item,
                             item->getQuantity());
@@ -977,19 +981,19 @@ void ItemContainer::mouseReleased(MouseEvent &event)
         else if (src == DragDropSource::Mail)
         {
             inventory = PlayerInfo::getInventory();
-            if (inventory)
+            if (inventory != nullptr)
             {
                 const Item *const item = inventory->getItem(dragDrop.getTag());
-                if (item)
+                if (item != nullptr)
                     mInventory->removeItemAt(dragDrop.getTag());
             }
             return;
         }
 
-        if (inventory)
+        if (inventory != nullptr)
         {
             const Item *const item = inventory->getItem(dragDrop.getTag());
-            if (item)
+            if (item != nullptr)
             {
                 if (srcContainer != InventoryType::TypeEnd)
                 {   // inventory <--> storage, cart
@@ -1013,13 +1017,13 @@ void ItemContainer::mouseReleased(MouseEvent &event)
 
 void ItemContainer::mouseMoved(MouseEvent &event)
 {
-    if (!mInventory)
+    if (mInventory == nullptr)
         return;
 
     const Item *const item = mInventory->getItem(
         getSlotIndex(event.getX(), event.getY()));
 
-    if (item && viewport)
+    if ((item != nullptr) && (viewport != nullptr))
     {
         itemPopup->setItem(item, false);
         itemPopup->position(viewport->mMouseX, viewport->mMouseY);
@@ -1057,7 +1061,7 @@ void ItemContainer::widgetMoved(const Event &event A_UNUSED)
 
 void ItemContainer::adjustHeight()
 {
-    if (!mGridColumns)
+    if (mGridColumns == 0)
         return;
 
     mGridRows = (mLastUsedSlot + 1) / mGridColumns;
@@ -1081,7 +1085,7 @@ void ItemContainer::adjustHeight()
 
 void ItemContainer::updateMatrix()
 {
-    if (!mInventory)
+    if (mInventory == nullptr)
         return;
 
     mRedraw = true;
@@ -1100,7 +1104,9 @@ void ItemContainer::updateMatrix()
     {
         Item *const item = mInventory->getItem(idx);
 
-        if (!item || item->getId() == 0 || !item->isHaveTag(mTag))
+        if (item == nullptr ||
+            item->getId() == 0 ||
+            !item->isHaveTag(mTag))
         {
             if (mShowEmptyRows == ShowEmptyRows_true)
                 sortedItems.push_back(new ItemIdPair(idx, nullptr));
@@ -1174,7 +1180,7 @@ void ItemContainer::updateMatrix()
 
 int ItemContainer::getSlotIndex(int x, int y) const
 {
-    if (!mShowMatrix)
+    if (mShowMatrix == nullptr)
         return Inventory::NO_SLOT_INDEX;
 
     if (x < mDimension.width && y < mDimension.height && x >= 0 && y >= 0)
@@ -1194,7 +1200,7 @@ int ItemContainer::getSlotIndex(int x, int y) const
 
 int ItemContainer::getSlotByXY(int x, int y) const
 {
-    if (!mShowMatrix)
+    if (mShowMatrix == nullptr)
         return Inventory::NO_SLOT_INDEX;
 
     if (x < mDimension.width && y < mDimension.height && x >= 0 && y >= 0)
@@ -1223,7 +1229,7 @@ void ItemContainer::setSortType(const int sortType)
 
 void ItemContainer::setCellBackgroundImage(const std::string &xmlName)
 {
-    if (mCellBackgroundImg)
+    if (mCellBackgroundImg != nullptr)
         mCellBackgroundImg->decRef();
     mCellBackgroundImg = Theme::getImageFromThemeXml(xmlName, "");
     mRedraw = true;
diff --git a/src/gui/widgets/itemcontainer.h b/src/gui/widgets/itemcontainer.h
index 2d732ad3c..ba640d374 100644
--- a/src/gui/widgets/itemcontainer.h
+++ b/src/gui/widgets/itemcontainer.h
@@ -126,7 +126,7 @@ class ItemContainer final : public Widget,
         void updateMatrix();
 
         bool getClickCount() const noexcept2 A_WARN_UNUSED
-        { return mClicks; }
+        { return mClicks != 0; }
 
         void unsetInventory() noexcept2
         { mInventory = nullptr; }
diff --git a/src/gui/widgets/itemlinkhandler.cpp b/src/gui/widgets/itemlinkhandler.cpp
index 90a26a4a0..295e41d16 100644
--- a/src/gui/widgets/itemlinkhandler.cpp
+++ b/src/gui/widgets/itemlinkhandler.cpp
@@ -95,7 +95,7 @@ void ItemLinkHandler::handleCommandLink(const std::string &link,
 
 void ItemLinkHandler::handleHelpLink(const std::string &link)
 {
-    if (helpWindow)
+    if (helpWindow != nullptr)
     {
         helpWindow->loadHelp(link.substr(7));
         helpWindow->requestMoveToTop();
@@ -105,7 +105,7 @@ void ItemLinkHandler::handleHelpLink(const std::string &link)
 void ItemLinkHandler::handleHttpLink(const std::string &link,
                                      const MouseEvent *const event)
 {
-    if (!event)
+    if (event == nullptr)
         return;
     std::string url = link;
     replaceAll(url, " ", "");
@@ -124,14 +124,14 @@ void ItemLinkHandler::handleHttpLink(const std::string &link,
     }
     else if (button == MouseButton::RIGHT)
     {
-        if (popupMenu)
+        if (popupMenu != nullptr)
             popupMenu->showLinkPopup(url);
     }
 }
 
 void ItemLinkHandler::handleItemLink(const std::string &link)
 {
-    if (!itemPopup || link.empty())
+    if ((itemPopup == nullptr) || link.empty())
         return;
 
     const char ch = link[0];
@@ -160,7 +160,7 @@ void ItemLinkHandler::handleItemLink(const std::string &link)
         {
             itemPopup->setVisible(Visible_false);
         }
-        else if (viewport)
+        else if (viewport != nullptr)
         {
             itemPopup->position(viewport->mMouseX,
                 viewport->mMouseY);
@@ -170,7 +170,7 @@ void ItemLinkHandler::handleItemLink(const std::string &link)
 
 void ItemLinkHandler::handleSearchLink(const std::string &link)
 {
-    if (helpWindow)
+    if (helpWindow != nullptr)
     {
         helpWindow->search(link.substr(1));
         helpWindow->requestMoveToTop();
@@ -205,7 +205,7 @@ void ItemLinkHandler::handleLink(const std::string &link,
     }
     else if (link == "news")
     {
-        if (helpWindow)
+        if (helpWindow != nullptr)
             helpWindow->loadHelpSimple("news");
     }
     else if (link == "copyright")
diff --git a/src/gui/widgets/itemshortcutcontainer.cpp b/src/gui/widgets/itemshortcutcontainer.cpp
index 424986efe..400ae0d88 100644
--- a/src/gui/widgets/itemshortcutcontainer.cpp
+++ b/src/gui/widgets/itemshortcutcontainer.cpp
@@ -63,7 +63,7 @@ ItemShortcutContainer::ItemShortcutContainer(Widget2 *const widget,
     mUnEquipedColor(getThemeColor(ThemeColorId::ITEM_NOT_EQUIPPED)),
     mUnEquipedColor2(getThemeColor(ThemeColorId::ITEM_NOT_EQUIPPED_OUTLINE))
 {
-    if (itemShortcut[mNumber])
+    if (itemShortcut[mNumber] != nullptr)
         mMaxItems = itemShortcut[mNumber]->getItemCount();
     else
         mMaxItems = 0;
@@ -88,7 +88,7 @@ void ItemShortcutContainer::draw(Graphics *const graphics)
 {
     BLOCK_START("ItemShortcutContainer::draw")
     const ItemShortcut *const selShortcut = itemShortcut[mNumber];
-    if (!selShortcut)
+    if (selShortcut == nullptr)
     {
         BLOCK_END("ItemShortcutContainer::draw")
         return;
@@ -96,7 +96,7 @@ void ItemShortcutContainer::draw(Graphics *const graphics)
 
     if (settings.guiAlpha != mAlpha)
     {
-        if (mBackgroundImg)
+        if (mBackgroundImg != nullptr)
             mBackgroundImg->setAlpha(mAlpha);
         mAlpha = settings.guiAlpha;
     }
@@ -105,7 +105,7 @@ void ItemShortcutContainer::draw(Graphics *const graphics)
     drawBackground(graphics);
 
     const Inventory *const inv = PlayerInfo::getInventory();
-    if (!inv)
+    if (inv == nullptr)
     {
         BLOCK_END("ItemShortcutContainer::draw")
         return;
@@ -136,11 +136,11 @@ void ItemShortcutContainer::draw(Graphics *const graphics)
         if (itemId < SPELL_MIN_ID)
         {
             const Item *const item = inv->findItem(itemId, itemColor);
-            if (item)
+            if (item != nullptr)
             {
                 // Draw item icon.
                 Image *const image = item->getImage();
-                if (image)
+                if (image != nullptr)
                 {
                     std::string caption;
                     if (item->getQuantity() > 1)
@@ -171,17 +171,17 @@ void ItemShortcutContainer::draw(Graphics *const graphics)
                 }
             }
         }
-        else if (itemId < SKILL_MIN_ID && spellManager)
+        else if (itemId < SKILL_MIN_ID && (spellManager != nullptr))
         {   // this is magic shortcut
             const TextCommand *const spell = spellManager
                 ->getSpellByItem(itemId);
-            if (spell)
+            if (spell != nullptr)
             {
                 if (!spell->isEmpty())
                 {
                     Image *const image = spell->getImage();
 
-                    if (image)
+                    if (image != nullptr)
                     {
                         image->setAlpha(1.0F);
                         graphics->drawImage(image, itemX, itemY);
@@ -195,15 +195,15 @@ void ItemShortcutContainer::draw(Graphics *const graphics)
                     itemX + 2, itemY + mBoxHeight / 2);
             }
         }
-        else if (skillDialog)
+        else if (skillDialog != nullptr)
         {
             const SkillInfo *const skill = skillDialog->getSkill(
                 itemId - SKILL_MIN_ID);
-            if (skill)
+            if (skill != nullptr)
             {
                 Image *const image = skill->data->icon;
 
-                if (image)
+                if (image != nullptr)
                 {
                     image->setAlpha(1.0F);
                     graphics->drawImage(image, itemX, itemY);
@@ -225,7 +225,7 @@ void ItemShortcutContainer::safeDraw(Graphics *const graphics)
 {
     BLOCK_START("ItemShortcutContainer::draw")
     const ItemShortcut *const selShortcut = itemShortcut[mNumber];
-    if (!selShortcut)
+    if (selShortcut == nullptr)
     {
         BLOCK_END("ItemShortcutContainer::draw")
         return;
@@ -233,7 +233,7 @@ void ItemShortcutContainer::safeDraw(Graphics *const graphics)
 
     if (settings.guiAlpha != mAlpha)
     {
-        if (mBackgroundImg)
+        if (mBackgroundImg != nullptr)
             mBackgroundImg->setAlpha(mAlpha);
         mAlpha = settings.guiAlpha;
     }
@@ -242,7 +242,7 @@ void ItemShortcutContainer::safeDraw(Graphics *const graphics)
     safeDrawBackground(graphics);
 
     const Inventory *const inv = PlayerInfo::getInventory();
-    if (!inv)
+    if (inv == nullptr)
     {
         BLOCK_END("ItemShortcutContainer::draw")
         return;
@@ -273,11 +273,11 @@ void ItemShortcutContainer::safeDraw(Graphics *const graphics)
         if (itemId < SPELL_MIN_ID)
         {
             const Item *const item = inv->findItem(itemId, itemColor);
-            if (item)
+            if (item != nullptr)
             {
                 // Draw item icon.
                 Image *const image = item->getImage();
-                if (image)
+                if (image != nullptr)
                 {
                     std::string caption;
                     if (item->getQuantity() > 1)
@@ -308,17 +308,17 @@ void ItemShortcutContainer::safeDraw(Graphics *const graphics)
                 }
             }
         }
-        else if (itemId < SKILL_MIN_ID && spellManager)
+        else if (itemId < SKILL_MIN_ID && (spellManager != nullptr))
         {   // this is magic shortcut
             const TextCommand *const spell = spellManager
                 ->getSpellByItem(itemId);
-            if (spell)
+            if (spell != nullptr)
             {
                 if (!spell->isEmpty())
                 {
                     Image *const image = spell->getImage();
 
-                    if (image)
+                    if (image != nullptr)
                     {
                         image->setAlpha(1.0F);
                         graphics->drawImage(image, itemX, itemY);
@@ -332,15 +332,15 @@ void ItemShortcutContainer::safeDraw(Graphics *const graphics)
                     itemX + 2, itemY + mBoxHeight / 2);
             }
         }
-        else if (skillDialog)
+        else if (skillDialog != nullptr)
         {
             const SkillInfo *const skill = skillDialog->getSkill(
                 itemId - SKILL_MIN_ID);
-            if (skill)
+            if (skill != nullptr)
             {
                 Image *const image = skill->data->icon;
 
-                if (image)
+                if (image != nullptr)
                 {
                     image->setAlpha(1.0F);
                     graphics->drawImage(image, itemX, itemY);
@@ -361,7 +361,7 @@ void ItemShortcutContainer::safeDraw(Graphics *const graphics)
 void ItemShortcutContainer::mouseDragged(MouseEvent &event)
 {
     ItemShortcut *const selShortcut = itemShortcut[mNumber];
-    if (!selShortcut)
+    if (selShortcut == nullptr)
         return;
 
     if (event.getButton() == MouseButton::LEFT)
@@ -383,13 +383,13 @@ void ItemShortcutContainer::mouseDragged(MouseEvent &event)
             event.consume();
             if (itemId < SPELL_MIN_ID)
             {   // items
-                if (!PlayerInfo::getInventory())
+                if (PlayerInfo::getInventory() == nullptr)
                     return;
 
                 const Item *const item = PlayerInfo::getInventory()->findItem(
                     itemId, itemColor);
 
-                if (item)
+                if (item != nullptr)
                 {
                     selShortcut->removeItem(index);
                     dragDrop.dragItem(item, DragDropSource::Shortcuts, index);
@@ -401,7 +401,7 @@ void ItemShortcutContainer::mouseDragged(MouseEvent &event)
             }
             else if (itemId < SKILL_MIN_ID)
             {   // spells/commands
-                if (!spellManager)
+                if (spellManager == nullptr)
                 {
                     dragDrop.clear();
                     return;
@@ -409,7 +409,7 @@ void ItemShortcutContainer::mouseDragged(MouseEvent &event)
 
                 const TextCommand *const spell = spellManager->getSpellByItem(
                     itemId);
-                if (spell)
+                if (spell != nullptr)
                 {
                     selShortcut->removeItem(index);
                     dragDrop.dragCommand(spell,
@@ -423,14 +423,14 @@ void ItemShortcutContainer::mouseDragged(MouseEvent &event)
             }
             else
             {   // skills
-                if (!skillDialog)
+                if (skillDialog == nullptr)
                 {
                     dragDrop.clear();
                     return;
                 }
                 const SkillInfo *const skill
                     = skillDialog->getSkillByItem(itemId);
-                if (skill)
+                if (skill != nullptr)
                 {
                     const std::string itemData = selShortcut->getItemData(
                         index);
@@ -454,7 +454,7 @@ void ItemShortcutContainer::mouseDragged(MouseEvent &event)
 void ItemShortcutContainer::mousePressed(MouseEvent &event)
 {
     ItemShortcut *const selShortcut = itemShortcut[mNumber];
-    if (!selShortcut)
+    if (selShortcut == nullptr)
         return;
 
     const int index = getIndexFromGrid(event.getX(), event.getY());
@@ -466,17 +466,17 @@ void ItemShortcutContainer::mousePressed(MouseEvent &event)
     {
         event.consume();
         // Stores the selected item if theirs one.
-        if (selShortcut->isItemSelected() && inventoryWindow &&
+        if (selShortcut->isItemSelected() && (inventoryWindow != nullptr) &&
             (inventoryWindow->isWindowVisible()
             || selShortcut->getSelectedItem() >= SPELL_MIN_ID))
         {
             selShortcut->setItem(index);
             selShortcut->setItemSelected(-1);
-            if (spellShortcut)
+            if (spellShortcut != nullptr)
                 spellShortcut->setItemSelected(-1);
             inventoryWindow->unselectItem();
         }
-        else if (selShortcut->getItem(index))
+        else if (selShortcut->getItem(index) != 0)
         {
             mItemClicked = true;
         }
@@ -484,7 +484,9 @@ void ItemShortcutContainer::mousePressed(MouseEvent &event)
     else if (event.getButton() == MouseButton::RIGHT)
     {
         event.consume();
-        if (popupMenu && selShortcut && viewport)
+        if (popupMenu != nullptr &&
+            selShortcut != nullptr &&
+            viewport != nullptr)
         {
             popupMenu->showItemPopup(viewport->mMouseX,
                 viewport->mMouseY,
@@ -497,7 +499,7 @@ void ItemShortcutContainer::mousePressed(MouseEvent &event)
 void ItemShortcutContainer::mouseReleased(MouseEvent &event)
 {
     ItemShortcut *const selShortcut = itemShortcut[mNumber];
-    if (!selShortcut)
+    if (selShortcut == nullptr)
         return;
 
     if (event.getButton() == MouseButton::LEFT)
@@ -511,7 +513,7 @@ void ItemShortcutContainer::mouseReleased(MouseEvent &event)
 
         if (dragDrop.isEmpty())
         {
-            if (selShortcut->getItem(index) && mItemClicked)
+            if ((selShortcut->getItem(index) != 0) && mItemClicked)
                 selShortcut->useItem(index);
         }
         else
@@ -541,7 +543,7 @@ void ItemShortcutContainer::mouseReleased(MouseEvent &event)
 void ItemShortcutContainer::mouseMoved(MouseEvent &event)
 {
     const ItemShortcut *const selShortcut = itemShortcut[mNumber];
-    if (!selShortcut)
+    if (selShortcut == nullptr)
         return;
 
     const int index = getIndexFromGrid(event.getX(), event.getY());
@@ -561,11 +563,11 @@ void ItemShortcutContainer::mouseMoved(MouseEvent &event)
         spellPopup->setVisible(Visible_false);
 
         Inventory *const inv = PlayerInfo::getInventory();
-        if (!inv)
+        if (inv == nullptr)
             return;
 
         const Item *const item = inv->findItem(itemId, itemColor);
-        if (item && viewport)
+        if ((item != nullptr) && (viewport != nullptr))
         {
             itemPopup->setItem(item, false);
             itemPopup->position(viewport->mMouseX, viewport->mMouseY);
@@ -575,12 +577,12 @@ void ItemShortcutContainer::mouseMoved(MouseEvent &event)
             itemPopup->setVisible(Visible_false);
         }
     }
-    else if (itemId < SKILL_MIN_ID && spellManager)
+    else if (itemId < SKILL_MIN_ID && (spellManager != nullptr))
     {
         skillPopup->setVisible(Visible_false);
         itemPopup->setVisible(Visible_false);
         const TextCommand *const spell = spellManager->getSpellByItem(itemId);
-        if (spell && viewport)
+        if ((spell != nullptr) && (viewport != nullptr))
         {
             spellPopup->setItem(spell);
             spellPopup->view(viewport->mMouseX,
@@ -591,12 +593,12 @@ void ItemShortcutContainer::mouseMoved(MouseEvent &event)
             spellPopup->setVisible(Visible_false);
         }
     }
-    else if (skillDialog)
+    else if (skillDialog != nullptr)
     {
         itemPopup->setVisible(Visible_false);
         spellPopup->setVisible(Visible_false);
         const SkillInfo *const skill = skillDialog->getSkillByItem(itemId);
-        if (!skill)
+        if (skill == nullptr)
             return;
 
         const std::string data = selShortcut->getItemData(index);
@@ -629,18 +631,18 @@ void ItemShortcutContainer::mouseMoved(MouseEvent &event)
 // Hide ItemTooltip
 void ItemShortcutContainer::mouseExited(MouseEvent &event A_UNUSED)
 {
-    if (itemPopup)
+    if (itemPopup != nullptr)
         itemPopup->setVisible(Visible_false);
-    if (spellPopup)
+    if (spellPopup != nullptr)
         spellPopup->setVisible(Visible_false);
-    if (skillPopup)
+    if (skillPopup != nullptr)
         skillPopup->setVisible(Visible_false);
 }
 
 void ItemShortcutContainer::widgetHidden(const Event &event A_UNUSED)
 {
-    if (itemPopup)
+    if (itemPopup != nullptr)
         itemPopup->setVisible(Visible_false);
-    if (spellPopup)
+    if (spellPopup != nullptr)
         spellPopup->setVisible(Visible_false);
 }
diff --git a/src/gui/widgets/label.cpp b/src/gui/widgets/label.cpp
index 52fdbd716..aeacddbdb 100644
--- a/src/gui/widgets/label.cpp
+++ b/src/gui/widgets/label.cpp
@@ -106,16 +106,16 @@ Label::Label(const Widget2 *const widget,
 
 Label::~Label()
 {
-    if (mWindow)
+    if (mWindow != nullptr)
         mWindow->removeWidgetListener(this);
 
-    if (gui)
+    if (gui != nullptr)
         gui->removeDragged(this);
 
     mInstances --;
     if (mInstances == 0)
     {
-        if (theme)
+        if (theme != nullptr)
             theme->unload(mSkin);
     }
     removeMouseListener(this);
@@ -130,12 +130,12 @@ void Label::init()
     mForegroundColor2 = getThemeColor(ThemeColorId::LABEL_OUTLINE);
     if (mInstances == 0)
     {
-        if (theme)
+        if (theme != nullptr)
             mSkin = theme->load("label.xml", "");
     }
     mInstances ++;
 
-    if (mSkin)
+    if (mSkin != nullptr)
         mPadding = mSkin->getPadding();
     else
         mPadding = 0;
@@ -179,7 +179,7 @@ void Label::draw(Graphics *const graphics)
     }
 
     const Image *const image = mTextChunk.img;
-    if (image)
+    if (image != nullptr)
         graphics->drawImage(image, textX, textY);
     BLOCK_END("Label::draw")
 }
@@ -262,14 +262,14 @@ void Label::setCaption(const std::string& caption)
 
 void Label::setParent(Widget *const widget)
 {
-    if (mWindow)
+    if (mWindow != nullptr)
         mWindow->addWidgetListener(this);
     Widget::setParent(widget);
 }
 
 void Label::setWindow(Widget *const widget)
 {
-    if (!widget && mWindow)
+    if ((widget == nullptr) && (mWindow != nullptr))
     {
         mWindow->removeWidgetListener(this);
         mWindow = nullptr;
diff --git a/src/gui/widgets/layoutarray.cpp b/src/gui/widgets/layoutarray.cpp
index 7bd6ff34f..de9c8cd30 100644
--- a/src/gui/widgets/layoutarray.cpp
+++ b/src/gui/widgets/layoutarray.cpp
@@ -61,15 +61,15 @@ LayoutCell &LayoutArray::at(const int x, const int y,
 {
     resizeGrid(x + w, y + h);
     LayoutCell *&cell = mCells[CAST_SIZE(y)][static_cast<size_t>(x)];
-    if (!cell)
+    if (cell == nullptr)
         cell = new LayoutCell;
     return *cell;
 }
 
 void LayoutArray::resizeGrid(int w, const int h)
 {
-    const bool extW = w && w > CAST_S32(mSizes[0].size());
-    const bool extH = h && h > CAST_S32(mSizes[1].size());
+    const bool extW = (w != 0) && w > CAST_S32(mSizes[0].size());
+    const bool extH = (h != 0) && h > CAST_S32(mSizes[1].size());
 
     if (!extW && !extH)
         return;
@@ -132,7 +132,7 @@ LayoutCell &LayoutArray::place(Widget *const widget, const int x,
     assert(cell.mType == LayoutCell::NONE);
     cell.mType = LayoutCell::WIDGET;
     cell.mWidget = widget;
-    if (widget)
+    if (widget != nullptr)
     {
         cell.mSize[0] = w == 1 ? widget->getWidth() : 0;
         cell.mSize[1] = h == 1 ? widget->getHeight() : 0;
@@ -166,7 +166,7 @@ void LayoutArray::align(int &restrict pos, int &restrict size, const int dim,
         return;
     int size_max = sizes[0];
     int cnt = cell.mExtent[dim];
-    if (sizeCount && cell.mExtent[dim] > sizeCount)
+    if ((sizeCount != 0) && cell.mExtent[dim] > sizeCount)
         cnt = sizeCount;
 
     for (int i = 1; i < cnt; ++i)
@@ -208,7 +208,7 @@ std::vector<int> LayoutArray::getSizes(const int dim, int upp) const
         {
             const LayoutCell *const cell = mCells[CAST_SIZE(gridY)]
                 [CAST_SIZE(gridX)];
-            if (!cell || cell->mType == LayoutCell::NONE)
+            if ((cell == nullptr) || cell->mType == LayoutCell::NONE)
                 continue;
 
             if (cell->mExtent[dim] == 1)
@@ -297,7 +297,7 @@ void LayoutArray::reflow(const int nx, const int ny,
         {
             LayoutCell *const cell = mCells[CAST_SIZE(gridY)]
                 [CAST_SIZE(gridX)];
-            if (cell && cell->mType != LayoutCell::NONE)
+            if ((cell != nullptr) && cell->mType != LayoutCell::NONE)
             {
                 int dx = x, dy = y, dw = 0, dh = 0;
                 align(dx, dw, 0, *cell,
diff --git a/src/gui/widgets/layoutcell.cpp b/src/gui/widgets/layoutcell.cpp
index 21efd4818..b898b1dfc 100644
--- a/src/gui/widgets/layoutcell.cpp
+++ b/src/gui/widgets/layoutcell.cpp
@@ -44,7 +44,7 @@ LayoutArray &LayoutCell::getArray()
         return tempArray;
     if (mType == ARRAY)
     {
-        if (!mArray)
+        if (mArray == nullptr)
             return tempArray;
         return *mArray;
     }
@@ -90,7 +90,7 @@ void LayoutCell::computeSizes()
         while (j != i->end())
         {
             LayoutCell *const cell = *j;
-            if (cell && cell->mType == ARRAY)
+            if ((cell != nullptr) && cell->mType == ARRAY)
                 cell->computeSizes();
 
             ++j;
diff --git a/src/gui/widgets/layouthelper.cpp b/src/gui/widgets/layouthelper.cpp
index 2de26dbab..19114c1ae 100644
--- a/src/gui/widgets/layouthelper.cpp
+++ b/src/gui/widgets/layouthelper.cpp
@@ -32,13 +32,13 @@ LayoutHelper::LayoutHelper(BasicContainer2 *const container) :
     mLayout(),
     mContainer(container)
 {
-    if (mContainer)
+    if (mContainer != nullptr)
         mContainer->addWidgetListener(this);
 }
 
 LayoutHelper::~LayoutHelper()
 {
-    if (mContainer)
+    if (mContainer != nullptr)
         mContainer->removeWidgetListener(this);
 }
 
@@ -51,7 +51,7 @@ LayoutCell &LayoutHelper::place(const int x, const int y,
                                 Widget *const wg,
                                 const int w, const int h)
 {
-    if (mContainer)
+    if (mContainer != nullptr)
         mContainer->add(wg);
     return mLayout.place(wg, x, y, w, h);
 }
@@ -64,13 +64,13 @@ ContainerPlacer LayoutHelper::getPlacer(const int x, const int y)
 void LayoutHelper::reflowLayout(int w, int h)
 {
     mLayout.reflow(w, h);
-    if (mContainer)
+    if (mContainer != nullptr)
         mContainer->setSize(w, h);
 }
 
 void LayoutHelper::widgetResized(const Event &event A_UNUSED)
 {
-    if (!mContainer)
+    if (mContainer == nullptr)
         return;
     const Rect area = mContainer->getChildrenArea();
     int w = area.width;
diff --git a/src/gui/widgets/linepart.cpp b/src/gui/widgets/linepart.cpp
index 0f9403c85..2e1cab392 100644
--- a/src/gui/widgets/linepart.cpp
+++ b/src/gui/widgets/linepart.cpp
@@ -27,7 +27,7 @@
 
 LinePart::~LinePart()
 {
-    if (mImage)
+    if (mImage != nullptr)
         mImage->decRef();
     mImage = nullptr;
 }
diff --git a/src/gui/widgets/listbox.cpp b/src/gui/widgets/listbox.cpp
index 0095baf1f..9628c2764 100644
--- a/src/gui/widgets/listbox.cpp
+++ b/src/gui/widgets/listbox.cpp
@@ -114,10 +114,10 @@ ListBox::ListBox(const Widget2 *const widget,
     mForegroundColor = getThemeColor(ThemeColorId::LISTBOX);
     mForegroundColor2 = getThemeColor(ThemeColorId::LISTBOX_OUTLINE);
 
-    if (theme)
+    if (theme != nullptr)
         mSkin = theme->load(skin, "listbox.xml");
 
-    if (mSkin)
+    if (mSkin != nullptr)
     {
         mPadding = mSkin->getPadding();
         mItemPadding = mSkin->getOption("itemPadding");
@@ -135,10 +135,10 @@ void ListBox::postInit()
 
 ListBox::~ListBox()
 {
-    if (gui)
+    if (gui != nullptr)
         gui->removeDragged(this);
 
-    if (theme)
+    if (theme != nullptr)
         theme->unload(mSkin);
 }
 
@@ -153,7 +153,7 @@ void ListBox::updateAlpha()
 
 void ListBox::draw(Graphics *const graphics)
 {
-    if (!mListModel)
+    if (mListModel == nullptr)
         return;
 
     BLOCK_START("ListBox::draw")
@@ -245,9 +245,15 @@ void ListBox::keyPressed(KeyEvent &event)
     else if (action == InputAction::GUI_UP)
     {
         if (mSelected > 0)
+        {
             setSelected(mSelected - 1);
-        else if (mSelected == 0 && mWrappingEnabled && getListModel())
+        }
+        else if (mSelected == 0 &&
+                 mWrappingEnabled &&
+                 getListModel() != nullptr)
+        {
             setSelected(getListModel()->getNumberOfElements() - 1);
+        }
         event.consume();
     }
     else if (action == InputAction::GUI_DOWN)
@@ -264,7 +270,7 @@ void ListBox::keyPressed(KeyEvent &event)
         setSelected(0);
         event.consume();
     }
-    else if (action == InputAction::GUI_END && getListModel())
+    else if (action == InputAction::GUI_END && (getListModel() != nullptr))
     {
         setSelected(getListModel()->getNumberOfElements() - 1);
         event.consume();
@@ -311,7 +317,7 @@ void ListBox::mouseReleased(MouseEvent &event)
                 mOldSelected = mSelected;
                 break;
             case 2:
-                if (gui)
+                if (gui != nullptr)
                     gui->resetClickCount();
                 if (mOldSelected == mSelected)
                     mouseReleased1(event);
@@ -343,13 +349,13 @@ void ListBox::mouseDragged(MouseEvent &event)
         return;
 
     // Make list selection update on drag, but guard against negative y
-    if (getRowHeight())
+    if (getRowHeight() != 0u)
         setSelected(std::max(0, getSelectionByMouse(event.getY())));
 }
 
 void ListBox::refocus()
 {
-    if (!mFocusHandler)
+    if (mFocusHandler == nullptr)
         return;
 
     if (isFocusable())
@@ -359,7 +365,7 @@ void ListBox::refocus()
 void ListBox::adjustSize()
 {
     BLOCK_START("ListBox::adjustSize")
-    if (mListModel)
+    if (mListModel != nullptr)
     {
         setHeight(CAST_S32(getRowHeight()) *
             mListModel->getNumberOfElements() + 2 * mPadding);
@@ -383,7 +389,7 @@ int ListBox::getSelectionByMouse(const int y) const
 
 void ListBox::setSelected(const int selected)
 {
-    if (!mListModel)
+    if (mListModel == nullptr)
     {
         mSelected = -1;
     }
diff --git a/src/gui/widgets/passwordfield.cpp b/src/gui/widgets/passwordfield.cpp
index 7400ffd76..bc2ca4827 100644
--- a/src/gui/widgets/passwordfield.cpp
+++ b/src/gui/widgets/passwordfield.cpp
@@ -29,7 +29,7 @@
 PasswordField::PasswordField(const Widget2 *const widget,
                              const std::string &text) :
     TextField(widget, text),
-    mPasswordChar(mSkin ? CAST_8(
+    mPasswordChar(mSkin != nullptr ? CAST_8(
                   mSkin->getOption("passwordChar", 42))
                   : CAST_8(42))
 {
@@ -40,7 +40,7 @@ void PasswordField::draw(Graphics *const graphics)
     BLOCK_START("PasswordField::draw")
     // std::string uses cow, thus cheap copy
     const std::string original = mText;
-    if (mPasswordChar)
+    if (mPasswordChar != 0)
         mText.assign(mText.length(), mPasswordChar);
     else
         mText.clear();
diff --git a/src/gui/widgets/playerbox.cpp b/src/gui/widgets/playerbox.cpp
index 47221af1f..b6217383f 100644
--- a/src/gui/widgets/playerbox.cpp
+++ b/src/gui/widgets/playerbox.cpp
@@ -76,7 +76,7 @@ PlayerBox::PlayerBox(Widget2 *const widget,
 
 PlayerBox::~PlayerBox()
 {
-    if (gui)
+    if (gui != nullptr)
         gui->removeDragged(this);
 
     Theme::unloadRect(mBackground);
@@ -90,13 +90,13 @@ void PlayerBox::init(std::string name, std::string selectedName)
     setFrameSize(2);
     addMouseListener(this);
 
-    if (theme)
+    if (theme != nullptr)
     {
         if (name.empty())
             name = "playerbox.xml";
         mSkin = theme->loadSkinRect(mBackground,
             name, "playerbox_background.xml");
-        if (mSkin)
+        if (mSkin != nullptr)
         {
             mDrawBackground = (mSkin->getOption("drawbackground") != 0);
             mOffsetX = mSkin->getOption("offsetX", -mapTileSize / 2);
@@ -120,7 +120,7 @@ void PlayerBox::init(std::string name, std::string selectedName)
 void PlayerBox::draw(Graphics *const graphics)
 {
     BLOCK_START("PlayerBox::draw")
-    if (mBeing)
+    if (mBeing != nullptr)
     {
         const int bs = mFrameSize;
         const int x = mDimension.width / 2 + bs + mOffsetX;
@@ -133,7 +133,7 @@ void PlayerBox::draw(Graphics *const graphics)
         const float alpha = settings.guiAlpha;
         for (int a = 0; a < 9; a++)
         {
-            if (mBackground.grid[a])
+            if (mBackground.grid[a] != nullptr)
                 mBackground.grid[a]->setAlpha(alpha);
         }
     }
diff --git a/src/gui/widgets/popup.cpp b/src/gui/widgets/popup.cpp
index 978e5b9ca..bf2b2bb83 100644
--- a/src/gui/widgets/popup.cpp
+++ b/src/gui/widgets/popup.cpp
@@ -60,17 +60,17 @@ Popup::Popup(const std::string &name,
     if (skin.empty())
         skin = "popup.xml";
 
-    if (theme)
+    if (theme != nullptr)
     {
         mSkin = theme->load(skin, "popup.xml");
-        if (mSkin)
+        if (mSkin != nullptr)
         {
             setPadding(mSkin->getPadding());
             setPalette(mSkin->getOption("palette"));
         }
     }
 
-    if (windowContainer)
+    if (windowContainer != nullptr)
         windowContainer->add(this);
 
     // Popups are invisible by default
@@ -83,9 +83,9 @@ Popup::~Popup()
 
     delete2(mVertexes);
 
-    if (mSkin)
+    if (mSkin != nullptr)
     {
-        if (theme)
+        if (theme != nullptr)
             theme->unload(mSkin);
         mSkin = nullptr;
     }
@@ -106,7 +106,7 @@ void Popup::draw(Graphics *const graphics)
 {
     BLOCK_START("Popup::draw")
 
-    if (mSkin)
+    if (mSkin != nullptr)
     {
         if (mRedraw)
         {
@@ -130,7 +130,7 @@ void Popup::safeDraw(Graphics *const graphics)
 {
     BLOCK_START("Popup::safeDraw")
 
-    if (mSkin)
+    if (mSkin != nullptr)
     {
         graphics->drawImageRect(0, 0,
             mDimension.width, mDimension.height,
@@ -169,7 +169,7 @@ void Popup::setContentSize(int width, int height)
 
 void Popup::setLocationRelativeTo(const Widget *const widget)
 {
-    if (!widget)
+    if (widget == nullptr)
         return;
 
     int wx, wy;
@@ -187,7 +187,7 @@ void Popup::setLocationRelativeTo(const Widget *const widget)
 
 void Popup::setMinWidth(const int width)
 {
-    if (mSkin)
+    if (mSkin != nullptr)
     {
         mMinWidth = width > mSkin->getMinWidth()
             ? width : mSkin->getMinWidth();
@@ -200,7 +200,7 @@ void Popup::setMinWidth(const int width)
 
 void Popup::setMinHeight(const int height)
 {
-    if (mSkin)
+    if (mSkin != nullptr)
     {
         mMinHeight = height > mSkin->getMinHeight() ?
             height : mSkin->getMinHeight();
@@ -248,7 +248,7 @@ void Popup::position(const int x, const int y)
 
 void Popup::mouseMoved(MouseEvent &event A_UNUSED)
 {
-    if (popupManager)
+    if (popupManager != nullptr)
     {
         popupManager->hideBeingPopup();
         popupManager->hideTextPopup();
diff --git a/src/gui/widgets/popuplist.cpp b/src/gui/widgets/popuplist.cpp
index d623fd811..0260945ce 100644
--- a/src/gui/widgets/popuplist.cpp
+++ b/src/gui/widgets/popuplist.cpp
@@ -61,7 +61,7 @@ void PopupList::postInit()
     Popup::postInit();
     add(mScrollArea);
 
-    if (gui)
+    if (gui != nullptr)
         gui->addGlobalFocusListener(this);
 
     addKeyListener(mDropDown);
@@ -71,9 +71,9 @@ void PopupList::postInit()
 
 PopupList::~PopupList()
 {
-    if (mParent)
+    if (mParent != nullptr)
         mParent->removeFocusListener(this);
-    if (gui)
+    if (gui != nullptr)
         gui->removeGlobalFocusListener(this);
     removeKeyListener(mDropDown);
 }
@@ -105,7 +105,7 @@ void PopupList::widgetResized(const Event &event)
 
 void PopupList::setSelected(const int selected)
 {
-    if (!mListBox)
+    if (mListBox == nullptr)
         return;
 
     mListBox->setSelected(selected);
@@ -113,7 +113,7 @@ void PopupList::setSelected(const int selected)
 
 int PopupList::getSelected() const
 {
-    if (!mListBox)
+    if (mListBox == nullptr)
         return -1;
 
     return mListBox->getSelected();
@@ -121,7 +121,7 @@ int PopupList::getSelected() const
 
 void PopupList::setListModel(ListModel *const model)
 {
-    if (mListBox)
+    if (mListBox != nullptr)
         mListBox->setListModel(model);
     mListModel = model;
 }
@@ -155,7 +155,7 @@ void PopupList::mouseReleased(MouseEvent& event)
     mPressedIndex = -2;
     if (event.getSource() == mScrollArea)
         return;
-    if (mDropDown)
+    if (mDropDown != nullptr)
         mDropDown->updateSelection();
     setVisible(Visible_false);
     if (mModal == Modal_true)
@@ -174,7 +174,7 @@ void PopupList::focusGained(const Event& event)
         return;
     }
 
-    if (mDropDown)
+    if (mDropDown != nullptr)
         mDropDown->updateSelection();
     setVisible(Visible_false);
     if (mModal == Modal_true)
@@ -183,6 +183,6 @@ void PopupList::focusGained(const Event& event)
 
 void PopupList::focusLost(const Event& event A_UNUSED)
 {
-    if (mDropDown)
+    if (mDropDown != nullptr)
         mDropDown->updateSelection();
 }
diff --git a/src/gui/widgets/progressbar.cpp b/src/gui/widgets/progressbar.cpp
index e84200973..7299140c6 100644
--- a/src/gui/widgets/progressbar.cpp
+++ b/src/gui/widgets/progressbar.cpp
@@ -80,10 +80,10 @@ ProgressBar::ProgressBar(const Widget2 *const widget,
     addWidgetListener(this);
     setSize(width, height);
 
-    if (theme)
+    if (theme != nullptr)
     {
         mSkin = theme->load(skin, "progressbar.xml");
-        if (mSkin)
+        if (mSkin != nullptr)
         {
             setPadding(mSkin->getPadding());
             mFillPadding = mSkin->getOption("fillPadding");
@@ -99,13 +99,13 @@ ProgressBar::ProgressBar(const Widget2 *const widget,
 
 ProgressBar::~ProgressBar()
 {
-    if (gui)
+    if (gui != nullptr)
         gui->removeDragged(this);
 
     mInstances--;
-    if (mSkin)
+    if (mSkin != nullptr)
     {
-        if (theme)
+        if (theme != nullptr)
             theme->unload(mSkin);
         mSkin = nullptr;
     }
@@ -157,7 +157,7 @@ void ProgressBar::updateAlpha()
 void ProgressBar::draw(Graphics *const graphics)
 {
     BLOCK_START("ProgressBar::draw")
-    if (!mSkin)
+    if (mSkin == nullptr)
     {
         BLOCK_END("ProgressBar::draw")
         return;
@@ -223,7 +223,7 @@ void ProgressBar::draw(Graphics *const graphics)
         }
 
         const Image *const image = mTextChunk.img;
-        if (image)
+        if (image != nullptr)
         {
             const int textX = (mDimension.width - font->getWidth(mText)) / 2;
             const int textY = (mDimension.height - font->getHeight()) / 2;
@@ -236,7 +236,7 @@ void ProgressBar::draw(Graphics *const graphics)
 void ProgressBar::safeDraw(Graphics *const graphics)
 {
     BLOCK_START("ProgressBar::safeDraw")
-    if (!mSkin)
+    if (mSkin == nullptr)
     {
         BLOCK_END("ProgressBar::safeDraw")
         return;
@@ -294,7 +294,7 @@ void ProgressBar::safeDraw(Graphics *const graphics)
         }
 
         const Image *const image = mTextChunk.img;
-        if (image)
+        if (image != nullptr)
         {
             const int textX = (mDimension.width - font->getWidth(mText)) / 2;
             const int textY = (mDimension.height - font->getHeight()) / 2;
diff --git a/src/gui/widgets/progressindicator.cpp b/src/gui/widgets/progressindicator.cpp
index 1b2b333e2..abeee678c 100644
--- a/src/gui/widgets/progressindicator.cpp
+++ b/src/gui/widgets/progressindicator.cpp
@@ -39,7 +39,7 @@ ProgressIndicator::ProgressIndicator(const Widget2 *const widget) :
     ImageSet *const images = Theme::getImageSetFromTheme(
         "progress-indicator.png", 32, 32);
 
-    if (images)
+    if (images != nullptr)
     {
         Animation *const anim = new Animation("progress indicator");
         for (ImageSet::size_type i = 0, fsz = images->size();
@@ -57,7 +57,7 @@ ProgressIndicator::ProgressIndicator(const Widget2 *const widget) :
 
 ProgressIndicator::~ProgressIndicator()
 {
-    if (gui)
+    if (gui != nullptr)
         gui->removeDragged(this);
 
     delete2(mIndicator);
@@ -66,7 +66,7 @@ ProgressIndicator::~ProgressIndicator()
 void ProgressIndicator::logic()
 {
     BLOCK_START("ProgressIndicator::logic")
-    if (mIndicator)
+    if (mIndicator != nullptr)
         mIndicator->update(10);
     BLOCK_END("ProgressIndicator::logic")
 }
@@ -74,7 +74,7 @@ void ProgressIndicator::logic()
 void ProgressIndicator::draw(Graphics *const graphics)
 {
     BLOCK_START("ProgressIndicator::draw")
-    if (mIndicator)
+    if (mIndicator != nullptr)
     {
         // Draw the indicator centered on the widget
         const int x = (mDimension.width - 32) / 2;
@@ -87,7 +87,7 @@ void ProgressIndicator::draw(Graphics *const graphics)
 void ProgressIndicator::safeDraw(Graphics *const graphics)
 {
     BLOCK_START("ProgressIndicator::draw")
-    if (mIndicator)
+    if (mIndicator != nullptr)
     {
         // Draw the indicator centered on the widget
         const int x = (mDimension.width - 32) / 2;
diff --git a/src/gui/widgets/radiobutton.cpp b/src/gui/widgets/radiobutton.cpp
index 3a781061c..71b7171ae 100644
--- a/src/gui/widgets/radiobutton.cpp
+++ b/src/gui/widgets/radiobutton.cpp
@@ -119,7 +119,7 @@ RadioButton::RadioButton(const Widget2 *const widget,
     mForegroundColor2 = getThemeColor(ThemeColorId::RADIOBUTTON_OUTLINE);
     if (instances == 0)
     {
-        if (theme)
+        if (theme != nullptr)
         {
             mSkin = theme->load("radio.xml", "");
             updateAlpha();
@@ -128,7 +128,7 @@ RadioButton::RadioButton(const Widget2 *const widget,
 
     instances++;
 
-    if (mSkin)
+    if (mSkin != nullptr)
     {
         mPadding = mSkin->getPadding();
         mImagePadding = mSkin->getOption("imagePadding");
@@ -142,19 +142,19 @@ RadioButton::RadioButton(const Widget2 *const widget,
 
 RadioButton::~RadioButton()
 {
-    if (mWindow)
+    if (mWindow != nullptr)
         mWindow->removeWidgetListener(this);
 
     setGroup(std::string());
 
-    if (gui)
+    if (gui != nullptr)
         gui->removeDragged(this);
 
     instances--;
 
     if (instances == 0)
     {
-        if (theme)
+        if (theme != nullptr)
             theme->unload(mSkin);
     }
 }
@@ -167,13 +167,13 @@ void RadioButton::updateAlpha()
     if (mAlpha != alpha)
     {
         mAlpha = alpha;
-        if (mSkin)
+        if (mSkin != nullptr)
         {
             const ImageRect &rect = mSkin->getBorder();
             for (int a = 0; a < 4; a ++)
             {
                 Image *const image = rect.grid[a];
-                if (image)
+                if (image != nullptr)
                     image->setAlpha(mAlpha);
             }
         }
@@ -182,7 +182,7 @@ void RadioButton::updateAlpha()
 
 void RadioButton::drawBox(Graphics *const graphics)
 {
-    if (!mSkin)
+    if (mSkin == nullptr)
         return;
 
     const ImageRect &rect = mSkin->getBorder();
@@ -217,7 +217,7 @@ void RadioButton::drawBox(Graphics *const graphics)
 
     updateAlpha();
 
-    if (box)
+    if (box != nullptr)
     {
         graphics->drawImage(box,
             mImagePadding,
@@ -244,7 +244,7 @@ void RadioButton::draw(Graphics *const graphics)
     }
 
     const Image *const image = mTextChunk.img;
-    if (image)
+    if (image != nullptr)
         graphics->drawImage(image, mTextX, mPadding);
 
     BLOCK_END("RadioButton::draw")
@@ -293,7 +293,7 @@ void RadioButton::setSelected(const bool selected)
              iter != iterEnd;
              ++ iter)
         {
-            if (iter->second && iter->second->isSelected())
+            if ((iter->second != nullptr) && iter->second->isSelected())
                 iter->second->setSelected(false);
         }
     }
@@ -348,7 +348,7 @@ void RadioButton::setCaption(const std::string& caption)
 
 void RadioButton::setParent(Widget *widget)
 {
-    if (mWindow)
+    if (mWindow != nullptr)
         mWindow->addWidgetListener(this);
     Widget::setParent(widget);
 }
@@ -361,7 +361,7 @@ void RadioButton::widgetHidden(const Event &event A_UNUSED)
 
 void RadioButton::setWindow(Widget *const widget)
 {
-    if (!widget && mWindow)
+    if ((widget == nullptr) && (mWindow != nullptr))
     {
         mWindow->removeWidgetListener(this);
         mWindow = nullptr;
diff --git a/src/gui/widgets/scrollarea.cpp b/src/gui/widgets/scrollarea.cpp
index 4ac8f5dce..630f7e9bf 100644
--- a/src/gui/widgets/scrollarea.cpp
+++ b/src/gui/widgets/scrollarea.cpp
@@ -148,7 +148,7 @@ ScrollArea::ScrollArea(Widget2 *const widget2,
 
 ScrollArea::~ScrollArea()
 {
-    if (gui)
+    if (gui != nullptr)
         gui->removeDragged(this);
 
     // Garbage collection
@@ -166,7 +166,7 @@ ScrollArea::~ScrollArea()
         {
             for (int f = UP; f < BUTTONS_DIR; f ++)
             {
-                if (buttons[f][i])
+                if (buttons[f][i] != nullptr)
                     buttons[f][i]->decRef();
             }
         }
@@ -201,7 +201,7 @@ void ScrollArea::init(std::string skinName)
         // +++ here probably need move background from static
         if (skinName.empty())
             skinName = "scroll_background.xml";
-        if (theme)
+        if (theme != nullptr)
         {
             theme->loadRect(background, skinName, "scroll_background.xml");
             theme->loadRect(vMarker, "scroll.xml", "");
@@ -213,14 +213,14 @@ void ScrollArea::init(std::string skinName)
         for (int i = 0; i < 2; i ++)
         {
             Skin *skin = nullptr;
-            if (theme)
+            if (theme != nullptr)
                 skin = theme->load(buttonFiles[i], "scrollbuttons.xml");
-            if (skin)
+            if (skin != nullptr)
             {
                 const ImageRect &rect = skin->getBorder();
                 for (int f = UP; f < BUTTONS_DIR; f ++)
                 {
-                    if (rect.grid[f])
+                    if (rect.grid[f] != nullptr)
                         rect.grid[f]->incRef();
                     buttons[f][i] = rect.grid[f];
                 }
@@ -236,7 +236,7 @@ void ScrollArea::init(std::string skinName)
                 for (int f = UP; f < BUTTONS_DIR; f ++)
                     buttons[f][i] = nullptr;
             }
-            if (theme)
+            if (theme != nullptr)
                 theme->unload(skin);
         }
     }
@@ -259,7 +259,7 @@ void ScrollArea::logic()
     setHorizontalScrollAmount(getHorizontalScrollAmount());
 
     Widget *const content = getContent();
-    if (content)
+    if (content != nullptr)
     {
         unsigned int frameSize = content->getFrameSize();
         content->setPosition(-mHScroll + frameSize, -mVScroll + frameSize);
@@ -301,15 +301,15 @@ void ScrollArea::updateAlpha()
         mAlpha = alpha;
         for (int a = 0; a < 9; a++)
         {
-            if (background.grid[a])
+            if (background.grid[a] != nullptr)
                 background.grid[a]->setAlpha(mAlpha);
-            if (hBackground.grid[a])
+            if (hBackground.grid[a] != nullptr)
                 hBackground.grid[a]->setAlpha(mAlpha);
-            if (vBackground.grid[a])
+            if (vBackground.grid[a] != nullptr)
                 vBackground.grid[a]->setAlpha(mAlpha);
-            if (vMarker.grid[a])
+            if (vMarker.grid[a] != nullptr)
                 vMarker.grid[a]->setAlpha(mAlpha);
-            if (vMarkerHi.grid[a])
+            if (vMarkerHi.grid[a] != nullptr)
                 vMarkerHi.grid[a]->setAlpha(mAlpha);
         }
     }
@@ -512,7 +512,7 @@ void ScrollArea::drawButton(Graphics *const graphics,
     Rect dim;
     const Image *const image = getImageByState(dim, dir);
 
-    if (image)
+    if (image != nullptr)
         graphics->drawImage(image, dim.x, dim.y);
 }
 
@@ -522,7 +522,7 @@ void ScrollArea::calcButton(Graphics *const graphics,
     Rect dim;
     const Image *const image = getImageByState(dim, dir);
 
-    if (image)
+    if (image != nullptr)
     {
         static_cast<Graphics*>(graphics)->calcTileCollection(
             mVertexes, image, dim.x, dim.y);
@@ -533,18 +533,18 @@ void ScrollArea::drawVBar(Graphics *const graphics) const
 {
     const Rect &dim = getVerticalBarDimension();
 
-    if (vBackground.grid[4])
+    if (vBackground.grid[4] != nullptr)
     {
         graphics->drawPattern(vBackground.grid[4],
             dim.x, dim.y, dim.width, dim.height);
     }
-    if (vBackground.grid[1])
+    if (vBackground.grid[1] != nullptr)
     {
         graphics->drawPattern(vBackground.grid[1],
             dim.x, dim.y,
             dim.width, vBackground.grid[1]->getHeight());
     }
-    if (vBackground.grid[7])
+    if (vBackground.grid[7] != nullptr)
     {
         graphics->drawPattern(vBackground.grid[7],
             dim.x, dim.height - vBackground.grid[7]->getHeight() + dim.y,
@@ -556,21 +556,21 @@ void ScrollArea::calcVBar(const Graphics *const graphics)
 {
     const Rect &dim = getVerticalBarDimension();
 
-    if (vBackground.grid[4])
+    if (vBackground.grid[4] != nullptr)
     {
         graphics->calcPattern(mVertexes,
             vBackground.grid[4],
             dim.x, dim.y,
             dim.width, dim.height);
     }
-    if (vBackground.grid[1])
+    if (vBackground.grid[1] != nullptr)
     {
         graphics->calcPattern(mVertexes,
             vBackground.grid[1],
             dim.x, dim.y,
             dim.width, vBackground.grid[1]->getHeight());
     }
-    if (vBackground.grid[7])
+    if (vBackground.grid[7] != nullptr)
     {
         graphics->calcPattern(mVertexes,
             vBackground.grid[7],
@@ -583,21 +583,21 @@ void ScrollArea::drawHBar(Graphics *const graphics) const
 {
     const Rect &dim = getHorizontalBarDimension();
 
-    if (hBackground.grid[4])
+    if (hBackground.grid[4] != nullptr)
     {
         graphics->drawPattern(hBackground.grid[4],
             dim.x, dim.y,
             dim.width, dim.height);
     }
 
-    if (hBackground.grid[3])
+    if (hBackground.grid[3] != nullptr)
     {
         graphics->drawPattern(hBackground.grid[3],
             dim.x, dim.y,
             hBackground.grid[3]->getWidth(), dim.height);
     }
 
-    if (hBackground.grid[5])
+    if (hBackground.grid[5] != nullptr)
     {
         graphics->drawPattern(hBackground.grid[5],
             dim.x + dim.width - hBackground.grid[5]->getWidth(),
@@ -611,7 +611,7 @@ void ScrollArea::calcHBar(const Graphics *const graphics)
 {
     const Rect &dim = getHorizontalBarDimension();
 
-    if (hBackground.grid[4])
+    if (hBackground.grid[4] != nullptr)
     {
         graphics->calcPattern(mVertexes,
             hBackground.grid[4],
@@ -619,7 +619,7 @@ void ScrollArea::calcHBar(const Graphics *const graphics)
             dim.width, dim.height);
     }
 
-    if (hBackground.grid[3])
+    if (hBackground.grid[3] != nullptr)
     {
         graphics->calcPattern(mVertexes,
             hBackground.grid[3],
@@ -627,7 +627,7 @@ void ScrollArea::calcHBar(const Graphics *const graphics)
             hBackground.grid[3]->getWidth(), dim.height);
     }
 
-    if (hBackground.grid[5])
+    if (hBackground.grid[5] != nullptr)
     {
         graphics->calcPattern(mVertexes,
             hBackground.grid[5],
@@ -736,7 +736,7 @@ void ScrollArea::widgetResized(const Event &event A_UNUSED)
     mRedraw = true;
     const unsigned int frameSize = 2 * mFrameSize;
     Widget *const content = getContent();
-    if (content)
+    if (content != nullptr)
     {
         content->setSize(mDimension.width - frameSize,
             mDimension.height - frameSize);
@@ -834,7 +834,9 @@ void ScrollArea::mousePressed(MouseEvent& event)
 
 void ScrollArea::mouseReleased(MouseEvent& event)
 {
-    if (event.getButton() == MouseButton::LEFT && mClickX && mClickY)
+    if (event.getButton() == MouseButton::LEFT &&
+        mClickX != 0 &&
+        mClickY != 0)
     {
         if (!event.isConsumed())
         {
@@ -869,7 +871,7 @@ void ScrollArea::mouseReleased(MouseEvent& event)
 
                 setHorizontalScrollAmount(s);
             }
-            else if (dy)
+            else if (dy != 0)
             {
                 int s = mVScroll + dy;
                 if (s < 0)
@@ -887,7 +889,7 @@ void ScrollArea::mouseReleased(MouseEvent& event)
             }
             mClickX = 0;
             mClickY = 0;
-            if (mMouseConsume && (dx || dy))
+            if (mMouseConsume && ((dx != 0) || (dy != 0)))
                 event.consume();
         }
     }
@@ -1007,17 +1009,17 @@ Rect ScrollArea::getVerticalMarkerDimension()
         height = mDimension.height - 2 * h2;
 
     const int maxV = getVerticalMaxScroll();
-    if (mMarkerSize && maxV)
+    if ((mMarkerSize != 0) && (maxV != 0))
     {
         pos = (mVScroll * height / maxV - mMarkerSize / 2);
         length = mMarkerSize;
     }
     else
     {
-        if (content)
+        if (content != nullptr)
         {
             const int h3 = content->getHeight();
-            if (h3)
+            if (h3 != 0)
                 length = (height * getChildrenArea().height) / h3;
             else
                 length = height;
@@ -1065,17 +1067,17 @@ Rect ScrollArea::getHorizontalMarkerDimension()
         width = mDimension.width - w2 - mScrollbarWidth;
 
     const int maxH = getHorizontalMaxScroll();
-    if (mMarkerSize && maxH)
+    if ((mMarkerSize != 0) && (maxH != 0))
     {
         pos = (mHScroll * width / maxH - mMarkerSize / 2);
         length = mMarkerSize;
     }
     else
     {
-        if (content)
+        if (content != nullptr)
         {
             const int w3 = content->getWidth();
-            if (w3)
+            if (w3 != 0)
                 length = (width * getChildrenArea().width) / w3;
             else
                 length = width;
@@ -1164,7 +1166,7 @@ Rect ScrollArea::getRightButtonDimension() const
 
 void ScrollArea::setContent(Widget* widget)
 {
-    if (widget)
+    if (widget != nullptr)
     {
         clear();
         add(widget);
@@ -1242,7 +1244,7 @@ int ScrollArea::getHorizontalMaxScroll()
     checkPolicies();
 
     const Widget *const content = getContent();
-    if (!content)
+    if (content == nullptr)
         return 0;
 
     const int value = content->getWidth() - getChildrenArea().width +
@@ -1259,7 +1261,7 @@ int ScrollArea::getVerticalMaxScroll()
     checkPolicies();
 
     const Widget *const content = getContent();
-    if (!content)
+    if (content == nullptr)
         return 0;
 
     int value;
@@ -1282,7 +1284,7 @@ void ScrollArea::setScrollbarWidth(const int width)
 void ScrollArea::showWidgetPart(Widget *const widget, const Rect &area)
 {
     const Widget *const content = getContent();
-    if (widget != content || !content)
+    if (widget != content || (content == nullptr))
         return;
 
     BasicContainer::showWidgetPart(widget, area);
@@ -1362,7 +1364,7 @@ void ScrollArea::checkPolicies()
     mVBarVisible = false;
 
     const Widget *const content = getContent();
-    if (!content)
+    if (content == nullptr)
     {
         mHBarVisible = (mHPolicy == SHOW_ALWAYS);
         mVBarVisible = (mVPolicy == SHOW_ALWAYS);
diff --git a/src/gui/widgets/selldialog.cpp b/src/gui/widgets/selldialog.cpp
index b455597a2..fc7bd9701 100644
--- a/src/gui/widgets/selldialog.cpp
+++ b/src/gui/widgets/selldialog.cpp
@@ -87,7 +87,7 @@ void SellDialog::postInit()
     setMinHeight(220);
     setDefaultSize(260, 230, ImagePosition::CENTER);
 
-    if (setupWindow)
+    if (setupWindow != nullptr)
         setupWindow->registerWindowForReset(this);
 
     // Create a ShopItems instance, that is aware of duplicate entries.
@@ -205,7 +205,7 @@ SellDialog::~SellDialog()
 void SellDialog::reset()
 {
     mShopItems->clear();
-    if (mSlider)
+    if (mSlider != nullptr)
         mSlider->setValue(0);
     mShopItemList->setSelected(-1);
     updateButtonsAndLabels();
@@ -213,7 +213,7 @@ void SellDialog::reset()
 
 void SellDialog::addItem(const Item *const item, const int price)
 {
-    if (!item)
+    if (item == nullptr)
         return;
 
     mShopItems->addItem2(item->getInvIndex(),
@@ -263,25 +263,30 @@ void SellDialog::action(const ActionEvent &event)
 
     if (eventId == "slider")
     {
-        if (mSlider)
+        if (mSlider != nullptr)
         {
             mAmountItems = CAST_S32(mSlider->getValue());
             updateButtonsAndLabels();
         }
     }
-    else if (eventId == "inc" && mSlider && mAmountItems < mMaxItems)
+    else if (eventId == "inc" &&
+             mSlider != nullptr &&
+             mAmountItems < mMaxItems)
     {
         mAmountItems++;
         mSlider->setValue(mAmountItems);
         updateButtonsAndLabels();
     }
-    else if (eventId == "dec" && mSlider && mAmountItems > 1)
+    else if (eventId == "dec" &&
+             mSlider != nullptr &&
+             mAmountItems > 1)
     {
         mAmountItems--;
         mSlider->setValue(mAmountItems);
         updateButtonsAndLabels();
     }
-    else if (eventId == "max" && mSlider)
+    else if (eventId == "max" &&
+             mSlider != nullptr)
     {
         mAmountItems = mMaxItems;
         mSlider->setValue(mAmountItems);
@@ -300,7 +305,7 @@ void SellDialog::valueChanged(const SelectionEvent &event A_UNUSED)
 {
     // Reset amount of items and update labels
     mAmountItems = 1;
-    if (mSlider)
+    if (mSlider != nullptr)
     {
         mSlider->setValue(0);
         mSlider->setScale(1, mMaxItems);
@@ -320,10 +325,10 @@ void SellDialog::updateButtonsAndLabels()
     int income = 0;
     ShopItem *item = nullptr;
 
-    if (selectedItem > -1 && mShopItems->at(selectedItem))
+    if (selectedItem > -1 && (mShopItems->at(selectedItem) != nullptr))
     {
         item = mShopItems->at(selectedItem);
-        if (item)
+        if (item != nullptr)
         {
             mMaxItems = item->getQuantity();
             if (mAmountItems > mMaxItems)
@@ -344,27 +349,27 @@ void SellDialog::updateButtonsAndLabels()
 
     // Update Buttons and slider
     mSellButton->setEnabled(mAmountItems > 0);
-    if (mDecreaseButton)
+    if (mDecreaseButton != nullptr)
         mDecreaseButton->setEnabled(mAmountItems > 1);
-    if (mIncreaseButton)
+    if (mIncreaseButton != nullptr)
         mIncreaseButton->setEnabled(mAmountItems < mMaxItems);
-    if (mSlider)
+    if (mSlider != nullptr)
         mSlider->setEnabled(mMaxItems > 1);
 
-    if (mQuantityLabel)
+    if (mQuantityLabel != nullptr)
     {
         // Update the quantity and money labels
         mQuantityLabel->setCaption(strprintf("%d / %d",
             mAmountItems, mMaxItems));
     }
-    if (mMoneyLabel)
+    if (mMoneyLabel != nullptr)
     {
         // TRANSLATORS: sell dialog label
         mMoneyLabel->setCaption(strprintf(_("Price: %s / Total: %s"),
             UnitsDb::formatCurrency(income).c_str(),
             UnitsDb::formatCurrency(mPlayerMoney + income).c_str()));
     }
-    if (item)
+    if (item != nullptr)
         item->update();
 }
 
@@ -374,7 +379,7 @@ void SellDialog::setVisible(Visible visible)
 
     if (visible == Visible_true)
     {
-        if (mShopItemList)
+        if (mShopItemList != nullptr)
             mShopItemList->requestFocus();
     }
     else
diff --git a/src/gui/widgets/serverslistbox.h b/src/gui/widgets/serverslistbox.h
index fb45dd01a..20d019f8d 100644
--- a/src/gui/widgets/serverslistbox.h
+++ b/src/gui/widgets/serverslistbox.h
@@ -47,7 +47,7 @@ class ServersListBox final : public ListBox
 
         void draw(Graphics *const graphics) override final A_NONNULL(2)
         {
-            if (!mListModel)
+            if (mListModel == nullptr)
                 return;
 
             ServersListModel *const model
diff --git a/src/gui/widgets/setupitem.cpp b/src/gui/widgets/setupitem.cpp
index 2ebd2ef19..8d6296d52 100644
--- a/src/gui/widgets/setupitem.cpp
+++ b/src/gui/widgets/setupitem.cpp
@@ -151,7 +151,7 @@ void SetupItem::save()
 
 std::string SetupItem::getActionEventId() const
 {
-    if (!mWidget)
+    if (mWidget == nullptr)
         return std::string();
 
     return mWidget->getActionEventId();
@@ -159,7 +159,7 @@ std::string SetupItem::getActionEventId() const
 
 void SetupItem::action(const ActionEvent &event)
 {
-    if (!mWidget)
+    if (mWidget == nullptr)
         return;
 
     if (event.getId() == mWidget->getActionEventId())
@@ -194,7 +194,7 @@ void SetupItem::externalUnloaded(const std::string &eventName A_UNUSED)
 
 void SetupItem::fixFirstItemSize(Widget *const widget)
 {
-    if (!widget)
+    if (widget == nullptr)
         return;
     const int maxSize = mParent->getPreferredFirstItemSize();
     if (widget->getWidth() < maxSize)
@@ -251,7 +251,7 @@ void SetupItemCheckBox::createControls()
 
 void SetupItemCheckBox::fromWidget()
 {
-    if (!mCheckBox)
+    if (mCheckBox == nullptr)
         return;
 
     if (mCheckBox->isSelected())
@@ -262,7 +262,7 @@ void SetupItemCheckBox::fromWidget()
 
 void SetupItemCheckBox::toWidget()
 {
-    if (!mCheckBox)
+    if (mCheckBox == nullptr)
         return;
 
     mCheckBox->setSelected(mValue != "0");
@@ -390,7 +390,7 @@ void SetupItemTextField::createControls()
 
 void SetupItemTextField::fromWidget()
 {
-    if (!mTextField)
+    if (mTextField == nullptr)
         return;
 
     mValue = mTextField->getText();
@@ -398,7 +398,7 @@ void SetupItemTextField::fromWidget()
 
 void SetupItemTextField::toWidget()
 {
-    if (!mTextField)
+    if (mTextField == nullptr)
         return;
 
     mTextField->setText(mValue);
@@ -406,11 +406,11 @@ void SetupItemTextField::toWidget()
 
 void SetupItemTextField::action(const ActionEvent &event)
 {
-    if (!mTextField)
+    if (mTextField == nullptr)
         return;
 
     const std::string &eventId = event.getId();
-    if (mWidget && eventId == mWidget->getActionEventId())
+    if ((mWidget != nullptr) && eventId == mWidget->getActionEventId())
     {
         fromWidget();
     }
@@ -528,7 +528,7 @@ void SetupItemIntTextField::createControls()
 
 void SetupItemIntTextField::fromWidget()
 {
-    if (!mTextField)
+    if (mTextField == nullptr)
         return;
 
     mValue = mTextField->getText();
@@ -536,7 +536,7 @@ void SetupItemIntTextField::fromWidget()
 
 void SetupItemIntTextField::toWidget()
 {
-    if (!mTextField)
+    if (mTextField == nullptr)
         return;
 
     mTextField->setText(mValue);
@@ -544,11 +544,11 @@ void SetupItemIntTextField::toWidget()
 
 void SetupItemIntTextField::action(const ActionEvent &event)
 {
-    if (!mTextField)
+    if (mTextField == nullptr)
         return;
 
     const std::string &eventId = event.getId();
-    if (mWidget && eventId == mWidget->getActionEventId())
+    if ((mWidget != nullptr) && eventId == mWidget->getActionEventId())
     {
         fromWidget();
     }
@@ -708,7 +708,7 @@ void SetupItemDropDown::createControls()
 
 void SetupItemDropDown::fromWidget()
 {
-    if (!mDropDown)
+    if (mDropDown == nullptr)
         return;
 
     mValue = toString(mDropDown->getSelected());
@@ -716,7 +716,7 @@ void SetupItemDropDown::fromWidget()
 
 void SetupItemDropDown::toWidget()
 {
-    if (!mDropDown)
+    if (mDropDown == nullptr)
         return;
 
     mDropDown->setSelected(atoi(mValue.c_str()));
@@ -810,7 +810,7 @@ void SetupItemSlider::createControls()
 
 void SetupItemSlider::fromWidget()
 {
-    if (!mSlider)
+    if (mSlider == nullptr)
         return;
 
     mValue = toString(mSlider->getValue());
@@ -818,7 +818,7 @@ void SetupItemSlider::fromWidget()
 
 void SetupItemSlider::toWidget()
 {
-    if (!mSlider)
+    if (mSlider == nullptr)
         return;
 
     mSlider->setValue(atof(mValue.c_str()));
@@ -945,7 +945,7 @@ void SetupItemSlider2::createControls()
 
 int SetupItemSlider2::getMaxWidth()
 {
-    if (!mValues || !gui)
+    if ((mValues == nullptr) || (gui == nullptr))
         return 1;
 
     int maxWidth = 0;
@@ -966,7 +966,7 @@ int SetupItemSlider2::getMaxWidth()
 
 void SetupItemSlider2::fromWidget()
 {
-    if (!mSlider)
+    if (mSlider == nullptr)
         return;
 
     int val = roundDouble(mSlider->getValue());
@@ -977,7 +977,7 @@ void SetupItemSlider2::fromWidget()
 
 void SetupItemSlider2::toWidget()
 {
-    if (!mSlider)
+    if (mSlider == nullptr)
         return;
 
     int val = roundDouble(atof(mValue.c_str()));
@@ -1107,7 +1107,7 @@ void SetupItemSliderList::createControls()
 
 void SetupItemSliderList::fromWidget()
 {
-    if (!mSlider)
+    if (mSlider == nullptr)
         return;
 
     mValue = mSlider->getSelectedString();
@@ -1115,7 +1115,7 @@ void SetupItemSliderList::fromWidget()
 
 void SetupItemSliderList::toWidget()
 {
-    if (!mSlider)
+    if (mSlider == nullptr)
         return;
 
     mSlider->setSelectedString(mValue);
@@ -1157,7 +1157,7 @@ void SetupItemSound::addMoreControls()
 {
     mButton = new Button(this, BUTTON_PLAY, 16, 16,
         mEventName + "_PLAY", this);
-    if (mHorizont)
+    if (mHorizont != nullptr)
         mHorizont->add(mButton);
 }
 
@@ -1165,7 +1165,7 @@ void SetupItemSound::action(const ActionEvent &event)
 {
     if (event.getId() == mEventName + "_PLAY")
     {
-        if (mSlider && mSlider->getSelected())
+        if ((mSlider != nullptr) && (mSlider->getSelected() != 0))
         {
             soundManager.playGuiSfx(pathJoin(branding.getStringValue(
                 "systemsounds"),
@@ -1202,7 +1202,7 @@ void SetupItemSliderInt::addMoreControls()
 
 void SetupItemSliderInt::fromWidget()
 {
-    if (!mSlider)
+    if (mSlider == nullptr)
         return;
 
     mValue = toString(mSlider->getSelected() + mMin);
@@ -1210,7 +1210,7 @@ void SetupItemSliderInt::fromWidget()
 
 void SetupItemSliderInt::toWidget()
 {
-    if (!mSlider)
+    if (mSlider == nullptr)
         return;
 
     mSlider->setSelected(atoi(mValue.c_str()) - mMin);
diff --git a/src/gui/widgets/setuptouchitem.cpp b/src/gui/widgets/setuptouchitem.cpp
index 8dbaf550f..122853c7e 100644
--- a/src/gui/widgets/setuptouchitem.cpp
+++ b/src/gui/widgets/setuptouchitem.cpp
@@ -87,7 +87,7 @@ SetupActionDropDown::~SetupActionDropDown()
 
 void SetupActionDropDown::createControls()
 {
-    if (!mModel)
+    if (mModel == nullptr)
         return;
 
     load();
@@ -115,7 +115,7 @@ void SetupActionDropDown::createControls()
 
 void SetupActionDropDown::fromWidget()
 {
-    if (!mDropDown || !mModel)
+    if ((mDropDown == nullptr) || (mModel == nullptr))
         return;
 
     mValue = toString(CAST_S32(mModel->getActionFromSelection(
@@ -124,7 +124,7 @@ void SetupActionDropDown::fromWidget()
 
 void SetupActionDropDown::toWidget()
 {
-    if (!mDropDown || !mModel)
+    if ((mDropDown == nullptr) || (mModel == nullptr))
         return;
 
     mDropDown->setSelected(mModel->getSelectionFromAction(
diff --git a/src/gui/widgets/shoplistbox.cpp b/src/gui/widgets/shoplistbox.cpp
index f1e5ed32f..3df46b854 100644
--- a/src/gui/widgets/shoplistbox.cpp
+++ b/src/gui/widgets/shoplistbox.cpp
@@ -91,7 +91,7 @@ void ShopListBox::setPlayersMoney(const int money)
 void ShopListBox::draw(Graphics *const graphics)
 {
     BLOCK_START("ShopListBox::draw")
-    if (!mListModel || !mShopItems)
+    if ((mListModel == nullptr) || (mShopItems == nullptr))
     {
         BLOCK_END("ShopListBox::draw")
         return;
@@ -116,7 +116,7 @@ void ShopListBox::draw(Graphics *const graphics)
         Color* backgroundColor = &mBackgroundColor;
 
         ShopItem *const item = mShopItems->at(i);
-        if (item &&
+        if ((item != nullptr) &&
             (item->getDisabled() ||
             (mPlayerMoney < item->getPrice() && mPriceCheck) ||
             (mProtectItems && PlayerInfo::isItemProtected(item->getId()))))
@@ -155,10 +155,10 @@ void ShopListBox::draw(Graphics *const graphics)
                 width, mRowHeight));
         }
 
-        if (mShopItems && item)
+        if ((mShopItems != nullptr) && (item != nullptr))
         {
             Image *const icon = item->getImage();
-            if (icon)
+            if (icon != nullptr)
             {
                 icon->setAlpha(1.0F);
                 graphics->drawImage(icon, mPadding, y + mPadding);
@@ -194,7 +194,7 @@ void ShopListBox::safeDraw(Graphics *const graphics)
 void ShopListBox::adjustSize()
 {
     BLOCK_START("ShopListBox::adjustSize")
-    if (mListModel)
+    if (mListModel != nullptr)
     {
         setHeight(mRowHeight * mListModel->getNumberOfElements()
             + 2 * mPadding);
@@ -209,10 +209,10 @@ void ShopListBox::setPriceCheck(const bool check)
 
 void ShopListBox::mouseMoved(MouseEvent &event)
 {
-    if (!itemPopup || !mRowHeight)
+    if ((itemPopup == nullptr) || (mRowHeight == 0u))
         return;
 
-    if (!mShopItems)
+    if (mShopItems == nullptr)
     {
         itemPopup->hide();
         return;
@@ -227,7 +227,7 @@ void ShopListBox::mouseMoved(MouseEvent &event)
     else
     {
         const Item *const item = mShopItems->at(index);
-        if (item)
+        if (item != nullptr)
         {
             itemPopup->setItem(item, false);
             itemPopup->position(viewport->mMouseX, viewport->mMouseY);
@@ -265,7 +265,7 @@ void ShopListBox::mouseReleased(MouseEvent& event)
             inventory = PlayerInfo::getCartInventory();
         else
             return;
-        if (!inventory)
+        if (inventory == nullptr)
             return;
         Item *const item = inventory->getItem(dragDrop.getTag());
         if (mType == ShopListBoxType::BuyShop)
@@ -292,7 +292,7 @@ void ShopListBox::mouseReleased(MouseEvent& event)
             return;
 
         Item *const item = mShopItems->at(mSelected);
-        if (popupMenu && viewport)
+        if ((popupMenu != nullptr) && (viewport != nullptr))
         {
             popupMenu->showItemPopup(viewport->mMouseX,
             viewport->mMouseY,
@@ -303,7 +303,7 @@ void ShopListBox::mouseReleased(MouseEvent& event)
 
 void ShopListBox::mouseExited(MouseEvent& event A_UNUSED)
 {
-    if (!itemPopup)
+    if (itemPopup == nullptr)
         return;
 
     itemPopup->hide();
diff --git a/src/gui/widgets/shortcutcontainer.cpp b/src/gui/widgets/shortcutcontainer.cpp
index e9611b69f..a2b90514d 100644
--- a/src/gui/widgets/shortcutcontainer.cpp
+++ b/src/gui/widgets/shortcutcontainer.cpp
@@ -61,7 +61,7 @@ ShortcutContainer::ShortcutContainer(Widget2 *const widget) :
     mBackgroundImg = Theme::getImageFromThemeXml(
         "item_shortcut_background.xml", "background.xml");
 
-    if (mBackgroundImg)
+    if (mBackgroundImg != nullptr)
     {
         mBackgroundImg->setAlpha(settings.guiAlpha);
         mBoxHeight = mBackgroundImg->getHeight();
@@ -76,13 +76,13 @@ ShortcutContainer::ShortcutContainer(Widget2 *const widget) :
 
 ShortcutContainer::~ShortcutContainer()
 {
-    if (mBackgroundImg)
+    if (mBackgroundImg != nullptr)
     {
         mBackgroundImg->decRef();
         mBackgroundImg = nullptr;
     }
 
-    if (gui)
+    if (gui != nullptr)
         gui->removeDragged(this);
 
     delete2(mVertexes);
@@ -123,7 +123,7 @@ int ShortcutContainer::getIndexFromGrid(const int pointX,
 
 void ShortcutContainer::drawBackground(Graphics *const g)
 {
-    if (mBackgroundImg)
+    if (mBackgroundImg != nullptr)
     {
         if (mRedraw)
         {
@@ -143,7 +143,7 @@ void ShortcutContainer::drawBackground(Graphics *const g)
 
 void ShortcutContainer::safeDrawBackground(Graphics *const g)
 {
-    if (mBackgroundImg)
+    if (mBackgroundImg != nullptr)
     {
         for (unsigned i = 0; i < mMaxItems; i ++)
         {
diff --git a/src/gui/widgets/skilllistbox.h b/src/gui/widgets/skilllistbox.h
index 2bada3a13..93c702381 100644
--- a/src/gui/widgets/skilllistbox.h
+++ b/src/gui/widgets/skilllistbox.h
@@ -58,8 +58,9 @@ class SkillListBox final : public ListBox
             mTextColor(getThemeColor(ThemeColorId::TEXT)),
             mTextColor2(getThemeColor(ThemeColorId::TEXT_OUTLINE)),
             mCooldownColor(getThemeColor(ThemeColorId::SKILL_COOLDOWN)),
-            mTextPadding(mSkin ? mSkin->getOption("textPadding", 34) : 34),
-            mSpacing(mSkin ? mSkin->getOption("spacing", 0) : 0),
+            mTextPadding(mSkin != nullptr ?
+                mSkin->getOption("textPadding", 34) : 34),
+            mSpacing(mSkin != nullptr ? mSkin->getOption("spacing", 0) : 0),
             mSkillClicked(false)
         {
             mRowHeight = getFont()->getHeight() * 2 + mSpacing + 2 * mPadding;
@@ -79,7 +80,7 @@ class SkillListBox final : public ListBox
         SkillInfo *getSelectedInfo() const
         {
             const int selected = getSelected();
-            if (!mListModel || selected < 0
+            if ((mListModel == nullptr) || selected < 0
                 || selected > mListModel->getNumberOfElements())
             {
                 return nullptr;
@@ -90,7 +91,7 @@ class SkillListBox final : public ListBox
 
         void draw(Graphics *const graphics) override final A_NONNULL(2)
         {
-            if (!mListModel)
+            if (mListModel == nullptr)
                 return;
 
             SkillModel *const model = static_cast<SkillModel*>(mListModel);
@@ -121,9 +122,9 @@ class SkillListBox final : public ListBox
                  ++i, y += getRowHeight())
             {
                 SkillInfo *const e = model->getSkillAt(i);
-                if (e)
+                if (e != nullptr)
                 {
-                    if (e->cooldown)
+                    if (e->cooldown != 0)
                     {
                         graphics->fillRectangle(Rect(mPadding, y,
                             usableWidth * 100 / e->cooldown, 10));
@@ -136,7 +137,7 @@ class SkillListBox final : public ListBox
                  ++i, y += getRowHeight())
             {
                 SkillInfo *const e = model->getSkillAt(i);
-                if (e)
+                if (e != nullptr)
                 {
                     const SkillData *const data = e->data;
                     const std::string &description = data->description;
@@ -183,10 +184,10 @@ class SkillListBox final : public ListBox
         const SkillInfo *getSkillByEvent(const MouseEvent &event) const
         {
             const int y = (event.getY() + mPadding) / getRowHeight();
-            if (!mModel || y >= mModel->getNumberOfElements())
+            if (mModel == nullptr || y >= mModel->getNumberOfElements())
                 return nullptr;
             const SkillInfo *const skill = mModel->getSkillAt(y);
-            if (!skill)
+            if (skill == nullptr)
                 return nullptr;
             return skill;
         }
@@ -194,11 +195,11 @@ class SkillListBox final : public ListBox
         void mouseMoved(MouseEvent &event) override final
         {
             ListBox::mouseMoved(event);
-            if (!viewport || !dragDrop.isEmpty())
+            if ((viewport == nullptr) || !dragDrop.isEmpty())
                 return;
 
             const SkillInfo *const skill = getSkillByEvent(event);
-            if (!skill)
+            if (skill == nullptr)
                 return;
             skillPopup->show(skill,
                 skill->customSelectedLevel,
@@ -219,7 +220,7 @@ class SkillListBox final : public ListBox
                     {
                         mSkillClicked = false;
                         const SkillInfo *const skill = getSkillByEvent(event);
-                        if (!skill)
+                        if (skill == nullptr)
                             return;
                         dragDrop.dragSkill(skill, DragDropSource::Skills);
                         dragDrop.setItem(skill->id + SKILL_MIN_ID);
@@ -245,13 +246,13 @@ class SkillListBox final : public ListBox
                 button == MouseButton::RIGHT)
             {
                 const SkillInfo *const skill = getSkillByEvent(event);
-                if (!skill)
+                if (skill == nullptr)
                     return;
                 event.consume();
                 mSkillClicked = true;
                 SkillModel *const model = static_cast<SkillModel*>(
                     mListModel);
-                if (model &&
+                if ((model != nullptr) &&
                     mSelected >= 0 &&
                     model->getSkillAt(mSelected) == skill)
                 {
diff --git a/src/gui/widgets/skillrectanglelistbox.h b/src/gui/widgets/skillrectanglelistbox.h
index dc5c664d8..88698de1c 100644
--- a/src/gui/widgets/skillrectanglelistbox.h
+++ b/src/gui/widgets/skillrectanglelistbox.h
@@ -73,13 +73,13 @@ class SkillRectangleListBox final : public Widget,
             mTextYOffset(44),
             mSkillClicked(false)
         {
-            if (theme)
+            if (theme != nullptr)
             {
                 mSkin = theme->load("skillrectanglelistbox.xml",
                     "listbox.xml");
             }
 
-            if (mSkin)
+            if (mSkin != nullptr)
             {
                 mPadding = mSkin->getPadding();
                 mBoxWidth = mSkin->getOption("boxWidth", 80);
@@ -103,7 +103,7 @@ class SkillRectangleListBox final : public Widget,
                  ++i)
             {
                 SkillInfo *const e = model->getSkillAt(i);
-                if (e)
+                if (e != nullptr)
                 {
                     if (e->x > maxX)
                         maxX = e->x;
@@ -127,7 +127,7 @@ class SkillRectangleListBox final : public Widget,
 
         SkillInfo *getSelectedInfo() const
         {
-            if (!mModel)
+            if (mModel == nullptr)
                 return nullptr;
             const int selected = mSelected;
             if (selected < 0 ||
@@ -141,7 +141,7 @@ class SkillRectangleListBox final : public Widget,
 
         void draw(Graphics *const graphics) override final A_NONNULL(2)
         {
-            if (!mModel)
+            if (mModel == nullptr)
                 return;
 
             SkillModel *const model = mModel;
@@ -155,7 +155,7 @@ class SkillRectangleListBox final : public Widget,
             if (mSelected >= 0)
             {
                 SkillInfo *const e = model->getSkillAt(mSelected);
-                if (e)
+                if (e != nullptr)
                 {
                     const int x = e->x * mBoxWidth + mPadding;
                     const int y = e->y * mBoxHeight + mPadding;
@@ -180,7 +180,7 @@ class SkillRectangleListBox final : public Widget,
                  ++i)
             {
                 SkillInfo *const e = model->getSkillAt(i);
-                if (e)
+                if (e != nullptr)
                 {
                     if (e->x > maxX)
                         maxX = e->x;
@@ -235,7 +235,7 @@ class SkillRectangleListBox final : public Widget,
 
         const SkillInfo *getSkillByEvent(const MouseEvent &event) const
         {
-            if (!mModel)
+            if (mModel == nullptr)
                 return nullptr;
             const int posX = (event.getX() - mPadding) / mBoxWidth;
             const int posY = (event.getY() - mPadding) / mBoxHeight;
@@ -244,7 +244,7 @@ class SkillRectangleListBox final : public Widget,
                  ++i)
             {
                 SkillInfo *const e = mModel->getSkillAt(i);
-                if (e)
+                if (e != nullptr)
                 {
                     if (posX == e->x && posY == e->y)
                         return e;
@@ -255,7 +255,7 @@ class SkillRectangleListBox final : public Widget,
 
         int getSelectionByEvent(const MouseEvent &event) const
         {
-            if (!mModel)
+            if (mModel == nullptr)
                 return -1;
             const int posX = (event.getX() - mPadding) / mBoxWidth;
             const int posY = (event.getY() - mPadding) / mBoxHeight;
@@ -264,7 +264,7 @@ class SkillRectangleListBox final : public Widget,
                  ++i)
             {
                 SkillInfo *const e = mModel->getSkillAt(i);
-                if (e)
+                if (e != nullptr)
                 {
                     if (posX == e->x && posY == e->y)
                         return i;
@@ -275,11 +275,11 @@ class SkillRectangleListBox final : public Widget,
 
         void mouseMoved(MouseEvent &event) override final
         {
-            if (!viewport || !dragDrop.isEmpty())
+            if ((viewport == nullptr) || !dragDrop.isEmpty())
                 return;
 
             const SkillInfo *const skill = getSkillByEvent(event);
-            if (!skill)
+            if (skill == nullptr)
                 return;
             skillPopup->show(skill,
                 skill->customSelectedLevel,
@@ -302,7 +302,7 @@ class SkillRectangleListBox final : public Widget,
                 {
                     mSkillClicked = false;
                     const SkillInfo *const skill = getSkillByEvent(event);
-                    if (!skill)
+                    if (skill == nullptr)
                         return;
                     dragDrop.dragSkill(skill, DragDropSource::Skills);
                     dragDrop.setItem(skill->id + SKILL_MIN_ID);
@@ -321,12 +321,12 @@ class SkillRectangleListBox final : public Widget,
                 button == MouseButton::RIGHT)
             {
                 const SkillInfo *const skill = getSkillByEvent(event);
-                if (!skill)
+                if (skill == nullptr)
                     return;
                 event.consume();
                 mSkillClicked = true;
                 SkillModel *const model = mModel;
-                if (model &&
+                if ((model != nullptr) &&
                     mSelected >= 0 &&
                     model->getSkillAt(mSelected) == skill)
                 {
@@ -381,7 +381,7 @@ class SkillRectangleListBox final : public Widget,
 
         void setSelected(const int selected)
         {
-            if (!mModel)
+            if (mModel == nullptr)
             {
                 mSelected = -1;
             }
diff --git a/src/gui/widgets/slider.cpp b/src/gui/widgets/slider.cpp
index 2c5ac7c20..0d25ad2c5 100644
--- a/src/gui/widgets/slider.cpp
+++ b/src/gui/widgets/slider.cpp
@@ -132,7 +132,7 @@ Slider::Slider(Widget2 *const widget,
 
 Slider::~Slider()
 {
-    if (gui)
+    if (gui != nullptr)
         gui->removeDragged(this);
 
     delete2(mVertexes);
@@ -158,7 +158,7 @@ void Slider::init()
     // Load resources
     if (mInstances == 0)
     {
-        if (theme)
+        if (theme != nullptr)
         {
             for (int mode = 0; mode < 2; mode ++)
                 theme->loadRect(buttons[mode], data[mode], "slider.xml", 0, 8);
@@ -168,7 +168,7 @@ void Slider::init()
 
     mInstances++;
 
-    if (buttons[0].grid[SliderGrid::HGRIP])
+    if (buttons[0].grid[SliderGrid::HGRIP] != nullptr)
         setMarkerLength(buttons[0].grid[SliderGrid::HGRIP]->getWidth());
 }
 
@@ -184,7 +184,7 @@ void Slider::updateAlpha()
         {
             for (int d = 0; d < SliderGrid::SLIDER_MAX; d ++)
             {
-                if (buttons[f].grid[d])
+                if (buttons[f].grid[d] != nullptr)
                     buttons[f].grid[d]->setAlpha(mAlpha);
             }
         }
@@ -194,9 +194,9 @@ void Slider::updateAlpha()
 void Slider::draw(Graphics *const graphics)
 {
     BLOCK_START("Slider::draw")
-    if (!buttons[0].grid[SliderGrid::HSTART] ||
-        !buttons[1].grid[SliderGrid::HSTART] ||
-        !buttons[0].grid[SliderGrid::HEND])
+    if ((buttons[0].grid[SliderGrid::HSTART] == nullptr) ||
+        (buttons[1].grid[SliderGrid::HSTART] == nullptr) ||
+        (buttons[0].grid[SliderGrid::HEND] == nullptr))
     {
         BLOCK_END("Slider::draw")
         return;
@@ -225,7 +225,7 @@ void Slider::draw(Graphics *const graphics)
             w -= width + buttons[0].grid[SliderGrid::HEND]->getWidth();
             x += width;
 
-            if (buttons[0].grid[SliderGrid::HMID])
+            if (buttons[0].grid[SliderGrid::HMID] != nullptr)
             {
                 const Image *const hMid = buttons[0].grid[SliderGrid::HMID];
                 graphics->calcPattern(mVertexes,
@@ -240,7 +240,7 @@ void Slider::draw(Graphics *const graphics)
                 x, y);
 
             const Image *const img = buttons[0].grid[SliderGrid::HGRIP];
-            if (img)
+            if (img != nullptr)
             {
                 graphics->calcTileCollection(mVertexes,
                     img,
@@ -256,11 +256,11 @@ void Slider::draw(Graphics *const graphics)
 
             const int width = buttons[1].grid[SliderGrid::HSTART]->getWidth();
             w -= width;
-            if (buttons[1].grid[SliderGrid::HEND])
+            if (buttons[1].grid[SliderGrid::HEND] != nullptr)
                 w -= buttons[1].grid[SliderGrid::HEND]->getWidth();
             x += width;
 
-            if (buttons[1].grid[SliderGrid::HMID])
+            if (buttons[1].grid[SliderGrid::HMID] != nullptr)
             {
                 const Image *const hMid = buttons[1].grid[SliderGrid::HMID];
                 graphics->calcPattern(mVertexes,
@@ -270,14 +270,14 @@ void Slider::draw(Graphics *const graphics)
             }
 
             x += w;
-            if (buttons[1].grid[SliderGrid::HEND])
+            if (buttons[1].grid[SliderGrid::HEND] != nullptr)
             {
                 graphics->calcTileCollection(mVertexes,
                     buttons[1].grid[SliderGrid::HEND], x, y);
             }
 
             const Image *const img = buttons[1].grid[SliderGrid::HGRIP];
-            if (img)
+            if (img != nullptr)
             {
                 graphics->calcTileCollection(mVertexes,
                     img,
@@ -295,9 +295,9 @@ void Slider::draw(Graphics *const graphics)
 void Slider::safeDraw(Graphics *const graphics)
 {
     BLOCK_START("Slider::draw")
-    if (!buttons[0].grid[SliderGrid::HSTART] ||
-        !buttons[1].grid[SliderGrid::HSTART] ||
-        !buttons[0].grid[SliderGrid::HEND])
+    if ((buttons[0].grid[SliderGrid::HSTART] == nullptr) ||
+        (buttons[1].grid[SliderGrid::HSTART] == nullptr) ||
+        (buttons[0].grid[SliderGrid::HEND] == nullptr))
     {
         BLOCK_END("Slider::draw")
         return;
@@ -319,7 +319,7 @@ void Slider::safeDraw(Graphics *const graphics)
         w -= width + buttons[0].grid[SliderGrid::HEND]->getWidth();
         x += width;
 
-        if (buttons[0].grid[SliderGrid::HMID])
+        if (buttons[0].grid[SliderGrid::HMID] != nullptr)
         {
             const Image *const hMid = buttons[0].grid[SliderGrid::HMID];
             graphics->drawPattern(hMid, x, y, w, hMid->getHeight());
@@ -329,7 +329,7 @@ void Slider::safeDraw(Graphics *const graphics)
         graphics->drawImage(buttons[0].grid[SliderGrid::HEND], x, y);
 
         const Image *const img = buttons[0].grid[SliderGrid::HGRIP];
-        if (img)
+        if (img != nullptr)
         {
             graphics->drawImage(img, getMarkerPosition(),
                 (mDimension.height - img->getHeight()) / 2);
@@ -341,22 +341,22 @@ void Slider::safeDraw(Graphics *const graphics)
 
         const int width = buttons[1].grid[SliderGrid::HSTART]->getWidth();
         w -= width;
-        if (buttons[1].grid[SliderGrid::HEND])
+        if (buttons[1].grid[SliderGrid::HEND] != nullptr)
             w -= buttons[1].grid[SliderGrid::HEND]->getWidth();
         x += width;
 
-        if (buttons[1].grid[SliderGrid::HMID])
+        if (buttons[1].grid[SliderGrid::HMID] != nullptr)
         {
             const Image *const hMid = buttons[1].grid[SliderGrid::HMID];
             graphics->drawPattern(hMid, x, y, w, hMid->getHeight());
         }
 
         x += w;
-        if (buttons[1].grid[SliderGrid::HEND])
+        if (buttons[1].grid[SliderGrid::HEND] != nullptr)
             graphics->drawImage(buttons[1].grid[SliderGrid::HEND], x, y);
 
         const Image *const img = buttons[1].grid[SliderGrid::HGRIP];
-        if (img)
+        if (img != nullptr)
         {
             graphics->drawImage(img, getMarkerPosition(),
                 (mDimension.height - img->getHeight()) / 2);
diff --git a/src/gui/widgets/sliderlist.cpp b/src/gui/widgets/sliderlist.cpp
index 3b42b43e5..edce0cf02 100644
--- a/src/gui/widgets/sliderlist.cpp
+++ b/src/gui/widgets/sliderlist.cpp
@@ -68,7 +68,7 @@ void SliderList::postInit2(ActionListener *const listener,
     if (!eventId.empty())
         setActionEventId(eventId);
 
-    if (listener)
+    if (listener != nullptr)
         addActionListener(listener);
 
     updateLabel();
@@ -135,7 +135,7 @@ void SliderList::safeDraw(Graphics *const graphics)
 
 void SliderList::updateLabel()
 {
-    if (!mListModel || mSelectedIndex < 0
+    if ((mListModel == nullptr) || mSelectedIndex < 0
         || mSelectedIndex >= mListModel->getNumberOfElements())
     {
         return;
@@ -157,7 +157,7 @@ void SliderList::updateLabel()
 
 void SliderList::action(const ActionEvent &event)
 {
-    if (!mListModel)
+    if (mListModel == nullptr)
         return;
 
     const std::string &eventId = event.getId();
@@ -179,7 +179,7 @@ void SliderList::action(const ActionEvent &event)
 
 void SliderList::setSelectedString(const std::string &str)
 {
-    if (!mListModel)
+    if (mListModel == nullptr)
         return;
 
     for (int f = 0; f < mListModel->getNumberOfElements(); f ++)
@@ -194,7 +194,7 @@ void SliderList::setSelectedString(const std::string &str)
 
 std::string SliderList::getSelectedString() const
 {
-    if (!mListModel)
+    if (mListModel == nullptr)
         return std::string();
 
     return mListModel->getElementAt(mSelectedIndex);
@@ -202,7 +202,7 @@ std::string SliderList::getSelectedString() const
 
 void SliderList::setSelected(const int idx)
 {
-    if (!mListModel)
+    if (mListModel == nullptr)
         return;
 
     mSelectedIndex = idx;
@@ -222,7 +222,7 @@ void SliderList::adjustSize()
 
 int SliderList::getMaxLabelWidth() const
 {
-    if (!mListModel || !gui)
+    if ((mListModel == nullptr) || (gui == nullptr))
         return 1;
 
     int maxWidth = 0;
diff --git a/src/gui/widgets/spellshortcutcontainer.cpp b/src/gui/widgets/spellshortcutcontainer.cpp
index 2b365c52d..6cc4def09 100644
--- a/src/gui/widgets/spellshortcutcontainer.cpp
+++ b/src/gui/widgets/spellshortcutcontainer.cpp
@@ -46,7 +46,7 @@ SpellShortcutContainer::SpellShortcutContainer(Widget2 *const widget,
     mNumber(number),
     mSpellClicked(false)
 {
-    if (spellShortcut)
+    if (spellShortcut != nullptr)
         mMaxItems = spellShortcut->getSpellsCount();
     else
         mMaxItems = 0;
@@ -65,14 +65,14 @@ void SpellShortcutContainer::setWidget2(const Widget2 *const widget)
 
 void SpellShortcutContainer::draw(Graphics *const graphics)
 {
-    if (!spellShortcut)
+    if (spellShortcut == nullptr)
         return;
 
     BLOCK_START("SpellShortcutContainer::draw")
     if (settings.guiAlpha != mAlpha)
     {
         mAlpha = settings.guiAlpha;
-        if (mBackgroundImg)
+        if (mBackgroundImg != nullptr)
             mBackgroundImg->setAlpha(mAlpha);
     }
 
@@ -95,17 +95,17 @@ void SpellShortcutContainer::draw(Graphics *const graphics)
                 mBoxWidth - 1, mBoxHeight - 1));
         }
 
-        if (!spellManager)
+        if (spellManager == nullptr)
             continue;
 
         const TextCommand *const spell = spellManager->getSpell(itemId);
-        if (spell)
+        if (spell != nullptr)
         {
             if (!spell->isEmpty())
             {
                 Image *const image = spell->getImage();
 
-                if (image)
+                if (image != nullptr)
                 {
                     image->setAlpha(1.0F);
                     graphics->drawImage(image, itemX, itemY);
@@ -125,14 +125,14 @@ void SpellShortcutContainer::draw(Graphics *const graphics)
 
 void SpellShortcutContainer::safeDraw(Graphics *const graphics)
 {
-    if (!spellShortcut)
+    if (spellShortcut == nullptr)
         return;
 
     BLOCK_START("SpellShortcutContainer::draw")
     if (settings.guiAlpha != mAlpha)
     {
         mAlpha = settings.guiAlpha;
-        if (mBackgroundImg)
+        if (mBackgroundImg != nullptr)
             mBackgroundImg->setAlpha(mAlpha);
     }
 
@@ -155,17 +155,17 @@ void SpellShortcutContainer::safeDraw(Graphics *const graphics)
                 mBoxWidth - 1, mBoxHeight - 1));
         }
 
-        if (!spellManager)
+        if (spellManager == nullptr)
             continue;
 
         const TextCommand *const spell = spellManager->getSpell(itemId);
-        if (spell)
+        if (spell != nullptr)
         {
             if (!spell->isEmpty())
             {
                 Image *const image = spell->getImage();
 
-                if (image)
+                if (image != nullptr)
                 {
                     image->setAlpha(1.0F);
                     graphics->drawImage(image, itemX, itemY);
@@ -200,7 +200,7 @@ void SpellShortcutContainer::mouseDragged(MouseEvent &event)
                 return;
             event.consume();
             TextCommand *const spell = spellManager->getSpell(itemId);
-            if (spell)
+            if (spell != nullptr)
             {
                 dragDrop.dragCommand(spell, DragDropSource::Spells, index);
                 dragDrop.setItem(spell->getId() + SPELL_MIN_ID);
@@ -234,7 +234,7 @@ void SpellShortcutContainer::mousePressed(MouseEvent &event)
     }
     else if (eventButton == MouseButton::MIDDLE)
     {
-        if (!spellShortcut || !spellManager)
+        if ((spellShortcut == nullptr) || (spellManager == nullptr))
             return;
 
         event.consume();
@@ -245,7 +245,7 @@ void SpellShortcutContainer::mousePressed(MouseEvent &event)
 
 void SpellShortcutContainer::mouseReleased(MouseEvent &event)
 {
-    if (!spellShortcut || !spellManager)
+    if ((spellShortcut == nullptr) || (spellManager == nullptr))
         return;
 
     const int index = getIndexFromGrid(event.getX(), event.getY());
@@ -287,11 +287,11 @@ void SpellShortcutContainer::mouseReleased(MouseEvent &event)
             {
                 const TextCommand *const
                     spell = spellManager->getSpell(itemId);
-                if (spell && !spell->isEmpty())
+                if ((spell != nullptr) && !spell->isEmpty())
                 {
                     const int num = itemShortcutWindow->getTabIndex();
                     if (num >= 0 && num < CAST_S32(SHORTCUT_TABS)
-                        && itemShortcut[num])
+                        && (itemShortcut[num] != nullptr))
                     {
                         itemShortcut[num]->setItemSelected(
                             spell->getId() + SPELL_MIN_ID);
@@ -303,7 +303,7 @@ void SpellShortcutContainer::mouseReleased(MouseEvent &event)
             {
                 const int num = itemShortcutWindow->getTabIndex();
                 if (num >= 0 && num < CAST_S32(SHORTCUT_TABS)
-                    && itemShortcut[num])
+                    && (itemShortcut[num] != nullptr))
                 {
                     itemShortcut[num]->setItemSelected(-1);
                 }
@@ -317,7 +317,7 @@ void SpellShortcutContainer::mouseReleased(MouseEvent &event)
         if (itemId >= 0)
             spell = spellManager->getSpell(itemId);
 
-        if (spell && popupMenu)
+        if ((spell != nullptr) && (popupMenu != nullptr))
         {
             popupMenu->showSpellPopup(viewport->mMouseX,
                 viewport->mMouseY,
@@ -329,8 +329,12 @@ void SpellShortcutContainer::mouseReleased(MouseEvent &event)
 // Show ItemTooltip
 void SpellShortcutContainer::mouseMoved(MouseEvent &event)
 {
-    if (!spellPopup || !spellShortcut || !spellManager)
+    if (spellPopup == nullptr ||
+        spellShortcut == nullptr ||
+        spellManager == nullptr)
+    {
         return;
+    }
 
     const int index = getIndexFromGrid(event.getX(), event.getY());
 
@@ -340,7 +344,7 @@ void SpellShortcutContainer::mouseMoved(MouseEvent &event)
     const int itemId = getItemByIndex(index);
     spellPopup->setVisible(Visible_false);
     const TextCommand *const spell = spellManager->getSpell(itemId);
-    if (spell && !spell->isEmpty())
+    if ((spell != nullptr) && !spell->isEmpty())
     {
         spellPopup->setItem(spell);
         spellPopup->view(viewport->mMouseX, viewport->mMouseY);
@@ -353,13 +357,13 @@ void SpellShortcutContainer::mouseMoved(MouseEvent &event)
 
 void SpellShortcutContainer::mouseExited(MouseEvent &event A_UNUSED)
 {
-    if (spellPopup)
+    if (spellPopup != nullptr)
         spellPopup->setVisible(Visible_false);
 }
 
 void SpellShortcutContainer::widgetHidden(const Event &event A_UNUSED)
 {
-    if (spellPopup)
+    if (spellPopup != nullptr)
         spellPopup->setVisible(Visible_false);
 }
 
diff --git a/src/gui/widgets/statspage.cpp b/src/gui/widgets/statspage.cpp
index db46931eb..eca98b1c4 100644
--- a/src/gui/widgets/statspage.cpp
+++ b/src/gui/widgets/statspage.cpp
@@ -72,7 +72,7 @@ void StatsPage::attributeChanged(const AttributesT id,
                                  const int newVal A_UNUSED)
 {
     const Attrs::const_iterator it = mAttrs.find(id);
-    if (it != mAttrs.end() && it->second)
+    if (it != mAttrs.end() && (it->second != nullptr))
         it->second->update();
 }
 
@@ -81,6 +81,6 @@ void StatsPage::statChanged(const AttributesT id,
                             const int oldVal2 A_UNUSED)
 {
     const Attrs::const_iterator it = mAttrs.find(id);
-    if (it != mAttrs.end() && it->second)
+    if (it != mAttrs.end() && (it->second != nullptr))
         it->second->update();
 }
diff --git a/src/gui/widgets/statspagebasic.cpp b/src/gui/widgets/statspagebasic.cpp
index 23fd22243..bdf90e14f 100644
--- a/src/gui/widgets/statspagebasic.cpp
+++ b/src/gui/widgets/statspagebasic.cpp
@@ -83,7 +83,7 @@ void StatsPageBasic::statChanged(const AttributesT id,
                                  const int oldVal2 A_UNUSED)
 {
     const Attrs::const_iterator it = mAttrs.find(id);
-    if (it != mAttrs.end() && it->second)
+    if (it != mAttrs.end() && (it->second != nullptr))
         it->second->update();
 }
 
@@ -105,7 +105,7 @@ void StatsPageBasic::attributeChanged(const AttributesT id,
             for (Attrs::const_iterator it = mAttrs.begin();
                  it != mAttrs.end(); ++it)
             {
-                if (it->second)
+                if (it->second != nullptr)
                     it->second->update();
             }
             return;
@@ -115,7 +115,7 @@ void StatsPageBasic::attributeChanged(const AttributesT id,
             for (Attrs::const_iterator it = mAttrs.begin();
                  it != mAttrs.end(); ++it)
             {
-                if (it->second)
+                if (it->second != nullptr)
                     it->second->update();
             }
             return;
@@ -125,7 +125,7 @@ void StatsPageBasic::attributeChanged(const AttributesT id,
     }
     PRAGMA45(GCC diagnostic pop)
     const Attrs::const_iterator it = mAttrs.find(id);
-    if (it != mAttrs.end() && it->second)
+    if (it != mAttrs.end() && (it->second != nullptr))
         it->second->update();
 }
 
@@ -137,7 +137,7 @@ void StatsPageBasic::setPointsNeeded(const AttributesT id,
     if (it != mAttrs.end())
     {
         AttrDisplay *const disp = it->second;
-        if (disp && disp->getType() == AttrDisplay::CHANGEABLE)
+        if ((disp != nullptr) && disp->getType() == AttrDisplay::CHANGEABLE)
             static_cast<ChangeDisplay*>(disp)->setPointsNeeded(needed);
     }
 }
@@ -151,7 +151,7 @@ std::string StatsPageBasic::getStatsStr() const
     {
         const ChangeDisplay *const attr = dynamic_cast<ChangeDisplay*>(
             (*it).second);
-        if (attr)
+        if (attr != nullptr)
         {
             str.append(strprintf("%s:%s ", attr->getShortName().c_str(),
                 attr->getValue().c_str()));
diff --git a/src/gui/widgets/tabbedarea.cpp b/src/gui/widgets/tabbedarea.cpp
index 6df39dfe6..95ea305d6 100644
--- a/src/gui/widgets/tabbedarea.cpp
+++ b/src/gui/widgets/tabbedarea.cpp
@@ -120,7 +120,7 @@ void TabbedArea::postInit()
 
 TabbedArea::~TabbedArea()
 {
-    if (gui)
+    if (gui != nullptr)
         gui->removeDragged(this);
 
     // +++ virtual method calls
@@ -141,16 +141,16 @@ void TabbedArea::enableScrollButtons(const bool enable)
 {
     if (mEnableScrollButtons && !enable)
     {
-        if (mArrowButton[0])
+        if (mArrowButton[0] != nullptr)
             remove(mArrowButton[0]);
-        if (mArrowButton[1])
+        if (mArrowButton[1] != nullptr)
             remove(mArrowButton[1]);
     }
     else if (!mEnableScrollButtons && enable)
     {
-        if (mArrowButton[0])
+        if (mArrowButton[0] != nullptr)
             add(mArrowButton[0]);
-        if (mArrowButton[1])
+        if (mArrowButton[1] != nullptr)
             add(mArrowButton[1]);
     }
     mEnableScrollButtons = enable;
@@ -220,7 +220,7 @@ Widget *TabbedArea::getCurrentWidget() const
 {
     const Tab *const tab = getSelectedTab();
 
-    if (tab)
+    if (tab != nullptr)
         return getWidget(tab->getCaption());
     else
         return nullptr;
@@ -229,7 +229,7 @@ Widget *TabbedArea::getCurrentWidget() const
 void TabbedArea::addTab(Tab *const tab,
                         Widget *const widget)
 {
-    if (!tab || !widget)
+    if ((tab == nullptr) || (widget == nullptr))
         return;
 
     tab->setTabbedArea(this);
@@ -238,7 +238,7 @@ void TabbedArea::addTab(Tab *const tab,
     mTabContainer->add(tab);
     mTabs.push_back(std::pair<Tab*, Widget*>(tab, widget));
 
-    if (!mSelectedTab && tab->mVisible == Visible_true)
+    if ((mSelectedTab == nullptr) && tab->mVisible == Visible_true)
         setSelectedTab(tab);
 
     adjustTabPositions();
@@ -255,7 +255,7 @@ void TabbedArea::addTab(Tab *const tab,
 
 void TabbedArea::adjustWidget(Widget *const widget) const
 {
-    if (!widget)
+    if (widget == nullptr)
         return;
     const int frameSize = 2 * mFrameSize;
     widget->setSize(getWidth() - frameSize,
@@ -386,7 +386,7 @@ void TabbedArea::mousePressed(MouseEvent &event)
             event.getX(), event.getY());
         Tab *const tab = dynamic_cast<Tab *>(widget);
 
-        if (tab)
+        if (tab != nullptr)
         {
             event.consume();
             setSelectedTab(tab);
@@ -414,7 +414,7 @@ void TabbedArea::setSelectedTab(Tab *const tab)
 
     Tab *const newTab = tab;
 
-    if (newTab)
+    if (newTab != nullptr)
         newTab->setCurrent();
 
     widgetResized(Event(nullptr));
@@ -428,7 +428,7 @@ void TabbedArea::setSelectedTabDefault()
         for (size_t i = 0; i < mTabs.size(); i++)
         {
             Tab *const tab = mTabs[i].first;
-            if (tab && tab->mVisible == Visible_true)
+            if ((tab != nullptr) && tab->mVisible == Visible_true)
             {
                 setSelectedTab(tab);
                 return;
@@ -454,7 +454,7 @@ void TabbedArea::setSelectedTabByName(const std::string &name)
 {
     FOR_EACH (TabContainer::const_iterator, itr, mTabs)
     {
-        if ((*itr).first && (*itr).first->getCaption() == name)
+        if (((*itr).first != nullptr) && (*itr).first->getCaption() == name)
         {
             setSelectedTab((*itr).first);
             return;
@@ -476,7 +476,7 @@ void TabbedArea::widgetResized(const Event &event A_UNUSED)
 
     Widget *const w = getCurrentWidget();
     ScrollArea *const scr = dynamic_cast<ScrollArea *>(w);
-    if (scr)
+    if (scr != nullptr)
     {
         if (mFollowDownScroll && height != 0)
         {
@@ -492,14 +492,14 @@ void TabbedArea::widgetResized(const Event &event A_UNUSED)
                         + rect.height - height;
                     w->setSize(mWidgetContainer->getWidth() - frameSize,
                         mWidgetContainer->getHeight() - frameSize);
-                    if (newScroll)
+                    if (newScroll != 0)
                         scr->setVerticalScrollAmount(newScroll);
                 }
             }
         }
     }
 
-    if (mArrowButton[1])
+    if (mArrowButton[1] != nullptr)
     {
         // Check whether there is room to show more tabs now.
         int innerWidth = w1 - 4 - mArrowButton[0]->getWidth()
@@ -508,10 +508,10 @@ void TabbedArea::widgetResized(const Event &event A_UNUSED)
             innerWidth = 0;
 
         int newWidth = mVisibleTabsWidth;
-        while (mTabScrollIndex && newWidth < innerWidth)
+        while ((mTabScrollIndex != 0u) && newWidth < innerWidth)
         {
             Tab *const tab = mTabs[mTabScrollIndex - 1].first;
-            if (tab && tab->mVisible == Visible_true)
+            if ((tab != nullptr) && tab->mVisible == Visible_true)
             {
                 newWidth += tab->getWidth();
                 if (newWidth < innerWidth)
@@ -519,7 +519,7 @@ void TabbedArea::widgetResized(const Event &event A_UNUSED)
             }
         }
 
-        if (mArrowButton[1])
+        if (mArrowButton[1] != nullptr)
         {
             // Move the right arrow to fit the windows content.
             newWidth = width - mArrowButton[1]->getWidth() - mRightMargin;
@@ -539,7 +539,7 @@ void TabbedArea::updateTabsWidth()
     FOR_EACH (TabContainer::const_iterator, itr, mTabs)
     {
         Tab *const tab = (*itr).first;
-        if (tab && tab->mVisible == Visible_true)
+        if ((tab != nullptr) && tab->mVisible == Visible_true)
             mTabsWidth += tab->getWidth();
     }
     updateVisibleTabsWidth();
@@ -551,7 +551,7 @@ void TabbedArea::updateVisibleTabsWidth()
     for (size_t i = mTabScrollIndex, sz = mTabs.size(); i < sz; ++i)
     {
         Tab *const tab = mTabs[i].first;
-        if (tab && tab->mVisible == Visible_true)
+        if ((tab != nullptr) && tab->mVisible == Visible_true)
             mVisibleTabsWidth += CAST_S32(tab->getWidth());
     }
 }
@@ -574,7 +574,7 @@ void TabbedArea::adjustSize()
     mWidgetContainer->setPosition(0, maxTabHeight);
     mWidgetContainer->setSize(width, height - maxTabHeight);
     Widget *const w = getCurrentWidget();
-    if (w)
+    if (w != nullptr)
     {
         const int wFrameSize = w->getFrameSize();
         const int frame2 = 2 * wFrameSize;
@@ -600,7 +600,7 @@ void TabbedArea::adjustTabPositions()
     for (size_t i = 0; i < sz; ++i)
     {
         const Tab *const tab = mTabs[i].first;
-        if (tab &&
+        if ((tab != nullptr) &&
             tab->mVisible == Visible_true &&
             tab->getHeight() > maxTabHeight)
         {
@@ -613,7 +613,7 @@ void TabbedArea::adjustTabPositions()
     for (size_t i = mTabScrollIndex; i < sz; ++i)
     {
         Tab *const tab = mTabs[i].first;
-        if (!tab || tab->mVisible == Visible_false)
+        if ((tab == nullptr) || tab->mVisible == Visible_false)
             continue;
         tab->setPosition(x, maxTabHeight - tab->getHeight());
         x += tab->getWidth();
@@ -626,7 +626,7 @@ void TabbedArea::adjustTabPositions()
         for (unsigned i = 0; i < mTabScrollIndex; ++i)
         {
             Tab *const tab = mTabs[i].first;
-            if (tab && tab->mVisible == Visible_true)
+            if ((tab != nullptr) && tab->mVisible == Visible_true)
             {
                 x -= tab->getWidth();
                 tab->setPosition(x, maxTabHeight - tab->getHeight());
@@ -640,7 +640,7 @@ void TabbedArea::action(const ActionEvent& actionEvent)
     Widget *const source = actionEvent.getSource();
     Tab *const tab = dynamic_cast<Tab *>(source);
 
-    if (tab)
+    if (tab != nullptr)
     {
         setSelectedTab(tab);
     }
@@ -649,7 +649,7 @@ void TabbedArea::action(const ActionEvent& actionEvent)
         const std::string &eventId = actionEvent.getId();
         if (eventId == "shift_left")
         {
-            if (mTabScrollIndex)
+            if (mTabScrollIndex != 0u)
                 --mTabScrollIndex;
         }
         else if (eventId == "shift_right")
@@ -665,7 +665,7 @@ void TabbedArea::action(const ActionEvent& actionEvent)
 void TabbedArea::updateArrowEnableState()
 {
     updateTabsWidth();
-    if (!mArrowButton[0] || !mArrowButton[1])
+    if ((mArrowButton[0] == nullptr) || (mArrowButton[1] == nullptr))
         return;
 
     const int width = mDimension.width;
@@ -684,7 +684,7 @@ void TabbedArea::updateArrowEnableState()
     }
 
     // Left arrow consistency check
-    if (!mTabScrollIndex)
+    if (mTabScrollIndex == 0u)
         mArrowButton[0]->setEnabled(false);
     else
         mArrowButton[0]->setEnabled(true);
@@ -801,7 +801,7 @@ void TabbedArea::death(const Event &event)
 {
     Tab *const tab = dynamic_cast<Tab*>(event.getSource());
 
-    if (tab)
+    if (tab != nullptr)
         removeTab(tab);
     else
         BasicContainer::death(event);
diff --git a/src/gui/widgets/tabs/chat/channeltab.cpp b/src/gui/widgets/tabs/chat/channeltab.cpp
index d67de5287..37e6237a0 100644
--- a/src/gui/widgets/tabs/chat/channeltab.cpp
+++ b/src/gui/widgets/tabs/chat/channeltab.cpp
@@ -39,7 +39,7 @@ ChannelTab::ChannelTab(const Widget2 *const widget,
 
 ChannelTab::~ChannelTab()
 {
-    if (chatWindow)
+    if (chatWindow != nullptr)
         chatWindow->removeChannel(mChannelName);
 }
 
@@ -55,11 +55,11 @@ bool ChannelTab::handleCommand(const std::string &restrict type,
 {
     if (type == "close")
     {
-        if (windowContainer)
+        if (windowContainer != nullptr)
             windowContainer->scheduleDelete(this);
         else
             delete this;
-        if (chatWindow)
+        if (chatWindow != nullptr)
             chatWindow->defaultTab();
     }
     else
diff --git a/src/gui/widgets/tabs/chat/chattab.cpp b/src/gui/widgets/tabs/chat/chattab.cpp
index e59d11eb4..fc2f09350 100644
--- a/src/gui/widgets/tabs/chat/chattab.cpp
+++ b/src/gui/widgets/tabs/chat/chattab.cpp
@@ -84,7 +84,7 @@ ChatTab::ChatTab(const Widget2 *const widget,
 
     mTextOutput->setOpaque(Opaque_false);
     mTextOutput->setMaxRow(config.getIntValue("ChatLogLength"));
-    if (chatWindow)
+    if (chatWindow != nullptr)
         mTextOutput->setLinkHandler(chatWindow->mItemLinkHandler);
     mTextOutput->setAlwaysUpdate(false);
 
@@ -92,13 +92,13 @@ ChatTab::ChatTab(const Widget2 *const widget,
         ScrollArea::SHOW_ALWAYS);
     mScrollArea->setScrollAmount(0, 1);
 
-    if (chatWindow)
+    if (chatWindow != nullptr)
         chatWindow->addTab(this);
 }
 
 ChatTab::~ChatTab()
 {
-    if (chatWindow)
+    if (chatWindow != nullptr)
         chatWindow->removeTab(this);
 
     delete2(mTextOutput);
@@ -225,7 +225,7 @@ void ChatTab::chatLog(std::string line,
 
     // if configured, move magic messages log to debug chat tab
     if (Net::getNetworkType() == ServerType::TMWATHENA
-        && localChatTab && this == localChatTab
+        && (localChatTab != nullptr) && this == localChatTab
         && ((config.getBoolValue("showMagicInDebug")
         && own == ChatMsgType::BY_PLAYER
         && tmp.text.length() > 1
@@ -235,7 +235,7 @@ void ChatTab::chatLog(std::string line,
         && (own == ChatMsgType::BY_SERVER
         || tmp.nick.empty()))))
     {
-        if (debugChatTab)
+        if (debugChatTab != nullptr)
             debugChatTab->chatLog(line, own, ignoreRecord, tryRemoveColors);
         return;
     }
@@ -247,7 +247,7 @@ void ChatTab::chatLog(std::string line,
     if (config.getBoolValue("useLocalTime"))
     {
         const tm *const timeInfo = localtime(&t);
-        if (timeInfo)
+        if (timeInfo != nullptr)
         {
             line = strprintf("%s[%02d:%02d] %s%s", lineColor.c_str(),
                 timeInfo->tm_hour, timeInfo->tm_min, tmp.nick.c_str(),
@@ -292,7 +292,7 @@ void ChatTab::chatLog(std::string line,
         addRow(line);
     }
 
-    if (chatWindow && this == localChatTab)
+    if ((chatWindow != nullptr) && this == localChatTab)
         chatWindow->addToAwayLog(line);
 
     mScrollArea->logic();
@@ -307,7 +307,7 @@ void ChatTab::chatLog(std::string line,
         }
 
         const TabbedArea *const tabArea = getTabbedArea();
-        if (!tabArea)
+        if (tabArea == nullptr)
             return;
 
         const bool notFocused = WindowManager::getIsMinimized() ||
@@ -317,7 +317,8 @@ void ChatTab::chatLog(std::string line,
         {
             if (getFlash() == 0)
             {
-                if (chatWindow && chatWindow->findHighlight(tmp.text))
+                if (chatWindow != nullptr &&
+                    chatWindow->findHighlight(tmp.text))
                 {
                     setFlash(2);
                     soundManager.playGuiSound(SOUND_HIGHLIGHT);
@@ -329,8 +330,11 @@ void ChatTab::chatLog(std::string line,
             }
             else if (getFlash() == 2)
             {
-                if (chatWindow && chatWindow->findHighlight(tmp.text))
+                if (chatWindow != nullptr &&
+                    chatWindow->findHighlight(tmp.text))
+                {
                     soundManager.playGuiSound(SOUND_HIGHLIGHT);
+                }
             }
         }
 
@@ -341,13 +345,13 @@ void ChatTab::chatLog(std::string line,
         {
             if (own == ChatMsgType::BY_GM)
             {
-                if (chatWindow)
+                if (chatWindow != nullptr)
                     chatWindow->unHideWindow();
                 soundManager.playGuiSound(SOUND_GLOBAL);
             }
             else if (own != ChatMsgType::BY_SERVER)
             {
-                if (chatWindow)
+                if (chatWindow != nullptr)
                     chatWindow->unHideWindow();
                 playNewMessageSound();
             }
@@ -358,7 +362,7 @@ void ChatTab::chatLog(std::string line,
 
 void ChatTab::chatLog(const std::string &nick, std::string msg)
 {
-    if (!localPlayer)
+    if (localPlayer == nullptr)
         return;
 
     const ChatMsgTypeT byWho = (nick == localPlayer->getName()
@@ -441,7 +445,7 @@ void ChatTab::handleCommandStr(const std::string &msg)
 
 void ChatTab::handleHelp(const std::string &msg)
 {
-    if (helpWindow)
+    if (helpWindow != nullptr)
     {
         helpWindow->search(msg);
         helpWindow->requestMoveToTop();
@@ -457,7 +461,7 @@ bool ChatTab::handleCommands(const std::string &type, const std::string &args)
 
 void ChatTab::saveToLogFile(const std::string &msg) const
 {
-    if (chatLogger)
+    if (chatLogger != nullptr)
     {
         if (getType() == ChatTabType::INPUT)
         {
@@ -498,7 +502,7 @@ void ChatTab::addRow(std::string &line)
 
 void ChatTab::loadFromLogFile(const std::string &name)
 {
-    if (chatLogger)
+    if (chatLogger != nullptr)
     {
         std::list<std::string> list;
         chatLogger->loadLast(name, list, 5);
diff --git a/src/gui/widgets/tabs/chat/emulateguildtab.cpp b/src/gui/widgets/tabs/chat/emulateguildtab.cpp
index 4c4401242..4374f6b2c 100644
--- a/src/gui/widgets/tabs/chat/emulateguildtab.cpp
+++ b/src/gui/widgets/tabs/chat/emulateguildtab.cpp
@@ -56,13 +56,15 @@ EmulateGuildTab::~EmulateGuildTab()
 bool EmulateGuildTab::handleCommand(const std::string &restrict type,
                                     const std::string &restrict args)
 {
-    if (type == "invite" && guildManager)
+    if (guildManager == nullptr)
+        return false;
+    if (type == "invite")
         guildManager->invite(args);
-    else if (type == "leave" && guildManager)
+    else if (type == "leave")
         guildManager->leave();
-    else if (type == "kick" && guildManager)
+    else if (type == "kick")
         guildManager->kick(args);
-    else if (type == "notice" && guildManager)
+    else if (type == "notice")
         guildManager->notice(args);
     else
         return false;
@@ -72,14 +74,14 @@ bool EmulateGuildTab::handleCommand(const std::string &restrict type,
 
 void EmulateGuildTab::handleInput(const std::string &msg)
 {
-    if (!guildManager)
+    if (guildManager == nullptr)
         return;
     guildManager->chat(ChatWindow::doReplace(msg));
 }
 
 void EmulateGuildTab::getAutoCompleteList(StringVect &names) const
 {
-    if (!guildManager)
+    if (guildManager == nullptr)
         return;
 
     guildManager->getNames(names);
diff --git a/src/gui/widgets/tabs/chat/guildtab.cpp b/src/gui/widgets/tabs/chat/guildtab.cpp
index 982c27da5..51416b8ef 100644
--- a/src/gui/widgets/tabs/chat/guildtab.cpp
+++ b/src/gui/widgets/tabs/chat/guildtab.cpp
@@ -60,23 +60,23 @@ GuildTab::~GuildTab()
 bool GuildTab::handleCommand(const std::string &restrict type,
                              const std::string &restrict args)
 {
-    if (type == "invite" && EAthena::taGuild)
+    if (type == "invite" && (EAthena::taGuild != nullptr))
     {
         guildHandler->invite(args);
     }
-    else if (type == "leave" && EAthena::taGuild)
+    else if (type == "leave" && (EAthena::taGuild != nullptr))
     {
         inputManager.executeChatCommand(InputAction::LEAVE_GUILD,
             std::string(),
             this);
     }
-    else if (type == "kick" && EAthena::taGuild)
+    else if (type == "kick" && (EAthena::taGuild != nullptr))
     {
         inputManager.executeChatCommand(InputAction::KICK_GUILD,
             args,
             this);
     }
-    else if (type == "notice" && EAthena::taGuild)
+    else if (type == "notice" && (EAthena::taGuild != nullptr))
     {
         inputManager.executeChatCommand(InputAction::GUILD_NOTICE,
             args,
@@ -92,7 +92,7 @@ bool GuildTab::handleCommand(const std::string &restrict type,
 
 void GuildTab::handleInput(const std::string &msg)
 {
-    if (!EAthena::taGuild)
+    if (EAthena::taGuild == nullptr)
         return;
 
     guildHandler->chat(ChatWindow::doReplace(msg));
@@ -100,7 +100,7 @@ void GuildTab::handleInput(const std::string &msg)
 
 void GuildTab::getAutoCompleteList(StringVect &names) const
 {
-    if (EAthena::taGuild)
+    if (EAthena::taGuild != nullptr)
         EAthena::taGuild->getNames(names);
 }
 
diff --git a/src/gui/widgets/tabs/chat/partytab.cpp b/src/gui/widgets/tabs/chat/partytab.cpp
index 366a78241..befbb0393 100644
--- a/src/gui/widgets/tabs/chat/partytab.cpp
+++ b/src/gui/widgets/tabs/chat/partytab.cpp
@@ -118,12 +118,12 @@ bool PartyTab::handleCommand(const std::string &restrict type,
 
 void PartyTab::getAutoCompleteList(StringVect &names) const
 {
-    if (!localPlayer)
+    if (localPlayer == nullptr)
         return;
 
     const Party *const p = localPlayer->getParty();
 
-    if (p)
+    if (p != nullptr)
         p->getNames(names);
 }
 
diff --git a/src/gui/widgets/tabs/chat/whispertab.cpp b/src/gui/widgets/tabs/chat/whispertab.cpp
index 1cbf471c7..d8672b22d 100644
--- a/src/gui/widgets/tabs/chat/whispertab.cpp
+++ b/src/gui/widgets/tabs/chat/whispertab.cpp
@@ -45,7 +45,7 @@ WhisperTab::WhisperTab(const Widget2 *const widget,
 
 WhisperTab::~WhisperTab()
 {
-    if (chatWindow)
+    if (chatWindow != nullptr)
         chatWindow->removeWhisper(mNick);
 }
 
@@ -55,7 +55,7 @@ void WhisperTab::handleInput(const std::string &msg)
     newMsg = ChatWindow::doReplace(msg);
     chatHandler->privateMessage(mNick, newMsg);
 
-    if (localPlayer)
+    if (localPlayer != nullptr)
         chatLog(localPlayer->getName(), newMsg);
     else
         chatLog("?", newMsg);
@@ -78,7 +78,7 @@ void WhisperTab::handleCommandStr(const std::string &msg)
     {
         std::string str = textToMe(args);
         chatHandler->privateMessage(mNick, str);
-        if (localPlayer)
+        if (localPlayer != nullptr)
             chatLog(localPlayer->getName(), str);
         else
             chatLog("?", str);
@@ -94,11 +94,11 @@ bool WhisperTab::handleCommand(const std::string &restrict type,
 {
     if (type == "close")
     {
-        if (windowContainer)
+        if (windowContainer != nullptr)
             windowContainer->scheduleDelete(this);
         else
             delete this;
-        if (chatWindow)
+        if (chatWindow != nullptr)
             chatWindow->defaultTab();
     }
     else
diff --git a/src/gui/widgets/tabs/debugwindowtabs.cpp b/src/gui/widgets/tabs/debugwindowtabs.cpp
index e75e1d42d..4a600d2fd 100644
--- a/src/gui/widgets/tabs/debugwindowtabs.cpp
+++ b/src/gui/widgets/tabs/debugwindowtabs.cpp
@@ -171,7 +171,7 @@ MapDebugTab::MapDebugTab(const Widget2 *const widget) :
 void MapDebugTab::logic()
 {
     BLOCK_START("MapDebugTab::logic")
-    if (localPlayer)
+    if (localPlayer != nullptr)
     {
         // TRANSLATORS: debug window label
         mXYLabel->setCaption(strprintf("%s (%d, %d)", _("Player Position:"),
@@ -184,7 +184,7 @@ void MapDebugTab::logic()
     }
 
     const Map *const map = Game::instance()->getCurrentMap();
-    if (map && viewport)
+    if ((map != nullptr) && (viewport != nullptr))
     {
           // Get the current mouse position
         const int mouseTileX = (viewport->mMouseX + viewport->getCameraX())
@@ -329,7 +329,7 @@ TargetDebugTab::TargetDebugTab(const Widget2 *const widget) :
 void TargetDebugTab::logic()
 {
     BLOCK_START("TargetDebugTab::logic")
-    if (localPlayer && localPlayer->getTarget())
+    if ((localPlayer != nullptr) && (localPlayer->getTarget() != nullptr))
     {
         const Being *const target = localPlayer->getTarget();
 
@@ -344,7 +344,7 @@ void TargetDebugTab::logic()
         mTargetTypeLabel->setCaption(strprintf("%s %d",
             // TRANSLATORS: debug window label
             _("Target type:"), toInt(target->getSubType(), int)));
-        if (target->getLevel())
+        if (target->getLevel() != 0)
         {
             mTargetLevelLabel->setCaption(strprintf("%s %d",
                 // TRANSLATORS: debug window label
@@ -389,7 +389,7 @@ void TargetDebugTab::logic()
             _("Effects:"), target->getStatusEffectsString().c_str()));
 
         const int delay = target->getAttackDelay();
-        if (delay)
+        if (delay != 0)
         {
             mAttackDelayLabel->setCaption(strprintf("%s %d",
                 // TRANSLATORS: debug window label
@@ -469,7 +469,7 @@ NetDebugTab::NetDebugTab(const Widget2 *const widget) :
 void NetDebugTab::logic()
 {
     BLOCK_START("NetDebugTab::logic")
-    if (localPlayer)
+    if (localPlayer != nullptr)
     {
         // TRANSLATORS: debug window label
         mPingLabel->setCaption(strprintf(_("Ping: %s ms"),
diff --git a/src/gui/widgets/tabs/setup_audio.cpp b/src/gui/widgets/tabs/setup_audio.cpp
index 0b958951a..7a37f2d89 100644
--- a/src/gui/widgets/tabs/setup_audio.cpp
+++ b/src/gui/widgets/tabs/setup_audio.cpp
@@ -181,10 +181,10 @@ void Setup_Audio::apply()
         soundManager.init();
         if (config.getBoolValue("playMusic"))
         {
-            if (viewport)
+            if (viewport != nullptr)
             {  // in game
                 const Map *const map = viewport->getMap();
-                if (map)
+                if (map != nullptr)
                 {
                     soundManager.playMusic(map->getMusicFile(),
                         SkipError_false);
diff --git a/src/gui/widgets/tabs/setup_chat.cpp b/src/gui/widgets/tabs/setup_chat.cpp
index c9d0565b9..b27e1ec53 100644
--- a/src/gui/widgets/tabs/setup_chat.cpp
+++ b/src/gui/widgets/tabs/setup_chat.cpp
@@ -333,7 +333,7 @@ void Setup_Chat::apply()
 {
     SetupTabScroll::apply();
 
-    if (chatWindow)
+    if (chatWindow != nullptr)
     {
         chatWindow->adjustTabSize();
         chatWindow->parseHighlights();
diff --git a/src/gui/widgets/tabs/setup_colors.cpp b/src/gui/widgets/tabs/setup_colors.cpp
index 9f7ad0154..f4efb2832 100644
--- a/src/gui/widgets/tabs/setup_colors.cpp
+++ b/src/gui/widgets/tabs/setup_colors.cpp
@@ -201,7 +201,7 @@ Setup_Colors::Setup_Colors(const Widget2 *const widget) :
 
 Setup_Colors::~Setup_Colors()
 {
-    if (mPreviewBox && mPreviewBox->getContent() == mPreview)
+    if ((mPreviewBox != nullptr) && mPreviewBox->getContent() == mPreview)
         delete2(mTextPreview)
     else
         delete2(mPreview)
@@ -246,7 +246,7 @@ void Setup_Colors::action(const ActionEvent &event)
 
 void Setup_Colors::valueChanged(const SelectionEvent &event A_UNUSED)
 {
-    if (!userPalette)
+    if (userPalette == nullptr)
         return;
 
     mSelected = mColorBox->getSelected();
@@ -308,7 +308,7 @@ void Setup_Colors::valueChanged(const SelectionEvent &event A_UNUSED)
             break;
         case UserColorId::ATTACK_RANGE_BORDER:
         case UserColorId::HOME_PLACE_BORDER:
-            if (gui)
+            if (gui != nullptr)
                 mTextPreview->setFont(gui->getFont());
             mTextPreview->setTextColor(col);
             mTextPreview->setOutline(false);
@@ -398,21 +398,21 @@ void Setup_Colors::valueChanged(const SelectionEvent &event A_UNUSED)
 void Setup_Colors::setEntry(Slider *const s, TextField *const t,
                             const int value)
 {
-    if (s)
+    if (s != nullptr)
         s->setValue(value);
-    if (t)
+    if (t != nullptr)
         t->setText(toString(value));
 }
 
 void Setup_Colors::apply()
 {
-    if (userPalette)
+    if (userPalette != nullptr)
         userPalette->commit();
 }
 
 void Setup_Colors::cancel()
 {
-    if (!userPalette)
+    if (userPalette == nullptr)
         return;
 
     userPalette->rollback();
@@ -430,7 +430,7 @@ void Setup_Colors::cancel()
 
 void Setup_Colors::updateGradType()
 {
-    if (mSelected == -1 || !userPalette)
+    if (mSelected == -1 || (userPalette == nullptr))
         return;
 
     mSelected = mColorBox->getSelected();
@@ -463,7 +463,7 @@ void Setup_Colors::updateGradType()
 
 void Setup_Colors::updateColor() const
 {
-    if (mSelected == -1 || !userPalette)
+    if (mSelected == -1 || (userPalette == nullptr))
         return;
 
     const UserColorIdT type = static_cast<UserColorIdT>(
diff --git a/src/gui/widgets/tabs/setup_input.cpp b/src/gui/widgets/tabs/setup_input.cpp
index 2b7c4bedd..dc1e531f8 100644
--- a/src/gui/widgets/tabs/setup_input.cpp
+++ b/src/gui/widgets/tabs/setup_input.cpp
@@ -91,7 +91,7 @@ Setup_Input::Setup_Input(const Widget2 *const widget) :
 
     mKeyListModel->setSize(mActionDataSize[0]);
     refreshKeys();
-    if (gui)
+    if (gui != nullptr)
         mKeyList->setFont(gui->getHelpFont());
     mKeyList->addActionListener(this);
 
@@ -106,7 +106,7 @@ Setup_Input::Setup_Input(const Widget2 *const widget) :
     mTabs->addActionListener(this);
     mTabs->setActionEventId("tabs_");
     int k = 0;
-    while (pages[k])
+    while (pages[k] != nullptr)
     {
         mTabs->addButton(gettext(pages[k]), pages[k], false);
         k ++;
@@ -257,13 +257,13 @@ void Setup_Input::action(const ActionEvent &event)
     {
         int k = 0;
         std::string str("tabs_");
-        while (pages[k])
+        while (pages[k] != nullptr)
         {
             if (str + pages[k] == id)
                 break;
             k ++;
         }
-        if (pages[k] && str + pages[k] == id)
+        if ((pages[k] != nullptr) && str + pages[k] == id)
         {
             mKeyListModel->setSelectedData(k);
             mKeyListModel->setSize(mActionDataSize[k]);
diff --git a/src/gui/widgets/tabs/setup_joystick.cpp b/src/gui/widgets/tabs/setup_joystick.cpp
index 784197eb9..12cf331a0 100644
--- a/src/gui/widgets/tabs/setup_joystick.cpp
+++ b/src/gui/widgets/tabs/setup_joystick.cpp
@@ -73,7 +73,7 @@ Setup_Joystick::Setup_Joystick(const Widget2 *const widget) :
     mNamesDropDown->setActionEventId("name");
     mNamesDropDown->addActionListener(this);
 
-    if (joystick)
+    if (joystick != nullptr)
     {
         mNamesDropDown->setSelected(joystick->getNumber());
     }
@@ -113,12 +113,12 @@ void Setup_Joystick::action(const ActionEvent &event)
     }
     else if (source == mNamesDropDown)
     {
-        if (joystick)
+        if (joystick != nullptr)
             joystick->setNumber(mNamesDropDown->getSelected());
     }
     else if (source == mDetectButton)
     {
-        if (joystick)
+        if (joystick != nullptr)
         {
             joystick->reload();
             Joystick::getNames(mNamesModel->getNames());
@@ -127,7 +127,7 @@ void Setup_Joystick::action(const ActionEvent &event)
     }
     else
     {
-        if (!joystick)
+        if (joystick == nullptr)
             return;
 
         if (joystick->isCalibrating())
@@ -155,7 +155,7 @@ void Setup_Joystick::setTempEnabled(const bool sel)
 {
     Joystick::setEnabled(sel);
     mCalibrateButton->setEnabled(sel);
-    if (joystick)
+    if (joystick != nullptr)
     {
         if (sel)
             joystick->open();
@@ -166,7 +166,7 @@ void Setup_Joystick::setTempEnabled(const bool sel)
 
 void Setup_Joystick::cancel()
 {
-    if (joystick)
+    if (joystick != nullptr)
         joystick->setEnabled(mOriginalJoystickEnabled);
 
     if (mOriginalJoystickEnabled != mJoystickEnabled->isSelected())
@@ -177,7 +177,7 @@ void Setup_Joystick::cancel()
 
 void Setup_Joystick::apply()
 {
-    if (!joystick)
+    if (joystick == nullptr)
         return;
 
     config.setValue("joystickEnabled", joystick->isEnabled());
diff --git a/src/gui/widgets/tabs/setup_mods.cpp b/src/gui/widgets/tabs/setup_mods.cpp
index 994001763..7ee8f2f34 100644
--- a/src/gui/widgets/tabs/setup_mods.cpp
+++ b/src/gui/widgets/tabs/setup_mods.cpp
@@ -82,7 +82,7 @@ void Setup_Mods::loadMods()
     FOR_EACH (ModInfoCIterator, it, mods)
     {
         const ModInfo *const info = (*it).second;
-        if (!info)
+        if (info == nullptr)
             continue;
 
         std::string name = info->getName();
@@ -108,7 +108,7 @@ void Setup_Mods::saveMods() const
     FOR_EACH (std::set<SetupItem*>::const_iterator, it, modsList)
     {
         const SetupItem *const item = *it;
-        if (!item)
+        if (item == nullptr)
             continue;
         const std::string val = item->getValue();
         if (val == "1")
diff --git a/src/gui/widgets/tabs/setup_players.cpp b/src/gui/widgets/tabs/setup_players.cpp
index cca3acee9..4f9d8f856 100644
--- a/src/gui/widgets/tabs/setup_players.cpp
+++ b/src/gui/widgets/tabs/setup_players.cpp
@@ -186,6 +186,6 @@ void Setup_Players::externalUpdated()
 void Setup_Players::apply()
 {
     SetupTabScroll::apply();
-    settings.enableRemoteCommands = serverConfig.getValue(
-        "enableRemoteCommands", 1);
+    settings.enableRemoteCommands = (serverConfig.getValue(
+        "enableRemoteCommands", 1) != 0);
 }
diff --git a/src/gui/widgets/tabs/setup_relations.cpp b/src/gui/widgets/tabs/setup_relations.cpp
index 0054da32b..d81bca9a9 100644
--- a/src/gui/widgets/tabs/setup_relations.cpp
+++ b/src/gui/widgets/tabs/setup_relations.cpp
@@ -70,10 +70,10 @@ Setup_Relations::Setup_Relations(const Widget2 *const widget) :
     mPlayerScrollArea(new ScrollArea(this, mPlayerTable)),
     // TRANSLATORS: relation dialog button
     mDefaultTrading(new CheckBox(this, _("Allow trading"),
-        player_relations.getDefault() & PlayerRelation::TRADE)),
+        (player_relations.getDefault() & PlayerRelation::TRADE) != 0u)),
     // TRANSLATORS: relation dialog button
     mDefaultWhisper(new CheckBox(this, _("Allow whispers"),
-       player_relations.getDefault() & PlayerRelation::WHISPER)),
+       (player_relations.getDefault() & PlayerRelation::WHISPER) != 0u)),
     // TRANSLATORS: relation dialog button
     mDeleteButton(new Button(this, _("Delete"), ACTION_DELETE, this)),
     mIgnoreActionChoicesModel(new IgnoreChoicesListModel),
@@ -112,7 +112,7 @@ Setup_Relations::Setup_Relations(const Widget2 *const widget) :
 
     int ignore_strategy_index = 0;  // safe default
 
-    if (player_relations.getPlayerIgnoreStrategy())
+    if (player_relations.getPlayerIgnoreStrategy() != nullptr)
     {
         ignore_strategy_index = player_relations.getPlayerIgnoreStrategyIndex(
             player_relations.getPlayerIgnoreStrategy()->mShortName);
@@ -177,10 +177,10 @@ void Setup_Relations::apply()
         | (mDefaultTrading->isSelected() ? PlayerRelation::TRADE : 0)
         | (mDefaultWhisper->isSelected() ? PlayerRelation::WHISPER : 0));
 
-    if (actorManager)
+    if (actorManager != nullptr)
         actorManager->updatePlayerNames();
 
-    if (localPlayer)
+    if (localPlayer != nullptr)
         localPlayer->setCheckNameSetting(true);
 }
 
@@ -231,10 +231,10 @@ void Setup_Relations::updatedPlayer(const std::string &name A_UNUSED)
 {
     mPlayerTableModel->playerRelationsUpdated();
     mDefaultTrading->setSelected(
-            player_relations.getDefault() & PlayerRelation::TRADE);
+            (player_relations.getDefault() & PlayerRelation::TRADE) != 0u);
     mDefaultWhisper->setSelected(
-            player_relations.getDefault() & PlayerRelation::WHISPER);
-    if (localPlayer)
+            (player_relations.getDefault() & PlayerRelation::WHISPER) != 0u);
+    if (localPlayer != nullptr)
         localPlayer->updateName();
 }
 
@@ -246,7 +246,7 @@ void Setup_Relations::updateAll()
     mPlayerTableModel = model;
     int ignore_strategy_index = 0;  // safe default
 
-    if (player_relations.getPlayerIgnoreStrategy())
+    if (player_relations.getPlayerIgnoreStrategy() != nullptr)
     {
         ignore_strategy_index = player_relations.getPlayerIgnoreStrategyIndex(
                 player_relations.getPlayerIgnoreStrategy()->mShortName);
@@ -260,7 +260,7 @@ void Setup_Relations::updateAll()
 void Setup_Relations::externalUpdated()
 {
     mDefaultTrading->setSelected(
-        player_relations.getDefault() & PlayerRelation::TRADE);
+        (player_relations.getDefault() & PlayerRelation::TRADE) != 0u);
     mDefaultWhisper->setSelected(
-        player_relations.getDefault() & PlayerRelation::WHISPER);
+        (player_relations.getDefault() & PlayerRelation::WHISPER) != 0u);
 }
diff --git a/src/gui/widgets/tabs/setup_theme.cpp b/src/gui/widgets/tabs/setup_theme.cpp
index c97f192a0..47cbb2b92 100644
--- a/src/gui/widgets/tabs/setup_theme.cpp
+++ b/src/gui/widgets/tabs/setup_theme.cpp
@@ -237,7 +237,7 @@ void Setup_Theme::updateInfo()
 {
     delete mInfo;
     mInfo = Theme::loadInfo(mTheme);
-    if (mInfo)
+    if (mInfo != nullptr)
     {
         // TRANSLATORS: theme name
         mThemeInfo = std::string(_("Name: ")).append(mInfo->name)
@@ -356,7 +356,7 @@ void Setup_Theme::apply()
     }
 
     config.setValue("selectedSkin", "");
-    if (config.getStringValue("theme") != mTheme && mInfo)
+    if (config.getStringValue("theme") != mTheme && (mInfo != nullptr))
     {
         updateField(font, mFont);
         updateField(boldFont, mBoldFont);
@@ -366,13 +366,13 @@ void Setup_Theme::apply()
         updateField(npcFont, mNpcFont);
         updateField(japanFont, mJapanFont);
         updateField(chinaFont, mChinaFont);
-        if (mInfo->fontSize)
+        if (mInfo->fontSize != 0)
         {
             const int size = mInfo->fontSize - 9;
             if (size >= 0)
                 mFontSizeDropDown->setSelected(size);
         }
-        if (mInfo->npcfontSize)
+        if (mInfo->npcfontSize != 0)
         {
             const int size = mInfo->npcfontSize - 9;
             if (size >= 0)
diff --git a/src/gui/widgets/tabs/setup_video.cpp b/src/gui/widgets/tabs/setup_video.cpp
index 24fa8951f..b11b20f39 100644
--- a/src/gui/widgets/tabs/setup_video.cpp
+++ b/src/gui/widgets/tabs/setup_video.cpp
@@ -360,7 +360,7 @@ void Setup_Video::action(const ActionEvent &event)
 
         if (mode == "custom")
         {
-            if (mDialog)
+            if (mDialog != nullptr)
             {
                 mode = mDialog->getText();
                 mDialog = nullptr;
@@ -379,7 +379,7 @@ void Setup_Video::action(const ActionEvent &event)
         }
         const int width = atoi(mode.substr(0, mode.find('x')).c_str());
         const int height = atoi(mode.substr(mode.find('x') + 1).c_str());
-        if (!width || !height)
+        if ((width == 0) || (height == 0))
             return;
 
         if (width != mainGraphics->mActualWidth
@@ -491,7 +491,7 @@ void Setup_Video::action(const ActionEvent &event)
     else if (id == "detect")
     {
         TestMain *test = graphicsManager.startDetection();
-        if (test)
+        if (test != nullptr)
         {
             Configuration &conf = test->getConfig();
             const int val = conf.getValueInt("opengl", -1);
diff --git a/src/gui/widgets/tabs/setuptabscroll.cpp b/src/gui/widgets/tabs/setuptabscroll.cpp
index 898db7b3e..0cb623687 100644
--- a/src/gui/widgets/tabs/setuptabscroll.cpp
+++ b/src/gui/widgets/tabs/setuptabscroll.cpp
@@ -72,7 +72,7 @@ void SetupTabScroll::clear()
 
 void SetupTabScroll::addControl(SetupItem *const widget)
 {
-    if (!widget)
+    if (widget == nullptr)
         return;
     const std::string actionId = widget->getActionEventId();
     if (!actionId.empty())
@@ -109,7 +109,7 @@ void SetupTabScroll::apply()
          iter = mItems.begin(), iter_end = mItems.end();
          iter != iter_end; ++ iter)
     {
-        if ((*iter).second)
+        if ((*iter).second != nullptr)
             (*iter).second->apply((*iter).first);
     }
 }
@@ -120,7 +120,7 @@ void SetupTabScroll::cancel()
          iter = mItems.begin(), iter_end = mItems.end();
          iter != iter_end; ++ iter)
     {
-        if ((*iter).second)
+        if ((*iter).second != nullptr)
             (*iter).second->cancel((*iter).first);
     }
 }
@@ -132,7 +132,7 @@ void SetupTabScroll::externalUpdated()
          iter != iter_end; ++ iter)
     {
         SetupItem *const widget = (*iter).second;
-        if (widget && widget->isMainConfig() == MainConfig_false)
+        if ((widget != nullptr) && widget->isMainConfig() == MainConfig_false)
             widget->externalUpdated((*iter).first);
     }
 }
@@ -144,7 +144,7 @@ void SetupTabScroll::externalUnloaded()
          iter != iter_end; ++ iter)
     {
         SetupItem *const widget = (*iter).second;
-        if (widget && widget->isMainConfig() == MainConfig_false)
+        if ((widget != nullptr) && widget->isMainConfig() == MainConfig_false)
             widget->externalUnloaded((*iter).first);
     }
 }
@@ -158,6 +158,6 @@ void SetupTabScroll::widgetResized(const Event &event A_UNUSED)
 void SetupTabScroll::reread(const std::string &name)
 {
     SetupItem *const item = mItems[name + "Event"];
-    if (item)
+    if (item != nullptr)
         item->rereadValue();
 }
diff --git a/src/gui/widgets/tabs/skilltab.h b/src/gui/widgets/tabs/skilltab.h
index 3845444d6..9086a4d0c 100644
--- a/src/gui/widgets/tabs/skilltab.h
+++ b/src/gui/widgets/tabs/skilltab.h
@@ -65,9 +65,9 @@ class SkillTab final : public Tab
 
         SkillInfo *getSelectedInfo() const
         {
-            if (mListBox)
+            if (mListBox != nullptr)
                 return mListBox->getSelectedInfo();
-            else if (mRectangleListBox)
+            else if (mRectangleListBox != nullptr)
                 return mRectangleListBox->getSelectedInfo();
             else
                 return nullptr;
@@ -76,7 +76,7 @@ class SkillTab final : public Tab
     protected:
         void setCurrent() override
         {
-            if (skillDialog)
+            if (skillDialog != nullptr)
                 skillDialog->updateTabSelection();
         }
 
diff --git a/src/gui/widgets/tabs/socialfriendsfunctor.h b/src/gui/widgets/tabs/socialfriendsfunctor.h
index a15f566d6..e68647a77 100644
--- a/src/gui/widgets/tabs/socialfriendsfunctor.h
+++ b/src/gui/widgets/tabs/socialfriendsfunctor.h
@@ -35,11 +35,14 @@ class SortFriendsFunctor final
         bool operator() (const Avatar *const m1,
                          const Avatar *const m2) const
         {
-            if (!m1 || !m2)
+            if ((m1 == nullptr) || (m2 == nullptr))
                 return false;
 
             if (m1->getOnline() != m2->getOnline())
-                return m1->getOnline() > m2->getOnline();
+            {
+                return static_cast<int>(m1->getOnline()) >
+                    static_cast<int>(m2->getOnline());
+            }
 
             if (m1->getName() != m2->getName())
             {
diff --git a/src/gui/widgets/tabs/socialfriendstab.h b/src/gui/widgets/tabs/socialfriendstab.h
index 616fba43d..dfae61090 100644
--- a/src/gui/widgets/tabs/socialfriendstab.h
+++ b/src/gui/widgets/tabs/socialfriendstab.h
@@ -71,7 +71,7 @@ class SocialFriendsTab final : public SocialTab
 
         void getPlayersAvatars()
         {
-            if (!actorManager)
+            if (actorManager == nullptr)
                 return;
 
             std::vector<Avatar*> *const avatars = mBeings->getMembers();
@@ -90,7 +90,7 @@ class SocialFriendsTab final : public SocialTab
             const std::set<std::string> &players2
                 = whoIsOnline->getOnlineNicks();
 
-            if (!players)
+            if (players == nullptr)
                 return;
 
             int online = 0;
@@ -99,8 +99,8 @@ class SocialFriendsTab final : public SocialTab
             FOR_EACHP (StringVectCIter, it, players)
             {
                 Avatar *const ava = new Avatar(*it);
-                if (actorManager->findBeingByName(*it, ActorType::Player)
-                    || players2.find(*it) != players2.end())
+                if (actorManager->findBeingByName(*it, ActorType::Player) !=
+                    nullptr || players2.find(*it) != players2.end())
                 {
                     ava->setOnline(true);
                     online ++;
diff --git a/src/gui/widgets/tabs/socialguildtab.h b/src/gui/widgets/tabs/socialguildtab.h
index 53b7d46f4..775e22c6f 100644
--- a/src/gui/widgets/tabs/socialguildtab.h
+++ b/src/gui/widgets/tabs/socialguildtab.h
@@ -78,7 +78,7 @@ class SocialGuildTab final : public SocialTab,
                 const std::string name = mInviteDialog->getText();
                 guildHandler->invite(name);
 
-                if (localChatTab)
+                if (localChatTab != nullptr)
                 {
                     localChatTab->chatLog(strprintf(
                         // TRANSLATORS: chat message
@@ -96,7 +96,7 @@ class SocialGuildTab final : public SocialTab,
             else if (eventId == "yes")
             {
                 guildHandler->leave(mGuild->getId());
-                if (localChatTab)
+                if (localChatTab != nullptr)
                 {
                     localChatTab->chatLog(strprintf(
                         // TRANSLATORS: chat message
@@ -137,7 +137,7 @@ class SocialGuildTab final : public SocialTab,
 
         void buildCounter(const int online0, const int total0) override final
         {
-            if (online0 || total0)
+            if ((online0 != 0) || (total0 != 0))
             {
                 // TRANSLATORS: social window label
                 mCounterString = strprintf(_("Members: %u/%u"),
@@ -146,11 +146,11 @@ class SocialGuildTab final : public SocialTab,
             }
             else
             {
-                if (!localPlayer)
+                if (localPlayer == nullptr)
                     return;
 
                 const Guild *const guild = localPlayer->getGuild();
-                if (!guild)
+                if (guild == nullptr)
                     return;
 
                 const Guild::MemberList *const members = guild->getMembers();
diff --git a/src/gui/widgets/tabs/socialguildtab2.h b/src/gui/widgets/tabs/socialguildtab2.h
index a21594aab..f26e99421 100644
--- a/src/gui/widgets/tabs/socialguildtab2.h
+++ b/src/gui/widgets/tabs/socialguildtab2.h
@@ -77,11 +77,11 @@ class SocialGuildTab2 final : public SocialTab,
         void buildCounter(const int online0 A_UNUSED,
                           const int total0 A_UNUSED) override final
         {
-            if (!localPlayer)
+            if (localPlayer == nullptr)
                 return;
 
             const Guild *const guild = localPlayer->getGuild();
-            if (!guild)
+            if (guild == nullptr)
                 return;
 
             const Guild::MemberList *const members = guild->getMembers();
diff --git a/src/gui/widgets/tabs/socialnavigationtab.h b/src/gui/widgets/tabs/socialnavigationtab.h
index 0f72b60f9..80b5910f3 100644
--- a/src/gui/widgets/tabs/socialnavigationtab.h
+++ b/src/gui/widgets/tabs/socialnavigationtab.h
@@ -72,11 +72,11 @@ class SocialNavigationTab final : public SocialTab
 
         void updateList() override final
         {
-            if (!socialWindow || !localPlayer)
+            if ((socialWindow == nullptr) || (localPlayer == nullptr))
                 return;
 
             const Map *const map = socialWindow->getMap();
-            if (!map || map->empty())
+            if ((map == nullptr) || map->empty())
                 return;
 
             if (socialWindow->getProcessedPortals())
@@ -105,7 +105,7 @@ class SocialNavigationTab final : public SocialTab
             while (i != portals.end())
             {
                 MapItem *portal = *i;
-                if (!portal)
+                if (portal == nullptr)
                     continue;
 
                 const int x = portal->getX();
@@ -115,7 +115,7 @@ class SocialNavigationTab final : public SocialTab
                     portal->getComment().c_str(), x, y);
 
                 Avatar *const ava = new Avatar(name);
-                if (localPlayer)
+                if (localPlayer != nullptr)
                     ava->setOnline(localPlayer->isReachable(x, y, true));
                 else
                     ava->setOnline(false);
@@ -130,21 +130,21 @@ class SocialNavigationTab final : public SocialTab
                 total ++;
 
                 if (config.getBoolValue("drawHotKeys")
-                    && idx < 80 && outfitWindow)
+                    && idx < 80 && (outfitWindow != nullptr))
                 {
                     Being *const being = actorManager
                         ->findPortalByTile(x, y);
-                    if (being)
+                    if (being != nullptr)
                     {
                         being->setName(keyboard.getKeyShortString(
                             outfitWindow->keyName(idx)));
                     }
 
-                    if (specialLayer)
+                    if (specialLayer != nullptr)
                     {
                         portal = specialLayer->getTile(
                             ava->getX(), ava->getY());
-                        if (portal)
+                        if (portal != nullptr)
                         {
                             portal->setName(keyboard.getKeyShortString(
                                 outfitWindow->keyName(idx)));
@@ -155,7 +155,7 @@ class SocialNavigationTab final : public SocialTab
                 ++i;
                 idx ++;
             }
-            if (socialWindow)
+            if (socialWindow != nullptr)
                 socialWindow->setProcessedPortals(true);
 
             // TRANSLATORS: social window label
@@ -167,7 +167,7 @@ class SocialNavigationTab final : public SocialTab
 
         void selectIndex(const unsigned num) override final
         {
-            if (!localPlayer)
+            if (localPlayer == nullptr)
                 return;
 
             std::vector<Avatar*> *const avatars = mBeings->getMembers();
@@ -175,19 +175,19 @@ class SocialNavigationTab final : public SocialTab
                 return;
 
             const Avatar *const ava = avatars->at(num);
-            if (ava && localPlayer)
+            if ((ava != nullptr) && (localPlayer != nullptr))
                 localPlayer->navigateTo(ava->getX(), ava->getY());
         }
 
         void updateNames()
         {
-            if (!socialWindow)
+            if (socialWindow == nullptr)
                 return;
 
             std::vector<Avatar*> *const avatars = mBeings->getMembers();
 
             const Map *const map = socialWindow->getMap();
-            if (!map)
+            if (map == nullptr)
                 return;
 
             std::vector<Avatar*>::const_iterator i = avatars->begin();
@@ -195,12 +195,12 @@ class SocialNavigationTab final : public SocialTab
             while (i != i_end)
             {
                 Avatar *const ava = *i;
-                if (!ava)
+                if (ava == nullptr)
                     break;
 
                 const  MapItem *const item = map->findPortalXY(
                     ava->getX(), ava->getY());
-                if (item)
+                if (item != nullptr)
                 {
                     const std::string name = strprintf("%s [%d %d]",
                         item->getComment().c_str(),
@@ -215,12 +215,12 @@ class SocialNavigationTab final : public SocialTab
 
         int getPortalIndex(const int x, const int y)
         {
-            if (!socialWindow)
+            if (socialWindow == nullptr)
                 return -1;
 
             std::vector<Avatar*> *const avatars = mBeings->getMembers();
             const Map *const map = socialWindow->getMap();
-            if (!map)
+            if (map == nullptr)
                 return -1;
 
             std::vector<Avatar*>::const_iterator i = avatars->begin();
@@ -229,7 +229,7 @@ class SocialNavigationTab final : public SocialTab
             while (i != i_end)
             {
                 const Avatar *const ava = *i;
-                if (!ava)
+                if (ava == nullptr)
                     break;
 
                 if (ava->getX() == x && ava->getY() == y)
@@ -243,23 +243,23 @@ class SocialNavigationTab final : public SocialTab
 
         void addPortal(const int x, const int y)
         {
-            if (!socialWindow || !localPlayer)
+            if ((socialWindow == nullptr) || (localPlayer == nullptr))
                 return;
 
             const Map *const map = socialWindow->getMap();
-            if (!map)
+            if (map == nullptr)
                 return;
 
             std::vector<Avatar*> *const avatars = mBeings->getMembers();
             const MapItem *const portal = map->findPortalXY(x, y);
-            if (!portal)
+            if (portal == nullptr)
                 return;
 
             const std::string name = strprintf("%s [%d %d]",
                 portal->getComment().c_str(), x, y);
 
             Avatar *const ava = new Avatar(name);
-            if (localPlayer)
+            if (localPlayer != nullptr)
                 ava->setOnline(localPlayer->isReachable(x, y, true));
             else
                 ava->setOnline(false);
@@ -272,11 +272,11 @@ class SocialNavigationTab final : public SocialTab
 
         void removePortal(const int x, const int y)
         {
-            if (!socialWindow || !localPlayer)
+            if ((socialWindow == nullptr) || (localPlayer == nullptr))
                 return;
 
             const Map *const map = socialWindow->getMap();
-            if (!map)
+            if (map == nullptr)
                 return;
 
             std::vector<Avatar*> *const avatars = mBeings->getMembers();
@@ -287,7 +287,7 @@ class SocialNavigationTab final : public SocialTab
             {
                 Avatar *ava = (*i);
 
-                if (!ava)
+                if (ava == nullptr)
                     break;
 
                 if (ava->getX() == x && ava->getY() == y)
diff --git a/src/gui/widgets/tabs/socialpartytab.h b/src/gui/widgets/tabs/socialpartytab.h
index 93625f7eb..b24f8f411 100644
--- a/src/gui/widgets/tabs/socialpartytab.h
+++ b/src/gui/widgets/tabs/socialpartytab.h
@@ -80,7 +80,7 @@ class SocialPartyTab final : public SocialTab,
                 const std::string name = mInviteDialog->getText();
                 partyHandler->invite(name);
 
-                if (localChatTab)
+                if (localChatTab != nullptr)
                 {
                     localChatTab->chatLog(strprintf(
                         // TRANSLATORS: chat message
@@ -97,7 +97,7 @@ class SocialPartyTab final : public SocialTab,
             else if (eventId == "yes")
             {
                 partyHandler->leave();
-                if (localChatTab)
+                if (localChatTab != nullptr)
                 {
                     localChatTab->chatLog(strprintf(
                         // TRANSLATORS: tab in social window
@@ -139,11 +139,11 @@ class SocialPartyTab final : public SocialTab,
         void buildCounter(const int online0 A_UNUSED,
                           const int total0 A_UNUSED) override final
         {
-            if (!localPlayer)
+            if (localPlayer == nullptr)
                 return;
 
             const Party *const party = localPlayer->getParty();
-            if (!party)
+            if (party == nullptr)
                 return;
 
             const Party::MemberList *const members = party->getMembers();
diff --git a/src/gui/widgets/tabs/socialplayerstab.h b/src/gui/widgets/tabs/socialplayerstab.h
index 2a80b3005..447e0791e 100644
--- a/src/gui/widgets/tabs/socialplayerstab.h
+++ b/src/gui/widgets/tabs/socialplayerstab.h
@@ -71,18 +71,18 @@ class SocialPlayersTab final : public SocialTab
 
         void updateAvatar(const std::string &name) override final
         {
-            if (!actorManager)
+            if (actorManager == nullptr)
                 return;
 
             BLOCK_START("SocialPlayersTab::updateAvatar")
             Avatar *const avatar = findAvatarbyName(name);
-            if (!avatar)
+            if (avatar == nullptr)
                 return;
-            if (Party::getParty(1))
+            if (Party::getParty(1) != nullptr)
             {
                 const PartyMember *const
                     pm = Party::getParty(1)->getMember(name);
-                if (pm && pm->getMaxHp() > 0)
+                if ((pm != nullptr) && pm->getMaxHp() > 0)
                 {
                     avatar->setMaxHp(pm->getMaxHp());
                     avatar->setHp(pm->getHp());
@@ -90,7 +90,7 @@ class SocialPlayersTab final : public SocialTab
             }
             const Being *const being = actorManager->findBeingByName(
                 name, ActorType::Player);
-            if (being)
+            if (being != nullptr)
             {
                 avatar->setDamageHp(being->getDamageTaken());
                 avatar->setLevel(being->getLevel());
@@ -103,17 +103,17 @@ class SocialPlayersTab final : public SocialTab
 
         void resetDamage(const std::string &name) override final
         {
-            if (!actorManager)
+            if (actorManager == nullptr)
                 return;
 
             Avatar *const avatar = findAvatarbyName(name);
-            if (!avatar)
+            if (avatar == nullptr)
                 return;
             avatar->setDamageHp(0);
             Being *const being = actorManager->findBeingByName(
                 name, ActorType::Player);
 
-            if (being)
+            if (being != nullptr)
                 being->setDamageTaken(0);
         }
 
@@ -126,7 +126,7 @@ class SocialPlayersTab final : public SocialTab
             while (i != i_end)
             {
                 ava = (*i);
-                if (ava && ava->getName() == name)
+                if ((ava != nullptr) && ava->getName() == name)
                     return ava;
                 ++i;
             }
@@ -139,7 +139,7 @@ class SocialPlayersTab final : public SocialTab
         void getPlayersAvatars()
         {
             std::vector<Avatar*> *const avatars = mBeings->getMembers();
-            if (actorManager)
+            if (actorManager != nullptr)
             {
                 StringVect names;
                 actorManager->getPlayerNames(names, NpcNames_false);
@@ -149,7 +149,7 @@ class SocialPlayersTab final : public SocialTab
                 {
                     bool finded = false;
                     const Avatar *const ava = (*ai);
-                    if (!ava)
+                    if (ava == nullptr)
                         break;
 
                     StringVectCIter i = names.begin();
diff --git a/src/gui/widgets/tabs/socialtab.h b/src/gui/widgets/tabs/socialtab.h
index 7458e62ee..34f864561 100644
--- a/src/gui/widgets/tabs/socialtab.h
+++ b/src/gui/widgets/tabs/socialtab.h
@@ -88,14 +88,14 @@ class SocialTab notfinal : public Tab
         virtual ~SocialTab()
         {
             // Cleanup dialogs
-            if (mInviteDialog)
+            if (mInviteDialog != nullptr)
             {
                 mInviteDialog->close();
                 mInviteDialog->scheduleDelete();
                 mInviteDialog = nullptr;
             }
 
-            if (mConfirmDialog)
+            if (mConfirmDialog != nullptr)
             {
                 mConfirmDialog->close();
                 mConfirmDialog->scheduleDelete();
@@ -122,13 +122,13 @@ class SocialTab notfinal : public Tab
 
         void updateCounter() const
         {
-            if (socialWindow)
+            if (socialWindow != nullptr)
                 socialWindow->updateCounter(this, mCounterString);
         }
 
         void updateMenu() const
         {
-            if (socialWindow)
+            if (socialWindow != nullptr)
                 socialWindow->updateMenu(this, mMenuAction);
         }
 
diff --git a/src/gui/widgets/tabs/tab.cpp b/src/gui/widgets/tabs/tab.cpp
index 95588e98d..a4a2f583b 100644
--- a/src/gui/widgets/tabs/tab.cpp
+++ b/src/gui/widgets/tabs/tab.cpp
@@ -130,11 +130,11 @@ Tab::Tab(const Widget2 *const widget) :
 
 Tab::~Tab()
 {
-    if (gui)
+    if (gui != nullptr)
         gui->removeDragged(this);
 
     mInstances--;
-    if (mInstances == 0 && theme)
+    if (mInstances == 0 && (theme != nullptr))
     {
         for (int mode = 0; mode < TAB_COUNT; mode ++)
             theme->unload(tabImg[mode]);
@@ -142,7 +142,7 @@ Tab::~Tab()
 
     delete2(mLabel);
 
-    if (mImage)
+    if (mImage != nullptr)
     {
         mImage->decRef();
         mImage = nullptr;
@@ -162,7 +162,7 @@ void Tab::init()
     if (mInstances == 0)
     {
         // Load the skin
-        if (theme)
+        if (theme != nullptr)
         {
             for (int mode = 0; mode < TAB_COUNT; mode ++)
                 tabImg[mode] = theme->load(data[mode], "tab.xml");
@@ -174,7 +174,7 @@ void Tab::init()
     add(mLabel);
 
     const Skin *const skin = tabImg[TAB_STANDARD];
-    if (!skin)
+    if (skin == nullptr)
         return;
     const int padding = skin->getPadding();
 
@@ -194,11 +194,11 @@ void Tab::updateAlpha()
             for (int t = 0; t < TAB_COUNT; t++)
             {
                 Skin *const skin = tabImg[t];
-                if (skin)
+                if (skin != nullptr)
                 {
                     const ImageRect &rect = skin->getBorder();
                     Image *const image = rect.grid[a];
-                    if (image)
+                    if (image != nullptr)
                         image->setAlpha(mAlpha);
                 }
             }
@@ -212,7 +212,7 @@ void Tab::draw(Graphics *const graphics)
     int mode = TAB_STANDARD;
 
     // check which type of tab to draw
-    if (mTabbedArea)
+    if (mTabbedArea != nullptr)
     {
         int labelMode = mFlash;
 
@@ -223,7 +223,7 @@ void Tab::draw(Graphics *const graphics)
             // if tab is selected, it doesnt need to highlight activity
             mFlash = 0;
         }
-        else if (!labelMode)
+        else if (labelMode == 0)
         {
             if (mHasMouse)
             {
@@ -269,7 +269,7 @@ void Tab::draw(Graphics *const graphics)
     }
 
     const Skin *const skin = tabImg[mode];
-    if (!skin)
+    if (skin == nullptr)
     {
         BLOCK_END("Tab::draw")
         return;
@@ -288,10 +288,10 @@ void Tab::draw(Graphics *const graphics)
             mDimension.width, mDimension.height,
             rect);
 
-        if (mImage)
+        if (mImage != nullptr)
         {
             const Skin *const skin1 = tabImg[TAB_STANDARD];
-            if (skin1)
+            if (skin1 != nullptr)
             {
                 const int padding = skin1->getPadding();
                 graphics->calcTileCollection(mVertexes,
@@ -315,7 +315,7 @@ void Tab::safeDraw(Graphics *const graphics)
     int mode = TAB_STANDARD;
 
     // check which type of tab to draw
-    if (mTabbedArea)
+    if (mTabbedArea != nullptr)
     {
         int labelMode = mFlash;
 
@@ -326,7 +326,7 @@ void Tab::safeDraw(Graphics *const graphics)
             // if tab is selected, it doesnt need to highlight activity
             mFlash = 0;
         }
-        else if (!labelMode)
+        else if (labelMode == 0)
         {
             if (mHasMouse)
             {
@@ -370,7 +370,7 @@ void Tab::safeDraw(Graphics *const graphics)
     }
 
     const Skin *const skin = tabImg[mode];
-    if (!skin)
+    if (skin == nullptr)
     {
         BLOCK_END("Tab::draw")
         return;
@@ -381,10 +381,10 @@ void Tab::safeDraw(Graphics *const graphics)
     graphics->drawImageRect(0, 0,
         mDimension.width, mDimension.height,
         skin->getBorder());
-    if (mImage)
+    if (mImage != nullptr)
     {
         const Skin *const skin1 = tabImg[TAB_STANDARD];
-        if (skin1)
+        if (skin1 != nullptr)
         {
             const int padding = skin1->getPadding();
             graphics->drawImage(mImage, padding, padding);
@@ -407,7 +407,7 @@ void Tab::widgetMoved(const Event &event A_UNUSED)
 
 void Tab::setLabelFont(Font *const font)
 {
-    if (!mLabel)
+    if (mLabel == nullptr)
         return;
 
     mLabel->setFont(font);
@@ -420,11 +420,11 @@ void Tab::setLabelFont(Font *const font)
 void Tab::adjustSize()
 {
     const Skin *const skin = tabImg[TAB_STANDARD];
-    if (!skin)
+    if (skin == nullptr)
         return;
     const int pad2 = skin->getPadding() * 2;
 
-    if (mImage)
+    if (mImage != nullptr)
     {
         const SDL_Rect &rect = mImage->mBounds;
         setSize(rect.w + pad2, rect.h + pad2);
@@ -435,7 +435,7 @@ void Tab::adjustSize()
                 mLabel->getHeight() + pad2);
     }
 
-    if (mTabbedArea)
+    if (mTabbedArea != nullptr)
         mTabbedArea->adjustTabPositions();
 }
 
@@ -458,7 +458,7 @@ void Tab::setCaption(const std::string &caption)
 
 void Tab::setImage(Image *const image)
 {
-    if (mImage)
+    if (mImage != nullptr)
         mImage->decRef();
     mImage = image;
     adjustSize();
diff --git a/src/gui/widgets/tabstrip.cpp b/src/gui/widgets/tabstrip.cpp
index 1f8db0d5e..2a8299ea1 100644
--- a/src/gui/widgets/tabstrip.cpp
+++ b/src/gui/widgets/tabstrip.cpp
@@ -50,7 +50,7 @@ Widget *TabStrip::createWidget(const std::string &text,
     widget->setStick(true);
     widget->setCaption(text);
     widget->adjustSize();
-    if ((!mCount && mPressFirst) || pressed)
+    if (((mCount == 0) && mPressFirst) || pressed)
         widget->setPressed(true);
     widget->setTag(CAST_S32(mWidgets.size()));
     return widget;
@@ -59,11 +59,11 @@ Widget *TabStrip::createWidget(const std::string &text,
 void TabStrip::action(const ActionEvent &event)
 {
     WidgetGroup::action(event);
-    if (event.getSource())
+    if (event.getSource() != nullptr)
     {
         Widget *const widget = event.getSource();
         Button *const button = static_cast<Button*>(widget);
-        if (!button)
+        if (button == nullptr)
             return;
         if (button->isPressed2())
         {
diff --git a/src/gui/widgets/textbox.cpp b/src/gui/widgets/textbox.cpp
index 5b8acdb2e..31e000082 100644
--- a/src/gui/widgets/textbox.cpp
+++ b/src/gui/widgets/textbox.cpp
@@ -101,14 +101,14 @@ TextBox::TextBox(const Widget2 *const widget) :
 
 TextBox::~TextBox()
 {
-    if (gui)
+    if (gui != nullptr)
         gui->removeDragged(this);
 }
 
 void TextBox::setTextWrapped(const std::string &text, const int minDimension)
 {
     // Make sure parent scroll area sets width of this widget
-    if (getParent())
+    if (getParent() != nullptr)
         getParent()->logic();
 
     // Take the supplied minimum dimension as a starting
@@ -384,7 +384,7 @@ void TextBox::keyPressed(KeyEvent& event)
         {
             Widget *const par = getParent();
 
-            if (par)
+            if (par != nullptr)
             {
                 const int rowsPerPage = par->getChildrenArea().height
                     / getFont()->getHeight();
@@ -400,7 +400,7 @@ void TextBox::keyPressed(KeyEvent& event)
         {
             Widget *const par = getParent();
 
-            if (par)
+            if (par != nullptr)
             {
                 const int rowsPerPage = par->getChildrenArea().height
                     / getFont()->getHeight();
@@ -605,7 +605,7 @@ void TextBox::mousePressed(MouseEvent& event)
     if (event.getButton() == MouseButton::LEFT)
     {
         const int height = getFont()->getHeight();
-        if (!height)
+        if (height == 0)
             return;
 
         event.consume();
diff --git a/src/gui/widgets/textfield.cpp b/src/gui/widgets/textfield.cpp
index ce37879a4..e536b5b13 100644
--- a/src/gui/widgets/textfield.cpp
+++ b/src/gui/widgets/textfield.cpp
@@ -123,7 +123,7 @@ TextField::TextField(const Widget2 *restrict const widget,
     mCaretColor(&getThemeColor(ThemeColorId::CARET)),
     mMinimum(0),
     mMaximum(0),
-    mLastEventPaste(false),
+    mLastEventPaste(0),
     mPadding(1),
     mNumeric(false),
     mLoseFocusOnTab(loseFocusOnTab),
@@ -144,7 +144,7 @@ TextField::TextField(const Widget2 *restrict const widget,
 
     if (instances == 0)
     {
-        if (theme)
+        if (theme != nullptr)
         {
             mSkin = theme->loadSkinRect(skin, "textfield.xml",
                 "textfield_background.xml");
@@ -153,7 +153,7 @@ TextField::TextField(const Widget2 *restrict const widget,
 
     instances++;
 
-    if (mSkin)
+    if (mSkin != nullptr)
     {
         mPadding = mSkin->getPadding();
         mFrameSize = mSkin->getOption("frameSize", 2);
@@ -163,22 +163,22 @@ TextField::TextField(const Widget2 *restrict const widget,
     if (!eventId.empty())
         setActionEventId(eventId);
 
-    if (listener)
+    if (listener != nullptr)
         addActionListener(listener);
 }
 
 TextField::~TextField()
 {
-    if (mWindow)
+    if (mWindow != nullptr)
         mWindow->removeWidgetListener(this);
 
-    if (gui)
+    if (gui != nullptr)
         gui->removeDragged(this);
 
     instances--;
     if (instances == 0)
     {
-        if (theme)
+        if (theme != nullptr)
         {
             theme->unload(mSkin);
             Theme::unloadRect(skin);
@@ -197,7 +197,7 @@ void TextField::updateAlpha()
         mAlpha = alpha;
         for (int a = 0; a < 9; a++)
         {
-            if (skin.grid[a])
+            if (skin.grid[a] != nullptr)
                 skin.grid[a]->setAlpha(mAlpha);
         }
     }
@@ -227,7 +227,7 @@ void TextField::draw(Graphics *const graphics)
     }
 
     const Image *const image = mTextChunk.img;
-    if (image)
+    if (image != nullptr)
         graphics->drawImage(image, mPadding - mXScroll, mPadding);
 
     BLOCK_END("TextField::draw")
@@ -269,7 +269,7 @@ void TextField::setNumeric(const bool numeric)
         return;
 
     const char *const text = mText.c_str();
-    for (const char *textPtr = text; *textPtr; ++textPtr)
+    for (const char *textPtr = text; *textPtr != 0; ++textPtr)
     {
         if (*textPtr < '0' || *textPtr > '9')
         {
@@ -318,7 +318,8 @@ void TextField::keyPressed(KeyEvent &event)
     {
         if (mNumeric)
         {
-            if ((val >= '0' && val <= '9') || (val == '-' && !mCaretPosition))
+            if ((val >= '0' && val <= '9') ||
+                (val == '-' && mCaretPosition == 0u))
             {
                 char buf[2];
                 buf[0] = CAST_8(val);
@@ -333,7 +334,7 @@ void TextField::keyPressed(KeyEvent &event)
                 return;
             }
         }
-        else if (!mMaximum ||
+        else if ((mMaximum == 0) ||
                  CAST_S32(mText.size()) < mMaximum)
         {
             int len;
@@ -566,7 +567,7 @@ void TextField::handleCtrlKeys(const InputActionT action, bool &consumed)
 #else  // USE_SDL2
 
             // hack to prevent paste key sticking
-            if (mLastEventPaste && mLastEventPaste > cur_time)
+            if ((mLastEventPaste != 0) && mLastEventPaste > cur_time)
                 break;
             handlePaste();
             mLastEventPaste = cur_time + 2;
@@ -771,7 +772,7 @@ void TextField::mousePressed(MouseEvent &event)
     if (event.getButton() == MouseButton::RIGHT)
     {
 #ifndef DYECMD
-        if (popupMenu)
+        if (popupMenu != nullptr)
             popupMenu->showTextFieldPopup(this);
 #endif  // DYECMD
     }
@@ -817,14 +818,14 @@ void TextField::widgetHidden(const Event &event A_UNUSED)
 
 void TextField::setParent(Widget *widget)
 {
-    if (mWindow)
+    if (mWindow != nullptr)
         mWindow->addWidgetListener(this);
     Widget::setParent(widget);
 }
 
 void TextField::setWindow(Widget *const widget)
 {
-    if (!widget && mWindow)
+    if ((widget == nullptr) && (mWindow != nullptr))
     {
         mWindow->removeWidgetListener(this);
         mWindow = nullptr;
diff --git a/src/gui/widgets/textpreview.cpp b/src/gui/widgets/textpreview.cpp
index 04d2b39aa..53f84badc 100644
--- a/src/gui/widgets/textpreview.cpp
+++ b/src/gui/widgets/textpreview.cpp
@@ -55,13 +55,13 @@ TextPreview::TextPreview(const Widget2 *const widget,
     mAllowLogic = false;
     if (instances == 0)
     {
-        if (theme)
+        if (theme != nullptr)
             mSkin = theme->load("textpreview.xml", "");
     }
 
     instances++;
 
-    if (mSkin)
+    if (mSkin != nullptr)
         mPadding = mSkin->getOption("padding", 0);
 
     adjustSize();
@@ -69,21 +69,21 @@ TextPreview::TextPreview(const Widget2 *const widget,
 
 TextPreview::~TextPreview()
 {
-    if (gui)
+    if (gui != nullptr)
         gui->removeDragged(this);
 
     instances--;
 
     if (instances == 0)
     {
-        if (theme)
+        if (theme != nullptr)
             theme->unload(mSkin);
     }
 }
 
 void TextPreview::draw(Graphics *const graphics)
 {
-    if (!mFont)
+    if (mFont == nullptr)
         return;
 
     BLOCK_START("TextPreview::draw")
@@ -103,7 +103,7 @@ void TextPreview::draw(Graphics *const graphics)
             mDimension.width, mDimension.height));
     }
 
-    if (mTextBGColor)
+    if (mTextBGColor != nullptr)
     {
         const int x = mFont->getWidth(mText) + 1
             + 2 * ((mOutline || mShadow) ? 1 :0);
diff --git a/src/gui/widgets/vertcontainer.cpp b/src/gui/widgets/vertcontainer.cpp
index 9aaad702d..e15dc2481 100644
--- a/src/gui/widgets/vertcontainer.cpp
+++ b/src/gui/widgets/vertcontainer.cpp
@@ -48,7 +48,7 @@ void VertContainer::add1(Widget *const widget, const int spacing)
 void VertContainer::add2(Widget *const widget, const bool resizable,
                          const int spacing)
 {
-    if (!widget)
+    if (widget == nullptr)
         return;
 
     Container::add(widget);
diff --git a/src/gui/widgets/virtshortcutcontainer.cpp b/src/gui/widgets/virtshortcutcontainer.cpp
index dda7217c4..6b7642a3d 100644
--- a/src/gui/widgets/virtshortcutcontainer.cpp
+++ b/src/gui/widgets/virtshortcutcontainer.cpp
@@ -52,7 +52,7 @@ VirtShortcutContainer::VirtShortcutContainer(Widget2 *const widget,
     mUnEquipedColor2(getThemeColor(ThemeColorId::ITEM_NOT_EQUIPPED_OUTLINE)),
     mShortcut(shortcut)
 {
-    if (mShortcut)
+    if (mShortcut != nullptr)
         mMaxItems = mShortcut->getItemCount();
     else
         mMaxItems = 0;
@@ -73,21 +73,21 @@ void VirtShortcutContainer::setWidget2(const Widget2 *const widget)
 
 void VirtShortcutContainer::draw(Graphics *const graphics)
 {
-    if (!mShortcut)
+    if (mShortcut == nullptr)
         return;
 
     BLOCK_START("VirtShortcutContainer::draw")
     if (settings.guiAlpha != mAlpha)
     {
         mAlpha = settings.guiAlpha;
-        if (mBackgroundImg)
+        if (mBackgroundImg != nullptr)
             mBackgroundImg->setAlpha(mAlpha);
     }
 
     drawBackground(graphics);
 
     const Inventory *const inv = PlayerInfo::getInventory();
-    if (!inv)
+    if (inv == nullptr)
     {
         BLOCK_END("VirtShortcutContainer::draw")
         return;
@@ -106,12 +106,12 @@ void VirtShortcutContainer::draw(Graphics *const graphics)
         const Item *const item = inv->findItem(mShortcut->getItem(i),
             mShortcut->getItemColor(i));
 
-        if (item)
+        if (item != nullptr)
         {
             // Draw item icon.
             Image *const image = item->getImage();
 
-            if (image)
+            if (image != nullptr)
             {
                 std::string caption;
                 if (item->getQuantity() > 1)
@@ -147,21 +147,21 @@ void VirtShortcutContainer::draw(Graphics *const graphics)
 
 void VirtShortcutContainer::safeDraw(Graphics *const graphics)
 {
-    if (!mShortcut)
+    if (mShortcut == nullptr)
         return;
 
     BLOCK_START("VirtShortcutContainer::safeDraw")
     if (settings.guiAlpha != mAlpha)
     {
         mAlpha = settings.guiAlpha;
-        if (mBackgroundImg)
+        if (mBackgroundImg != nullptr)
             mBackgroundImg->setAlpha(mAlpha);
     }
 
     safeDrawBackground(graphics);
 
     const Inventory *const inv = PlayerInfo::getInventory();
-    if (!inv)
+    if (inv == nullptr)
     {
         BLOCK_END("VirtShortcutContainer::safeDraw")
         return;
@@ -180,12 +180,12 @@ void VirtShortcutContainer::safeDraw(Graphics *const graphics)
         const Item *const item = inv->findItem(mShortcut->getItem(i),
             mShortcut->getItemColor(i));
 
-        if (item)
+        if (item != nullptr)
         {
             // Draw item icon.
             Image *const image = item->getImage();
 
-            if (image)
+            if (image != nullptr)
             {
                 std::string caption;
                 if (item->getQuantity() > 1)
@@ -221,7 +221,7 @@ void VirtShortcutContainer::safeDraw(Graphics *const graphics)
 
 void VirtShortcutContainer::mouseDragged(MouseEvent &event)
 {
-    if (!mShortcut)
+    if (mShortcut == nullptr)
         return;
 
     if (event.getButton() == MouseButton::LEFT)
@@ -240,12 +240,12 @@ void VirtShortcutContainer::mouseDragged(MouseEvent &event)
                 return;
 
             const Inventory *const inv = PlayerInfo::getInventory();
-            if (!inv)
+            if (inv == nullptr)
                 return;
 
             Item *const item = inv->findItem(itemId, itemColor);
 
-            if (item)
+            if (item != nullptr)
             {
                 dragDrop.dragItem(item, DragDropSource::Drop);
                 mShortcut->removeItem(index);
@@ -260,7 +260,7 @@ void VirtShortcutContainer::mouseDragged(MouseEvent &event)
 
 void VirtShortcutContainer::mousePressed(MouseEvent &event)
 {
-    if (!mShortcut || !inventoryWindow)
+    if ((mShortcut == nullptr) || (inventoryWindow == nullptr))
         return;
 
     const int index = getIndexFromGrid(event.getX(), event.getY());
@@ -290,13 +290,13 @@ void VirtShortcutContainer::mousePressed(MouseEvent &event)
     else if (eventButton == MouseButton::RIGHT)
     {
         const Inventory *const inv = PlayerInfo::getInventory();
-        if (!inv)
+        if (inv == nullptr)
             return;
 
         Item *const item = inv->findItem(mShortcut->getItem(index),
             mShortcut->getItemColor(index));
 
-        if (popupMenu)
+        if (popupMenu != nullptr)
         {
             popupMenu->showDropPopup(viewport->mMouseX,
                 viewport->mMouseY,
@@ -307,7 +307,7 @@ void VirtShortcutContainer::mousePressed(MouseEvent &event)
 
 void VirtShortcutContainer::mouseReleased(MouseEvent &event)
 {
-    if (!mShortcut)
+    if (mShortcut == nullptr)
         return;
 
     if (event.getButton() == MouseButton::LEFT)
@@ -339,7 +339,7 @@ void VirtShortcutContainer::mouseReleased(MouseEvent &event)
 // Show ItemTooltip
 void VirtShortcutContainer::mouseMoved(MouseEvent &event)
 {
-    if (!mShortcut)
+    if (mShortcut == nullptr)
         return;
 
     const int index = getIndexFromGrid(event.getX(), event.getY());
@@ -354,12 +354,12 @@ void VirtShortcutContainer::mouseMoved(MouseEvent &event)
         return;
 
     const Inventory *const inv = PlayerInfo::getInventory();
-    if (!inv)
+    if (inv == nullptr)
         return;
 
     const Item *const item = inv->findItem(itemId, itemColor);
 
-    if (item && viewport)
+    if ((item != nullptr) && (viewport != nullptr))
     {
         itemPopup->setItem(item, false);
         itemPopup->position(viewport->mMouseX, viewport->mMouseY);
@@ -372,12 +372,12 @@ void VirtShortcutContainer::mouseMoved(MouseEvent &event)
 
 void VirtShortcutContainer::mouseExited(MouseEvent &event A_UNUSED)
 {
-    if (itemPopup)
+    if (itemPopup != nullptr)
         itemPopup->setVisible(Visible_false);
 }
 
 void VirtShortcutContainer::widgetHidden(const Event &event A_UNUSED)
 {
-    if (itemPopup)
+    if (itemPopup != nullptr)
         itemPopup->setVisible(Visible_false);
 }
diff --git a/src/gui/widgets/widget.cpp b/src/gui/widgets/widget.cpp
index 9523cb4b5..260272936 100644
--- a/src/gui/widgets/widget.cpp
+++ b/src/gui/widgets/widget.cpp
@@ -179,7 +179,7 @@ void Widget::setDimension(const Rect& dimension)
 
 bool Widget::isFocused() const
 {
-    if (!mFocusHandler)
+    if (mFocusHandler == nullptr)
         return false;
 
     return (mFocusHandler->isFocused(this));
@@ -187,7 +187,7 @@ bool Widget::isFocused() const
 
 void Widget::setFocusable(const bool focusable)
 {
-    if (!focusable && isFocused() && mFocusHandler)
+    if (!focusable && isFocused() && (mFocusHandler != nullptr))
         mFocusHandler->focusNone();
     mFocusable = focusable;
 }
@@ -199,7 +199,7 @@ bool Widget::isFocusable() const
 
 void Widget::requestFocus()
 {
-    if (!mFocusHandler)
+    if (mFocusHandler == nullptr)
         return;
 
     if (isFocusable())
@@ -208,19 +208,19 @@ void Widget::requestFocus()
 
 void Widget::requestMoveToTop()
 {
-    if (mParent)
+    if (mParent != nullptr)
         mParent->moveToTop(this);
 }
 
 void Widget::requestMoveToBottom()
 {
-    if (mParent)
+    if (mParent != nullptr)
         mParent->moveToBottom(this);
 }
 
 void Widget::setVisible(Visible visible)
 {
-    if (visible == Visible_false && isFocused() && mFocusHandler)
+    if (visible == Visible_false && isFocused() && (mFocusHandler != nullptr))
         mFocusHandler->focusNone();
 
     if (visible == Visible_true)
@@ -233,13 +233,13 @@ void Widget::setVisible(Visible visible)
 
 void Widget::setFocusHandler(FocusHandler *const focusHandler)
 {
-    if (mFocusHandler)
+    if (mFocusHandler != nullptr)
     {
         releaseModalFocus();
         mFocusHandler->remove(this);
     }
 
-    if (focusHandler)
+    if (focusHandler != nullptr)
         focusHandler->add(this);
 
     mFocusHandler = focusHandler;
@@ -307,7 +307,7 @@ void Widget::removeWidgetListener(WidgetListener *const widgetListener)
 
 void Widget::getAbsolutePosition(int& x, int& y) const
 {
-    if (!mParent)
+    if (mParent == nullptr)
     {
         x = mDimension.x;
         y = mDimension.y;
@@ -326,7 +326,7 @@ void Widget::getAbsolutePosition(int& x, int& y) const
 
 Font* Widget::getFont() const
 {
-    if (!mCurrentFont)
+    if (mCurrentFont == nullptr)
         return mGlobalFont;
     return mCurrentFont;
 }
@@ -337,7 +337,7 @@ void Widget::setGlobalFont(Font *const font)
 
     FOR_EACH (std::list<Widget*>::const_iterator, iter, mAllWidgets)
     {
-        if (!(*iter)->mCurrentFont)
+        if ((*iter)->mCurrentFont == nullptr)
             (*iter)->fontChanged();
     }
 }
@@ -375,38 +375,38 @@ bool Widget::isEnabled() const
 
 void Widget::requestModalFocus()
 {
-    if (!mFocusHandler)
+    if (mFocusHandler == nullptr)
         return;
     mFocusHandler->requestModalFocus(this);
 }
 
 void Widget::requestModalMouseInputFocus()
 {
-    if (!mFocusHandler)
+    if (mFocusHandler == nullptr)
         return;
     mFocusHandler->requestModalMouseInputFocus(this);
 }
 
 void Widget::releaseModalFocus()
 {
-    if (!mFocusHandler)
+    if (mFocusHandler == nullptr)
         return;
     mFocusHandler->releaseModalFocus(this);
 }
 
 void Widget::releaseModalMouseInputFocus()
 {
-    if (!mFocusHandler)
+    if (mFocusHandler == nullptr)
         return;
     mFocusHandler->releaseModalMouseInputFocus(this);
 }
 
 bool Widget::isModalFocused() const
 {
-    if (!mFocusHandler)
+    if (mFocusHandler == nullptr)
         return false;
 
-    if (mParent)
+    if (mParent != nullptr)
     {
         return (mFocusHandler->getModalFocused() == this)
             || mParent->isModalFocused();
@@ -417,10 +417,10 @@ bool Widget::isModalFocused() const
 
 bool Widget::isModalMouseInputFocused() const
 {
-    if (!mFocusHandler)
+    if (mFocusHandler == nullptr)
         return false;
 
-    if (mParent)
+    if (mParent != nullptr)
     {
         return (mFocusHandler->getModalMouseInputFocused() == this)
             || mParent->isModalMouseInputFocused();
@@ -506,7 +506,7 @@ void Widget::distributeShownEvent()
 
 void Widget::showPart(const Rect &rectangle)
 {
-    if (mParent)
+    if (mParent != nullptr)
         mParent->showWidgetPart(this, rectangle);
 }
 
@@ -517,7 +517,7 @@ void Widget::windowResized()
 
 Widget *Widget::callPostInit(Widget *const widget)
 {
-    if (widget)
+    if (widget != nullptr)
         widget->postInit();
     return widget;
 }
diff --git a/src/gui/widgets/widget.h b/src/gui/widgets/widget.h
index 2a8cae343..bbb1bc103 100644
--- a/src/gui/widgets/widget.h
+++ b/src/gui/widgets/widget.h
@@ -377,7 +377,7 @@ class Widget notfinal : public Widget2
         bool isVisible() const A_WARN_UNUSED
         {
             return mVisible == Visible_true &&
-                (!mParent || mParent->isVisible());
+                ((mParent == nullptr) || mParent->isVisible());
         }
 
         /**
diff --git a/src/gui/widgets/widget2.h b/src/gui/widgets/widget2.h
index d76bd696e..ed9110ba4 100644
--- a/src/gui/widgets/widget2.h
+++ b/src/gui/widgets/widget2.h
@@ -52,7 +52,7 @@ class Widget2 notfinal
                                               bool &valid)
                                               const A_WARN_UNUSED A_INLINE
         {
-            if (!theme)
+            if (theme == nullptr)
                 return Palette::BLACK;
             const ThemeColorIdT colorId = theme->getIdByChar(c, valid);
             if (valid)
@@ -63,7 +63,7 @@ class Widget2 notfinal
 
         virtual void setWidget2(const Widget2 *const widget)
         {
-            mPaletteOffset = widget ? widget->mPaletteOffset : 0;
+            mPaletteOffset = widget != nullptr ? widget->mPaletteOffset : 0;
         }
 
         void setPalette(int palette)
@@ -101,8 +101,8 @@ class Widget2 notfinal
 
     protected:
         explicit Widget2(const Widget2 *const widget) :
-            mPaletteOffset(widget ? widget->mPaletteOffset : 0),
-            mWindow(widget ? widget->getWindow() : nullptr),
+            mPaletteOffset(widget != nullptr ? widget->mPaletteOffset : 0),
+            mWindow(widget != nullptr ? widget->getWindow() : nullptr),
             mForegroundColor2()
         {
             checkPalette();
diff --git a/src/gui/widgets/widgetgroup.cpp b/src/gui/widgets/widgetgroup.cpp
index 18bd81a4f..72524b07c 100644
--- a/src/gui/widgets/widgetgroup.cpp
+++ b/src/gui/widgets/widgetgroup.cpp
@@ -46,7 +46,7 @@ void WidgetGroup::addButton(const std::string &restrict text,
         return;
 
     Widget *const widget = createWidget(text, pressed);
-    if (widget)
+    if (widget != nullptr)
     {
         widget->setActionEventId(mActionEventId + tag);
         widget->addActionListener(this);
@@ -66,7 +66,7 @@ void WidgetGroup::action(const ActionEvent &event)
 void WidgetGroup::addWidget(Widget *const widget,
                             const int spacing)
 {
-    if (!widget)
+    if (widget == nullptr)
         return;
 
     Container::add(widget);
diff --git a/src/gui/widgets/window.cpp b/src/gui/widgets/window.cpp
index 86c2188d1..4a3103b99 100644
--- a/src/gui/widgets/window.cpp
+++ b/src/gui/widgets/window.cpp
@@ -180,10 +180,10 @@ Window::Window(const std::string &caption,
 
     int childPalette = 1;
     // Loads the skin
-    if (theme)
+    if (theme != nullptr)
     {
         mSkin = theme->load(skin, "window.xml");
-        if (mSkin)
+        if (mSkin != nullptr)
         {
             setPadding(mSkin->getPadding());
             if (getOptionBool("titlebarBold"))
@@ -191,10 +191,10 @@ Window::Window(const std::string &caption,
             mTitlePadding = mSkin->getTitlePadding();
             mGripPadding = getOption("resizePadding");
             mCaptionOffsetX = getOption("captionoffsetx");
-            if (!mCaptionOffsetX)
+            if (mCaptionOffsetX == 0)
                 mCaptionOffsetX = 7;
             mCaptionOffsetY = getOption("captionoffsety");
-            if (!mCaptionOffsetY)
+            if (mCaptionOffsetY == 0)
                 mCaptionOffsetY = 5;
             mCaptionAlign = static_cast<Graphics::Alignment>(
                 getOption("captionalign"));
@@ -205,7 +205,7 @@ Window::Window(const std::string &caption,
             }
             setTitleBarHeight(CAST_U32(
                 getOption("titlebarHeight")));
-            if (!mTitleBarHeight)
+            if (mTitleBarHeight == 0u)
                 mTitleBarHeight = mCaptionFont->getHeight() + mPadding;
 
             mTitleBarHeight += getOption("titlebarHeightRelative");
@@ -219,7 +219,7 @@ Window::Window(const std::string &caption,
     }
 
     // Add this window to the window container
-    if (windowContainer)
+    if (windowContainer != nullptr)
         windowContainer->add(this);
 
     if (mModal == Modal_true)
@@ -241,11 +241,11 @@ Window::~Window()
 {
     logger->log("Window::~Window(\"%s\")", getCaption().c_str());
 
-    if (gui)
+    if (gui != nullptr)
         gui->removeDragged(this);
 
 #ifndef DYECMD
-    if (setupWindow)
+    if (setupWindow != nullptr)
         setupWindow->unregisterWindowForReset(this);
 #endif  // DYECMD
 
@@ -265,13 +265,13 @@ Window::~Window()
 
     windowInstances--;
 
-    if (mSkin)
+    if (mSkin != nullptr)
     {
-        if (theme)
+        if (theme != nullptr)
             theme->unload(mSkin);
         mSkin = nullptr;
     }
-    if (mGrip)
+    if (mGrip != nullptr)
     {
         mGrip->decRef();
         mGrip = nullptr;
@@ -290,7 +290,7 @@ void Window::setWindowContainer(WindowContainer *const wc)
 
 void Window::draw(Graphics *const graphics)
 {
-    if (!mSkin)
+    if (mSkin == nullptr)
         return;
 
     BLOCK_START("Window::draw")
@@ -318,7 +318,7 @@ void Window::draw(Graphics *const graphics)
         {
             const Image *const button = mSkin->getCloseImage(
                 mResizeHandles == CLOSE);
-            if (button)
+            if (button != nullptr)
             {
                 graphics->calcTileCollection(mVertexes,
                     button,
@@ -330,7 +330,7 @@ void Window::draw(Graphics *const graphics)
         if (mStickyButton)
         {
             const Image *const button = mSkin->getStickyImage(mSticky);
-            if (button)
+            if (button != nullptr)
             {
                 graphics->calcTileCollection(mVertexes,
                     button,
@@ -339,7 +339,7 @@ void Window::draw(Graphics *const graphics)
             }
         }
 
-        if (mGrip)
+        if (mGrip != nullptr)
         {
             graphics->calcTileCollection(mVertexes,
                 mGrip,
@@ -383,7 +383,7 @@ void Window::draw(Graphics *const graphics)
         }
 
         const Image *const image = mTextChunk.img;
-        if (image)
+        if (image != nullptr)
             graphics->drawImage(image, x, mCaptionOffsetY);
     }
 
@@ -402,7 +402,7 @@ void Window::draw(Graphics *const graphics)
 
 void Window::safeDraw(Graphics *const graphics)
 {
-    if (!mSkin)
+    if (mSkin == nullptr)
         return;
 
     BLOCK_START("Window::safeDraw")
@@ -417,18 +417,18 @@ void Window::safeDraw(Graphics *const graphics)
     {
         const Image *const button = mSkin->getCloseImage(
             mResizeHandles == CLOSE);
-        if (button)
+        if (button != nullptr)
             graphics->drawImage(button, mCloseRect.x, mCloseRect.y);
     }
     // Draw Sticky Button
     if (mStickyButton)
     {
         const Image *const button = mSkin->getStickyImage(mSticky);
-        if (button)
+        if (button != nullptr)
             graphics->drawImage(button, mStickyRect.x, mStickyRect.y);
     }
 
-    if (mGrip)
+    if (mGrip != nullptr)
         graphics->drawImage(mGrip, mGripRect.x, mGripRect.y);
 
     // Draw title
@@ -460,7 +460,7 @@ void Window::safeDraw(Graphics *const graphics)
         }
 
         const Image *const image = mTextChunk.img;
-        if (image)
+        if (image != nullptr)
             graphics->drawImage(image, x, mCaptionOffsetY);
     }
 
@@ -488,7 +488,7 @@ void Window::setContentSize(int width, int height)
 
 void Window::setLocationRelativeTo(const Widget *const widget)
 {
-    if (!widget)
+    if (widget == nullptr)
         return;
 
     int wx, wy;
@@ -505,7 +505,7 @@ void Window::setLocationRelativeTo(const Widget *const widget)
 
 void Window::setLocationHorisontallyRelativeTo(const Widget *const widget)
 {
-    if (!widget)
+    if (widget == nullptr)
         return;
 
     int wx, wy;
@@ -566,7 +566,7 @@ void Window::setLocationRelativeTo(const ImagePosition::Type &position,
 
 void Window::setMinWidth(const int width)
 {
-    if (mSkin)
+    if (mSkin != nullptr)
     {
         mMinWinWidth = width > mSkin->getMinWidth()
             ? width : mSkin->getMinWidth();
@@ -579,7 +579,7 @@ void Window::setMinWidth(const int width)
 
 void Window::setMinHeight(const int height)
 {
-    if (mSkin)
+    if (mSkin != nullptr)
     {
         mMinWinHeight = height > mSkin->getMinHeight()
             ? height : mSkin->getMinHeight();
@@ -605,12 +605,12 @@ void Window::setResizable(const bool r)
     if ((mGrip != nullptr) == r)
         return;
 
-    if (mGrip)
+    if (mGrip != nullptr)
         mGrip->decRef();
     if (r)
     {
         mGrip = Theme::getImageFromThemeXml("resize.xml", "");
-        if (mGrip)
+        if (mGrip != nullptr)
         {
             mGripRect.x = mDimension.width - mGrip->getWidth() - mGripPadding;
             mGripRect.y = mDimension.height - mGrip->getHeight()
@@ -632,26 +632,26 @@ void Window::widgetResized(const Event &event A_UNUSED)
 {
     const Rect area = getChildrenArea();
 
-    if (mGrip)
+    if (mGrip != nullptr)
     {
         mGripRect.x = mDimension.width - mGrip->getWidth() - mGripPadding;
         mGripRect.y = mDimension.height - mGrip->getHeight() - mGripPadding;
     }
 
-    if (mLayout)
+    if (mLayout != nullptr)
     {
         int w = area.width;
         int h = area.height;
         mLayout->reflow(w, h);
     }
-    if (mSkin)
+    if (mSkin != nullptr)
     {
         const bool showClose = mCloseWindowButton
-            && mSkin->getCloseImage(false);
+            && (mSkin->getCloseImage(false) != nullptr);
         if (showClose)
         {
             const Image *const button = mSkin->getCloseImage(false);
-            if (button)
+            if (button != nullptr)
             {
                 const int buttonWidth = button->getWidth();
                 mCloseRect.x = mDimension.width - buttonWidth - mClosePadding;
@@ -663,7 +663,7 @@ void Window::widgetResized(const Event &event A_UNUSED)
         if (mStickyButton)
         {
             const Image *const button = mSkin->getStickyImage(mSticky);
-            if (button)
+            if (button != nullptr)
             {
                 const int buttonWidth = button->getWidth();
                 int x = mDimension.width - buttonWidth
@@ -709,10 +709,10 @@ void Window::widgetHidden(const Event &event A_UNUSED)
     mTextChanged = true;
     mRedraw = true;
 
-    if (gui)
+    if (gui != nullptr)
         gui->setCursorType(Cursor::CURSOR_POINTER);
 
-    if (!mFocusHandler)
+    if (mFocusHandler == nullptr)
         return;
 
     for (WidgetListConstIterator it = mWidgets.begin();
@@ -732,7 +732,7 @@ void Window::setCloseButton(const bool flag)
 
 bool Window::isResizable() const
 {
-    return mGrip;
+    return mGrip != nullptr;
 }
 
 void Window::setStickyButton(const bool flag)
@@ -781,11 +781,11 @@ void Window::setVisible(const Visible visible, const bool forceSticky)
     {
         if (mPlayVisibleSound)
             soundManager.playGuiSound(SOUND_SHOW_WINDOW);
-        if (gui)
+        if (gui != nullptr)
         {
             MouseEvent *const event = reinterpret_cast<MouseEvent*>(
                 gui->createMouseEvent(this));
-            if (event)
+            if (event != nullptr)
             {
                 const int x = event->getX();
                 const int y = event->getY();
@@ -817,7 +817,7 @@ void Window::mousePressed(MouseEvent &event)
 
     if (event.getSource() == this)
     {
-        if (getParent())
+        if (getParent() != nullptr)
             getParent()->moveToTop(this);
 
         mDragOffsetX = event.getX();
@@ -832,21 +832,25 @@ void Window::mousePressed(MouseEvent &event)
         const int y = event.getY();
 
         // Handle close button
-        if (mCloseWindowButton && mSkin && mCloseRect.isPointInRect(x, y))
+        if (mCloseWindowButton &&
+            mSkin != nullptr &&
+            mCloseRect.isPointInRect(x, y))
         {
             mouseResize = 0;
-            mMoved = 0;
+            mMoved = false;
             event.consume();
             close();
             return;
         }
 
         // Handle sticky button
-        if (mStickyButton && mSkin && mStickyRect.isPointInRect(x, y))
+        if (mStickyButton &&
+            mSkin != nullptr &&
+            mStickyRect.isPointInRect(x, y))
         {
             setSticky(!isSticky());
             mouseResize = 0;
-            mMoved = 0;
+            mMoved = false;
             event.consume();
             return;
         }
@@ -856,14 +860,14 @@ void Window::mousePressed(MouseEvent &event)
         if (mouseResize != 0)
             event.consume();
         if (canMove())
-            mMoved = !mouseResize;
+            mMoved = (mouseResize == 0);
         else
             mMoved = false;
     }
 #ifndef DYECMD
     else if (button == MouseButton::RIGHT)
     {
-        if (popupMenu)
+        if (popupMenu != nullptr)
         {
             event.consume();
             popupMenu->showWindowPopup(this);
@@ -879,10 +883,10 @@ void Window::close()
 
 void Window::mouseReleased(MouseEvent &event A_UNUSED)
 {
-    if (mGrip && mouseResize)
+    if ((mGrip != nullptr) && (mouseResize != 0))
     {
         mouseResize = 0;
-        if (gui)
+        if (gui != nullptr)
             gui->setCursorType(Cursor::CURSOR_POINTER);
     }
 
@@ -896,13 +900,13 @@ void Window::mouseEntered(MouseEvent &event)
 
 void Window::mouseExited(MouseEvent &event A_UNUSED)
 {
-    if (mGrip && !mouseResize && gui)
+    if ((mGrip != nullptr) && (mouseResize == 0) && (gui != nullptr))
         gui->setCursorType(Cursor::CURSOR_POINTER);
 }
 
 void Window::updateResizeHandler(MouseEvent &event)
 {
-    if (!gui)
+    if (gui == nullptr)
         return;
 
 #ifndef DYECMD
@@ -940,7 +944,7 @@ void Window::updateResizeHandler(MouseEvent &event)
 void Window::mouseMoved(MouseEvent &event)
 {
     updateResizeHandler(event);
-    if (popupManager && !event.isConsumed())
+    if ((popupManager != nullptr) && !event.isConsumed())
     {
         popupManager->hideBeingPopup();
         popupManager->hideTextPopup();
@@ -983,31 +987,31 @@ void Window::mouseDragged(MouseEvent &event)
             std::max(0, mDimension.y)));
     }
 
-    if (mouseResize && !mMoved)
+    if ((mouseResize != 0) && !mMoved)
     {
         const int dx = event.getX() - mDragOffsetX;
         const int dy = event.getY() - mDragOffsetY;
         Rect newDim = getDimension();
 
-        if (mouseResize & (TOP | BOTTOM))
+        if ((mouseResize & (TOP | BOTTOM)) != 0)
         {
             const int newHeight = newDim.height
-                + ((mouseResize & TOP) ? -dy : dy);
+                + ((mouseResize & TOP) != 0 ? -dy : dy);
             newDim.height = std::min(mMaxWinHeight,
                 std::max(mMinWinHeight, newHeight));
 
-            if (mouseResize & TOP)
+            if ((mouseResize & TOP) != 0)
                 newDim.y -= newDim.height - getHeight();
         }
 
-        if (mouseResize & (LEFT | RIGHT))
+        if ((mouseResize & (LEFT | RIGHT)) != 0)
         {
             const int newWidth = newDim.width
-                + ((mouseResize & LEFT) ? -dx : dx);
+                + ((mouseResize & LEFT) != 0 ? -dx : dx);
             newDim.width = std::min(mMaxWinWidth,
                 std::max(mMinWinWidth, newWidth));
 
-            if (mouseResize & LEFT)
+            if ((mouseResize & LEFT) != 0)
                 newDim.x -= newDim.width - mDimension.width;
         }
 
@@ -1028,10 +1032,10 @@ void Window::mouseDragged(MouseEvent &event)
             newDim.height = mainGraphics->mHeight - newDim.y;
 
         // Update mouse offset when dragging bottom or right border
-        if (mouseResize & BOTTOM)
+        if ((mouseResize & BOTTOM) != 0)
             mDragOffsetY += newDim.height - mDimension.height;
 
-        if (mouseResize & RIGHT)
+        if ((mouseResize & RIGHT) != 0)
             mDragOffsetX += newDim.width - mDimension.width;
 
         // Set the new window and content dimensions
@@ -1046,7 +1050,7 @@ void Window::setModal(const Modal modal)
         mModal = modal;
         if (mModal == Modal_true)
         {
-            if (gui)
+            if (gui != nullptr)
                 gui->setCursorType(Cursor::CURSOR_POINTER);
             requestModalFocus();
         }
@@ -1078,7 +1082,7 @@ void Window::loadWindowState()
             + "Sticky", isSticky()));
     }
 
-    if (mGrip)
+    if (mGrip != nullptr)
     {
         int width = config.getValueInt(name + "WinWidth", mDefaultWidth);
         int height = config.getValueInt(name + "WinHeight", mDefaultHeight);
@@ -1102,7 +1106,7 @@ void Window::loadWindowState()
     // Check if the window is off screen...
     ensureOnScreen();
 
-    if (viewport)
+    if (viewport != nullptr)
     {
         int width = mDimension.width;
         int height = mDimension.height;
@@ -1133,7 +1137,7 @@ void Window::saveWindowState()
         if (mStickyButton)
             config.setValue(mWindowName + "Sticky", isSticky());
 
-        if (mGrip)
+        if (mGrip != nullptr)
         {
             if (getMinWidth() > mDimension.width)
                 setWidth(getMinWidth());
@@ -1257,7 +1261,7 @@ void Window::adjustPositionAfterResize(const int oldScreenWidth,
 
 void Window::adjustSizeToScreen()
 {
-    if (!mGrip)
+    if (mGrip == nullptr)
         return;
 
     const int screenWidth = mainGraphics->mWidth;
@@ -1289,7 +1293,7 @@ int Window::getResizeHandles(const MouseEvent &event)
 
     if (!mStickyButtonLock || !mSticky)
     {
-        if (mGrip &&
+        if ((mGrip != nullptr) &&
             (y > mTitleBarHeight ||
             (CAST_S32(y) < mPadding &&
             CAST_S32(mTitleBarHeight) > mPadding)))
@@ -1319,7 +1323,7 @@ bool Window::isResizeAllowed(const MouseEvent &event) const
 {
     const int y = event.getY();
 
-    if (mGrip &&
+    if ((mGrip != nullptr) &&
         (y > CAST_S32(mTitleBarHeight) ||
         y < mPadding))
     {
@@ -1337,7 +1341,7 @@ bool Window::isResizeAllowed(const MouseEvent &event) const
 
 Layout &Window::getLayout()
 {
-    if (!mLayout)
+    if (mLayout == nullptr)
         mLayout = new Layout;
     return *mLayout;
 }
@@ -1347,7 +1351,7 @@ void Window::clearLayout()
     clear();
 
     // Recreate layout instance when one is present
-    if (mLayout)
+    if (mLayout != nullptr)
     {
         delete mLayout;
         mLayout = new Layout;
@@ -1368,7 +1372,7 @@ ContainerPlacer Window::getPlacer(const int x, const int y)
 
 void Window::reflowLayout(int w, int h)
 {
-    if (!mLayout)
+    if (mLayout == nullptr)
         return;
 
     mLayout->reflow(w, h);
@@ -1378,7 +1382,7 @@ void Window::reflowLayout(int w, int h)
 
 void Window::redraw()
 {
-    if (mLayout)
+    if (mLayout != nullptr)
     {
         const Rect area = getChildrenArea();
         int w = area.width;
@@ -1426,10 +1430,10 @@ Rect Window::getWindowArea() const
 
 int Window::getOption(const std::string &name, const int def) const
 {
-    if (mSkin)
+    if (mSkin != nullptr)
     {
         const int val = mSkin->getOption(name);
-        if (val)
+        if (val != 0)
             return val;
         return def;
     }
@@ -1438,8 +1442,8 @@ int Window::getOption(const std::string &name, const int def) const
 
 bool Window::getOptionBool(const std::string &name, const bool def) const
 {
-    if (mSkin)
-        return mSkin->getOption(name, def) != 0;
+    if (mSkin != nullptr)
+        return mSkin->getOption(name, static_cast<int>(def)) != 0;
     return def;
 }
 
diff --git a/src/gui/widgets/windowcontainer.cpp b/src/gui/widgets/windowcontainer.cpp
index 9529945b0..38efd1a77 100644
--- a/src/gui/widgets/windowcontainer.cpp
+++ b/src/gui/widgets/windowcontainer.cpp
@@ -44,7 +44,7 @@ void WindowContainer::slowLogic()
 
 void WindowContainer::scheduleDelete(Widget *const widget)
 {
-    if (widget)
+    if (widget != nullptr)
         mDeathList.push_back(widget);
 }
 
diff --git a/src/gui/windowmanager.cpp b/src/gui/windowmanager.cpp
index ffc3e6593..c683a6f77 100644
--- a/src/gui/windowmanager.cpp
+++ b/src/gui/windowmanager.cpp
@@ -194,7 +194,7 @@ void WindowManager::updateTitle()
 
 void WindowManager::setFramerate(const unsigned int fpsLimit)
 {
-    if (!fpsLimit)
+    if (fpsLimit == 0u)
         return;
 
     if (!settings.limitFps)
@@ -240,7 +240,7 @@ void WindowManager::resizeVideo(int actualWidth,
     actualWidth = std::max(470, actualWidth);
     actualHeight = std::max(320, actualHeight);
 
-    if (!mainGraphics)
+    if (mainGraphics == nullptr)
         return;
     if (!always
         && mainGraphics->mActualWidth == actualWidth
@@ -255,21 +255,21 @@ void WindowManager::resizeVideo(int actualWidth,
         const int height = mainGraphics->mHeight;
         touchManager.resize(width, height);
 
-        if (gui)
+        if (gui != nullptr)
             gui->videoResized();
 
-        if (desktop)
+        if (desktop != nullptr)
             desktop->setSize(width, height);
 
         client->moveButtons(width);
 
 #ifndef DYECMD
         Game *const game = Game::instance();
-        if (game)
+        if (game != nullptr)
             game->videoResized(width, height);
 #endif  // DYECMD
 
-        if (gui)
+        if (gui != nullptr)
             gui->draw();
 
         config.setValue("screenwidth", actualWidth);
@@ -285,7 +285,7 @@ bool WindowManager::setFullScreen(const bool fs)
     return true;
 #else  // __native_client__
 
-    if (!mainGraphics)
+    if (mainGraphics == nullptr)
         return false;
     return mainGraphics->setFullscreen(fs);
 #endif  // __native_client__
@@ -400,7 +400,7 @@ void WindowManager::setIcon()
 #else  // WIN32
 
     mIcon = MIMG_Load(iconFile.c_str());
-    if (mIcon)
+    if (mIcon != nullptr)
     {
 #ifdef USE_SDL2
         SDL_SetSurfaceAlphaMod(mIcon, SDL_ALPHA_OPAQUE);
diff --git a/src/gui/windowmenu.cpp b/src/gui/windowmenu.cpp
index e9a37b2d4..f45b292f0 100644
--- a/src/gui/windowmenu.cpp
+++ b/src/gui/windowmenu.cpp
@@ -51,9 +51,9 @@ WindowMenu::WindowMenu(const Widget2 *const widget) :
     ActionListener(),
     SelectionListener(),
     MouseListener(),
-    mSkin(theme ? theme->load("windowmenu.xml", "") : nullptr),
-    mPadding(mSkin ? mSkin->getPadding() : 1),
-    mSpacing(mSkin ? mSkin->getOption("spacing", 3) : 3),
+    mSkin(theme != nullptr ? theme->load("windowmenu.xml", "") : nullptr),
+    mPadding(mSkin != nullptr ? mSkin->getPadding() : 1),
+    mSpacing(mSkin != nullptr ? mSkin->getOption("spacing", 3) : 3),
     mButtons(),
     mButtonTexts(),
     mButtonNames(),
@@ -192,7 +192,7 @@ WindowMenu::WindowMenu(const Widget2 *const widget) :
         _("Setup"), x, h, InputAction::WINDOW_SETUP);
 
     x += mPadding - mSpacing;
-    if (mainGraphics)
+    if (mainGraphics != nullptr)
         setDimension(Rect(mainGraphics->mWidth - x, 0, x, h));
 
     loadButtons();
@@ -219,16 +219,16 @@ WindowMenu::~WindowMenu()
     FOR_EACH (std::vector <Button*>::iterator, it, mButtons)
     {
         Button *const btn = *it;
-        if (!btn)
+        if (btn == nullptr)
             continue;
         if (btn->mVisible == Visible_false)
             delete btn;
     }
     delete_all(mButtonTexts);
     mButtonTexts.clear();
-    if (mSkin)
+    if (mSkin != nullptr)
     {
-        if (theme)
+        if (theme != nullptr)
             theme->unload(mSkin);
         mSkin = nullptr;
     }
@@ -243,7 +243,7 @@ void WindowMenu::action(const ActionEvent &event)
         return;
 
     const ButtonInfo *const info = (*it).second;
-    if (!info)
+    if (info == nullptr)
         return;
 
     inputManager.executeAction(info->key);
@@ -272,7 +272,7 @@ void WindowMenu::addButton(const char *const text,
 
 void WindowMenu::mousePressed(MouseEvent &event)
 {
-    if (!popupManager)
+    if (popupManager == nullptr)
         return;
 
     if (event.getButton() == MouseButton::RIGHT)
@@ -282,9 +282,9 @@ void WindowMenu::mousePressed(MouseEvent &event)
 
         event.consume();
         Button *const btn = dynamic_cast<Button*>(event.getSource());
-        if (!btn)
+        if (btn == nullptr)
             return;
-        if (popupMenu)
+        if (popupMenu != nullptr)
         {
             popupMenu->showPopup(getX() + event.getX(),
                 getY() + event.getY(), btn);
@@ -296,7 +296,7 @@ void WindowMenu::mouseMoved(MouseEvent &event)
 {
     mHaveMouse = true;
 
-    if (!textPopup)
+    if (textPopup == nullptr)
         return;
 
     if (event.getSource() == this)
@@ -308,7 +308,7 @@ void WindowMenu::mouseMoved(MouseEvent &event)
     const Button *const btn = dynamic_cast<const Button *>(
         event.getSource());
 
-    if (!btn)
+    if (btn == nullptr)
     {
         textPopup->hide();
         return;
@@ -334,7 +334,7 @@ void WindowMenu::mouseMoved(MouseEvent &event)
 void WindowMenu::mouseExited(MouseEvent& event A_UNUSED)
 {
     mHaveMouse = false;
-    if (!textPopup)
+    if (textPopup == nullptr)
         return;
 
     textPopup->hide();
@@ -344,7 +344,7 @@ void WindowMenu::showButton(const std::string &name,
                             const Visible visible)
 {
     const ButtonInfo *const info = mButtonNames[name];
-    if (!info || !info->button)
+    if ((info == nullptr) || (info->button == nullptr))
         return;
 
     info->button->setVisible(visible);
@@ -362,7 +362,7 @@ void WindowMenu::updateButtons()
     FOR_EACH (std::vector <Button*>::iterator, it, mButtons)
     {
         Button *const btn = *it;
-        if (!btn)
+        if (btn == nullptr)
             continue;
         if (btn->mVisible == Visible_true)
         {
@@ -373,7 +373,7 @@ void WindowMenu::updateButtons()
         }
     }
     x += mPadding - mSpacing;
-    if (mainGraphics)
+    if (mainGraphics != nullptr)
         setDimension(Rect(mainGraphics->mWidth - x, 0, x, h));
 }
 
@@ -388,8 +388,12 @@ void WindowMenu::loadButtons()
                  it_fend = mButtonNames.end(); it != it_fend; ++it)
             {
                 const ButtonInfo *const info = (*it).second;
-                if (!info || !info->button || info->visible == Visible_true)
+                if (info == nullptr ||
+                    info->button == nullptr ||
+                    info->visible == Visible_true)
+                {
                     continue;
+                }
                 info->button->setVisible(Visible_false);
             }
             updateButtons();
@@ -403,7 +407,7 @@ void WindowMenu::loadButtons()
             if (str.empty() || str == "SET")
                 continue;
             const ButtonInfo *const info = mButtonNames[str];
-            if (!info || !info->button)
+            if ((info == nullptr) || (info->button == nullptr))
                 continue;
             info->button->setVisible(Visible_false);
         }
@@ -415,7 +419,7 @@ void WindowMenu::loadButtons()
              it_fend = mButtonNames.end(); it != it_fend; ++it)
         {
             const ButtonInfo *const info = (*it).second;
-            if (!info || !info->button)
+            if ((info == nullptr) || (info->button == nullptr))
                 continue;
             Button *const button = info->button;
             const std::string &str = button->getActionEventId();
@@ -432,7 +436,7 @@ void WindowMenu::saveButtons() const
     FOR_EACH (std::vector <Button*>::const_iterator, it, mButtons)
     {
         const Button *const btn = *it;
-        if (btn && btn->mVisible == Visible_false)
+        if ((btn != nullptr) && btn->mVisible == Visible_false)
         {
             config.setValue("windowmenu" + toString(i),
                 btn->getActionEventId());
@@ -445,8 +449,11 @@ void WindowMenu::saveButtons() const
 
 void WindowMenu::drawChildren(Graphics *const graphics)
 {
-    if (mHaveMouse || !mAutoHide || (mAutoHide == 1
-        && mainGraphics && (mSmallWindow || mainGraphics->mWidth > 800)))
+    if (mHaveMouse ||
+        mAutoHide == 0 ||
+        (mAutoHide == 1 &&
+        mainGraphics != nullptr &&
+        (mSmallWindow || mainGraphics->mWidth > 800)))
     {
         Container::drawChildren(graphics);
     }
@@ -454,8 +461,11 @@ void WindowMenu::drawChildren(Graphics *const graphics)
 
 void WindowMenu::safeDrawChildren(Graphics *const graphics)
 {
-    if (mHaveMouse || !mAutoHide || (mAutoHide == 1
-        && mainGraphics && (mSmallWindow || mainGraphics->mWidth > 800)))
+    if (mHaveMouse ||
+        mAutoHide == 0 ||
+        (mAutoHide == 1 &&
+        mainGraphics != nullptr &&
+        (mSmallWindow || mainGraphics->mWidth > 800)))
     {
         Container::safeDrawChildren(graphics);
     }
diff --git a/src/gui/windows/bankwindow.cpp b/src/gui/windows/bankwindow.cpp
index d6e33148c..242d30aa1 100644
--- a/src/gui/windows/bankwindow.cpp
+++ b/src/gui/windows/bankwindow.cpp
@@ -55,7 +55,7 @@ BankWindow::BankWindow() :
     setWindowName("Bank");
     setCloseButton(true);
 
-    if (setupWindow)
+    if (setupWindow != nullptr)
         setupWindow->registerWindowForReset(this);
 
     mBankMoneyLabel->adjustSize();
diff --git a/src/gui/windows/buydialog.cpp b/src/gui/windows/buydialog.cpp
index a07f9d849..edac6293d 100644
--- a/src/gui/windows/buydialog.cpp
+++ b/src/gui/windows/buydialog.cpp
@@ -74,7 +74,7 @@ namespace
             bool operator() (const ShopItem *const item1,
                              const ShopItem *const item2) const
             {
-                if (!item1 || !item2)
+                if ((item1 == nullptr) || (item2 == nullptr))
                     return false;
 
                 const int price1 = item1->getPrice();
@@ -93,7 +93,7 @@ namespace
             bool operator() (const ShopItem *const item1,
                              const ShopItem *const item2) const
             {
-                if (!item1 || !item2)
+                if ((item1 == nullptr) || (item2 == nullptr))
                     return false;
 
                 const std::string &name1 = item1->getDisplayName();
@@ -112,7 +112,7 @@ namespace
             bool operator() (const ShopItem *const item1,
                              const ShopItem *const item2) const
             {
-                if (!item1 || !item2)
+                if ((item1 == nullptr) || (item2 == nullptr))
                     return false;
 
                 const int id1 = item1->getId();
@@ -131,7 +131,7 @@ namespace
             bool operator() (const ShopItem *const item1,
                              const ShopItem *const item2) const
             {
-                if (!item1 || !item2)
+                if ((item1 == nullptr) || (item2 == nullptr))
                     return false;
 
                 const int weight1 = item1->getInfo().getWeight();
@@ -150,7 +150,7 @@ namespace
             bool operator() (const ShopItem *const item1,
                              const ShopItem *const item2) const
             {
-                if (!item1 || !item2)
+                if ((item1 == nullptr) || (item2 == nullptr))
                     return false;
 
                 const int amount1 = item1->getQuantity();
@@ -169,7 +169,7 @@ namespace
             bool operator() (const ShopItem *const item1,
                              const ShopItem *const item2) const
             {
-                if (!item1 || !item2)
+                if ((item1 == nullptr) || (item2 == nullptr))
                     return false;
 
                 const ItemDbTypeT type1 = item1->getInfo().getType();
@@ -263,7 +263,7 @@ BuyDialog::BuyDialog(const Being *const being,
     mFilterTextField(new TextField(this, "", LoseFocusOnTab_true,
         this, "namefilter", true)),
     mFilterLabel(nullptr),
-    mNick(being ? being->getName() : std::string()),
+    mNick(being != nullptr ? being->getName() : std::string()),
     mCurrency(currency),
     mNpcId(fromInt(Vending, BeingId)),
     mMoney(0),
@@ -293,7 +293,7 @@ void BuyDialog::init()
     }
 #endif  // TMWA_SUPPORT
 
-    if (setupWindow)
+    if (setupWindow != nullptr)
         setupWindow->registerWindowForReset(this);
 
     mShopItems = new ShopItems(false,
@@ -376,7 +376,7 @@ void BuyDialog::init()
     placer(0, 6, mAmountLabel, 2);
     placer(2, 6, mAmountField, 2);
     placer(0, 7, mMoneyLabel, 8);
-    if (mSortDropDown)
+    if (mSortDropDown != nullptr)
     {
         placer(0, 8, mSortDropDown, 2);
     }
@@ -409,7 +409,7 @@ void BuyDialog::init()
     instances.push_back(this);
     setVisible(Visible_true);
 
-    if (mSortDropDown)
+    if (mSortDropDown != nullptr)
         mSortDropDown->setSelected(config.getIntValue("buySortOrder"));
 }
 
@@ -418,7 +418,7 @@ BuyDialog::~BuyDialog()
     delete2(mShopItems);
     delete2(mSortModel);
     instances.remove(this);
-    if (buySellHandler)
+    if (buySellHandler != nullptr)
         buySellHandler->cleanDialogReference(this);
 }
 
@@ -459,7 +459,7 @@ ShopItem *BuyDialog::addItem(const int id,
 
 void BuyDialog::sort()
 {
-    if (mSortDropDown && mShopItems)
+    if ((mSortDropDown != nullptr) && (mShopItems != nullptr))
     {
         std::vector<ShopItem*> &items = mShopItems->items();
         switch (mSortDropDown->getSelected())
@@ -525,7 +525,7 @@ void BuyDialog::action(const ActionEvent &event)
     else if (eventId == "sort")
     {
         sort();
-        if (mSortDropDown)
+        if (mSortDropDown != nullptr)
             config.setValue("buySortOrder", mSortDropDown->getSelected());
         return;
     }
@@ -576,7 +576,7 @@ void BuyDialog::action(const ActionEvent &event)
     else if (eventId == "buy" && mAmountItems > 0 && mAmountItems <= mMaxItems)
     {
         ShopItem *const item = mShopItems->at(selectedItem);
-        if (!item)
+        if (item == nullptr)
             return;
         if (mNpcId == fromInt(Items, BeingId))
         {
@@ -587,7 +587,7 @@ void BuyDialog::action(const ActionEvent &event)
 #ifdef TMWA_SUPPORT
         else if (mNpcId == fromInt(Nick, BeingId))
         {
-            if (tradeWindow)
+            if (tradeWindow != nullptr)
             {
                 buySellHandler->sendBuyRequest(mNick,
                     item, mAmountItems);
@@ -600,7 +600,7 @@ void BuyDialog::action(const ActionEvent &event)
         {
             item->increaseUsedQuantity(mAmountItems);
             item->update();
-            if (mConfirmButton)
+            if (mConfirmButton != nullptr)
                 mConfirmButton->setEnabled(true);
         }
 #ifdef TMWA_SUPPORT
@@ -613,7 +613,7 @@ void BuyDialog::action(const ActionEvent &event)
             {
                 item->increaseUsedQuantity(mAmountItems);
                 item->update();
-                if (mConfirmButton)
+                if (mConfirmButton != nullptr)
                     mConfirmButton->setEnabled(true);
             }
             else if (mNpcId == fromInt(Market, BeingId))
@@ -656,7 +656,7 @@ void BuyDialog::action(const ActionEvent &event)
             const Being *const being = actorManager->findBeingByName(
                 mNick,
                 ActorType::Player);
-            if (being)
+            if (being != nullptr)
             {
                 vendingHandler->buyItems(being,
                     items);
@@ -680,7 +680,7 @@ void BuyDialog::updateSlider(const int selectedItem)
     // that can be bought
     mMaxItems -= mAmountItems;
     const ShopItem *const item = mShopItems->at(selectedItem);
-    if (item)
+    if (item != nullptr)
         setMoney(mMoney - mAmountItems * item->getPrice());
     else
         setMoney(mMoney);
@@ -711,14 +711,14 @@ void BuyDialog::updateButtonsAndLabels()
     if (selectedItem > -1)
     {
         const ShopItem *const item = mShopItems->at(selectedItem);
-        if (item)
+        if (item != nullptr)
         {
             const int itemPrice = item->getPrice();
 
             // Calculate how many the player can afford
             if (mNpcId == fromInt(Items, BeingId))
                 mMaxItems = 100;
-            else if (itemPrice)
+            else if (itemPrice != 0)
                 mMaxItems = mMoney / itemPrice;
             else
                 mMaxItems = 1;
@@ -755,7 +755,7 @@ void BuyDialog::setVisible(Visible visible)
 {
     Window::setVisible(visible);
 
-    if (visible == Visible_true && mShopItemList)
+    if (visible == Visible_true && (mShopItemList != nullptr))
         mShopItemList->requestFocus();
     else
         scheduleDelete();
@@ -765,7 +765,7 @@ void BuyDialog::closeAll()
 {
     FOR_EACH (DialogList::const_iterator, it, instances)
     {
-        if (*it)
+        if (*it != nullptr)
             (*it)->close();
     }
 }
@@ -778,7 +778,7 @@ void BuyDialog::applyNameFilter(const std::string &filter)
     FOR_EACH (std::vector<ShopItem*>::iterator, it, items)
     {
         ShopItem *const item = *it;
-        if (!item)
+        if (item == nullptr)
             continue;
         std::string name = item->getName();
         toLower(name);
diff --git a/src/gui/windows/buyingstoreselldialog.cpp b/src/gui/windows/buyingstoreselldialog.cpp
index 8fd3103e6..369d52223 100644
--- a/src/gui/windows/buyingstoreselldialog.cpp
+++ b/src/gui/windows/buyingstoreselldialog.cpp
@@ -53,15 +53,15 @@ void BuyingStoreSellDialog::sellAction(const ActionEvent &event A_UNUSED)
 
     const int selectedItem = mShopItemList->getSelected();
     const ShopItem *const item1 = mShopItems->at(selectedItem);
-    if (!item1 || PlayerInfo::isItemProtected(item1->getId()))
+    if ((item1 == nullptr) || PlayerInfo::isItemProtected(item1->getId()))
         return;
     const Being *const being = actorManager->findBeing(mAccountId);
-    if (!being)
+    if (being == nullptr)
         return;
     const Item *const item2 = PlayerInfo::getInventory()->findItem(
         item1->getId(),
         item1->getColor());
-    if (!item2)
+    if (item2 == nullptr)
         return;
 
     mPlayerMoney += mAmountItems * item1->getPrice();
diff --git a/src/gui/windows/buyselldialog.cpp b/src/gui/windows/buyselldialog.cpp
index 0914dc43e..009a24839 100644
--- a/src/gui/windows/buyselldialog.cpp
+++ b/src/gui/windows/buyselldialog.cpp
@@ -64,7 +64,7 @@ void BuySellDialog::init()
     setWindowName("BuySell");
     setCloseButton(true);
 
-    if (setupWindow)
+    if (setupWindow != nullptr)
         setupWindow->registerWindowForReset(this);
 
     static const char *const buttonNames[] =
@@ -81,16 +81,18 @@ void BuySellDialog::init()
     int x = buttonPadding;
     const int y = buttonPadding;
 
-    for (const char *const *curBtn = buttonNames; *curBtn; curBtn++)
+    for (const char *const *curBtn = buttonNames;
+         *curBtn != nullptr;
+         curBtn++)
     {
         Button *const btn = new Button(this, gettext(*curBtn), *curBtn, this);
-        if (!mBuyButton)
+        if (mBuyButton == nullptr)
             mBuyButton = btn;  // For focus request
         btn->setPosition(x, y);
         add(btn);
         x += btn->getWidth() + buttonPadding;
     }
-    if (mBuyButton)
+    if (mBuyButton != nullptr)
     {
         mBuyButton->requestFocus();
         setContentSize(x, 2 * y + mBuyButton->getHeight());
@@ -116,7 +118,7 @@ void BuySellDialog::setVisible(Visible visible)
 
     if (visible == Visible_true)
     {
-        if (mBuyButton)
+        if (mBuyButton != nullptr)
             mBuyButton->requestFocus();
     }
     else
@@ -133,7 +135,7 @@ void BuySellDialog::action(const ActionEvent &event)
         if (mNpcId != BeingId_negOne)
         {
             const Being *const being = actorManager->findBeing(mNpcId);
-            if (being)
+            if (being != nullptr)
                 npcHandler->buy(being);
             else
                 npcHandler->buy(mNpcId);
@@ -158,7 +160,7 @@ void BuySellDialog::closeAll()
 {
     FOR_EACH (DialogList::const_iterator, it, dialogInstances)
     {
-        if (*it)
+        if (*it != nullptr)
             (*it)->close();
     }
 }
diff --git a/src/gui/windows/charcreatedialog.cpp b/src/gui/windows/charcreatedialog.cpp
index bf90a3fb3..535ee956f 100644
--- a/src/gui/windows/charcreatedialog.cpp
+++ b/src/gui/windows/charcreatedialog.cpp
@@ -162,12 +162,12 @@ CharCreateDialog::CharCreateDialog(CharSelectDialog *const parent,
             beingSlot.cardsId);
     }
 
-    if (!maxHairColor)
+    if (maxHairColor == 0u)
         maxHairColor = ColorDB::getHairSize();
-    if (!maxHairStyle)
+    if (maxHairStyle == 0u)
         maxHairStyle = ItemDB::getNumOfHairstyles();
 
-    if (maxHairStyle)
+    if (maxHairStyle != 0u)
     {
         mHairStyle = (CAST_U32(rand())
             % maxHairStyle) + minHairStyle;
@@ -176,7 +176,7 @@ CharCreateDialog::CharCreateDialog(CharSelectDialog *const parent,
     {
         mHairStyle = 0;
     }
-    if (maxHairColor)
+    if (maxHairColor != 0u)
     {
         mHairColor = (CAST_U32(rand())
             % maxHairColor) + minHairColor;
@@ -311,13 +311,13 @@ CharCreateDialog::CharCreateDialog(CharSelectDialog *const parent,
     const uint32_t labelX = mPadding;
     uint32_t nameX = leftX + labelPadding;
     uint32_t y = 30;
-    if (mPrevHairColorButton)
+    if (mPrevHairColorButton != nullptr)
         nameX += mPrevHairColorButton->getWidth();
-    else if (mPrevHairStyleButton)
+    else if (mPrevHairStyleButton != nullptr)
         nameX += mPrevHairStyleButton->getWidth();
-    else if (mPrevLookButton)
+    else if (mPrevLookButton != nullptr)
         nameX += mPrevLookButton->getWidth();
-    else if (mPrevRaceButton)
+    else if (mPrevRaceButton != nullptr)
         nameX += mPrevRaceButton->getWidth();
 
     if (maxHairColor > minHairColor)
@@ -341,27 +341,27 @@ CharCreateDialog::CharCreateDialog(CharSelectDialog *const parent,
 
     if (serverFeatures->haveLookSelection() && mMinLook < mMaxLook)
     {
-        if (mPrevLookButton)
+        if (mPrevLookButton != nullptr)
             mPrevLookButton->setPosition(leftX, y);
-        if (mNextLookButton)
+        if (mNextLookButton != nullptr)
             mNextLookButton->setPosition(rightX, y);
         y += 5;
-        if (mLookLabel)
+        if (mLookLabel != nullptr)
             mLookLabel->setPosition(labelX, y);
-        if (mLookNameLabel)
+        if (mLookNameLabel != nullptr)
             mLookNameLabel->setPosition(nameX, y);  // 93
         y += 24;
     }
     if (serverFeatures->haveRaceSelection() && mMinRace < mMaxRace)
     {
-        if (mPrevRaceButton)
+        if (mPrevRaceButton != nullptr)
             mPrevRaceButton->setPosition(leftX, y);
-        if (mNextRaceButton)
+        if (mNextRaceButton != nullptr)
             mNextRaceButton->setPosition(rightX, y);
         y += 5;
-        if (mRaceLabel)
+        if (mRaceLabel != nullptr)
             mRaceLabel->setPosition(labelX, y);
-        if (mRaceNameLabel)
+        if (mRaceNameLabel != nullptr)
             mRaceNameLabel->setPosition(nameX, y);
     }
     mMaxY = y + 29 + getTitlePadding();
@@ -429,7 +429,7 @@ CharCreateDialog::~CharCreateDialog()
 {
     delete2(mPlayer);
 
-    if (charServerHandler)
+    if (charServerHandler != nullptr)
         charServerHandler->setCharCreateDialog(nullptr);
 }
 
@@ -688,7 +688,7 @@ void CharCreateDialog::setAttributes(const StringVect &labels,
     }
 
     updateSliders();
-    if (!available)
+    if (available == 0)
     {
         mAttributesLeft->setVisible(Visible_false);
         h = y;
@@ -744,13 +744,13 @@ void CharCreateDialog::updateHair()
         mHairStyle = minHairStyle;
     }
     const ItemInfo &item = ItemDB::get(-mHairStyle);
-    if (mHairStyleNameLabel)
+    if (mHairStyleNameLabel != nullptr)
     {
         mHairStyleNameLabel->setCaption(item.getName());
         mHairStyleNameLabel->resizeTo(150, 150);
     }
 
-    if (ColorDB::getHairSize())
+    if (ColorDB::getHairSize() != 0)
         mHairColor %= ColorDB::getHairSize();
     else
         mHairColor = 0;
@@ -761,7 +761,7 @@ void CharCreateDialog::updateHair()
     {
         mHairColor = minHairColor;
     }
-    if (mHairColorNameLabel)
+    if (mHairColorNameLabel != nullptr)
     {
         mHairColorNameLabel->setCaption(ColorDB::getHairColorName(
             fromInt(mHairColor, ItemColor)));
@@ -803,12 +803,12 @@ void CharCreateDialog::updateLook()
     }
     mPlayer->setSubtype(fromInt(mRace, BeingTypeId),
         CAST_U8(mLook));
-    if (mRaceNameLabel)
+    if (mRaceNameLabel != nullptr)
     {
         mRaceNameLabel->setCaption(item.getName());
         mRaceNameLabel->resizeTo(150, 150);
     }
-    if (mLookNameLabel)
+    if (mLookNameLabel != nullptr)
     {
         mLookNameLabel->setCaption(item.getColorName(
             fromInt(mLook, ItemColor)));
@@ -819,14 +819,14 @@ void CharCreateDialog::updateLook()
 void CharCreateDialog::logic()
 {
     BLOCK_START("CharCreateDialog::logic")
-    if (mPlayer)
+    if (mPlayer != nullptr)
         mPlayer->logic();
     BLOCK_END("CharCreateDialog::logic")
 }
 
 void CharCreateDialog::updatePlayer()
 {
-    if (mPlayer)
+    if (mPlayer != nullptr)
     {
         mPlayer->setDirection(directions[mDirection]);
         mPlayer->setAction(actions[mAction], 0);
@@ -857,7 +857,7 @@ void CharCreateDialog::setButtonsPosition(const int w, const int h)
     const int h2 = h - 5 - mCancelButton->getHeight();
     if (mainGraphics->getHeight() < 480)
     {
-        if (mMaxPoints)
+        if (mMaxPoints != 0)
         {
             mCreateButton->setPosition(337, 160);
             mCancelButton->setPosition(337 + mCreateButton->getWidth(), 160);
diff --git a/src/gui/windows/chardeleteconfirm.h b/src/gui/windows/chardeleteconfirm.h
index 9c2d43318..7049050a3 100644
--- a/src/gui/windows/chardeleteconfirm.h
+++ b/src/gui/windows/chardeleteconfirm.h
@@ -51,7 +51,7 @@ class CharDeleteConfirm final : public ConfirmDialog
 
         void action(const ActionEvent &event) override final
         {
-            if (event.getId() == "yes" && mMaster)
+            if (event.getId() == "yes" && (mMaster != nullptr))
                 mMaster->askPasswordForDeletion(mIndex);
 
             ConfirmDialog::action(event);
diff --git a/src/gui/windows/charselectdialog.cpp b/src/gui/windows/charselectdialog.cpp
index d697ebf2b..cd801f61d 100644
--- a/src/gui/windows/charselectdialog.cpp
+++ b/src/gui/windows/charselectdialog.cpp
@@ -209,13 +209,13 @@ void CharSelectDialog::action(const ActionEvent &event)
             return;
         }
         else if (eventId == "delete"
-                 && mCharacterEntries[selected]->getCharacter())
+                 && (mCharacterEntries[selected]->getCharacter() != nullptr))
         {
             CREATEWIDGET(CharDeleteConfirm, this, selected);
             return;
         }
         else if (eventId == "rename"
-                 && mCharacterEntries[selected]->getCharacter())
+                 && (mCharacterEntries[selected]->getCharacter() != nullptr))
         {
             const LocalPlayer *const player = mCharacterEntries[
                 selected]->getCharacter()->dummy;
@@ -232,11 +232,11 @@ void CharSelectDialog::action(const ActionEvent &event)
         {
             Net::Character *const character = mCharacterEntries[
                 selected]->getCharacter();
-            if (!character)
+            if (character == nullptr)
                 return;
 
             const LocalPlayer *const data = character->dummy;
-            if (!data)
+            if (data == nullptr)
                 return;
 
             const std::string msg = strprintf(
@@ -282,7 +282,7 @@ void CharSelectDialog::action(const ActionEvent &event)
     }
     else if (eventId == "try delete character")
     {
-        if (mDeleteDialog && mDeleteIndex != -1)
+        if ((mDeleteDialog != nullptr) && mDeleteIndex != -1)
         {
             if (serverFeatures->haveEmailOnDelete())
             {
@@ -316,8 +316,8 @@ void CharSelectDialog::action(const ActionEvent &event)
 
 void CharSelectDialog::use(const int selected)
 {
-    if (mCharacterEntries[selected]
-        && mCharacterEntries[selected]->getCharacter())
+    if ((mCharacterEntries[selected] != nullptr)
+        && (mCharacterEntries[selected]->getCharacter() != nullptr))
     {
         attemptCharacterSelect(selected);
     }
@@ -363,7 +363,7 @@ void CharSelectDialog::keyPressed(KeyEvent &event)
             int idx = mCharacterView->getSelected();
             if (idx >= 0)
             {
-                if (!idx || idx == SLOTS_PER_ROW)
+                if ((idx == 0) || idx == SLOTS_PER_ROW)
                     break;
                 idx --;
                 mCharacterView->show(idx);
@@ -406,8 +406,8 @@ void CharSelectDialog::keyPressed(KeyEvent &event)
         {
             event.consume();
             const int idx = mCharacterView->getSelected();
-            if (idx >= 0 && mCharacterEntries[idx]
-                && mCharacterEntries[idx]->getCharacter())
+            if (idx >= 0 && (mCharacterEntries[idx] != nullptr)
+                && (mCharacterEntries[idx]->getCharacter() != nullptr))
             {
                 CREATEWIDGET(CharDeleteConfirm, this, idx);
             }
@@ -435,7 +435,7 @@ void CharSelectDialog::attemptCharacterDelete(const int index,
     if (mLocked)
         return;
 
-    if (mCharacterEntries[index])
+    if (mCharacterEntries[index] != nullptr)
     {
         mCharServerHandler->deleteCharacter(
             mCharacterEntries[index]->getCharacter(),
@@ -474,11 +474,11 @@ void CharSelectDialog::askPasswordForDeletion(const int index)
  */
 void CharSelectDialog::attemptCharacterSelect(const int index)
 {
-    if (mLocked || !mCharacterEntries[index])
+    if (mLocked || (mCharacterEntries[index] == nullptr))
         return;
 
     setVisible(Visible_false);
-    if (mCharServerHandler)
+    if (mCharServerHandler != nullptr)
     {
         mCharServerHandler->chooseCharacter(
             mCharacterEntries[index]->getCharacter());
@@ -492,7 +492,7 @@ void CharSelectDialog::setCharacters(const Net::Characters &characters)
     FOR_EACH (std::vector<CharacterDisplay*>::const_iterator,
               iter, mCharacterEntries)
     {
-        if (*iter)
+        if (*iter != nullptr)
             (*iter)->setCharacter(nullptr);
     }
 
@@ -503,7 +503,7 @@ void CharSelectDialog::setCharacters(const Net::Characters &characters)
 
 void CharSelectDialog::setCharacter(Net::Character *const character)
 {
-    if (!character)
+    if (character == nullptr)
         return;
     const int characterSlot = character->slot;
     if (characterSlot >= CAST_S32(mCharacterEntries.size()))
@@ -512,7 +512,7 @@ void CharSelectDialog::setCharacter(Net::Character *const character)
         return;
     }
 
-    if (mCharacterEntries[characterSlot])
+    if (mCharacterEntries[characterSlot] != nullptr)
         mCharacterEntries[characterSlot]->setCharacter(character);
 }
 
@@ -531,17 +531,17 @@ void CharSelectDialog::setLocked(const bool locked)
 {
     mLocked = locked;
 
-    if (mSwitchLoginButton)
+    if (mSwitchLoginButton != nullptr)
         mSwitchLoginButton->setEnabled(!locked);
-    if (mChangePasswordButton)
+    if (mChangePasswordButton != nullptr)
         mChangePasswordButton->setEnabled(!locked);
     mPlayButton->setEnabled(!locked);
-    if (mDeleteButton)
+    if (mDeleteButton != nullptr)
         mDeleteButton->setEnabled(!locked);
 
     for (size_t i = 0, sz = mCharacterEntries.size(); i < sz; ++i)
     {
-        if (mCharacterEntries[i])
+        if (mCharacterEntries[i] != nullptr)
             mCharacterEntries[i]->setActive(!mLocked);
     }
 }
@@ -554,13 +554,14 @@ bool CharSelectDialog::selectByName(const std::string &name,
 
     for (size_t i = 0, sz = mCharacterEntries.size(); i < sz; ++i)
     {
-        if (mCharacterEntries[i])
+        if (mCharacterEntries[i] != nullptr)
         {
             const Net::Character *const character
                 = mCharacterEntries[i]->getCharacter();
-            if (character)
+            if (character != nullptr)
             {
-                if (character->dummy && character->dummy->getName() == name)
+                if (character->dummy != nullptr &&
+                    character->dummy->getName() == name)
                 {
                     mCharacterView->show(CAST_S32(i));
                     updateState();
@@ -597,14 +598,15 @@ void CharSelectDialog::updateState()
     }
     mPlayButton->setEnabled(true);
 
-    if (mCharacterEntries[idx] && mCharacterEntries[idx]->getCharacter())
+    if (mCharacterEntries[idx] != nullptr &&
+        mCharacterEntries[idx]->getCharacter() != nullptr)
     {
         // TRANSLATORS: char select dialog. button.
         mPlayButton->setCaption(_("Play"));
 
         const LocalPlayer *const player = mCharacterEntries[
             idx]->getCharacter()->dummy;
-        if (player && mRenameButton)
+        if ((player != nullptr) && (mRenameButton != nullptr))
             mRenameButton->setEnabled(player->getRename() ? true : false);
     }
     else
@@ -621,13 +623,13 @@ void CharSelectDialog::setName(const BeingId id, const std::string &newName)
          i < fsz;
          ++i)
     {
-        if (!mCharacterEntries[i])
+        if (mCharacterEntries[i] == nullptr)
             continue;
         CharacterDisplay *const character = mCharacterEntries[i];
-        if (!character)
+        if (character == nullptr)
             continue;
         LocalPlayer *const player = character->getCharacter()->dummy;
-        if (player && player->getId() == id)
+        if ((player != nullptr) && player->getId() == id)
         {
             player->setName(newName);
             character->update();
diff --git a/src/gui/windows/chatwindow.cpp b/src/gui/windows/chatwindow.cpp
index 45353fdc7..a9c686f3a 100644
--- a/src/gui/windows/chatwindow.cpp
+++ b/src/gui/windows/chatwindow.cpp
@@ -112,21 +112,23 @@ ChatWindow::ChatWindow() :
     mHighlights(),
     mGlobalsFilter(),
     mChatColor(config.getIntValue("chatColor")),
-    mEmoteButtonSpacing(mSkin ? mSkin->getOption("emoteButtonSpacing", 2) : 2),
-    mEmoteButtonY(mSkin ? mSkin->getOption("emoteButtonY", -2) : -2),
+    mEmoteButtonSpacing(mSkin != nullptr ?
+                        mSkin->getOption("emoteButtonSpacing", 2) : 2),
+    mEmoteButtonY(mSkin != nullptr ?
+                  mSkin->getOption("emoteButtonY", -2) : -2),
     mChatHistoryIndex(0),
     mReturnToggles(config.getBoolValue("ReturnToggles")),
     mGMLoaded(false),
     mHaveMouse(false),
     mAutoHide(config.getBoolValue("autohideChat")),
     mShowBattleEvents(config.getBoolValue("showBattleEvents")),
-    mShowAllLang(serverConfig.getValue("showAllLang", 0)),
+    mShowAllLang(serverConfig.getValue("showAllLang", 0) != 0),
     mEnableTradeFilter(config.getBoolValue("enableTradeFilter")),
     mTmpVisible(false)
 {
     setWindowName("Chat");
 
-    if (setupWindow)
+    if (setupWindow != nullptr)
         setupWindow->registerWindowForReset(this);
 
     setShowTitle(false);
@@ -159,7 +161,7 @@ ChatWindow::ChatWindow() :
 
     setTitleBarHeight(getPadding() + getTitlePadding());
 
-    if (emoteWindow)
+    if (emoteWindow != nullptr)
         emoteWindow->addListeners(this);
 
     mChatButton->adjustSize();
@@ -191,7 +193,7 @@ ChatWindow::ChatWindow() :
     updateTabsMargin();
 
     fillCommands();
-    if (localPlayer && localPlayer->isGM())
+    if ((localPlayer != nullptr) && localPlayer->isGM())
         loadGMCommands();
     initTradeFilter();
     loadCustomList();
@@ -312,10 +314,10 @@ void ChatWindow::adjustTabSize()
     }
 
     const ChatTab *const tab = getFocused();
-    if (tab)
+    if (tab != nullptr)
     {
         Widget *const content = tab->mScrollArea;
-        if (content)
+        if (content != nullptr)
         {
             const int contentFrame2 = 2 * content->getFrameSize();
             content->setSize(mChatTabs->getWidth() - contentFrame2,
@@ -344,7 +346,7 @@ ChatTab *ChatWindow::getFocused() const
 
 void ChatWindow::clearTab(ChatTab *const tab)
 {
-    if (tab)
+    if (tab != nullptr)
         tab->clearText();
 }
 
@@ -355,7 +357,7 @@ void ChatWindow::clearTab() const
 
 void ChatWindow::prevTab()
 {
-    if (!mChatTabs)
+    if (mChatTabs == nullptr)
         return;
 
     int tab = mChatTabs->getSelectedTabIndex();
@@ -369,7 +371,7 @@ void ChatWindow::prevTab()
 
 void ChatWindow::nextTab()
 {
-    if (!mChatTabs)
+    if (mChatTabs == nullptr)
         return;
 
     int tab = mChatTabs->getSelectedTabIndex();
@@ -383,7 +385,7 @@ void ChatWindow::nextTab()
 
 void ChatWindow::selectTabByType(const ChatTabTypeT &type)
 {
-    if (!mChatTabs)
+    if (mChatTabs == nullptr)
         return;
 
     int sz = mChatTabs->getNumberOfTabs();
@@ -391,7 +393,7 @@ void ChatWindow::selectTabByType(const ChatTabTypeT &type)
     {
         ChatTab *const tab = dynamic_cast<ChatTab*>(
             mChatTabs->getTabByIndex(f));
-        if (tab && tab->getType() == type)
+        if ((tab != nullptr) && tab->getType() == type)
         {
             mChatTabs->setSelectedTab(tab);
             break;
@@ -401,12 +403,12 @@ void ChatWindow::selectTabByType(const ChatTabTypeT &type)
 
 void ChatWindow::closeTab() const
 {
-    if (!mChatTabs)
+    if (mChatTabs == nullptr)
         return;
 
     ChatTab *const tab = dynamic_cast<ChatTab*>(mChatTabs->getTabByIndex(
         mChatTabs->getSelectedTabIndex()));
-    if (!tab)
+    if (tab == nullptr)
         return;
     const ChatTabTypeT &type = tab->getType();
     if (type == ChatTabType::WHISPER || type == ChatTabType::CHANNEL)
@@ -415,7 +417,7 @@ void ChatWindow::closeTab() const
 
 void ChatWindow::defaultTab()
 {
-    if (mChatTabs)
+    if (mChatTabs != nullptr)
         mChatTabs->setSelectedTabByIndex(CAST_U32(0));
 }
 
@@ -446,7 +448,7 @@ void ChatWindow::action(const ActionEvent &event)
         {
             // Remove focus and hide input
             mChatInput->unprotectFocus();
-            if (mFocusHandler)
+            if (mFocusHandler != nullptr)
                 mFocusHandler->focusNone();
 
             // If the chatWindow is shown up because you want to send a message
@@ -457,7 +459,7 @@ void ChatWindow::action(const ActionEvent &event)
     }
     else if (eventId == "emote")
     {
-        if (emoteWindow)
+        if (emoteWindow != nullptr)
         {
             const std::string str = emoteWindow->getSelectedEmote();
             if (!str.empty())
@@ -469,7 +471,7 @@ void ChatWindow::action(const ActionEvent &event)
     }
     else if (eventId == "openemote")
     {
-        if (emoteWindow)
+        if (emoteWindow != nullptr)
         {
             if (emoteWindow->mVisible == Visible_true)
                 emoteWindow->hide();
@@ -479,7 +481,7 @@ void ChatWindow::action(const ActionEvent &event)
     }
     else if (eventId == "color")
     {
-        if (emoteWindow)
+        if (emoteWindow != nullptr)
         {
             const std::string str = emoteWindow->getSelectedColor();
             if (!str.empty())
@@ -491,7 +493,7 @@ void ChatWindow::action(const ActionEvent &event)
     }
     else if (eventId == "font")
     {
-        if (emoteWindow)
+        if (emoteWindow != nullptr)
         {
             const std::string str = emoteWindow->getSelectedFont();
             if (!str.empty())
@@ -503,7 +505,7 @@ void ChatWindow::action(const ActionEvent &event)
     }
     else if (eventId == "text")
     {
-        if (emoteWindow && reverseDictionary)
+        if ((emoteWindow != nullptr) && (reverseDictionary != nullptr))
         {
             const int idx = emoteWindow->getSelectedTextIndex();
             if (idx >= 0)
@@ -517,14 +519,14 @@ void ChatWindow::action(const ActionEvent &event)
     }
     else if (eventId == ACTION_COLOR_PICKER)
     {
-        if (mColorPicker)
+        if (mColorPicker != nullptr)
         {
             mChatColor = mColorPicker->getSelected();
             config.setValue("chatColor", mChatColor);
         }
     }
 
-    if (mColorPicker)
+    if (mColorPicker != nullptr)
     {
         const Visible vis = fromBool(config.getBoolValue(
             "showChatColorsList"), Visible);
@@ -571,7 +573,7 @@ void ChatWindow::removeTab(ChatTab *const tab)
 
 void ChatWindow::addTab(ChatTab *const tab)
 {
-    if (!tab)
+    if (tab == nullptr)
         return;
 
     mChatTabs->addTab(tab, tab->mScrollArea);
@@ -632,7 +634,7 @@ void ChatWindow::ignoreAllWhispers()
          ++ iter)
     {
         WhisperTab *const tab = iter->second;
-        if (tab)
+        if (tab != nullptr)
         {
             if (player_relations.getRelation(tab->getNick())
                 != Relation::IGNORED)
@@ -654,7 +656,7 @@ void ChatWindow::chatInput(const std::string &message) const
     if (config.getBoolValue("allowCommandsInChatTabs")
         && msg.length() > 1
         && ((msg.at(0) == '#' && msg.at(1) != '#') || msg.at(0) == '@')
-        && localChatTab)
+        && (localChatTab != nullptr))
     {
         tab = localChatTab;
     }
@@ -664,14 +666,14 @@ void ChatWindow::chatInput(const std::string &message) const
         if (tab == nullptr)
             tab = localChatTab;
     }
-    if (tab)
+    if (tab != nullptr)
         tab->chatInput(msg);
     Game::instance()->setValidSpeed();
 }
 
 void ChatWindow::localChatInput(const std::string &msg) const
 {
-    if (localChatTab)
+    if (localChatTab != nullptr)
         localChatTab->chatInput(msg);
     else
         chatInput(msg);
@@ -679,7 +681,7 @@ void ChatWindow::localChatInput(const std::string &msg) const
 
 void ChatWindow::doPresent() const
 {
-    if (!actorManager)
+    if (actorManager == nullptr)
         return;
 
     const ActorSprites &actors = actorManager->getAll();
@@ -702,7 +704,7 @@ void ChatWindow::doPresent() const
         _("Present: %s; %d players are present."),
         response.c_str(), playercount);
 
-    if (getFocused())
+    if (getFocused() != nullptr)
         getFocused()->chatLog(log, ChatMsgType::BY_SERVER);
 }
 
@@ -712,7 +714,7 @@ void ChatWindow::scroll(const int amount) const
         return;
 
     ChatTab *const tab = getFocused();
-    if (tab)
+    if (tab != nullptr)
         tab->scroll(amount);
 }
 
@@ -723,11 +725,11 @@ void ChatWindow::mousePressed(MouseEvent &event)
 
     if (event.getButton() == MouseButton::RIGHT)
     {
-        if (popupMenu)
+        if (popupMenu != nullptr)
         {
             ChatTab *const cTab = dynamic_cast<ChatTab*>(
                 mChatTabs->getSelectedTab());
-            if (cTab)
+            if (cTab != nullptr)
             {
                 event.consume();
                 if (inputManager.isActionActive(InputAction::CHAT_MOD))
@@ -757,13 +759,13 @@ void ChatWindow::mousePressed(MouseEvent &event)
         if (clicks == 2)
         {
             toggleChatFocus();
-            if (gui)
+            if (gui != nullptr)
                 gui->resetClickCount();
         }
         else if (clicks == 1)
         {
             const ChatTab *const tab = getFocused();
-            if (tab)
+            if (tab != nullptr)
                 mMoved = !isResizeAllowed(event);
         }
     }
@@ -862,9 +864,9 @@ void ChatWindow::keyPressed(KeyEvent &event)
              mChatInput->mVisible == Visible_true)
     {
         const ChatTab *const tab = getFocused();
-        if (tab && tab->hasRows())
+        if ((tab != nullptr) && tab->hasRows())
         {
-            if (!mChatHistoryIndex)
+            if (mChatHistoryIndex == 0u)
             {
                 mChatHistoryIndex = CAST_U32(
                     tab->getRows().size());
@@ -894,7 +896,7 @@ void ChatWindow::keyPressed(KeyEvent &event)
              mChatInput->mVisible == Visible_true)
     {
         const ChatTab *const tab = getFocused();
-        if (tab && tab->hasRows())
+        if ((tab != nullptr) && tab->hasRows())
         {
             const std::list<std::string> &rows = tab->getRows();
             const size_t &tabSize = rows.size();
@@ -928,7 +930,7 @@ void ChatWindow::keyPressed(KeyEvent &event)
     }
     else if (actionId == InputAction::GUI_F1)
     {
-        if (emoteWindow)
+        if (emoteWindow != nullptr)
         {
             if (emoteWindow->mVisible == Visible_true)
                 emoteWindow->hide();
@@ -998,7 +1000,7 @@ void ChatWindow::statChanged(const AttributesT id,
         return;
 
     const std::pair<int, int> exp = PlayerInfo::getStatExperience(id);
-    if (oldVal1 > exp.first || !oldVal2)
+    if (oldVal1 > exp.first || (oldVal2 == 0))
         return;
 
     const int change = exp.first - oldVal1;
@@ -1082,7 +1084,7 @@ void ChatWindow::addWhisper(const std::string &restrict nick,
                             const std::string &restrict mes,
                             const ChatMsgTypeT own)
 {
-    if (mes.empty() || !localPlayer)
+    if (mes.empty() || (localPlayer == nullptr))
         return;
 
     std::string playerName = localPlayer->getName();
@@ -1104,11 +1106,11 @@ void ChatWindow::addWhisper(const std::string &restrict nick,
     else if (config.getBoolValue("whispertab"))
     {
         tab = addWhisperTab(nick, nick);
-        if (tab)
+        if (tab != nullptr)
             saveState();
     }
 
-    if (tab)
+    if (tab != nullptr)
     {
         if (own == ChatMsgType::BY_PLAYER)
         {
@@ -1149,7 +1151,7 @@ void ChatWindow::addWhisper(const std::string &restrict nick,
             localPlayer->afkRespond(tab, nick);
         }
     }
-    else if (localChatTab)
+    else if (localChatTab != nullptr)
     {
         if (own == ChatMsgType::BY_PLAYER)
         {
@@ -1166,7 +1168,7 @@ void ChatWindow::addWhisper(const std::string &restrict nick,
                 " : ").append(mes),
                 ChatMsgType::ACT_WHISPER,
                 IgnoreRecord_false);
-            if (localPlayer)
+            if (localPlayer != nullptr)
                 localPlayer->afkRespond(nullptr, nick);
         }
     }
@@ -1176,7 +1178,7 @@ WhisperTab *ChatWindow::addWhisperTab(const std::string &caption,
                                       const std::string &nick,
                                       const bool switchTo)
 {
-    if (!localPlayer)
+    if (localPlayer == nullptr)
         return nullptr;
 
     std::string playerName = localPlayer->getName();
@@ -1198,7 +1200,7 @@ WhisperTab *ChatWindow::addWhisperTab(const std::string &caption,
     else
     {
         ret = new WhisperTab(this, caption, nick);
-        if (gui && !player_relations.isGoodName(nick))
+        if ((gui != nullptr) && !player_relations.isGoodName(nick))
             ret->setLabelFont(gui->getSecureFont());
         mWhispers[tempNick] = ret;
         if (config.getBoolValue("showChatHistory"))
@@ -1213,7 +1215,7 @@ WhisperTab *ChatWindow::addWhisperTab(const std::string &caption,
 
 WhisperTab *ChatWindow::getWhisperTab(const std::string &nick) const
 {
-    if (!localPlayer)
+    if (localPlayer == nullptr)
         return nullptr;
 
     std::string playerName = localPlayer->getName();
@@ -1240,7 +1242,7 @@ ChatTab *ChatWindow::addSpecialChannelTab(const std::string &name,
     ChatTab *ret = nullptr;
     if (name == TRADE_CHANNEL)
     {
-        if (!tradeChatTab)
+        if (tradeChatTab == nullptr)
         {
             tradeChatTab = new TradeTab(chatWindow);
             tradeChatTab->setAllowHighlight(false);
@@ -1250,7 +1252,7 @@ ChatTab *ChatWindow::addSpecialChannelTab(const std::string &name,
     }
     else if (name == GM_CHANNEL)
     {
-        if (!gmChatTab)
+        if (gmChatTab == nullptr)
         {
             gmChatTab = new GmTab(chatWindow);
             chatHandler->joinChannel(gmChatTab->getChannelName());
@@ -1270,7 +1272,7 @@ ChatTab *ChatWindow::addChannelTab(const std::string &name,
     toLower(tempName);
 
     ChatTab *const tab = addSpecialChannelTab(name, switchTo);
-    if (tab)
+    if (tab != nullptr)
         return tab;
 
     const ChannelMap::const_iterator i = mChannels.find(tempName);
@@ -1304,7 +1306,7 @@ ChatTab *ChatWindow::addChatTab(const std::string &name,
         name[0] == '#')
     {
         ChatTab *const tab = addChannelTab(name, switchTo);
-        if (tab && join)
+        if ((tab != nullptr) && join)
             chatHandler->joinChannel(name);
         return tab;
     }
@@ -1319,11 +1321,11 @@ void ChatWindow::postConnection()
     FOR_EACH (ChannelMap::const_iterator, iter, mChannels)
     {
         ChatTab *const tab = iter->second;
-        if (!tab)
+        if (tab == nullptr)
             return;
         chatHandler->joinChannel(tab->getChannelName());
     }
-    if (langChatTab)
+    if (langChatTab != nullptr)
         chatHandler->joinChannel(langChatTab->getChannelName());
 }
 
@@ -1417,32 +1419,32 @@ void ChatWindow::autoComplete()
         mChatTabs->getSelectedTab());
     StringVect nameList;
 
-    if (cTab)
+    if (cTab != nullptr)
         cTab->getAutoCompleteList(nameList);
     std::string newName = autoComplete(nameList, name);
-    if (!newName.empty() && !startName)
+    if (!newName.empty() && (startName == 0))
         secureChatCommand(newName);
 
-    if (cTab && newName.empty())
+    if ((cTab != nullptr) && newName.empty())
     {
         cTab->getAutoCompleteCommands(nameList);
         newName = autoComplete(nameList, name);
     }
 
-    if (newName.empty() && actorManager)
+    if (newName.empty() && (actorManager != nullptr))
     {
         actorManager->getPlayerNames(nameList, NpcNames_true);
         newName = autoComplete(nameList, name);
-        if (!newName.empty() && !startName)
+        if (!newName.empty() && (startName == 0))
             secureChatCommand(newName);
     }
     if (newName.empty())
         newName = autoCompleteHistory(name);
-    if (newName.empty() && spellManager)
+    if (newName.empty() && (spellManager != nullptr))
         newName = spellManager->autoComplete(name);
     if (newName.empty())
         newName = autoComplete(name, &mCommands);
-    if (newName.empty() && actorManager)
+    if (newName.empty() && (actorManager != nullptr))
     {
         actorManager->getMobNames(nameList);
         newName = autoComplete(nameList, name);
@@ -1504,7 +1506,7 @@ std::string ChatWindow::autoComplete(const StringVect &names,
 std::string ChatWindow::autoComplete(const std::string &partName,
                                      const History *const words) const
 {
-    if (!words)
+    if (words == nullptr)
         return "";
 
     ChatCommands::const_iterator i = words->begin();
@@ -1585,7 +1587,7 @@ bool ChatWindow::resortChatLog(std::string line,
         prefix = std::string("##3").append(channel).append("##0");
     }
     else if (mEnableTradeFilter &&
-             tradeChatTab &&
+             (tradeChatTab != nullptr) &&
              findI(line, mTradeFilter) != std::string::npos)
     {
         // TRANSLATORS: prefix for moved message to trade tab.
@@ -1661,7 +1663,7 @@ bool ChatWindow::resortChatLog(std::string line,
                 replaceAll(line, ": \302\202\304", ": ");
             }
 
-            if (tradeChatTab)
+            if (tradeChatTab != nullptr)
             {
                 line = line.erase(idx + 2, 2);
                 tradeChatTab->chatLog(prefix + line,
@@ -1669,7 +1671,7 @@ bool ChatWindow::resortChatLog(std::string line,
                     ignoreRecord,
                     tryRemoveColors);
             }
-            else if (localChatTab)
+            else if (localChatTab != nullptr)
             {
                 line = line.erase(idx + 2, 2);
                 localChatTab->chatLog(prefix + line,
@@ -1683,7 +1685,7 @@ bool ChatWindow::resortChatLog(std::string line,
 
     if (!channel.empty())
     {
-        if (langChatTab)
+        if (langChatTab != nullptr)
         {
             if (langChatTab->getChannelName() == channel)
             {
@@ -1710,7 +1712,7 @@ bool ChatWindow::resortChatLog(std::string line,
                 tryRemoveColors);
         }
     }
-    else if (localChatTab && channel.empty())
+    else if ((localChatTab != nullptr) && channel.empty())
     {
         localChatTab->chatLog(line, own, ignoreRecord, tryRemoveColors);
     }
@@ -1723,9 +1725,9 @@ void ChatWindow::battleChatLog(const std::string &line, ChatMsgTypeT own,
 {
     if (own == ChatMsgType::BY_UNKNOWN)
         own = ChatMsgType::BY_SERVER;
-    if (battleChatTab)
+    if (battleChatTab != nullptr)
         battleChatTab->chatLog(line, own, ignoreRecord, tryRemoveColors);
-    else if (debugChatTab)
+    else if (debugChatTab != nullptr)
         debugChatTab->chatLog(line, own, ignoreRecord, tryRemoveColors);
 }
 
@@ -1748,11 +1750,11 @@ void ChatWindow::channelChatLog(const std::string &channel,
     else
     {
         tab = addChannelTab(channel, false);
-        if (tab)
+        if (tab != nullptr)
             saveState();
     }
 
-    if (tab)
+    if (tab != nullptr)
         tab->chatLog(line, own, ignoreRecord, tryRemoveColors);
 }
 
@@ -1764,7 +1766,8 @@ void ChatWindow::initTradeFilter()
     std::ifstream tradeFile;
     struct stat statbuf;
 
-    if (!stat(tradeListName.c_str(), &statbuf) && S_ISREG(statbuf.st_mode))
+    if (stat(tradeListName.c_str(), &statbuf) == 0 &&
+        S_ISREG(statbuf.st_mode))
     {
         tradeFile.open(tradeListName.c_str(), std::ios::in);
         if (tradeFile.is_open())
@@ -1785,18 +1788,18 @@ void ChatWindow::updateOnline(const std::set<std::string> &onlinePlayers) const
 {
     const Party *party = nullptr;
     const Guild *guild = nullptr;
-    if (localPlayer)
+    if (localPlayer != nullptr)
     {
         party = localPlayer->getParty();
         guild = localPlayer->getGuild();
     }
     FOR_EACH (TabMap::const_iterator, iter, mWhispers)
     {
-        if (!iter->second)
+        if (iter->second == nullptr)
             return;
 
         WhisperTab *const tab = static_cast<WhisperTab*>(iter->second);
-        if (!tab)
+        if (tab == nullptr)
             continue;
 
         if (onlinePlayers.find(tab->getNick()) != onlinePlayers.end())
@@ -1806,29 +1809,29 @@ void ChatWindow::updateOnline(const std::set<std::string> &onlinePlayers) const
         else
         {
             const std::string &nick = tab->getNick();
-            if (actorManager)
+            if (actorManager != nullptr)
             {
                 const Being *const being = actorManager->findBeingByName(
                     nick, ActorType::Player);
-                if (being)
+                if (being != nullptr)
                 {
                     tab->setWhisperTabColors();
                     continue;
                 }
             }
-            if (party)
+            if (party != nullptr)
             {
                 const PartyMember *const pm = party->getMember(nick);
-                if (pm && pm->getOnline())
+                if ((pm != nullptr) && pm->getOnline())
                 {
                     tab->setWhisperTabColors();
                     continue;
                 }
             }
-            if (guild)
+            if (guild != nullptr)
             {
                 const GuildMember *const gm = guild->getMember(nick);
-                if (gm && gm->getOnline())
+                if ((gm != nullptr) && gm->getOnline())
                 {
                     tab->setWhisperTabColors();
                     continue;
@@ -1854,11 +1857,11 @@ void ChatWindow::loadState()
             "chatWhisperFlags" + toString(num), 1);
 
         ChatTab *const tab = addChatTab(nick, false, false);
-        if (tab)
+        if (tab != nullptr)
         {
-            tab->setAllowHighlight(flags & 1);
-            tab->setRemoveNames((flags & 2) / 2);
-            tab->setNoAway((flags & 4) / 4);
+            tab->setAllowHighlight((flags & 1) != 0);
+            tab->setRemoveNames(((flags & 2) / 2) != 0);
+            tab->setNoAway(((flags & 4) / 4) != 0);
         }
         num ++;
     }
@@ -1870,7 +1873,7 @@ void ChatWindow::saveState() const
     for (ChannelMap::const_iterator iter = mChannels.begin(),
          iter_end = mChannels.end(); iter != iter_end && num < 50; ++iter)
     {
-        if (!iter->second)
+        if (iter->second == nullptr)
             return;
         if (!saveTab(num, iter->second))
             continue;
@@ -1880,7 +1883,7 @@ void ChatWindow::saveState() const
     for (TabMap::const_iterator iter = mWhispers.begin(),
          iter_end = mWhispers.end(); iter != iter_end && num < 50; ++iter)
     {
-        if (!iter->second)
+        if (iter->second == nullptr)
             return;
         if (!saveTab(num, iter->second))
             continue;
@@ -1898,7 +1901,7 @@ void ChatWindow::saveState() const
 bool ChatWindow::saveTab(const int num,
                          const ChatTab *const tab) const
 {
-    if (!tab)
+    if (tab == nullptr)
         return false;
 
     serverConfig.setValue("chatWhisper" + toString(num),
@@ -1927,7 +1930,7 @@ void ChatWindow::loadCustomList()
     std::string listName = settings.serverConfigDir
         + "/customwords.txt";
 
-    if (!stat(listName.c_str(), &statbuf) && S_ISREG(statbuf.st_mode))
+    if ((stat(listName.c_str(), &statbuf) == 0) && S_ISREG(statbuf.st_mode))
     {
         listFile.open(listName.c_str(), std::ios::in);
         if (listFile.is_open())
@@ -1958,7 +1961,7 @@ void ChatWindow::addToAwayLog(const std::string &line)
 
 void ChatWindow::displayAwayLog() const
 {
-    if (!localChatTab)
+    if (localChatTab == nullptr)
         return;
 
     std::list<std::string>::const_iterator i = mAwayLog.begin();
@@ -1975,7 +1978,7 @@ void ChatWindow::displayAwayLog() const
 void ChatWindow::parseHighlights()
 {
     mHighlights.clear();
-    if (!localPlayer)
+    if (localPlayer == nullptr)
         return;
 
     splitToStringVector(mHighlights, config.getStringValue(
@@ -1987,7 +1990,7 @@ void ChatWindow::parseHighlights()
 void ChatWindow::parseGlobalsFilter()
 {
     mGlobalsFilter.clear();
-    if (!localPlayer)
+    if (localPlayer == nullptr)
         return;
 
     splitToStringVector(mGlobalsFilter, config.getStringValue(
@@ -2004,11 +2007,11 @@ bool ChatWindow::findHighlight(const std::string &str)
 void ChatWindow::copyToClipboard(const int x, const int y) const
 {
     const ChatTab *const tab = getFocused();
-    if (!tab)
+    if (tab == nullptr)
         return;
 
     const BrowserBox *const text = tab->mTextOutput;
-    if (!text)
+    if (text == nullptr)
         return;
 
     std::string str = text->getTextAtPos(x, y);
@@ -2071,7 +2074,7 @@ void ChatWindow::safeDraw(Graphics *const graphics)
 
 void ChatWindow::updateVisibility()
 {
-    if (!gui)
+    if (gui == nullptr)
         return;
 
     int mouseX = 0;
@@ -2107,10 +2110,15 @@ void ChatWindow::logicChildren()
 
 void ChatWindow::addGlobalMessage(const std::string &line)
 {
-    if (debugChatTab && findI(line, mGlobalsFilter) != std::string::npos)
+    if (debugChatTab != nullptr &&
+        findI(line, mGlobalsFilter) != std::string::npos)
+    {
         debugChatTab->chatLog(line, ChatMsgType::BY_OTHER);
+    }
     else
+    {
         localChatTab->chatLog(line, ChatMsgType::BY_GM);
+    }
 }
 
 bool ChatWindow::isTabPresent(const ChatTab *const tab) const
@@ -2120,13 +2128,13 @@ bool ChatWindow::isTabPresent(const ChatTab *const tab) const
 
 void ChatWindow::debugMessage(const std::string &msg)
 {
-    if (debugChatTab)
+    if (debugChatTab != nullptr)
         debugChatTab->chatLog(msg, ChatMsgType::BY_SERVER);
 }
 
 void ChatWindow::showGMTab()
 {
-    if (!gmChatTab &&
+    if ((gmChatTab == nullptr) &&
         config.getBoolValue("enableGmTab") &&
         localPlayer->getGMLevel() >= paths.getIntValue("gmTabMinimalLevel"))
     {
@@ -2145,7 +2153,7 @@ void ChatWindow::toggleChatFocus()
 void ChatWindow::joinRoom(const bool isJoin)
 {
     Tab *const tab = mChatTabs->getTabByIndex(0);
-    if (tab)
+    if (tab != nullptr)
     {
         std::string name;
         if (isJoin)
diff --git a/src/gui/windows/confirmdialog.cpp b/src/gui/windows/confirmdialog.cpp
index 201b3af79..913fb7c41 100644
--- a/src/gui/windows/confirmdialog.cpp
+++ b/src/gui/windows/confirmdialog.cpp
@@ -65,7 +65,7 @@ void ConfirmDialog::postInit()
     int inWidth = yesButton->getWidth() + noButton->getWidth() +
         (2 * mPadding);
 
-    if (ignoreButton)
+    if (ignoreButton != nullptr)
         inWidth += ignoreButton->getWidth();
 
     const int fontHeight = getFont()->getHeight();
@@ -90,7 +90,7 @@ void ConfirmDialog::postInit()
     yesButton->setPosition((width - inWidth) / 2, height + buttonPadding);
     noButton->setPosition(yesButton->getX() + yesButton->getWidth()
         + (2 * mPadding), height + buttonPadding);
-    if (ignoreButton)
+    if (ignoreButton != nullptr)
     {
         ignoreButton->setPosition(noButton->getX() + noButton->getWidth()
             + (2 * mPadding), height + buttonPadding);
@@ -100,10 +100,10 @@ void ConfirmDialog::postInit()
     add(yesButton);
     add(noButton);
 
-    if (mIgnore && ignoreButton)
+    if (mIgnore && (ignoreButton != nullptr))
         add(ignoreButton);
 
-    if (getParent())
+    if (getParent() != nullptr)
     {
         center();
         getParent()->moveToTop(this);
diff --git a/src/gui/windows/cutinwindow.cpp b/src/gui/windows/cutinwindow.cpp
index 79bc1e1e9..2713dfdfc 100644
--- a/src/gui/windows/cutinwindow.cpp
+++ b/src/gui/windows/cutinwindow.cpp
@@ -69,7 +69,7 @@ void CutInWindow::safeDraw(Graphics *const graphics)
 
 void CutInWindow::draw2(Graphics *const graphics)
 {
-    if (mImage)
+    if (mImage != nullptr)
         mImage->drawRaw(graphics, mPadding, mTitleBarHeight);
 }
 
@@ -87,7 +87,7 @@ void CutInWindow::show(const std::string &name,
             pathJoin(paths.getStringValue("cutInsDir"),
             name).append(
             ".xml"));
-        if (mImage)
+        if (mImage != nullptr)
         {
             mImage->update(1);
             const bool showTitle = (cutin == CutIn::MovableClose);
@@ -145,7 +145,7 @@ void CutInWindow::hide()
 
 void CutInWindow::logic()
 {
-    if (mImage)
+    if (mImage != nullptr)
     {
         const int time = tick_time * MILLISECONDS_IN_A_TICK;
         mImage->update(time);
diff --git a/src/gui/windows/debugwindow.cpp b/src/gui/windows/debugwindow.cpp
index 1648a37ed..8b4144b98 100644
--- a/src/gui/windows/debugwindow.cpp
+++ b/src/gui/windows/debugwindow.cpp
@@ -47,7 +47,7 @@ DebugWindow::DebugWindow() :
     mNetWidget(new NetDebugTab(this))
 {
     setWindowName("Debug");
-    if (setupWindow)
+    if (setupWindow != nullptr)
         setupWindow->registerWindowForReset(this);
 
     setResizable(true);
@@ -94,7 +94,7 @@ void DebugWindow::postInit()
 void DebugWindow::slowLogic()
 {
     BLOCK_START("DebugWindow::slowLogic")
-    if (!isWindowVisible() || !mTabs)
+    if (!isWindowVisible() || (mTabs == nullptr))
     {
         BLOCK_END("DebugWindow::slowLogic")
         return;
@@ -114,7 +114,7 @@ void DebugWindow::slowLogic()
             break;
     }
 
-    if (localPlayer)
+    if (localPlayer != nullptr)
         localPlayer->tryPingRequest();
     BLOCK_END("DebugWindow::slowLogic")
 }
@@ -124,10 +124,10 @@ void DebugWindow::draw(Graphics *const g)
     BLOCK_START("DebugWindow::draw")
     Window::draw(g);
 
-    if (localPlayer)
+    if (localPlayer != nullptr)
     {
         const Being *const target = localPlayer->getTarget();
-        if (target)
+        if (target != nullptr)
         {
             target->draw(g, -target->getPixelX() + mapTileSize / 2
                 + mDimension.width / 2, -target->getPixelY() + mapTileSize
@@ -142,10 +142,10 @@ void DebugWindow::safeDraw(Graphics *const g)
     BLOCK_START("DebugWindow::draw")
     Window::safeDraw(g);
 
-    if (localPlayer)
+    if (localPlayer != nullptr)
     {
         const Being *const target = localPlayer->getTarget();
-        if (target)
+        if (target != nullptr)
         {
             target->draw(g, -target->getPixelX() + mapTileSize / 2
                 + mDimension.width / 2, -target->getPixelY() + mapTileSize
diff --git a/src/gui/windows/didyouknowwindow.cpp b/src/gui/windows/didyouknowwindow.cpp
index f5a01b42d..f358ece83 100644
--- a/src/gui/windows/didyouknowwindow.cpp
+++ b/src/gui/windows/didyouknowwindow.cpp
@@ -75,7 +75,7 @@ DidYouKnowWindow::DidYouKnowWindow() :
     setResizable(true);
     setStickyButtonLock(true);
 
-    if (setupWindow)
+    if (setupWindow != nullptr)
         setupWindow->registerWindowForReset(this);
     setDefaultSize(500, 400, ImagePosition::CENTER);
 
@@ -84,7 +84,7 @@ DidYouKnowWindow::DidYouKnowWindow() :
     Button *const okButton = new Button(this, _("Close"), "close", this);
 
     mBrowserBox->setLinkHandler(mItemLinkHandler);
-    if (gui)
+    if (gui != nullptr)
         mBrowserBox->setFont(gui->getHelpFont());
     mBrowserBox->setProcessVars(true);
     mBrowserBox->setEnableImages(true);
@@ -144,7 +144,7 @@ void DidYouKnowWindow::action(const ActionEvent &event)
 void DidYouKnowWindow::loadData(int num)
 {
     mBrowserBox->clearRows();
-    if (!num)
+    if (num == 0)
     {
         const int curTip = config.getIntValue("currentTip");
         if (curTip == 1)
diff --git a/src/gui/windows/editserverdialog.cpp b/src/gui/windows/editserverdialog.cpp
index d4bec498f..37683caf5 100644
--- a/src/gui/windows/editserverdialog.cpp
+++ b/src/gui/windows/editserverdialog.cpp
@@ -228,7 +228,7 @@ void EditServerDialog::action(const ActionEvent &event)
                 mPortField->getText().c_str()));
             mServer.persistentIp = mPersistentIp->isSelected();
 
-            if (mTypeField)
+            if (mTypeField != nullptr)
             {
                 switch (mTypeField->getSelected())
                 {
diff --git a/src/gui/windows/eggselectiondialog.cpp b/src/gui/windows/eggselectiondialog.cpp
index 6055eada2..5e77d8ec1 100644
--- a/src/gui/windows/eggselectiondialog.cpp
+++ b/src/gui/windows/eggselectiondialog.cpp
@@ -60,7 +60,7 @@ void EggSelectionDialog::sellAction(const ActionEvent &event A_UNUSED)
 
     const int selectedItem = mShopItemList->getSelected();
     const ShopItem *const item = mShopItems->at(selectedItem);
-    if (!item)
+    if (item == nullptr)
         return;
     inventoryHandler->selectEgg(item);
     scheduleDelete();
diff --git a/src/gui/windows/emotewindow.cpp b/src/gui/windows/emotewindow.cpp
index 796e3f342..0125177b1 100644
--- a/src/gui/windows/emotewindow.cpp
+++ b/src/gui/windows/emotewindow.cpp
@@ -77,7 +77,7 @@ EmoteWindow::EmoteWindow() :
     setShowTitle(false);
     setResizable(true);
 
-    if (setupWindow)
+    if (setupWindow != nullptr)
         setupWindow->registerWindowForReset(this);
 
     addMouseListener(this);
@@ -110,12 +110,12 @@ void EmoteWindow::postInit()
     mFontPage->setCenter(true);
     mTextPage->setCenter(true);
 
-    if (mImageSet && mImageSet->size() >= 3)
+    if ((mImageSet != nullptr) && mImageSet->size() >= 3)
     {
         for (int f = 0; f < 3; f ++)
         {
             Image *const image = mImageSet->get(f);
-            if (image)
+            if (image != nullptr)
                 image->incRef();
         }
 
@@ -155,7 +155,7 @@ EmoteWindow::~EmoteWindow()
     delete2(mTextPage);
     delete2(mTextModel);
     delete2(mScrollTextPage);
-    if (mImageSet)
+    if (mImageSet != nullptr)
     {
         mImageSet->decRef();
         mImageSet = nullptr;
@@ -230,7 +230,7 @@ std::string EmoteWindow::getSelectedFont() const
     if (index < 0)
         return std::string();
 
-    if (!index)
+    if (index == 0)
         return "##b";
     else
         return "##B";
diff --git a/src/gui/windows/equipmentwindow.cpp b/src/gui/windows/equipmentwindow.cpp
index c0ed8b5d4..d77302035 100644
--- a/src/gui/windows/equipmentwindow.cpp
+++ b/src/gui/windows/equipmentwindow.cpp
@@ -104,10 +104,10 @@ EquipmentWindow::EquipmentWindow(Equipment *const equipment,
 
     mYPadding = mTabs->getHeight() + getOption("tabPadding", 2);
 
-    if (setupWindow)
+    if (setupWindow != nullptr)
         setupWindow->registerWindowForReset(this);
 
-    if (!mBoxSize)
+    if (mBoxSize == 0)
         mBoxSize = 36;
 
     // Control that shows the Player
@@ -154,7 +154,7 @@ EquipmentWindow::~EquipmentWindow()
 {
     if (this == beingEquipmentWindow)
     {
-        if (mEquipment)
+        if (mEquipment != nullptr)
             delete mEquipment->getBackend();
         delete2(mEquipment)
     }
@@ -165,14 +165,14 @@ EquipmentWindow::~EquipmentWindow()
         boxes.clear();
         delete *it;
     }
-    if (mImageSet)
+    if (mImageSet != nullptr)
     {
         mImageSet->decRef();
         mImageSet = nullptr;
     }
-    if (mSlotBackground)
+    if (mSlotBackground != nullptr)
         mSlotBackground->decRef();
-    if (mSlotHighlightedBackground)
+    if (mSlotHighlightedBackground != nullptr)
         mSlotHighlightedBackground->decRef();
     delete2(mVertexes);
 }
@@ -194,7 +194,7 @@ void EquipmentWindow::draw(Graphics *const graphics)
         FOR_EACH (std::vector<EquipmentBox*>::const_iterator, it, boxes)
         {
             const EquipmentBox *const box = *it;
-            if (!box)
+            if (box == nullptr)
             {
                 i ++;
                 continue;
@@ -217,7 +217,7 @@ void EquipmentWindow::draw(Graphics *const graphics)
     }
     graphics->drawTileCollection(mVertexes);
 
-    if (!mEquipment)
+    if (mEquipment == nullptr)
     {
         BLOCK_END("EquipmentWindow::draw")
         return;
@@ -229,14 +229,14 @@ void EquipmentWindow::draw(Graphics *const graphics)
          it_end = boxes.end(); it != it_end; ++ it, ++ i)
     {
         const EquipmentBox *const box = *it;
-        if (!box)
+        if (box == nullptr)
             continue;
         const Item *const item = mEquipment->getEquipment(i);
-        if (item)
+        if (item != nullptr)
         {
             // Draw Item.
             Image *const image = item->getImage();
-            if (image)
+            if (image != nullptr)
             {
                 image->setAlpha(1.0F);  // Ensure the image is drawn
                                         // with maximum opacity
@@ -254,7 +254,7 @@ void EquipmentWindow::draw(Graphics *const graphics)
                 }
             }
         }
-        else if (box->image)
+        else if (box->image != nullptr)
         {
             graphics->drawImage(box->image,
                 box->x + mItemPadding,
@@ -279,7 +279,7 @@ void EquipmentWindow::safeDraw(Graphics *const graphics)
          it_end = boxes.end(); it != it_end; ++ it, ++ i)
     {
         const EquipmentBox *const box = *it;
-        if (!box)
+        if (box == nullptr)
             continue;
         if (i == mSelected)
         {
@@ -292,7 +292,7 @@ void EquipmentWindow::safeDraw(Graphics *const graphics)
         }
     }
 
-    if (!mEquipment)
+    if (mEquipment == nullptr)
     {
         BLOCK_END("EquipmentWindow::draw")
         return;
@@ -304,14 +304,14 @@ void EquipmentWindow::safeDraw(Graphics *const graphics)
          it_end = boxes.end(); it != it_end; ++ it, ++ i)
     {
         const EquipmentBox *const box = *it;
-        if (!box)
+        if (box == nullptr)
             continue;
         const Item *const item = mEquipment->getEquipment(i);
-        if (item)
+        if (item != nullptr)
         {
             // Draw Item.
             Image *const image = item->getImage();
-            if (image)
+            if (image != nullptr)
             {
                 image->setAlpha(1.0F);  // Ensure the image is drawn
                                         // with maximum opacity
@@ -329,7 +329,7 @@ void EquipmentWindow::safeDraw(Graphics *const graphics)
                 }
             }
         }
-        else if (box->image)
+        else if (box->image != nullptr)
         {
             graphics->drawImage(box->image,
                 box->x + mItemPadding,
@@ -344,17 +344,17 @@ void EquipmentWindow::action(const ActionEvent &event)
     const std::string &eventId = event.getId();
     if (eventId == "unequip")
     {
-        if (!mEquipment || mSelected == -1)
+        if ((mEquipment == nullptr) || mSelected == -1)
             return;
 
         const Item *const item = mEquipment->getEquipment(mSelected);
         PlayerInfo::unequipItem(item, Sfx_true);
         setSelected(-1);
     }
-    else if (!eventId.find("tab_"))
+    else if (eventId.find("tab_") == 0u)
     {
         Button *const button = dynamic_cast<Button*>(event.getSource());
-        if (!button)
+        if (button == nullptr)
             return;
         mSelectedTab = button->getTag();
         updatePage();
@@ -367,13 +367,13 @@ void EquipmentWindow::action(const ActionEvent &event)
         {
             return;
         }
-        Inventory *const inventory = localPlayer
+        Inventory *const inventory = localPlayer != nullptr
             ? PlayerInfo::getInventory() : nullptr;
-        if (!inventory)
+        if (inventory == nullptr)
             return;
         Item *const item = inventory->findItem(dragDrop.getItem(),
             dragDrop.getItemColor());
-        if (!item)
+        if (item == nullptr)
             return;
 
         if (dragDrop.getSource() == DragDropSource::Inventory)
@@ -402,7 +402,7 @@ void EquipmentWindow::updatePage()
 
 const Item *EquipmentWindow::getItem(const int x, const int y) const
 {
-    if (!mEquipment)
+    if (mEquipment == nullptr)
         return nullptr;
 
     int i = 0;
@@ -412,7 +412,7 @@ const Item *EquipmentWindow::getItem(const int x, const int y) const
          it_end = boxes.end(); it != it_end; ++ it, ++ i)
     {
         const EquipmentBox *const box = *it;
-        if (!box)
+        if (box == nullptr)
             continue;
         const Rect tRect(box->x, box->y, mBoxSize, mBoxSize);
 
@@ -424,7 +424,7 @@ const Item *EquipmentWindow::getItem(const int x, const int y) const
 
 void EquipmentWindow::mousePressed(MouseEvent& event)
 {
-    if (!mEquipment)
+    if (mEquipment == nullptr)
     {
         Window::mousePressed(event);
         return;
@@ -450,7 +450,7 @@ void EquipmentWindow::mousePressed(MouseEvent& event)
              it_end = boxes.end(); it != it_end; ++ it, ++ i)
         {
             const EquipmentBox *const box = *it;
-            if (!box)
+            if (box == nullptr)
                 continue;
             const Item *const item = mEquipment->getEquipment(i);
             const Rect tRect(box->x, box->y, mBoxSize, mBoxSize);
@@ -458,7 +458,7 @@ void EquipmentWindow::mousePressed(MouseEvent& event)
             if (tRect.isPointInRect(x, y))
             {
                 inBox = true;
-                if (item)
+                if (item != nullptr)
                 {
                     event.consume();
                     setSelected(i);
@@ -474,7 +474,7 @@ void EquipmentWindow::mousePressed(MouseEvent& event)
     {
         if (const Item *const item = getItem(x, y))
         {
-            if (itemPopup)
+            if (itemPopup != nullptr)
                 itemPopup->setVisible(Visible_false);
 
             /* Convert relative to the window coordinates to absolute screen
@@ -482,7 +482,7 @@ void EquipmentWindow::mousePressed(MouseEvent& event)
              */
             const int mx = x + getX();
             const int my = y + getY();
-            if (popupMenu)
+            if (popupMenu != nullptr)
             {
                 event.consume();
                 if (mForing)
@@ -510,14 +510,14 @@ void EquipmentWindow::mouseReleased(MouseEvent &event)
     {
         return;
     }
-    Inventory *const inventory = localPlayer
+    Inventory *const inventory = localPlayer != nullptr
         ? PlayerInfo::getInventory() : nullptr;
-    if (!inventory)
+    if (inventory == nullptr)
         return;
 
     Item *const item = inventory->findItem(dragDrop.getItem(),
         dragDrop.getItemColor());
-    if (!item)
+    if (item == nullptr)
         return;
 
     if (dragDrop.getSource() == DragDropSource::Inventory)
@@ -540,7 +540,7 @@ void EquipmentWindow::mouseReleased(MouseEvent &event)
                  it != it_end; ++ it)
             {
                 const EquipmentBox *const box = *it;
-                if (!box)
+                if (box == nullptr)
                     continue;
                 const Rect tRect(box->x, box->y, mBoxSize, mBoxSize);
 
@@ -561,7 +561,7 @@ void EquipmentWindow::mouseMoved(MouseEvent &event)
 {
     Window::mouseMoved(event);
 
-    if (!itemPopup)
+    if (itemPopup == nullptr)
         return;
 
     const int x = event.getX();
@@ -569,7 +569,7 @@ void EquipmentWindow::mouseMoved(MouseEvent &event)
 
     const Item *const item = getItem(x, y);
 
-    if (item)
+    if (item != nullptr)
     {
         itemPopup->setItem(item, false);
         itemPopup->position(x + getX(), y + getY());
@@ -583,7 +583,7 @@ void EquipmentWindow::mouseMoved(MouseEvent &event)
 // Hide ItemTooltip
 void EquipmentWindow::mouseExited(MouseEvent &event A_UNUSED)
 {
-    if (itemPopup)
+    if (itemPopup != nullptr)
         itemPopup->setVisible(Visible_false);
 }
 
@@ -591,9 +591,9 @@ void EquipmentWindow::setSelected(const int index)
 {
     mSelected = index;
     mRedraw = true;
-    if (mUnequip)
+    if (mUnequip != nullptr)
         mUnequip->setEnabled(mSelected != -1);
-    if (itemPopup)
+    if (itemPopup != nullptr)
         itemPopup->setVisible(Visible_false);
 }
 
@@ -601,10 +601,10 @@ void EquipmentWindow::setBeing(Being *const being)
 {
     mPlayerBox->setPlayer(being);
     mBeing = being;
-    if (mEquipment)
+    if (mEquipment != nullptr)
         delete mEquipment->getBackend();
     delete mEquipment;
-    if (!being)
+    if (being == nullptr)
     {
         mEquipment = nullptr;
         return;
@@ -631,14 +631,14 @@ void EquipmentWindow::fillBoxes()
         UseVirtFs_true,
         SkipError_false);
     XmlNodeConstPtr root = doc->rootNode();
-    if (!root)
+    if (root == nullptr)
     {
         delete doc;
         fillDefault();
         return;
     }
 
-    if (mImageSet)
+    if (mImageSet != nullptr)
         mImageSet->decRef();
 
     mImageSet = Theme::getImageSetFromTheme(XML::getProperty(
@@ -668,7 +668,7 @@ void EquipmentWindow::addDefaultPage()
 
 void EquipmentWindow::loadPage(XmlNodeConstPtr node)
 {
-    if (!node)
+    if (node == nullptr)
         return;
     // TRANSLATORS: unknown equipment page name
     const std::string &name = XML::langProperty(node, "name", _("Unknown"));
@@ -696,7 +696,7 @@ void EquipmentWindow::loadSlot(XmlNodeConstPtr slotNode,
                                const ImageSet *const imageset,
                                const int page)
 {
-    if (!imageset)
+    if (imageset == nullptr)
         return;
     const int slot = parseSlotName(XML::getProperty(slotNode, "name", ""));
     if (slot < 0)
@@ -712,7 +712,7 @@ void EquipmentWindow::loadSlot(XmlNodeConstPtr slotNode,
         image = imageset->get(imageIndex);
 
     std::vector<EquipmentBox*> &boxes = mPages[page]->boxes;
-    if (boxes[slot])
+    if (boxes[slot] != nullptr)
     {
         EquipmentBox *const box = boxes[slot];
         box->x = x;
@@ -740,7 +740,7 @@ void EquipmentWindow::prepareSlotNames()
         UseVirtFs_true,
         SkipError_false);
     XmlNodeConstPtrConst root = doc.rootNode();
-    if (!root)
+    if (root == nullptr)
         return;
 
     for_each_xml_child_node(slotNode, root)
@@ -776,7 +776,7 @@ int EquipmentWindow::parseSlotName(const std::string &name)
 
 void EquipmentWindow::fillDefault()
 {
-    if (mImageSet)
+    if (mImageSet != nullptr)
         mImageSet->decRef();
 
     addDefaultPage();
@@ -802,7 +802,7 @@ void EquipmentWindow::addBox(const int idx, int x, int y, const int imageIndex)
 {
     Image *image = nullptr;
 
-    if (mImageSet && imageIndex >= 0 && imageIndex
+    if ((mImageSet != nullptr) && imageIndex >= 0 && imageIndex
         < CAST_S32(mImageSet->size()))
     {
         image = mImageSet->get(imageIndex);
diff --git a/src/gui/windows/equipmentwindow.h b/src/gui/windows/equipmentwindow.h
index 00db41fd8..9bd9dd26f 100644
--- a/src/gui/windows/equipmentwindow.h
+++ b/src/gui/windows/equipmentwindow.h
@@ -79,7 +79,10 @@ class EquipmentWindow final : public Window,
         void mousePressed(MouseEvent& event) override final;
 
         const Item* getEquipment(const int i) const A_WARN_UNUSED
-        { return mEquipment ? mEquipment->getEquipment(i) : nullptr; }
+        {
+            return mEquipment != nullptr ?
+                mEquipment->getEquipment(i) : nullptr;
+        }
 
         void setBeing(Being *const being);
 
diff --git a/src/gui/windows/helpwindow.cpp b/src/gui/windows/helpwindow.cpp
index 226284a35..3a2c542ad 100644
--- a/src/gui/windows/helpwindow.cpp
+++ b/src/gui/windows/helpwindow.cpp
@@ -72,7 +72,7 @@ HelpWindow::HelpWindow() :
     setResizable(true);
     setStickyButtonLock(true);
 
-    if (setupWindow)
+    if (setupWindow != nullptr)
         setupWindow->registerWindowForReset(this);
 
     setDefaultSize(500, 400, ImagePosition::CENTER);
@@ -80,7 +80,7 @@ HelpWindow::HelpWindow() :
     mBrowserBox->setOpaque(Opaque_false);
 
     mBrowserBox->setLinkHandler(this);
-    if (gui)
+    if (gui != nullptr)
         mBrowserBox->setFont(gui->getHelpFont());
     mBrowserBox->setProcessVars(true);
     mBrowserBox->setEnableImages(true);
@@ -196,7 +196,7 @@ void HelpWindow::search(const std::string &text0)
         }
         else
         {
-            if (!translator)
+            if (translator == nullptr)
                 return;
             mBrowserBox->clearRows();
             loadFile("header");
diff --git a/src/gui/windows/insertcarddialog.cpp b/src/gui/windows/insertcarddialog.cpp
index efcd8877c..590df6aba 100644
--- a/src/gui/windows/insertcarddialog.cpp
+++ b/src/gui/windows/insertcarddialog.cpp
@@ -43,7 +43,7 @@ InsertCardDialog::InsertCardDialog(const int itemIndex,
 {
     // TRANSLATORS: insert card dialog name
     setWindowName(_("Insert card"));
-    if (item)
+    if (item != nullptr)
     {
         // TRANSLATORS: insert card dialog name
         setCaption(strprintf(_("Insert card %s"),
@@ -72,7 +72,7 @@ void InsertCardDialog::sellAction(const ActionEvent &event A_UNUSED)
 
     const int selectedItem = mShopItemList->getSelected();
     const ShopItem *const item = mShopItems->at(selectedItem);
-    if (!item)
+    if (item == nullptr)
         return;
     inventoryHandler->insertCard(mItemIndex, item->getInvIndex());
     scheduleDelete();
diff --git a/src/gui/windows/inventorywindow.cpp b/src/gui/windows/inventorywindow.cpp
index 7f4f4600b..a39e648b4 100644
--- a/src/gui/windows/inventorywindow.cpp
+++ b/src/gui/windows/inventorywindow.cpp
@@ -116,7 +116,7 @@ InventoryWindow::InventoryWindow(Inventory *const inventory) :
     mSlotsBar->setColor(getThemeColor(ThemeColorId::SLOTS_BAR),
         getThemeColor(ThemeColorId::SLOTS_BAR_OUTLINE));
 
-    if (inventory)
+    if (inventory != nullptr)
     {
         setCaption(gettext(inventory->getName().c_str()));
         setWindowName(inventory->getName());
@@ -151,8 +151,8 @@ InventoryWindow::InventoryWindow(Inventory *const inventory) :
         mSortDropDown->setSelected(0);
     }
 
-    if (setupWindow &&
-        inventory &&
+    if ((setupWindow != nullptr) &&
+        (inventory != nullptr) &&
         inventory->getType() != InventoryType::Storage)
     {
         setupWindow->registerWindowForReset(this);
@@ -184,7 +184,7 @@ InventoryWindow::InventoryWindow(Inventory *const inventory) :
     for (size_t f = 0; f < sz; f ++)
         mFilter->addButton(tags[f], tags[f], false);
 
-    if (!mInventory)
+    if (mInventory == nullptr)
     {
         invInstances.push_back(this);
         return;
@@ -352,14 +352,17 @@ void InventoryWindow::postInit()
 
     mItems->setSortType(mSortDropDown->getSelected());
     widgetResized(Event(nullptr));
-    if (mInventory && mInventory->getType() == InventoryType::Storage)
+    if (mInventory != nullptr &&
+        mInventory->getType() == InventoryType::Storage)
+    {
         setVisible(Visible_true);
+    }
 }
 
 InventoryWindow::~InventoryWindow()
 {
     invInstances.remove(this);
-    if (mInventory)
+    if (mInventory != nullptr)
         mInventory->removeInventoyListener(this);
     if (!invInstances.empty())
         invInstances.front()->updateDropButton();
@@ -370,7 +373,7 @@ InventoryWindow::~InventoryWindow()
 
 void InventoryWindow::storeSortOrder() const
 {
-    if (mInventory)
+    if (mInventory != nullptr)
     {
         switch (mInventory->getType())
         {
@@ -422,20 +425,20 @@ void InventoryWindow::action(const ActionEvent &event)
     }
     else if (eventId == "store")
     {
-        if (!inventoryWindow || !inventoryWindow->isWindowVisible())
+        if (inventoryWindow == nullptr || !inventoryWindow->isWindowVisible())
             return;
 
         Item *const item = inventoryWindow->getSelectedItem();
 
-        if (!item)
+        if (item == nullptr)
             return;
 
-        if (storageWindow)
+        if (storageWindow != nullptr)
         {
             ItemAmountWindow::showWindow(ItemAmountWindowUsage::StoreAdd,
                 this, item);
         }
-        else if (cartWindow && cartWindow->isWindowVisible())
+        else if ((cartWindow != nullptr) && cartWindow->isWindowVisible())
         {
             ItemAmountWindow::showWindow(ItemAmountWindowUsage::CartAdd,
                 this, item);
@@ -452,7 +455,7 @@ void InventoryWindow::action(const ActionEvent &event)
         mItems->setName(mNameFilter->getText());
         mItems->updateMatrix();
     }
-    else if (!eventId.find("tag_"))
+    else if (eventId.find("tag_") == 0u)
     {
         std::string tagName = event.getId().substr(4);
         mItems->setFilter(ItemDB::getTagId(tagName));
@@ -461,7 +464,7 @@ void InventoryWindow::action(const ActionEvent &event)
 
     Item *const item = mItems->getSelectedItem();
 
-    if (!item)
+    if (item == nullptr)
         return;
 
     if (eventId == "use")
@@ -481,7 +484,7 @@ void InventoryWindow::action(const ActionEvent &event)
                 item->getQuantity(),
                 InventoryType::Storage);
         }
-        else if (cartWindow && cartWindow->isWindowVisible())
+        else if ((cartWindow != nullptr) && cartWindow->isWindowVisible())
         {
             inventoryHandler->moveItem2(InventoryType::Inventory,
                 item->getInvIndex(),
@@ -512,12 +515,12 @@ void InventoryWindow::action(const ActionEvent &event)
     }
     else if (eventId == "retrieve")
     {
-        if (storageWindow)
+        if (storageWindow != nullptr)
         {
             ItemAmountWindow::showWindow(ItemAmountWindowUsage::StoreRemove,
                 this, item);
         }
-        else if (cartWindow && cartWindow->isWindowVisible())
+        else if ((cartWindow != nullptr) && cartWindow->isWindowVisible())
         {
             ItemAmountWindow::showWindow(ItemAmountWindowUsage::CartRemove,
                 this, item);
@@ -538,7 +541,7 @@ void InventoryWindow::unselectItem()
 void InventoryWindow::widgetHidden(const Event &event)
 {
     Window::widgetHidden(event);
-    if (itemPopup)
+    if (itemPopup != nullptr)
         itemPopup->setVisible(Visible_false);
 }
 
@@ -548,23 +551,23 @@ void InventoryWindow::mouseClicked(MouseEvent &event)
 
     const int clicks = event.getClickCount();
 
-    if (clicks == 2 && gui)
+    if (clicks == 2 && (gui != nullptr))
         gui->resetClickCount();
 
     const bool mod = (isStorageActive() &&
         inputManager.isActionActive(InputAction::STOP_ATTACK));
 
-    const bool mod2 = (tradeWindow &&
+    const bool mod2 = ((tradeWindow != nullptr) &&
         tradeWindow->isWindowVisible() &&
         inputManager.isActionActive(InputAction::STOP_ATTACK));
 
-    if (mInventory)
+    if (mInventory != nullptr)
     {
         if (!mod && !mod2 && event.getButton() == MouseButton::RIGHT)
         {
             Item *const item = mItems->getSelectedItem();
 
-            if (!item)
+            if (item == nullptr)
                 return;
 
             /* Convert relative to the window coordinates to absolute screen
@@ -573,7 +576,7 @@ void InventoryWindow::mouseClicked(MouseEvent &event)
             const int mx = event.getX() + getX();
             const int my = event.getY() + getY();
 
-            if (popupMenu)
+            if (popupMenu != nullptr)
             {
                 popupMenu->showPopup(this,
                     mx, my,
@@ -592,7 +595,7 @@ void InventoryWindow::mouseClicked(MouseEvent &event)
     {
         Item *const item = mItems->getSelectedItem();
 
-        if (!item)
+        if (item == nullptr)
             return;
 
         if (mod)
@@ -643,7 +646,7 @@ void InventoryWindow::mouseClicked(MouseEvent &event)
             }
             else
             {
-                if (tradeWindow)
+                if (tradeWindow != nullptr)
                     tradeWindow->tradeItem(item, item->getQuantity(), true);
             }
         }
@@ -657,7 +660,8 @@ void InventoryWindow::mouseClicked(MouseEvent &event)
                         ItemAmountWindowUsage::StoreAdd,
                         inventoryWindow, item);
                 }
-                else if (tradeWindow && tradeWindow->isWindowVisible())
+                else if (tradeWindow != nullptr &&
+                         tradeWindow->isWindowVisible())
                 {
                     if (PlayerInfo::isItemProtected(item->getId()))
                         return;
@@ -686,11 +690,11 @@ void InventoryWindow::mouseClicked(MouseEvent &event)
 void InventoryWindow::mouseMoved(MouseEvent &event)
 {
     Window::mouseMoved(event);
-    if (!textPopup)
+    if (textPopup == nullptr)
         return;
 
     const Widget *const src = event.getSource();
-    if (!src)
+    if (src == nullptr)
     {
         textPopup->hide();
         return;
@@ -708,7 +712,7 @@ void InventoryWindow::mouseMoved(MouseEvent &event)
     else
     {
         const Button *const btn = dynamic_cast<const Button *>(src);
-        if (!btn)
+        if (btn == nullptr)
         {
             textPopup->hide();
             return;
@@ -738,12 +742,12 @@ void InventoryWindow::keyReleased(KeyEvent &event)
 
 void InventoryWindow::valueChanged(const SelectionEvent &event A_UNUSED)
 {
-    if (!mInventory || !mInventory->isMainInventory())
+    if ((mInventory == nullptr) || !mInventory->isMainInventory())
         return;
 
     Item *const item = mItems->getSelectedItem();
 
-    if (mSplit && item && inventoryHandler->
+    if (mSplit && (item != nullptr) && inventoryHandler->
         canSplit(mItems->getSelectedItem()))
     {
         ItemAmountWindow::showWindow(ItemAmountWindowUsage::ItemSplit,
@@ -754,29 +758,29 @@ void InventoryWindow::valueChanged(const SelectionEvent &event A_UNUSED)
 
 void InventoryWindow::updateButtons(const Item *item)
 {
-    if (!mInventory || !mInventory->isMainInventory())
+    if ((mInventory == nullptr) || !mInventory->isMainInventory())
         return;
 
     const Item *const selectedItem = mItems->getSelectedItem();
-    if (item && selectedItem != item)
+    if ((item != nullptr) && selectedItem != item)
         return;
 
-    if (!item)
+    if (item == nullptr)
         item = selectedItem;
 
-    if (!item || item->getQuantity() == 0)
+    if ((item == nullptr) || item->getQuantity() == 0)
     {
-        if (mUseButton)
+        if (mUseButton != nullptr)
             mUseButton->setEnabled(false);
-        if (mDropButton)
+        if (mDropButton != nullptr)
             mDropButton->setEnabled(false);
         return;
     }
 
-    if (mDropButton)
+    if (mDropButton != nullptr)
         mDropButton->setEnabled(true);
 
-    if (mUseButton)
+    if (mUseButton != nullptr)
     {
         const ItemInfo &info = item->getInfo();
         const std::string &str = (item->isEquipment() == Equipm_true
@@ -800,7 +804,7 @@ void InventoryWindow::updateButtons(const Item *item)
 
 void InventoryWindow::close()
 {
-    if (!mInventory)
+    if (mInventory == nullptr)
     {
         Window::close();
         return;
@@ -814,7 +818,7 @@ void InventoryWindow::close()
             break;
 
         case InventoryType::Storage:
-            if (inventoryHandler)
+            if (inventoryHandler != nullptr)
             {
                 inventoryHandler->closeStorage();
                 inventoryHandler->forgotStorage();
@@ -835,7 +839,7 @@ void InventoryWindow::close()
 
 void InventoryWindow::updateWeight()
 {
-    if (!mInventory || !mWeightBar)
+    if ((mInventory == nullptr) || (mWeightBar == nullptr))
         return;
     const InventoryTypeT type = mInventory->getType();
     if (type != InventoryType::Inventory &&
@@ -868,7 +872,7 @@ void InventoryWindow::slotsChanged(const Inventory *const inventory)
         const int usedSlots = mInventory->getNumberOfSlotsUsed();
         const int maxSlots = mInventory->getSize();
 
-        if (maxSlots)
+        if (maxSlots != 0)
         {
             mSlotsBar->setProgress(static_cast<float>(usedSlots)
                 / static_cast<float>(maxSlots));
@@ -881,10 +885,11 @@ void InventoryWindow::slotsChanged(const Inventory *const inventory)
 
 void InventoryWindow::updateDropButton()
 {
-    if (!mDropButton)
+    if (mDropButton == nullptr)
         return;
 
-    if (isStorageActive() || (cartWindow && cartWindow->isWindowVisible()))
+    if (isStorageActive() ||
+        (cartWindow != nullptr && cartWindow->isWindowVisible()))
     {
         // TRANSLATORS: inventory button
         mDropButton->setCaption(_("Store"));
@@ -892,7 +897,7 @@ void InventoryWindow::updateDropButton()
     else
     {
         const Item *const item = mItems->getSelectedItem();
-        if (item && item->getQuantity() > 1)
+        if ((item != nullptr) && item->getQuantity() > 1)
         {
             // TRANSLATORS: inventory button
             mDropButton->setCaption(_("Drop..."));
@@ -907,14 +912,14 @@ void InventoryWindow::updateDropButton()
 
 bool InventoryWindow::isInputFocused() const
 {
-    return mNameFilter && mNameFilter->isFocused();
+    return (mNameFilter != nullptr) && mNameFilter->isFocused();
 }
 
 bool InventoryWindow::isAnyInputFocused()
 {
     FOR_EACH (WindowList::const_iterator, it, invInstances)
     {
-        if ((*it) && (*it)->isInputFocused())
+        if (((*it) != nullptr) && (*it)->isInputFocused())
             return true;
     }
     return false;
@@ -925,7 +930,7 @@ InventoryWindow *InventoryWindow::getFirstVisible()
     std::set<Widget*> list;
     FOR_EACH (WindowList::const_iterator, it, invInstances)
     {
-        if ((*it) && (*it)->isWindowVisible())
+        if (((*it) != nullptr) && (*it)->isWindowVisible())
             list.insert(*it);
     }
     InventoryWindow *const window = dynamic_cast<InventoryWindow*>(
@@ -936,14 +941,14 @@ InventoryWindow *InventoryWindow::getFirstVisible()
 void InventoryWindow::nextTab()
 {
     const InventoryWindow *const window = getFirstVisible();
-    if (window)
+    if (window != nullptr)
         window->mFilter->nextTab();
 }
 
 void InventoryWindow::prevTab()
 {
     const InventoryWindow *const window = getFirstVisible();
-    if (window)
+    if (window != nullptr)
         window->mFilter->prevTab();
 }
 
@@ -951,7 +956,7 @@ void InventoryWindow::widgetResized(const Event &event)
 {
     Window::widgetResized(event);
 
-    if (!mInventory)
+    if (mInventory == nullptr)
         return;
     const InventoryTypeT type = mInventory->getType();
     if (type != InventoryType::Inventory &&
@@ -988,10 +993,10 @@ void InventoryWindow::setVisible(Visible visible)
 
 void InventoryWindow::unsetInventory()
 {
-    if (mInventory)
+    if (mInventory != nullptr)
     {
         mInventory->removeInventoyListener(this);
-        if (mItems)
+        if (mItems != nullptr)
             mItems->unsetInventory();
     }
     mInventory = nullptr;
@@ -1013,13 +1018,13 @@ void InventoryWindow::attributeChanged(const AttributesT id,
 void InventoryWindow::combineItems(const int index1,
                                    const int index2)
 {
-    if (!mInventory)
+    if (mInventory == nullptr)
         return;
     const Item *item1 = mInventory->getItem(index1);
-    if (!item1)
+    if (item1 == nullptr)
         return;
     const Item *item2 = mInventory->getItem(index2);
-    if (!item2)
+    if (item2 == nullptr)
         return;
 
     if (item1->getType() != ItemType::Card)
@@ -1046,15 +1051,15 @@ void InventoryWindow::combineItems(const int index1,
 
 void InventoryWindow::moveItemToCraft(const int craftSlot)
 {
-    if (!npcHandler)
+    if (npcHandler == nullptr)
         return;
 
     Item *const item = mItems->getSelectedItem();
-    if (!item)
+    if (item == nullptr)
         return;
 
     NpcDialog *const dialog = npcHandler->getCurrentNpcDialog();
-    if (dialog &&
+    if ((dialog != nullptr) &&
         dialog->getInputState() == NpcInputState::ITEM_CRAFT)
     {
         if (item->getQuantity() > 1
diff --git a/src/gui/windows/inventorywindow.h b/src/gui/windows/inventorywindow.h
index 5159973d3..e1acc962b 100644
--- a/src/gui/windows/inventorywindow.h
+++ b/src/gui/windows/inventorywindow.h
@@ -126,13 +126,16 @@ class InventoryWindow final : public Window,
         void slotsChanged(const Inventory *const inventory) override final;
 
         bool isMainInventory() const A_WARN_UNUSED
-        { return mInventory ? mInventory->isMainInventory() : false; }
+        {
+            return mInventory != nullptr ?
+                mInventory->isMainInventory() : false;
+        }
 
         /**
          * Returns true if any instances exist.
          */
         static bool isStorageActive() A_WARN_UNUSED
-        { return storageWindow; }
+        { return storageWindow != nullptr; }
 
         void updateDropButton();
 
diff --git a/src/gui/windows/itemamountwindow.cpp b/src/gui/windows/itemamountwindow.cpp
index dc318b103..d31e263c4 100644
--- a/src/gui/windows/itemamountwindow.cpp
+++ b/src/gui/windows/itemamountwindow.cpp
@@ -65,12 +65,12 @@ void ItemAmountWindow::finish(Item *const item,
                               const int price,
                               const ItemAmountWindowUsageT usage)
 {
-    if (!item)
+    if (item == nullptr)
         return;
     switch (usage)
     {
         case ItemAmountWindowUsage::TradeAdd:
-            if (tradeWindow)
+            if (tradeWindow != nullptr)
                 tradeWindow->tradeItem(item, amount);
             break;
         case ItemAmountWindowUsage::ItemDrop:
@@ -88,11 +88,11 @@ void ItemAmountWindow::finish(Item *const item,
                 item->getInvIndex(), amount, InventoryType::Inventory);
             break;
         case ItemAmountWindowUsage::ShopBuyAdd:
-            if (shopWindow)
+            if (shopWindow != nullptr)
                 shopWindow->addBuyItem(item, amount, price);
             break;
         case ItemAmountWindowUsage::ShopSellAdd:
-            if (shopWindow)
+            if (shopWindow != nullptr)
                 shopWindow->addSellItem(item, amount, price);
             break;
         case ItemAmountWindowUsage::CartAdd:
@@ -104,13 +104,13 @@ void ItemAmountWindow::finish(Item *const item,
                 item->getInvIndex(), amount, InventoryType::Inventory);
             break;
         case ItemAmountWindowUsage::MailAdd:
-            if (mailEditWindow)
+            if (mailEditWindow != nullptr)
                 mailEditWindow->addItem(item, amount);
             break;
         case ItemAmountWindowUsage::CraftAdd:
         {
             NpcDialog *const dialog = npcHandler->getCurrentNpcDialog();
-            if (dialog)
+            if (dialog != nullptr)
                 dialog->addCraftItem(item, amount, price);  // price as slot
             break;
         }
@@ -130,7 +130,7 @@ ItemAmountWindow::ItemAmountWindow(const ItemAmountWindowUsageT usage,
     mItemPriceTextField(nullptr),
     mGPLabel(nullptr),
     mItem(item),
-    mItemIcon(new Icon(this, item ? item->getImage() : nullptr)),
+    mItemIcon(new Icon(this, item != nullptr ? item->getImage() : nullptr)),
     mItemAmountSlide(new Slider(this, 1.0, maxRange, 1.0)),
     mItemPriceSlide(nullptr),
     mItemDropDown(nullptr),
@@ -140,12 +140,12 @@ ItemAmountWindow::ItemAmountWindow(const ItemAmountWindowUsageT usage,
     mUsage(usage),
     mEnabledKeyboard(keyboard.isEnabled())
 {
-    if (!mItem)
+    if (mItem == nullptr)
         return;
 
     if (usage == ItemAmountWindowUsage::ShopBuyAdd)
         mMax = 10000;
-    else if (!mMax)
+    else if (mMax == 0)
         mMax = mItem->getQuantity();
 
     keyboard.setEnabled(false);
@@ -318,7 +318,7 @@ void ItemAmountWindow::mouseMoved(MouseEvent &event)
 {
     Window::mouseMoved(event);
 
-    if (!viewport || !itemPopup)
+    if ((viewport == nullptr) || (itemPopup == nullptr))
         return;
 
     if (event.getSource() == mItemIcon)
@@ -331,7 +331,7 @@ void ItemAmountWindow::mouseMoved(MouseEvent &event)
 // Hide ItemTooltip
 void ItemAmountWindow::mouseExited(MouseEvent &event A_UNUSED)
 {
-    if (itemPopup)
+    if (itemPopup != nullptr)
         itemPopup->setVisible(Visible_false);
 }
 
@@ -350,7 +350,7 @@ void ItemAmountWindow::action(const ActionEvent &event)
     }
     else if (eventId == "ok")
     {
-        if (mItemPriceTextField)
+        if (mItemPriceTextField != nullptr)
         {
             finish(mItem,
                 mItemAmountTextField->getValue(),
@@ -379,7 +379,7 @@ void ItemAmountWindow::action(const ActionEvent &event)
     }
     else if (eventId == "itemType")
     {
-        if (!mItemDropDown || !mItemsModal)
+        if ((mItemDropDown == nullptr) || (mItemsModal == nullptr))
             return;
 
         const int id = ItemDB::get(mItemsModal->getElementAt(
@@ -398,7 +398,7 @@ void ItemAmountWindow::action(const ActionEvent &event)
 
         if (mUsage == ItemAmountWindowUsage::ShopBuyAdd)
             mMax = 10000;
-        else if (!mMax)
+        else if (mMax == 0)
             mMax = mItem->getQuantity();
 
         mItemIcon->setImage(mItem->getImage());
@@ -417,7 +417,7 @@ void ItemAmountWindow::action(const ActionEvent &event)
     mItemAmountTextField->setValue(amount);
     mItemAmountSlide->setValue(amount);
 
-    if (mItemPriceTextField && mItemPriceSlide)
+    if ((mItemPriceTextField != nullptr) && (mItemPriceSlide != nullptr))
     {
         if (mPrice > 7)
             mPrice = 7;
@@ -443,7 +443,7 @@ void ItemAmountWindow::action(const ActionEvent &event)
         else if (eventId == "slidePrice")
         {
             price = CAST_S32(mItemPriceSlide->getValue());
-            if (price)
+            if (price != 0)
                 mPrice = CAST_S32(log(static_cast<float>(price)));
             else
                 mPrice = 0;
@@ -470,10 +470,10 @@ void ItemAmountWindow::showWindow(const ItemAmountWindowUsageT usage,
                                   int maxRange,
                                   int tag)
 {
-    if (!item)
+    if (item == nullptr)
         return;
 
-    if (!maxRange)
+    if (maxRange == 0)
         maxRange = item->getQuantity();
 
     if (usage != ItemAmountWindowUsage::ShopBuyAdd &&
diff --git a/src/gui/windows/killstats.cpp b/src/gui/windows/killstats.cpp
index 005052fd4..da3b6224e 100644
--- a/src/gui/windows/killstats.cpp
+++ b/src/gui/windows/killstats.cpp
@@ -108,13 +108,13 @@ KillStats::KillStats() :
     setStickyButtonLock(true);
     setDefaultSize(250, 250, 350, 300);
 
-    if (setupWindow)
+    if (setupWindow != nullptr)
         setupWindow->registerWindowForReset(this);
 
     const int xp(PlayerInfo::getAttribute(Attributes::PLAYER_EXP));
     int xpNextLevel(PlayerInfo::getAttribute(Attributes::PLAYER_EXP_NEEDED));
 
-    if (!xpNextLevel)
+    if (xpNextLevel == 0)
         xpNextLevel = 1;
 
     // TRANSLATORS: kill stats window label
@@ -205,7 +205,7 @@ void KillStats::gainXp(int xp)
         Attributes::PLAYER_EXP_NEEDED);
     if (xp == expNeed)
         xp = 0;
-    else if (!xp)
+    else if (xp == 0)
         return;
 
     mKillCounter++;
@@ -213,7 +213,7 @@ void KillStats::gainXp(int xp)
 
     mExpCounter = mExpCounter + xp;
     mExpTCounter = mExpTCounter + xp;
-    if (!mKillCounter)
+    if (mKillCounter == 0)
         mKillCounter = 1;
 
     const float AvgExp = static_cast<float>(mExpCounter)
@@ -223,7 +223,7 @@ void KillStats::gainXp(int xp)
     if (mKillTimer == 0)
         mKillTimer = cur_time;
 
-    if (!xpNextLevel)
+    if (xpNextLevel == 0)
         xpNextLevel = 1;
 
     double timeDiff = difftime(cur_time, mKillTimer) / 60;
diff --git a/src/gui/windows/logindialog.cpp b/src/gui/windows/logindialog.cpp
index 731db0cc9..746d37878 100644
--- a/src/gui/windows/logindialog.cpp
+++ b/src/gui/windows/logindialog.cpp
@@ -85,7 +85,8 @@ LoginDialog::LoginDialog(LoginData &data,
     mRegisterButton(new Button(this, _("Register"), "register", this)),
     // TRANSLATORS: login dialog checkbox
     mCustomUpdateHost(new CheckBox(this, _("Custom update host"),
-        mLoginData->updateType & UpdateType::Custom, this, "customhost")),
+        (mLoginData->updateType & UpdateType::Custom) != 0,
+        this, "customhost")),
     mUpdateHostText(new TextField(this, serverConfig.getValue(
         "customUpdateHost", ""))),
     mUpdateListModel(nullptr),
@@ -96,7 +97,7 @@ LoginDialog::LoginDialog(LoginData &data,
     setCloseButton(true);
     setWindowName("Login");
 
-    if (charServerHandler)
+    if (charServerHandler != nullptr)
         charServerHandler->clear();
 
     mergeUpdateHosts();
@@ -155,7 +156,7 @@ LoginDialog::LoginDialog(LoginData &data,
     place(0, 6, mUpdateTypeLabel, 1);
     place(1, 6, mUpdateTypeDropDown, 8);
     int n = 7;
-    if (mUpdateHostDropDown)
+    if (mUpdateHostDropDown != nullptr)
     {
         place(0, 7, mUpdateHostDropDown, 9);
         n += 1;
@@ -176,7 +177,7 @@ void LoginDialog::postInit()
     setVisible(Visible_true);
 
     const int h = 200;
-    if (mUpdateHostDropDown)
+    if (mUpdateHostDropDown != nullptr)
         setContentSize(310, 250);
     setContentSize(310, h);
 #ifdef ANDROID
@@ -196,7 +197,7 @@ void LoginDialog::postInit()
         mPassField->requestFocus();
 
     mLoginButton->setEnabled(canSubmit());
-    if (loginHandler)
+    if (loginHandler != nullptr)
     {
         mRegisterButton->setEnabled(loginHandler->isRegistrationEnabled()
             || !mLoginData->registerUrl.empty());
@@ -209,9 +210,9 @@ void LoginDialog::postInit()
 
 LoginDialog::~LoginDialog()
 {
-    if (mUpdateTypeDropDown)
+    if (mUpdateTypeDropDown != nullptr)
         mUpdateTypeDropDown->hideDrop(false);
-    if (mUpdateHostDropDown)
+    if (mUpdateHostDropDown != nullptr)
         mUpdateHostDropDown->hideDrop(false);
 
     delete2(mUpdateTypeModel);
@@ -329,7 +330,7 @@ void LoginDialog::prepareUpdate()
     else
     {
         std::string str;
-        if (mUpdateHostDropDown)
+        if (mUpdateHostDropDown != nullptr)
         {
             const int sel = mUpdateHostDropDown->getSelected();
             if (sel >= 0)
diff --git a/src/gui/windows/maileditwindow.cpp b/src/gui/windows/maileditwindow.cpp
index c37cf0bac..a2f7fe6c8 100644
--- a/src/gui/windows/maileditwindow.cpp
+++ b/src/gui/windows/maileditwindow.cpp
@@ -132,17 +132,17 @@ void MailEditWindow::action(const ActionEvent &event)
     else if (eventId == "send")
     {
         const int money = mMoneyField->getValue();
-        if (money)
+        if (money != 0)
             mailHandler->setAttachMoney(money);
         const Item *const tempItem = mInventory->getItem(0);
-        if (tempItem)
+        if (tempItem != nullptr)
         {
             const Inventory *const inv = PlayerInfo::getInventory();
-            if (inv)
+            if (inv != nullptr)
             {
                 const Item *const item = inv->findItem(
                     tempItem->getId(), ItemColor_one);
-                if (item)
+                if (item != nullptr)
                 {
                     mailHandler->setAttach(item->getInvIndex(),
                         tempItem->getQuantity());
@@ -164,7 +164,7 @@ void MailEditWindow::action(const ActionEvent &event)
     {
         Item *const item = inventoryWindow->getSelectedItem();
 
-        if (!item)
+        if (item == nullptr)
             return;
 
         ItemAmountWindow::showWindow(ItemAmountWindowUsage::MailAdd,
@@ -175,7 +175,7 @@ void MailEditWindow::action(const ActionEvent &event)
 void MailEditWindow::addItem(const Item *const item,
                              const int amount)
 {
-    if (!item)
+    if (item == nullptr)
         return;
     mInventory->addItem(item->getId(),
         item->getType(),
diff --git a/src/gui/windows/mailviewwindow.cpp b/src/gui/windows/mailviewwindow.cpp
index 54c3edca7..19d1211bb 100644
--- a/src/gui/windows/mailviewwindow.cpp
+++ b/src/gui/windows/mailviewwindow.cpp
@@ -99,7 +99,7 @@ MailViewWindow::MailViewWindow(const MailMessage *const message) :
     placer(0, n++, mTimeLabel);
     placer(0, n++, mFromLabel);
     placer(0, n++, mSubjectLabel);
-    if (message->money)
+    if (message->money != 0)
     {
         // TRANSLATORS: mail view window label
         mMoneyLabel = new Label(this, strprintf("%s %d", _("Money:"),
@@ -107,7 +107,7 @@ MailViewWindow::MailViewWindow(const MailMessage *const message) :
         placer(0, n++, mMoneyLabel);
     }
     placer(0, n++, mMessageLabel);
-    if (message->itemId)
+    if (message->itemId != 0)
     {
         const ItemInfo &item = ItemDB::get(message->itemId);
         // +++ need use message->cards and ItemColorManager for colors
@@ -135,7 +135,7 @@ MailViewWindow::MailViewWindow(const MailMessage *const message) :
         placer(0, n, mItemLabel);
         placer(1, n++, mIcon);
     }
-    if (message->money || message->itemId)
+    if ((message->money != 0) || (message->itemId != 0))
     {
         mGetAttachButton = new Button(this,
             // TRANSLATORS: mail view attach button
@@ -158,10 +158,10 @@ MailViewWindow::MailViewWindow(const MailMessage *const message) :
 
 MailViewWindow::~MailViewWindow()
 {
-    if (mIcon)
+    if (mIcon != nullptr)
     {
         Image *const image = mIcon->getImage();
-        if (image)
+        if (image != nullptr)
             image->decRef();
     }
     delete2(mMessage);
@@ -177,24 +177,24 @@ void MailViewWindow::action(const ActionEvent &event)
     }
     else if (eventId == "attach")
     {
-        if (mGetAttachButton)
+        if (mGetAttachButton != nullptr)
             mailHandler->getAttach(mMessage->id);
     }
     else if (eventId == "next")
     {
-        if (mMessage)
+        if (mMessage != nullptr)
             mailWindow->viewNext(mMessage->id);
     }
     else if (eventId == "prev")
     {
-        if (mMessage)
+        if (mMessage != nullptr)
             mailWindow->viewPrev(mMessage->id);
     }
     else if (eventId == "reply")
     {
-        if (!mMessage)
+        if (mMessage == nullptr)
             return;
-        if (mailEditWindow)
+        if (mailEditWindow != nullptr)
             mailEditWindow->scheduleDelete();
         CREATEWIDGETV0(mailEditWindow, MailEditWindow);
         mailEditWindow->setTo(mMessage->sender);
diff --git a/src/gui/windows/mailwindow.cpp b/src/gui/windows/mailwindow.cpp
index 96df275e6..98570340f 100644
--- a/src/gui/windows/mailwindow.cpp
+++ b/src/gui/windows/mailwindow.cpp
@@ -78,7 +78,7 @@ MailWindow::MailWindow() :
     setSaveVisible(true);
     setStickyButtonLock(true);
 
-    if (setupWindow)
+    if (setupWindow != nullptr)
         setupWindow->registerWindowForReset(this);
 
     setDefaultSize(310, 180, ImagePosition::CENTER);
@@ -122,7 +122,7 @@ void MailWindow::action(const ActionEvent &event)
     }
     else if (eventId == "new")
     {
-        if (!mailEditWindow)
+        if (mailEditWindow == nullptr)
         {
             CREATEWIDGETV0(mailEditWindow, MailEditWindow);
         }
@@ -164,7 +164,7 @@ void MailWindow::clear()
 
 void MailWindow::addMail(MailMessage *const message)
 {
-    if (!message)
+    if (message == nullptr)
         return;
     mMessages.push_back(message);
     mMailModel->add(strprintf("%s %s",
@@ -184,7 +184,7 @@ void MailWindow::removeMail(const int id)
     FOR_EACH (std::vector<MailMessage*>::iterator, it, mMessages)
     {
         MailMessage *message = *it;
-        if (message && message->id == id)
+        if ((message != nullptr) && message->id == id)
         {
             mMessages.erase(it);
             delete message;
@@ -195,7 +195,7 @@ void MailWindow::removeMail(const int id)
     FOR_EACH (std::vector<MailMessage*>::iterator, it, mMessages)
     {
         MailMessage *message = *it;
-        if (message)
+        if (message != nullptr)
         {
             mMailModel->add(strprintf("%s %s",
                 message->unread ? " " : "U",
@@ -206,7 +206,7 @@ void MailWindow::removeMail(const int id)
 
 void MailWindow::showMessage(MailMessage *const mail)
 {
-    if (!mail)
+    if (mail == nullptr)
         return;
     const std::map<int, MailMessage*>::const_iterator
         it = mMessagesMap.find(mail->id);
@@ -225,7 +225,7 @@ void MailWindow::viewNext(const int id)
     FOR_EACH (std::vector<MailMessage*>::iterator, it, mMessages)
     {
         MailMessage *message = *it;
-        if (message && message->id == id)
+        if ((message != nullptr) && message->id == id)
         {
             ++ it;
             if (it == mMessages.end())
@@ -249,7 +249,7 @@ void MailWindow::viewPrev(const int id)
     FOR_EACH (std::vector<MailMessage*>::iterator, it, mMessages)
     {
         MailMessage *message = *it;
-        if (message && message->id == id)
+        if ((message != nullptr) && message->id == id)
         {
             if (it == mMessages.begin())
             {
@@ -288,7 +288,7 @@ void MailWindow::postConnection()
 
 void MailWindow::createMail(const std::string &to)
 {
-    if (mailEditWindow)
+    if (mailEditWindow != nullptr)
         return;
 
     CREATEWIDGETV0(mailEditWindow, MailEditWindow);
diff --git a/src/gui/windows/minimap.cpp b/src/gui/windows/minimap.cpp
index 2cee038bd..869fede55 100644
--- a/src/gui/windows/minimap.cpp
+++ b/src/gui/windows/minimap.cpp
@@ -79,7 +79,7 @@ Minimap::Minimap() :
     // set this to false as the minimap window size is changed
     // depending on the map size
     setResizable(true);
-    if (setupWindow)
+    if (setupWindow != nullptr)
         setupWindow->registerWindowForReset(this);
 
     setDefaultVisible(true);
@@ -103,7 +103,7 @@ Minimap::~Minimap()
 
 void Minimap::deleteMapImage()
 {
-    if (mMapImage)
+    if (mMapImage != nullptr)
     {
         if (mCustomMapImage)
             delete mMapImage;
@@ -118,7 +118,7 @@ void Minimap::setMap(const Map *const map)
     BLOCK_START("Minimap::setMap")
     std::string caption;
 
-    if (map)
+    if (map != nullptr)
         caption = map->getName();
 
     if (caption.empty())
@@ -130,14 +130,14 @@ void Minimap::setMap(const Map *const map)
     setCaption(caption);
     deleteMapImage();
 
-    if (map)
+    if (map != nullptr)
     {
         if (config.getBoolValue("showExtMinimaps"))
         {
             SDL_Surface *const surface = MSDL_CreateRGBSurface(SDL_SWSURFACE,
                 map->getWidth(), map->getHeight(), 32,
                 0x00ff0000, 0x0000ff00, 0x000000ff, 0x00000000);
-            if (!surface)
+            if (surface == nullptr)
             {
                 if (!isSticky())
                     setVisible(Visible_false);
@@ -148,7 +148,7 @@ void Minimap::setMap(const Map *const map)
             // I'm not sure if the locks are necessary since it's a SWSURFACE
             SDL_LockSurface(surface);
             int* data = static_cast<int*>(surface->pixels);
-            if (!data)
+            if (data == nullptr)
             {
                 if (!isSticky())
                     setVisible(Visible_false);
@@ -163,7 +163,7 @@ void Minimap::setMap(const Map *const map)
 
             for (int ptr = 0; ptr < size; ptr ++)
             {
-                *(data ++) = (map->mMetaTiles[ptr].blockmask & mask) ?
+                *(data ++) = (map->mMetaTiles[ptr].blockmask & mask) != 0 ?
                     0x0 : 0x00ffffff;
             }
 
@@ -200,7 +200,7 @@ void Minimap::setMap(const Map *const map)
         }
     }
 
-    if (mMapImage && map)
+    if ((mMapImage != nullptr) && (map != nullptr))
     {
         const int width = mMapImage->mBounds.w + 2 * getPadding();
         const int height = mMapImage->mBounds.h
@@ -265,7 +265,9 @@ void Minimap::safeDraw(Graphics *const graphics)
 
 void Minimap::draw2(Graphics *const graphics)
 {
-    if (!userPalette || !localPlayer || !viewport)
+    if (userPalette == nullptr ||
+        localPlayer == nullptr ||
+        viewport == nullptr)
     {
         BLOCK_END("Minimap::draw")
         return;
@@ -275,7 +277,7 @@ void Minimap::draw2(Graphics *const graphics)
 
     graphics->pushClipArea(a);
 
-    if (!actorManager)
+    if (actorManager == nullptr)
     {
         BLOCK_END("Minimap::draw")
         return;
@@ -284,7 +286,7 @@ void Minimap::draw2(Graphics *const graphics)
     mMapOriginX = 0;
     mMapOriginY = 0;
 
-    if (mMapImage)
+    if (mMapImage != nullptr)
     {
         const SDL_Rect &rect = mMapImage->mBounds;
         const int w = rect.w;
@@ -316,11 +318,11 @@ void Minimap::draw2(Graphics *const graphics)
     const ActorSprites &actors = actorManager->getAll();
     FOR_EACH (ActorSpritesConstIterator, it, actors)
     {
-        if (!(*it) || (*it)->getType() == ActorType::FloorItem)
+        if (((*it) == nullptr) || (*it)->getType() == ActorType::FloorItem)
             continue;
 
         const Being *const being = static_cast<const Being *>(*it);
-        if (!being)
+        if (being == nullptr)
             continue;
 
         int dotSize = 2;
@@ -380,7 +382,7 @@ void Minimap::draw2(Graphics *const graphics)
             }
         }
 
-        if (userPalette)
+        if (userPalette != nullptr)
             graphics->setColor(userPalette->getColor(type));
 
         const int offsetHeight = CAST_S32(static_cast<float>(
@@ -397,12 +399,12 @@ void Minimap::draw2(Graphics *const graphics)
     if (localPlayer->isInParty())
     {
         const Party *const party = localPlayer->getParty();
-        if (party)
+        if (party != nullptr)
         {
             const PartyMember *const m = party->getMember(
                 localPlayer->getName());
             const Party::MemberList *const members = party->getMembers();
-            if (m)
+            if (m != nullptr)
             {
                 const std::string curMap = m->getMap();
                 Party::MemberList::const_iterator it = members->begin();
@@ -411,10 +413,10 @@ void Minimap::draw2(Graphics *const graphics)
                 while (it != it_end)
                 {
                     const PartyMember *const member = *it;
-                    if (member && member->getMap() == curMap
+                    if ((member != nullptr) && member->getMap() == curMap
                         && member->getOnline() && member != m)
                     {
-                        if (userPalette)
+                        if (userPalette != nullptr)
                         {
                             graphics->setColor(userPalette->getColor(
                                 UserColorId::PARTY));
@@ -454,14 +456,14 @@ void Minimap::draw2(Graphics *const graphics)
 
     if (w <= a.width)
     {
-        if (x < 0 && w)
+        if (x < 0 && (w != 0))
             x = 0;
         if (x + w > a.width)
             x = a.width - w;
     }
     if (h <= a.height)
     {
-        if (y < 0 && h)
+        if (y < 0 && (h != 0))
             y = 0;
         if (y + h > a.height)
             y = a.height - h;
@@ -484,7 +486,7 @@ void Minimap::mouseReleased(MouseEvent &event)
 {
     Window::mouseReleased(event);
 
-    if (!localPlayer || !popupManager)
+    if ((localPlayer == nullptr) || (popupManager == nullptr))
         return;
 
     if (event.getButton() == MouseButton::LEFT)
diff --git a/src/gui/windows/ministatuswindow.cpp b/src/gui/windows/ministatuswindow.cpp
index f57ea2e79..b3e63c226 100644
--- a/src/gui/windows/ministatuswindow.cpp
+++ b/src/gui/windows/ministatuswindow.cpp
@@ -114,14 +114,14 @@ MiniStatusWindow::MiniStatusWindow() :
         // TRANSLATORS: status bar name
         "status bar", _("status bar"))),
     mStatusPopup(CREATEWIDGETR0(StatusPopup)),
-    mSpacing(mSkin ? mSkin->getOption("spacing", 3) : 3),
-    mIconPadding(mSkin ? mSkin->getOption("iconPadding", 3) : 3),
-    mIconSpacing(mSkin ? mSkin->getOption("iconSpacing", 2) : 2),
+    mSpacing(mSkin != nullptr ? mSkin->getOption("spacing", 3) : 3),
+    mIconPadding(mSkin != nullptr ? mSkin->getOption("iconPadding", 3) : 3),
+    mIconSpacing(mSkin != nullptr ? mSkin->getOption("iconSpacing", 2) : 2),
     mMaxX(0)
 {
     StatusWindow::updateHPBar(mHpBar);
 
-    if (statusWindow)
+    if (statusWindow != nullptr)
         statusWindow->updateMPBar(mMpBar);
 
     const bool job = serverConfig.getValueBool("showJob", true);
@@ -145,7 +145,7 @@ MiniStatusWindow::MiniStatusWindow() :
     setVisible(Visible_true);
     addMouseListener(this);
     Inventory *const inv = PlayerInfo::getInventory();
-    if (inv)
+    if (inv != nullptr)
         inv->addInventoyListener(this);
 
     StatusWindow::updateMoneyBar(mMoneyBar);
@@ -160,13 +160,13 @@ MiniStatusWindow::~MiniStatusWindow()
     mIcons.clear();
 
     Inventory *const inv = PlayerInfo::getInventory();
-    if (inv)
+    if (inv != nullptr)
         inv->removeInventoyListener(this);
 
     FOR_EACH (ProgressBarVectorCIter, it, mBars)
     {
         ProgressBar *bar = *it;
-        if (!bar)
+        if (bar == nullptr)
             continue;
         if (bar->mVisible == Visible_false)
             delete bar;
@@ -205,7 +205,7 @@ void MiniStatusWindow::updateBars()
     FOR_EACH (ProgressBarVectorCIter, it, mBars)
     {
         ProgressBar *const bar = *it;
-        if (!bar)
+        if (bar == nullptr)
             continue;
         if (bar->mVisible == Visible_true)
         {
@@ -216,7 +216,7 @@ void MiniStatusWindow::updateBars()
         }
     }
 
-    if (lastBar)
+    if (lastBar != nullptr)
     {
         setContentSize(lastBar->getX() + lastBar->getWidth(),
             lastBar->getY() + lastBar->getHeight());
@@ -249,7 +249,7 @@ void MiniStatusWindow::drawIcons(Graphics *const graphics)
     for (size_t i = 0, sz = mIcons.size(); i < sz; i ++)
     {
         const AnimatedSprite *const icon = mIcons[i];
-        if (icon)
+        if (icon != nullptr)
         {
             icon->draw(graphics, icon_x, mIconPadding);
             icon_x += mIconSpacing + icon->getWidth();
@@ -261,7 +261,7 @@ void MiniStatusWindow::statChanged(const AttributesT id A_UNUSED,
                                    const int oldVal1 A_UNUSED,
                                    const int oldVal2 A_UNUSED)
 {
-    if (statusWindow)
+    if (statusWindow != nullptr)
         statusWindow->updateMPBar(mMpBar);
     StatusWindow::updateJobBar(mJobBar);
 }
@@ -301,9 +301,9 @@ void MiniStatusWindow::attributeChanged(const AttributesT id,
 
 void MiniStatusWindow::updateStatus()
 {
-    if (statusWindow)
+    if (statusWindow != nullptr)
         statusWindow->updateStatusBar(mStatusBar);
-    if (mStatusPopup && mStatusPopup->isPopupVisible())
+    if ((mStatusPopup != nullptr) && mStatusPopup->isPopupVisible())
         mStatusPopup->update();
 }
 
@@ -315,7 +315,7 @@ void MiniStatusWindow::logic()
     for (size_t i = 0, sz = mIcons.size(); i < sz; i++)
     {
         AnimatedSprite *const icon = mIcons[i];
-        if (icon)
+        if (icon != nullptr)
             icon->update(tick_time * 10);
     }
     BLOCK_END("MiniStatusWindow::logic")
@@ -351,7 +351,7 @@ void MiniStatusWindow::mouseMoved(MouseEvent &event)
     else if (event.getSource() == mXpBar)
     {
         std::string level;
-        if (localPlayer && localPlayer->isGM())
+        if ((localPlayer != nullptr) && localPlayer->isGM())
         {
             // TRANSLATORS: status bar label
             level = strprintf(_("Level: %d (GM %d)"),
@@ -430,7 +430,7 @@ void MiniStatusWindow::mouseMoved(MouseEvent &event)
     else if (event.getSource() == mInvSlotsBar)
     {
         const Inventory *const inv = PlayerInfo::getInventory();
-        if (inv)
+        if (inv != nullptr)
         {
             const int usedSlots = inv->getNumberOfSlotsUsed();
             const int maxSlots = inv->getSize();
@@ -459,10 +459,10 @@ void MiniStatusWindow::mousePressed(MouseEvent &event)
     {
         const ProgressBar *const bar = dynamic_cast<ProgressBar*>(
             event.getSource());
-        if (!bar)
+        if (bar == nullptr)
             return;
         event.consume();
-        if (popupManager)
+        if (popupManager != nullptr)
         {
             popupMenu->showPopup(getX() + event.getX(),
                 getY() + event.getY(), bar);
@@ -482,7 +482,7 @@ void MiniStatusWindow::showBar(const std::string &name,
                                const Visible visible)
 {
     ProgressBar *const bar = mBarNames[name];
-    if (!bar)
+    if (bar == nullptr)
         return;
     bar->setVisible(visible);
     updateBars();
@@ -491,19 +491,19 @@ void MiniStatusWindow::showBar(const std::string &name,
 
 void MiniStatusWindow::loadBars()
 {
-    if (!config.getIntValue("ministatussaved"))
+    if (config.getIntValue("ministatussaved") == 0)
     {
-        if (mWeightBar)
+        if (mWeightBar != nullptr)
             mWeightBar->setVisible(Visible_false);
-        if (mInvSlotsBar)
+        if (mInvSlotsBar != nullptr)
             mInvSlotsBar->setVisible(Visible_false);
-        if (mMoneyBar)
+        if (mMoneyBar != nullptr)
             mMoneyBar->setVisible(Visible_false);
-        if (mArrowsBar)
+        if (mArrowsBar != nullptr)
             mArrowsBar->setVisible(Visible_false);
-        if (mStatusBar)
+        if (mStatusBar != nullptr)
             mStatusBar->setVisible(Visible_false);
-        if (mJobBar)
+        if (mJobBar != nullptr)
             mJobBar->setVisible(Visible_true);
         return;
     }
@@ -515,7 +515,7 @@ void MiniStatusWindow::loadBars()
         if (str.empty())
             continue;
         ProgressBar *const bar = mBarNames[str];
-        if (!bar)
+        if (bar == nullptr)
             continue;
         bar->setVisible(Visible_false);
     }
@@ -542,7 +542,7 @@ void MiniStatusWindow::saveBars() const
 
 void MiniStatusWindow::slotsChanged(const Inventory *const inventory)
 {
-    if (!inventory)
+    if (inventory == nullptr)
         return;
 
     if (inventory->getType() == InventoryType::Inventory)
diff --git a/src/gui/windows/npcdialog.cpp b/src/gui/windows/npcdialog.cpp
index a6c7fe857..453f35126 100644
--- a/src/gui/windows/npcdialog.cpp
+++ b/src/gui/windows/npcdialog.cpp
@@ -226,10 +226,10 @@ void NpcDialog::postInit()
     enableVisibleSound(true);
     soundManager.playGuiSound(SOUND_SHOW_WINDOW);
 
-    if (actorManager)
+    if (actorManager != nullptr)
     {
         const Being *const being = actorManager->findBeing(mNpcId);
-        if (being)
+        if (being != nullptr)
         {
             showAvatar(NPCDB::getAvatarFor(fromInt(
                 being->getSubType(), BeingTypeId)));
@@ -246,7 +246,7 @@ NpcDialog::~NpcDialog()
     CHECKLISTENERS
     clearLayout();
 
-    if (mPlayerBox)
+    if (mPlayerBox != nullptr)
     {
         delete mPlayerBox->getBeing();
         delete mPlayerBox;
@@ -276,7 +276,7 @@ NpcDialog::~NpcDialog()
 
     FOR_EACH (ImageVectorIter, it, mImages)
     {
-        if (*it)
+        if (*it != nullptr)
             (*it)->decRef();
     }
 
@@ -328,7 +328,7 @@ void NpcDialog::action(const ActionEvent &event)
         else if (mActionState == NpcActionState::CLOSE
                  || mActionState == NpcActionState::WAIT)
         {
-            if (cutInWindow)
+            if (cutInWindow != nullptr)
                 cutInWindow->hide();
             closeDialog();
         }
@@ -340,9 +340,9 @@ void NpcDialog::action(const ActionEvent &event)
             {
                 case NpcInputState::LIST:
                 {
-                    if (mDialogInfo)
+                    if (mDialogInfo != nullptr)
                         return;
-                    if (gui)
+                    if (gui != nullptr)
                         gui->resetClickCount();
                     const int selectedIndex = mItemList->getSelected();
 
@@ -401,7 +401,7 @@ void NpcDialog::action(const ActionEvent &event)
                     else
                     {
                         const Item *item = mInventory->getItem(0);
-                        if (item)
+                        if (item != nullptr)
                         {
                             str = strprintf("%d,%d", item->getId(),
                                 toInt(item->getColor(), int));
@@ -414,7 +414,7 @@ void NpcDialog::action(const ActionEvent &event)
                         {
                             str.append(";");
                             item = mInventory->getItem(f);
-                            if (item)
+                            if (item != nullptr)
                             {
                                 str.append(strprintf("%d,%d", item->getId(),
                                     toInt(item->getColor(), int)));
@@ -449,7 +449,7 @@ void NpcDialog::action(const ActionEvent &event)
                     else
                     {
                         const Item *item = mInventory->getItem(0);
-                        if (item)
+                        if (item != nullptr)
                         {
                             str = strprintf("%d", item->getTag());
                         }
@@ -461,7 +461,7 @@ void NpcDialog::action(const ActionEvent &event)
                         {
                             str.append(";");
                             item = mInventory->getItem(f);
-                            if (item)
+                            if (item != nullptr)
                                 str.append(strprintf("%d", item->getTag()));
                             else
                                 str.append("-1");
@@ -600,18 +600,18 @@ void NpcDialog::action(const ActionEvent &event)
                     npcHandler->listInput(mNpcId, 255);
                     break;
             }
-            if (cutInWindow)
+            if (cutInWindow != nullptr)
                 cutInWindow->hide();
             closeDialog();
         }
     }
     else if (eventId == "add")
     {
-        if (inventoryWindow)
+        if (inventoryWindow != nullptr)
         {
             Item *const item = inventoryWindow->getSelectedItem();
             Inventory *const inventory = PlayerInfo::getInventory();
-            if (inventory)
+            if (inventory != nullptr)
             {
                 if (mInputState == NpcInputState::ITEM_CRAFT)
                 {
@@ -684,7 +684,7 @@ void NpcDialog::choiceRequest()
     mItems.clear();
     FOR_EACH (ImageVectorIter, it, mImages)
     {
-        if (*it)
+        if (*it != nullptr)
             (*it)->decRef();
     }
     mImages.clear();
@@ -765,7 +765,7 @@ bool NpcDialog::isAnyInputFocused()
 {
     FOR_EACH (DialogList::const_iterator, it, instances)
     {
-        if ((*it) && (*it)->isInputFocused())
+        if (((*it) != nullptr) && (*it)->isInputFocused())
             return true;
     }
 
@@ -851,7 +851,7 @@ NpcDialog *NpcDialog::getActive()
 
     FOR_EACH (DialogList::const_iterator, it, instances)
     {
-        if ((*it) && (*it)->isFocused())
+        if (((*it) != nullptr) && (*it)->isFocused())
             return (*it);
     }
 
@@ -862,7 +862,7 @@ void NpcDialog::closeAll()
 {
     FOR_EACH (DialogList::const_iterator, it, instances)
     {
-        if (*it)
+        if (*it != nullptr)
             (*it)->close();
     }
 }
@@ -908,7 +908,7 @@ void NpcDialog::placeMenuControls()
 void NpcDialog::placeSkinControls()
 {
     createSkinControls();
-    if (mDialogInfo && mDialogInfo->hideText)
+    if ((mDialogInfo != nullptr) && mDialogInfo->hideText)
     {
         if (mShowAvatar)
         {
@@ -988,7 +988,7 @@ void NpcDialog::placeIntInputControls()
 
 void NpcDialog::placeItemInputControls()
 {
-    if (mDialogInfo)
+    if (mDialogInfo != nullptr)
     {
         mItemContainer->setCellBackgroundImage(mDialogInfo->inventory.cell);
         mItemContainer->setMaxColumns(mDialogInfo->inventory.columns);
@@ -1004,7 +1004,7 @@ void NpcDialog::placeItemInputControls()
     else
         mItemContainer->setInventory(mInventory);
 
-    if (mDialogInfo && mDialogInfo->hideText)
+    if ((mDialogInfo != nullptr) && mDialogInfo->hideText)
     {
         if (mShowAvatar)
         {
@@ -1064,7 +1064,7 @@ void NpcDialog::buildLayout()
         switch (mInputState)
         {
             case NpcInputState::LIST:
-                if (!mDialogInfo)
+                if (mDialogInfo == nullptr)
                     placeMenuControls();
                 else
                     placeSkinControls();
@@ -1099,7 +1099,7 @@ void NpcDialog::buildLayout()
 
 void NpcDialog::saveCamera()
 {
-    if (!viewport || mCameraMode >= 0)
+    if ((viewport == nullptr) || mCameraMode >= 0)
         return;
 
     mCameraMode = CAST_S32(settings.cameraMode);
@@ -1109,12 +1109,12 @@ void NpcDialog::saveCamera()
 
 void NpcDialog::restoreCamera()
 {
-    if (!viewport || mCameraMode == -1)
+    if ((viewport == nullptr) || mCameraMode == -1)
         return;
 
     if (CAST_S32(settings.cameraMode) != mCameraMode)
         viewport->toggleCameraMode();
-    if (mCameraMode)
+    if (mCameraMode != 0)
     {
         viewport->setCameraRelativeX(mCameraX);
         viewport->setCameraRelativeY(mCameraY);
@@ -1139,14 +1139,14 @@ void NpcDialog::showAvatar(const BeingTypeId avatarId)
             const BeingInfo *const info = AvatarDB::get(avatarId);
             const int pad2 = 2 * mPadding;
             int width = 0;
-            if (info)
+            if (info != nullptr)
             {
                 width = info->getWidth();
                 mPlayerBox->setWidth(width + pad2);
                 mPlayerBox->setHeight(info->getHeight() + pad2);
             }
             const Sprite *const sprite = mAvatarBeing->mSprites[0];
-            if (sprite && !width)
+            if ((sprite != nullptr) && (width == 0))
             {
                 mPlayerBox->setWidth(sprite->getWidth() + pad2);
                 mPlayerBox->setHeight(sprite->getHeight() + pad2);
@@ -1172,14 +1172,14 @@ void NpcDialog::showAvatar(const BeingTypeId avatarId)
 void NpcDialog::setAvatarDirection(const uint8_t direction)
 {
     Being *const being = mPlayerBox->getBeing();
-    if (being)
+    if (being != nullptr)
         being->setDirection(direction);
 }
 
 void NpcDialog::setAvatarAction(const int actionId)
 {
     Being *const being = mPlayerBox->getBeing();
-    if (being)
+    if (being != nullptr)
         being->setAction(static_cast<BeingActionT>(actionId), 0);
 }
 
@@ -1187,13 +1187,13 @@ void NpcDialog::logic()
 {
     BLOCK_START("NpcDialog::logic")
     Window::logic();
-    if (mShowAvatar && mAvatarBeing)
+    if (mShowAvatar && (mAvatarBeing != nullptr))
     {
         mAvatarBeing->logic();
         if (mPlayerBox->getWidth() < CAST_S32(3 * getPadding()))
         {
             const Sprite *const sprite = mAvatarBeing->mSprites[0];
-            if (sprite)
+            if (sprite != nullptr)
             {
                 mPlayerBox->setWidth(sprite->getWidth() + 2 * getPadding());
                 mPlayerBox->setHeight(sprite->getHeight() + 2 * getPadding());
@@ -1228,7 +1228,7 @@ void NpcDialog::mousePressed(MouseEvent &event)
         && event.getSource() == mTextBox)
     {
         event.consume();
-        if (popupMenu)
+        if (popupMenu != nullptr)
         {
             popupMenu->showNpcDialogPopup(mNpcId,
                 viewport->mMouseX,
@@ -1252,7 +1252,7 @@ void NpcDialog::setSkin(const std::string &skin)
         return;
     }
     const NpcDialogInfo *const dialog = NpcDialogDB::getDialog(skin);
-    if (!dialog)
+    if (dialog == nullptr)
     {
         logger->log("Error: creating controls for not existing npc dialog %s",
             skin.c_str());
@@ -1271,7 +1271,7 @@ void NpcDialog::createSkinControls()
 {
     deleteSkinControls();
 
-    if (!mDialogInfo)
+    if (mDialogInfo == nullptr)
         return;
 
     FOR_EACH (std::vector<NpcImageInfo*>::const_iterator,
@@ -1280,7 +1280,7 @@ void NpcDialog::createSkinControls()
     {
         const NpcImageInfo *const info = *it;
         Image *const image = Theme::getImageFromTheme(info->name);
-        if (image)
+        if (image != nullptr)
         {
             Icon *const icon = new Icon(this, image, AutoRelease_true);
             icon->setPosition(info->x, info->y);
@@ -1338,18 +1338,18 @@ void NpcDialog::createSkinControls()
 void NpcDialog::restoreVirtuals()
 {
     Inventory *const inventory = PlayerInfo::getInventory();
-    if (inventory)
+    if (inventory != nullptr)
         inventory->restoreVirtuals();
 }
 
 std::string NpcDialog::complexItemToStr(const ComplexItem *const item)
 {
     std::string str;
-    if (item)
+    if (item != nullptr)
     {
         const std::vector<Item*> &items = item->getChilds();
         const size_t sz = items.size();
-        if (!sz)
+        if (sz == 0u)
             return str;
 
         const Item *item2 = items[0];
@@ -1382,7 +1382,7 @@ void NpcDialog::addCraftItem(Item *const item,
 
     Inventory *const inventory = PlayerInfo::getInventory();
 
-    if (!inventory)
+    if (inventory == nullptr)
         return;
 
     if (mComplexInventory->addVirtualItem(
diff --git a/src/gui/windows/npcdialog.h b/src/gui/windows/npcdialog.h
index 0c16c7df2..8e041b087 100644
--- a/src/gui/windows/npcdialog.h
+++ b/src/gui/windows/npcdialog.h
@@ -223,7 +223,7 @@ class NpcDialog final : public Window,
         void mousePressed(MouseEvent &event) override final;
 
         int isCloseState() const
-        { return mActionState == NpcActionState::CLOSE; }
+        { return static_cast<int>(mActionState == NpcActionState::CLOSE); }
 
         void setSkin(const std::string &skin);
 
diff --git a/src/gui/windows/npcselldialog.cpp b/src/gui/windows/npcselldialog.cpp
index 7238cd8c6..c00edda6c 100644
--- a/src/gui/windows/npcselldialog.cpp
+++ b/src/gui/windows/npcselldialog.cpp
@@ -57,7 +57,7 @@ void NpcSellDialog::sellAction(const ActionEvent &event)
     const std::string &eventId = event.getId();
     const int selectedItem = mShopItemList->getSelected();
     const ShopItem *const item = mShopItems->at(selectedItem);
-    if (!item || PlayerInfo::isItemProtected(item->getId()))
+    if ((item == nullptr) || PlayerInfo::isItemProtected(item->getId()))
         return;
 
     if (eventId == "presell")
@@ -101,7 +101,7 @@ void NpcSellDialog::sellManyItems(const std::string &eventId)
         ShopItem *const item = mShopItems->at(selectedItem);
         item->increaseUsedQuantity(mAmountItems);
         item->update();
-        if (mConfirmButton)
+        if (mConfirmButton != nullptr)
             mConfirmButton->setEnabled(true);
     }
 }
@@ -130,7 +130,7 @@ void NpcSellDialog::sellOneItem()
     mAmountItems = 1;
     mSlider->setValue(0);
 
-    if (mMaxItems)
+    if (mMaxItems != 0)
     {
         updateButtonsAndLabels();
     }
diff --git a/src/gui/windows/outfitwindow.cpp b/src/gui/windows/outfitwindow.cpp
index 21e17b8e3..51254e9a0 100644
--- a/src/gui/windows/outfitwindow.cpp
+++ b/src/gui/windows/outfitwindow.cpp
@@ -73,7 +73,7 @@ OutfitWindow::OutfitWindow() :
         serverConfig.getValueBool("OutfitUnequip0", true))),
     // TRANSLATORS: outfits window checkbox
     mAwayOutfitCheck(new CheckBox(this, _("Away outfit"),
-        serverConfig.getValue("OutfitAwayIndex", OUTFITS_COUNT - 1))),
+        serverConfig.getValue("OutfitAwayIndex", OUTFITS_COUNT - 1) != 0u)),
     // TRANSLATORS: outfits window label
     mKeyLabel(new Label(this, strprintf(_("Key: %s"),
         keyName(0).c_str()))),
@@ -100,7 +100,7 @@ OutfitWindow::OutfitWindow() :
     setMinWidth(145);
     setMinHeight(220);
 
-    if (setupWindow)
+    if (setupWindow != nullptr)
         setupWindow->registerWindowForReset(this);
 
     mCurrentLabel->setAlignment(Graphics::CENTER);
@@ -181,7 +181,7 @@ void OutfitWindow::load()
     if (mAwayOutfit >= CAST_S32(OUTFITS_COUNT))
         mAwayOutfit = CAST_S32(OUTFITS_COUNT) - 1;
 
-    if (mAwayOutfitCheck)
+    if (mAwayOutfitCheck != nullptr)
         mAwayOutfitCheck->setSelected(mAwayOutfit == mCurrentOutfit);
 }
 
@@ -195,7 +195,7 @@ void OutfitWindow::save() const
         for (unsigned i = 0; i < OUTFIT_ITEM_COUNT; i++)
         {
             const int val = mItems[o][i];
-            const int res = val ? val : -1;
+            const int res = val != 0 ? val : -1;
             if (res != -1)
                 good = true;
             outfitStr.append(toString(res));
@@ -255,7 +255,7 @@ void OutfitWindow::action(const ActionEvent &event)
     else if (eventId == "equip")
     {
         wearOutfit(mCurrentOutfit);
-        if (Game::instance())
+        if (Game::instance() != nullptr)
             Game::instance()->setValidSpeed();
     }
     else if (eventId == "away")
@@ -279,9 +279,9 @@ void OutfitWindow::wearOutfit(const int outfit, const bool unwearEmpty,
         const Item *const item = PlayerInfo::getInventory()->findItem(
             mItems[outfit][i],
             mItemColors[outfit][i]);
-        if (item
+        if ((item != nullptr)
             && item->isEquipped() == Equipped_false
-            && item->getQuantity())
+            && (item->getQuantity() != 0))
         {
             if (item->isEquipment() == Equipm_true)
             {
@@ -348,15 +348,15 @@ void OutfitWindow::draw(Graphics *const graphics)
 
         bool foundItem = false;
         const Inventory *const inv = PlayerInfo::getInventory();
-        if (inv)
+        if (inv != nullptr)
         {
             const Item *const item = inv->findItem(mItems[mCurrentOutfit][i],
                 mItemColors[mCurrentOutfit][i]);
-            if (item)
+            if (item != nullptr)
             {
                 // Draw item icon.
                 const Image *const image = item->getImage();
-                if (image)
+                if (image != nullptr)
                 {
                     graphics->drawImage(image, itemX, itemY);
                     foundItem = true;
@@ -367,7 +367,7 @@ void OutfitWindow::draw(Graphics *const graphics)
         {
             Image *const image = Item::getImage(mItems[mCurrentOutfit][i],
                 mItemColors[mCurrentOutfit][i]);
-            if (image)
+            if (image != nullptr)
             {
                 graphics->drawImage(image, itemX, itemY);
                 image->decRef();
@@ -404,15 +404,15 @@ void OutfitWindow::safeDraw(Graphics *const graphics)
 
         bool foundItem = false;
         const Inventory *const inv = PlayerInfo::getInventory();
-        if (inv)
+        if (inv != nullptr)
         {
             const Item *const item = inv->findItem(mItems[mCurrentOutfit][i],
                 mItemColors[mCurrentOutfit][i]);
-            if (item)
+            if (item != nullptr)
             {
                 // Draw item icon.
                 const Image *const image = item->getImage();
-                if (image)
+                if (image != nullptr)
                 {
                     graphics->drawImage(image, itemX, itemY);
                     foundItem = true;
@@ -423,7 +423,7 @@ void OutfitWindow::safeDraw(Graphics *const graphics)
         {
             Image *const image = Item::getImage(mItems[mCurrentOutfit][i],
                 mItemColors[mCurrentOutfit][i]);
-            if (image)
+            if (image != nullptr)
             {
                 graphics->drawImage(image, itemX, itemY);
                 image->decRef();
@@ -462,10 +462,10 @@ void OutfitWindow::mouseDragged(MouseEvent &event)
             mMoved = false;
             event.consume();
             const Inventory *const inv = PlayerInfo::getInventory();
-            if (inv)
+            if (inv != nullptr)
             {
                 Item *const item = inv->findItem(itemId, itemColor);
-                if (item)
+                if (item != nullptr)
                     dragDrop.dragItem(item, DragDropSource::Outfit);
                 else
                     dragDrop.clear();
@@ -479,7 +479,7 @@ void OutfitWindow::mouseDragged(MouseEvent &event)
 void OutfitWindow::mousePressed(MouseEvent &event)
 {
     const int index = getIndexFromGrid(event.getX(), event.getY());
-    if (event.getButton() == MouseButton::RIGHT && popupMenu)
+    if (event.getButton() == MouseButton::RIGHT && (popupMenu != nullptr))
     {
         popupMenu->showOutfitsWindowPopup(viewport->mMouseX,
             viewport->mMouseY);
@@ -565,14 +565,14 @@ void OutfitWindow::unequipNotInOutfit(const int outfit) const
     // here we think that outfit is correct index
 
     const Inventory *const inventory = PlayerInfo::getInventory();
-    if (!inventory)
+    if (inventory == nullptr)
         return;
 
     const unsigned int invSize = inventory->getSize();
     for (unsigned i = 0; i < invSize; i++)
     {
         const Item *const item = inventory->getItem(i);
-        if (item && item->isEquipped() == Equipped_true)
+        if ((item != nullptr) && item->isEquipped() == Equipped_true)
         {
             bool found = false;
             for (unsigned f = 0; f < OUTFIT_ITEM_COUNT; f++)
@@ -680,14 +680,14 @@ void OutfitWindow::copyFromEquiped()
 void OutfitWindow::copyFromEquiped(const int dst)
 {
     const Inventory *const inventory = PlayerInfo::getInventory();
-    if (!inventory)
+    if (inventory == nullptr)
         return;
 
     int outfitCell = 0;
     for (unsigned i = 0, sz = inventory->getSize(); i < sz; i++)
     {
         const Item *const item = inventory->getItem(i);
-        if (item && item->isEquipped() == Equipped_true)
+        if ((item != nullptr) && item->isEquipped() == Equipped_true)
         {
             mItems[dst][outfitCell] = item->getId();
             mItemColors[dst][outfitCell++] = item->getColor();
diff --git a/src/gui/windows/questswindow.cpp b/src/gui/windows/questswindow.cpp
index bf3b1c19a..5515489e6 100644
--- a/src/gui/windows/questswindow.cpp
+++ b/src/gui/windows/questswindow.cpp
@@ -100,7 +100,7 @@ QuestsWindow::QuestsWindow() :
     setMinWidth(310);
     setMinHeight(220);
 
-    if (setupWindow)
+    if (setupWindow != nullptr)
         setupWindow->registerWindowForReset(this);
 
     mQuestsListBox->setActionEventId("select");
@@ -111,7 +111,7 @@ QuestsWindow::QuestsWindow() :
     mText->setLinkHandler(mItemLinkHandler);
     mTextScrollArea->setHorizontalScrollPolicy(ScrollArea::SHOW_NEVER);
     mQuestsListBox->setWidth(500);
-    if (!gui || gui->getNpcFont()->getHeight() < 20)
+    if ((gui == nullptr) || gui->getNpcFont()->getHeight() < 20)
         mQuestsListBox->setRowHeight(20);
     else
         mQuestsListBox->setRowHeight(gui->getNpcFont()->getHeight());
@@ -143,12 +143,12 @@ QuestsWindow::~QuestsWindow()
     delete2(mItemLinkHandler);
     mQuestLinks.clear();
     mQuestReverseLinks.clear();
-    if (mCompleteIcon)
+    if (mCompleteIcon != nullptr)
     {
         mCompleteIcon->decRef();
         mCompleteIcon = nullptr;
     }
-    if (mIncompleteIcon)
+    if (mIncompleteIcon != nullptr)
     {
         mIncompleteIcon->decRef();
         mIncompleteIcon = nullptr;
@@ -200,7 +200,7 @@ void QuestsWindow::rebuild(const bool playSound)
         const std::vector<QuestItem*> &quests = (*mQuests)[var];
         FOR_EACH (std::vector<QuestItem*>::const_iterator, it2, quests)
         {
-            if (!*it2)
+            if (*it2 == nullptr)
                 continue;
             QuestItem *const quest = *it2;
             // complete quest
@@ -238,7 +238,7 @@ void QuestsWindow::rebuild(const bool playSound)
         mQuestLinks.push_back(quest);
         mQuestReverseLinks[quest->var] = k;
         names.push_back(quest->name);
-        if (mCompleteIcon)
+        if (mCompleteIcon != nullptr)
         {
             mCompleteIcon->incRef();
             images.push_back(mCompleteIcon);
@@ -262,7 +262,7 @@ void QuestsWindow::rebuild(const bool playSound)
         mQuestLinks.push_back(quest);
         mQuestReverseLinks[quest->var] = k;
         names.push_back(quest->name);
-        if (mIncompleteIcon)
+        if (mIncompleteIcon != nullptr)
         {
             mIncompleteIcon->incRef();
             images.push_back(mIncompleteIcon);
@@ -285,7 +285,7 @@ void QuestsWindow::rebuild(const bool playSound)
     {
         mQuestsListBox->setSelected(updatedQuest);
         showQuest(mQuestLinks[updatedQuest]);
-        if (playSound && effectManager)
+        if (playSound && (effectManager != nullptr))
         {
             switch (newCompleteStatus)
             {
@@ -306,7 +306,7 @@ void QuestsWindow::rebuild(const bool playSound)
 
 void QuestsWindow::showQuest(const QuestItem *const quest)
 {
-    if (!quest)
+    if (quest == nullptr)
         return;
 
     const std::vector<QuestItemText> &texts = quest->texts;
@@ -373,14 +373,14 @@ void QuestsWindow::setMap(const Map *const map)
     {
         mMap = map;
         mMapEffects.clear();
-        if (!mMap)
+        if (mMap == nullptr)
             return;
 
         const std::string name = mMap->getProperty("shortName");
         FOR_EACHP (std::vector<QuestEffect*>::const_iterator, it,  mAllEffects)
         {
             const QuestEffect *const effect = *it;
-            if (effect && name == effect->map)
+            if ((effect != nullptr) && name == effect->map)
                 mMapEffects.push_back(effect);
         }
         updateEffects();
@@ -396,7 +396,7 @@ void QuestsWindow::updateEffects()
               it,  mMapEffects)
     {
         const QuestEffect *const effect = *it;
-        if (effect)
+        if (effect != nullptr)
         {
             const NpcQuestVarMapCIter varIt = mVars->find(effect->var);
             if (varIt != mVars->end())
@@ -407,7 +407,7 @@ void QuestsWindow::updateEffects()
             }
         }
     }
-    if (!actorManager)
+    if (actorManager == nullptr)
         return;
 
     std::set<BeingTypeId> removeEffects;
@@ -452,7 +452,7 @@ void QuestsWindow::updateEffects()
 
 void QuestsWindow::addEffect(Being *const being)
 {
-    if (!being)
+    if (being == nullptr)
         return;
     const BeingTypeId id = being->getSubType();
     const std::map<BeingTypeId, const QuestEffect*>::const_iterator
@@ -460,7 +460,7 @@ void QuestsWindow::addEffect(Being *const being)
     if (it != mNpcEffects.end())
     {
         const QuestEffect *const effect = (*it).second;
-        if (effect)
+        if (effect != nullptr)
             being->addSpecialEffect(effect->effectId);
     }
 }
diff --git a/src/gui/windows/quitdialog.cpp b/src/gui/windows/quitdialog.cpp
index 4a786d22a..e04b28d18 100644
--- a/src/gui/windows/quitdialog.cpp
+++ b/src/gui/windows/quitdialog.cpp
@@ -130,7 +130,7 @@ void QuitDialog::postInit()
 
 QuitDialog::~QuitDialog()
 {
-    if (mMyPointer)
+    if (mMyPointer != nullptr)
         *mMyPointer = nullptr;
     delete2(mForceQuit);
     delete2(mLogoutQuit);
@@ -150,10 +150,10 @@ void QuitDialog::action(const ActionEvent &event)
     soundManager.playGuiSound(SOUND_HIDE_WINDOW);
     if (event.getId() == "ok")
     {
-        if (viewport)
+        if (viewport != nullptr)
         {
             const Map *const map = viewport->getMap();
-            if (map)
+            if (map != nullptr)
                 map->saveExtraLayer();
         }
 
@@ -166,7 +166,7 @@ void QuitDialog::action(const ActionEvent &event)
             DialogsManager::closeDialogs();
             client->setState(State::EXIT);
         }
-        else if (mRate && mRate->isSelected())
+        else if ((mRate != nullptr) && mRate->isSelected())
         {
             openBrowser("https://play.google.com/store/apps/details?"
                 "id=org.evolonline.beta.manaplus");
@@ -241,7 +241,7 @@ void QuitDialog::keyPressed(KeyEvent &event)
 
         if (it == mOptions.end())
         {
-            if (mOptions[0])
+            if (mOptions[0] != nullptr)
                 mOptions[0]->setSelected(true);
             return;
         }
diff --git a/src/gui/windows/registerdialog.cpp b/src/gui/windows/registerdialog.cpp
index c1940eb8d..699023d93 100644
--- a/src/gui/windows/registerdialog.cpp
+++ b/src/gui/windows/registerdialog.cpp
@@ -211,14 +211,15 @@ void RegisterDialog::action(const ActionEvent &event)
             errorMsg = _("Passwords do not match.");
             error = 2;
         }
-        else if (mEmailField &&
+        else if ((mEmailField != nullptr) &&
                  mEmailField->getText().find('@') == std::string::npos)
         {
             // TRANSLATORS: error message
             errorMsg = _("Incorrect email.");
             error = 1;
         }
-        else if (mEmailField && mEmailField->getText().size() > 40)
+        else if (mEmailField != nullptr &&
+                 mEmailField->getText().size() > 40)
         {
             // TRANSLATORS: error message
             errorMsg = _("Email too long.");
@@ -257,7 +258,7 @@ void RegisterDialog::action(const ActionEvent &event)
             mLoginData->password = mPasswordField->getText();
             if (features.getIntValue("forceAccountGender") == -1)
             {
-                if (mFemaleButton && mFemaleButton->isSelected())
+                if ((mFemaleButton != nullptr) && mFemaleButton->isSelected())
                     mLoginData->gender = Gender::FEMALE;
                 else
                     mLoginData->gender = Gender::MALE;
@@ -268,7 +269,7 @@ void RegisterDialog::action(const ActionEvent &event)
                     CAST_U8(features.getIntValue("forceAccountGender")));
             }
 
-            if (mEmailField)
+            if (mEmailField != nullptr)
                 mLoginData->email = mEmailField->getText();
             mLoginData->registerLogin = true;
 
@@ -306,7 +307,7 @@ bool RegisterDialog::canSubmit() const
            !mPasswordField->getText().empty() &&
            !mConfirmField->getText().empty() &&
            client->getState() == State::REGISTER &&
-           (!mEmailField || !mEmailField->getText().empty());
+           ((mEmailField == nullptr) || !mEmailField->getText().empty());
 }
 
 void RegisterDialog::close()
diff --git a/src/gui/windows/serverdialog.cpp b/src/gui/windows/serverdialog.cpp
index a86fa0b1e..51f937666 100644
--- a/src/gui/windows/serverdialog.cpp
+++ b/src/gui/windows/serverdialog.cpp
@@ -199,7 +199,7 @@ void ServerDialog::postInit()
 
 ServerDialog::~ServerDialog()
 {
-    if (mDownload)
+    if (mDownload != nullptr)
     {
         mDownload->cancel();
         delete2(mDownload)
@@ -216,7 +216,7 @@ void ServerDialog::connectToSelectedServer()
     if (index < 0)
         return;
 
-    if (mDownload)
+    if (mDownload != nullptr)
         mDownload->cancel();
 
     mQuitButton->setEnabled(false);
@@ -244,7 +244,7 @@ void ServerDialog::connectToSelectedServer()
     settings.supportUrl = mServerInfo->supportUrl;
     settings.updateMirrors = mServerInfo->updateMirrors;
 
-    if (chatLogger)
+    if (chatLogger != nullptr)
         chatLogger->setServerName(mServerInfo->hostname);
 
     saveCustomServers(*mServerInfo);
@@ -254,7 +254,7 @@ void ServerDialog::connectToSelectedServer()
         if (mServerInfo->hostname != LoginDialog::savedPasswordKey)
         {
             LoginDialog::savedPassword.clear();
-            if (desktop)
+            if (desktop != nullptr)
                 desktop->reloadWallpaper();
         }
     }
@@ -433,7 +433,7 @@ void ServerDialog::downloadServerList()
     if (listFile.empty())
         listFile = "http://manaplus.org/serverlist.xml";
 
-    if (mDownload)
+    if (mDownload != nullptr)
     {
         mDownload->cancel();
         delete2(mDownload)
@@ -485,7 +485,7 @@ void ServerDialog::loadServers(const bool addNew)
         SkipError_false);
     XmlNodeConstPtr rootNode = doc.rootNode();
 
-    if (!rootNode || !xmlNameEqual(rootNode, "serverlist"))
+    if ((rootNode == nullptr) || !xmlNameEqual(rootNode, "serverlist"))
     {
         logger->log1("Error loading server list!");
         return;
@@ -663,7 +663,7 @@ void ServerDialog::loadCustomServers()
         server.hostname = config.getValue(hostKey, "");
         server.type = ServerInfo::parseType(config.getValue(typeKey, ""));
         server.persistentIp = config.getValue(
-            persistentIpKey, 0) ? true : false;
+            persistentIpKey, 0) != 0 ? true : false;
         server.packetVersion = config.getValue(packetVersionKey, 0);
 
         const int defaultPort = defaultPortForServerType(server.type);
@@ -747,13 +747,13 @@ int ServerDialog::downloadUpdate(void *ptr,
                                  size_t total,
                                  const size_t remaining)
 {
-    if (!ptr || status == DownloadStatus::Cancelled)
+    if ((ptr == nullptr) || status == DownloadStatus::Cancelled)
         return -1;
 
     ServerDialog *const sd = reinterpret_cast<ServerDialog*>(ptr);
     bool finished = false;
 
-    if (!sd->mDownload)
+    if (sd->mDownload == nullptr)
         return -1;
 
     if (status == DownloadStatus::Complete)
@@ -769,7 +769,7 @@ int ServerDialog::downloadUpdate(void *ptr,
     else
     {
         float progress = static_cast<float>(remaining);
-        if (total)
+        if (total != 0u)
             progress /= static_cast<float>(total);
 
         if (progress != progress || progress < 0.0F)
@@ -809,7 +809,7 @@ bool ServerDialog::needUpdateServers() const
 
 void ServerDialog::close()
 {
-    if (mDownload)
+    if (mDownload != nullptr)
         mDownload->cancel();
     client->setState(State::FORCE_QUIT);
     Window::close();
diff --git a/src/gui/windows/setupwindow.cpp b/src/gui/windows/setupwindow.cpp
index 07ecc9ed7..bf5272d24 100644
--- a/src/gui/windows/setupwindow.cpp
+++ b/src/gui/windows/setupwindow.cpp
@@ -111,7 +111,9 @@ void SetupWindow::postInit()
     };
     int x = width;
     mButtonPadding = getOption("buttonPadding", 5);
-    for (const char *const * curBtn = buttonNames; *curBtn; ++ curBtn)
+    for (const char *const * curBtn = buttonNames;
+         *curBtn != nullptr;
+         ++ curBtn)
     {
         Button *const btn = new Button(this, gettext(*curBtn), *curBtn, this);
         mButtons.push_back(btn);
@@ -120,7 +122,7 @@ void SetupWindow::postInit()
         add(btn);
 
         // Store this button, as it needs to be enabled/disabled
-        if (!strcmp(*curBtn, "Reset Windows"))
+        if (strcmp(*curBtn, "Reset Windows") == 0)
             mResetWindows = btn;
     }
 
@@ -148,7 +150,7 @@ void SetupWindow::postInit()
     }
     add(mPanel);
 
-    if (mResetWindows)
+    if (mResetWindows != nullptr)
     {
         mVersion->setPosition(9,
             height - mVersion->getHeight() - mResetWindows->getHeight() - 9);
@@ -175,7 +177,7 @@ SetupWindow::~SetupWindow()
 
 void SetupWindow::action(const ActionEvent &event)
 {
-    if (Game::instance())
+    if (Game::instance() != nullptr)
         Game::instance()->resetAdjustLevel();
     const std::string &eventId = event.getId();
 
@@ -190,7 +192,7 @@ void SetupWindow::action(const ActionEvent &event)
     }
     else if (eventId == "Store")
     {
-        if (chatWindow)
+        if (chatWindow != nullptr)
             chatWindow->saveState();
         config.write();
         serverConfig.write();
@@ -199,12 +201,12 @@ void SetupWindow::action(const ActionEvent &event)
     {
         // Bail out if this action happens to be activated before the windows
         // are created (though it should be disabled then)
-        if (!statusWindow)
+        if (statusWindow == nullptr)
             return;
 
         FOR_EACH (std::list<Window*>::const_iterator, it, mWindowsToReset)
         {
-            if (*it)
+            if (*it != nullptr)
                 (*it)->resetToDefaultSize();
         }
     }
@@ -212,7 +214,7 @@ void SetupWindow::action(const ActionEvent &event)
 
 void SetupWindow::setInGame(const bool inGame)
 {
-    if (mResetWindows)
+    if (mResetWindows != nullptr)
         mResetWindows->setEnabled(inGame);
 }
 
@@ -227,14 +229,14 @@ void SetupWindow::externalUpdate()
     mPanel->addTab(mQuickTab->getName(), mQuickTab);
     FOR_EACH (std::list<SetupTab*>::const_iterator, it, mTabs)
     {
-        if (*it)
+        if (*it != nullptr)
             (*it)->externalUpdated();
     }
 }
 
 void SetupWindow::unloadTab(SetupTab *const page)
 {
-    if (page)
+    if (page != nullptr)
     {
         mTabs.remove(page);
         mPanel->removeTab(mPanel->getTab(page->getName()));
@@ -253,7 +255,7 @@ void SetupWindow::externalUnload()
 {
     FOR_EACH (std::list<SetupTab*>::const_iterator, it, mTabs)
     {
-        if (*it)
+        if (*it != nullptr)
             (*it)->externalUnloaded();
     }
     unloadAdditionalTabs();
@@ -281,7 +283,7 @@ void SetupWindow::hideWindows()
     FOR_EACH (std::list<Window*>::const_iterator, it, mWindowsToReset)
     {
         Window *const window = *it;
-        if (window && !window->isSticky())
+        if ((window != nullptr) && !window->isSticky())
             window->setVisible(Visible_false);
     }
     setVisible(Visible_false);
@@ -320,7 +322,7 @@ void SetupWindow::widgetResized(const Event &event)
         x -= btn->getWidth() + mButtonPadding;
         btn->setPosition(x, height - btn->getHeight() - mButtonPadding);
     }
-    if (mResetWindows)
+    if (mResetWindows != nullptr)
     {
         mVersion->setPosition(9,
             height - mVersion->getHeight() - mResetWindows->getHeight() - 9);
diff --git a/src/gui/windows/shopselldialog.cpp b/src/gui/windows/shopselldialog.cpp
index 5b9d88df2..26911836b 100644
--- a/src/gui/windows/shopselldialog.cpp
+++ b/src/gui/windows/shopselldialog.cpp
@@ -49,11 +49,11 @@ void ShopSellDialog::sellAction(const ActionEvent &event A_UNUSED)
 
     const int selectedItem = mShopItemList->getSelected();
     ShopItem *const item = mShopItems->at(selectedItem);
-    if (!item || PlayerInfo::isItemProtected(item->getId()))
+    if (item == nullptr || PlayerInfo::isItemProtected(item->getId()))
         return;
     buySellHandler->sendSellRequest(mNick, item, mAmountItems);
 
-    if (tradeWindow)
+    if (tradeWindow != nullptr)
         tradeWindow->addAutoItem(mNick, item, mAmountItems);
 }
 
diff --git a/src/gui/windows/shopwindow.cpp b/src/gui/windows/shopwindow.cpp
index 4ba33a214..5dbc0bec9 100644
--- a/src/gui/windows/shopwindow.cpp
+++ b/src/gui/windows/shopwindow.cpp
@@ -155,7 +155,7 @@ ShopWindow::ShopWindow() :
     else
         setDefaultSize(380, 300, ImagePosition::CENTER);
 
-    if (setupWindow)
+    if (setupWindow != nullptr)
         setupWindow->registerWindowForReset(this);
 
     const int size = config.getIntValue("fontSize")
@@ -280,18 +280,19 @@ void ShopWindow::action(const ActionEvent &event)
     {
         if (isBuySelected)
         {
-            if (mBuyShopItemList && mBuyShopItemList->getSelected() >= 0)
+            if (mBuyShopItemList != nullptr &&
+                mBuyShopItemList->getSelected() >= 0)
             {
                 mBuyShopItems->del(mBuyShopItemList->getSelected());
-                if (isShopEmpty() && localPlayer)
+                if (isShopEmpty() && (localPlayer != nullptr))
                     localPlayer->updateStatus();
             }
         }
-        else if (mSellShopItemList
+        else if ((mSellShopItemList != nullptr)
                  && mSellShopItemList->getSelected() >= 0)
         {
             mSellShopItems->del(mSellShopItemList->getSelected());
-            if (isShopEmpty() && localPlayer)
+            if (isShopEmpty() && (localPlayer != nullptr))
                 localPlayer->updateStatus();
         }
     }
@@ -338,20 +339,20 @@ void ShopWindow::action(const ActionEvent &event)
                 std::vector<ShopItem*> &oldItems = mSellShopItems->items();
                 std::vector<ShopItem*> items;
                 const Inventory *const inv = PlayerInfo::getCartInventory();
-                if (!inv)
+                if (inv == nullptr)
                     return;
                 FOR_EACH (std::vector<ShopItem*>::iterator, it, oldItems)
                 {
                     ShopItem *const item = *it;
-                    if (!item)
+                    if (item == nullptr)
                         continue;
                     const Item *const cartItem = inv->findItem(item->getId(),
                         item->getColor());
-                    if (!cartItem)
+                    if (cartItem == nullptr)
                         continue;
                     item->setInvIndex(cartItem->getInvIndex());
                     const int amount = cartItem->getQuantity();
-                    if (!amount)
+                    if (amount == 0)
                         continue;
                     if (item->getQuantity() > amount)
                         item->setQuantity(amount);
@@ -380,12 +381,12 @@ void ShopWindow::action(const ActionEvent &event)
 
     const Inventory *const inv = mHaveVending && !isBuySelected
         ? PlayerInfo::getCartInventory() : PlayerInfo::getInventory();
-    if (!inv)
+    if (inv == nullptr)
         return;
 
     // +++ need support for colors
     Item *const item = inv->findItem(mSelectedItem, ItemColor_zero);
-    if (item)
+    if (item != nullptr)
     {
         if (eventId == "add")
         {
@@ -424,7 +425,7 @@ void ShopWindow::updateButtonsAndLabels()
         allowDel = !mEnableBuyingStore
             && mBuyShopItemList->getSelected() != -1
             && mBuyShopItems->getNumberOfElements() > 0;
-        if (mPublishButton)
+        if (mPublishButton != nullptr)
         {
             if (mEnableBuyingStore)
             {
@@ -449,7 +450,7 @@ void ShopWindow::updateButtonsAndLabels()
         allowDel = !mEnableVending
             && mSellShopItemList->getSelected() != -1
             && sellNotEmpty;
-        if (mPublishButton)
+        if (mPublishButton != nullptr)
         {
             if (mEnableVending)
             {
@@ -464,7 +465,7 @@ void ShopWindow::updateButtonsAndLabels()
             mPublishButton->adjustSize();
             if (sellNotEmpty
                 && mSellShopSize > 0
-                && localPlayer
+                && (localPlayer != nullptr)
                 && localPlayer->getHaveCart())
             {
                 mPublishButton->setEnabled(true);
@@ -477,7 +478,7 @@ void ShopWindow::updateButtonsAndLabels()
     }
     mAddButton->setEnabled(allowAdd);
     mDeleteButton->setEnabled(allowDel);
-    if (mRenameButton)
+    if (mRenameButton != nullptr)
         mRenameButton->setEnabled(!mEnableVending);
 }
 
@@ -489,7 +490,7 @@ void ShopWindow::setVisible(Visible visible)
 void ShopWindow::addBuyItem(const Item *const item, const int amount,
                             const int price)
 {
-    if (!item)
+    if (item == nullptr)
         return;
     const bool emp = isShopEmpty();
     mBuyShopItems->addItemNoDup(item->getId(),
@@ -497,7 +498,7 @@ void ShopWindow::addBuyItem(const Item *const item, const int amount,
         item->getColor(),
         amount,
         price);
-    if (emp && localPlayer)
+    if (emp && (localPlayer != nullptr))
         localPlayer->updateStatus();
 
     updateButtonsAndLabels();
@@ -506,7 +507,7 @@ void ShopWindow::addBuyItem(const Item *const item, const int amount,
 void ShopWindow::addSellItem(const Item *const item, const int amount,
                              const int price)
 {
-    if (!item)
+    if (item == nullptr)
         return;
     const bool emp = isShopEmpty();
     mSellShopItems->addItemNoDup(item->getId(),
@@ -514,7 +515,7 @@ void ShopWindow::addSellItem(const Item *const item, const int amount,
         item->getColor(),
         amount,
         price);
-    if (emp && localPlayer)
+    if (emp && (localPlayer != nullptr))
         localPlayer->updateStatus();
 
     updateButtonsAndLabels();
@@ -531,7 +532,7 @@ void ShopWindow::loadList()
     const std::string shopListName = settings.serverConfigDir
         + "/shoplist.txt";
 
-    if (!stat(shopListName.c_str(), &statbuf) && S_ISREG(statbuf.st_mode))
+    if ((stat(shopListName.c_str(), &statbuf) == 0) && S_ISREG(statbuf.st_mode))
     {
         shopFile.open(shopListName.c_str(), std::ios::in);
         if (!shopFile.is_open())
@@ -554,10 +555,10 @@ void ShopWindow::loadList()
                 while (ss >> buf)
                     tokens.push_back(atoi(buf.c_str()));
 
-                if (tokens.size() == 5 && tokens[0])
+                if (tokens.size() == 5 && (tokens[0] != 0))
                 {
                     // +++ need impliment colors?
-                    if (tokens[1] && tokens[2])
+                    if ((tokens[1] != 0) && (tokens[2] != 0))
                     {
                         mBuyShopItems->addItem(
                             tokens[0],
@@ -566,7 +567,7 @@ void ShopWindow::loadList()
                             tokens[1],
                             tokens[2]);
                     }
-                    if (tokens[3] && tokens[4])
+                    if ((tokens[3] != 0) && (tokens[4] != 0))
                     {
                         mSellShopItems->addItem(
                             tokens[0],
@@ -601,20 +602,20 @@ void ShopWindow::saveList() const
     FOR_EACH (std::vector<ShopItem*>::const_iterator, it, items)
     {
         ShopItem *const item = *(it);
-        if (item)
+        if (item != nullptr)
             mapItems[item->getId()] = item;
     }
 
     items = mSellShopItems->items();
     FOR_EACH (std::vector<ShopItem*>::const_iterator, it, items)
     {
-        if (!(*it))
+        if ((*it) == nullptr)
             continue;
         const ShopItem *const sellItem = *(it);
         const ShopItem *const buyItem = mapItems[sellItem->getId()];
 
         shopFile << sellItem->getId();
-        if (buyItem)
+        if (buyItem != nullptr)
         {
             shopFile << strprintf(" %d %d ", buyItem->getQuantity(),
                 buyItem->getPrice());
@@ -635,7 +636,7 @@ void ShopWindow::saveList() const
          ++mapIt)
     {
         const ShopItem *const buyItem = (*mapIt).second;
-        if (buyItem)
+        if (buyItem != nullptr)
         {
             shopFile << buyItem->getId();
             shopFile << strprintf(" %d %d ", buyItem->getQuantity(),
@@ -650,7 +651,7 @@ void ShopWindow::saveList() const
 #ifdef TMWA_SUPPORT
 void ShopWindow::announce(ShopItems *const list, const int mode)
 {
-    if (!list)
+    if (list == nullptr)
         return;
 
     std::string data;
@@ -659,14 +660,14 @@ void ShopWindow::announce(ShopItems *const list, const int mode)
     else
         data.append("Sell ");
 
-    if (mAnnonceTime && (mAnnonceTime + (2 * 60) > cur_time
-        || mAnnonceTime > cur_time))
+    if (mAnnonceTime != 0 &&
+        (mAnnonceTime + (2 * 60) > cur_time || mAnnonceTime > cur_time))
     {
         return;
     }
 
     mAnnonceTime = cur_time;
-    if (mAnnounceButton)
+    if (mAnnounceButton != nullptr)
         mAnnounceButton->setEnabled(false);
 
     std::vector<ShopItem*> items = list->items();
@@ -709,20 +710,23 @@ void ShopWindow::announce(ShopItems *const list, const int mode)
 
 void ShopWindow::startTrade()
 {
-    if (!actorManager || !tradeWindow)
+    if (actorManager == nullptr ||
+        tradeWindow == nullptr)
+    {
         return;
+    }
 
     const Being *const being = actorManager->findBeingByName(
         mTradeNick, ActorType::Player);
     tradeWindow->clear();
-    if (mTradeMoney)
+    if (mTradeMoney != 0)
     {
         tradeWindow->addAutoMoney(mTradeNick, mTradeMoney);
     }
     else
     {
         tradeWindow->addAutoItem(mTradeNick, mTradeItem,
-                                 mTradeItem->getQuantity());
+            mTradeItem->getQuantity());
     }
     tradeHandler->request(being);
     tradePartnerName = mTradeNick;
@@ -747,11 +751,11 @@ void ShopWindow::giveList(const std::string &nick, const int mode)
         list = mSellShopItems;
         data.append("B1");
     }
-    if (!list)
+    if (list == nullptr)
         return;
 
     const Inventory *const inv = PlayerInfo::getInventory();
-    if (!inv)
+    if (inv == nullptr)
         return;
 
     std::vector<ShopItem*> items = list->items();
@@ -759,20 +763,20 @@ void ShopWindow::giveList(const std::string &nick, const int mode)
     FOR_EACH (std::vector<ShopItem*>::const_iterator, it, items)
     {
         const ShopItem *const item = *(it);
-        if (!item)
+        if (item == nullptr)
             continue;
 
         if (mode == SELL)
         {
             const Item *const item2 = inv->findItem(item->getId(),
                 ItemColor_zero);
-            if (item2)
+            if (item2 != nullptr)
             {
                 int amount = item->getQuantity();
                 if (item2->getQuantity() < amount)
                     amount = item2->getQuantity();
 
-                if (amount)
+                if (amount != 0)
                 {
                     data.append(strprintf("%s%s%s",
                         encodeStr(item->getId(), 2).c_str(),
@@ -807,7 +811,7 @@ void ShopWindow::sendMessage(const std::string &nick,
                              std::string data,
                              const bool random)
 {
-    if (!chatWindow)
+    if (chatWindow == nullptr)
         return;
 
     if (random)
@@ -827,7 +831,7 @@ void ShopWindow::sendMessage(const std::string &nick,
 void ShopWindow::showList(const std::string &nick, std::string data)
 {
     const Inventory *const inv = PlayerInfo::getInventory();
-    if (!inv)
+    if (inv == nullptr)
         return;
 
     BuyDialog *buyDialog = nullptr;
@@ -847,9 +851,9 @@ void ShopWindow::showList(const std::string &nick, std::string data)
         return;
     }
 
-    if (buyDialog)
+    if (buyDialog != nullptr)
         buyDialog->setMoney(PlayerInfo::getAttribute(Attributes::MONEY));
-    if (sellDialog)
+    if (sellDialog != nullptr)
         sellDialog->setMoney(PlayerInfo::getAttribute(Attributes::MONEY));
 
     for (unsigned f = 0; f < data.length(); f += 9)
@@ -860,7 +864,7 @@ void ShopWindow::showList(const std::string &nick, std::string data)
         const int id = decodeStr(data.substr(f, 2));
         const int price = decodeStr(data.substr(f + 2, 4));
         int amount = decodeStr(data.substr(f + 6, 3));
-        if (buyDialog && amount > 0)
+        if (buyDialog != nullptr && amount > 0)
         {
             buyDialog->addItem(id,
                 ItemType::Unknown,
@@ -868,10 +872,10 @@ void ShopWindow::showList(const std::string &nick, std::string data)
                 amount,
                 price);
         }
-        if (sellDialog)
+        if (sellDialog != nullptr)
         {
             const Item *const item = inv->findItem(id, ItemColor_zero);
-            if (item)
+            if (item != nullptr)
             {
                 if (item->getQuantity() < amount)
                     amount = item->getQuantity();
@@ -886,28 +890,29 @@ void ShopWindow::showList(const std::string &nick, std::string data)
                 amount,
                 price);
 
-            if (shopItem && amount <= 0)
+            if (shopItem != nullptr && amount <= 0)
                 shopItem->setDisabled(true);
         }
     }
-    if (buyDialog)
+    if (buyDialog != nullptr)
         buyDialog->sort();
 }
 
-void ShopWindow::processRequest(const std::string &nick, std::string data,
+void ShopWindow::processRequest(const std::string &nick,
+                                std::string data,
                                 const int mode)
 {
-    if (!localPlayer ||
+    if (localPlayer == nullptr ||
         !mTradeNick.empty() ||
         PlayerInfo::isTrading() == Trading_true ||
-        !actorManager ||
-        !actorManager->findBeingByName(nick, ActorType::Player))
+        actorManager == nullptr ||
+        actorManager->findBeingByName(nick, ActorType::Player) == nullptr)
     {
         return;
     }
 
     const Inventory *const inv = PlayerInfo::getInventory();
-    if (!inv)
+    if (inv == nullptr)
         return;
 
     const size_t idx = data.find(' ');
@@ -964,8 +969,9 @@ void ShopWindow::processRequest(const std::string &nick, std::string data,
         // +++ need support for colors
         const Item *const item2 = inv->findItem(mTradeItem->getId(),
             ItemColor_zero);
-        if (!item2 || item2->getQuantity() < amount
-            || !findShopItem(mTradeItem, SELL))
+        if (item2 == nullptr ||
+            item2->getQuantity() < amount ||
+            !findShopItem(mTradeItem, SELL))
         {
             sendMessage(nick,
                 // TRANSLATORS: error buy/sell shop request
@@ -1026,13 +1032,13 @@ void ShopWindow::processRequest(const std::string &nick, std::string data,
 void ShopWindow::updateTimes()
 {
     BLOCK_START("ShopWindow::updateTimes")
-    if (!mAnnounceButton)
+    if (mAnnounceButton == nullptr)
     {
         BLOCK_END("ShopWindow::updateTimes")
         return;
     }
-    if (mAnnonceTime + (2 * 60) < cur_time
-        || mAnnonceTime > cur_time)
+    if (mAnnonceTime + (2 * 60) < cur_time ||
+        mAnnonceTime > cur_time)
     {
         mAnnounceButton->setEnabled(true);
     }
@@ -1041,7 +1047,7 @@ void ShopWindow::updateTimes()
 
 bool ShopWindow::checkFloodCounter(time_t &counterTime)
 {
-    if (!counterTime || counterTime > cur_time)
+    if (counterTime == 0 || counterTime > cur_time)
         counterTime = cur_time;
     else if (counterTime + 10 > cur_time)
         return false;
@@ -1053,7 +1059,7 @@ bool ShopWindow::checkFloodCounter(time_t &counterTime)
 bool ShopWindow::findShopItem(const ShopItem *const shopItem,
                               const int mode) const
 {
-    if (!shopItem)
+    if (shopItem == nullptr)
         return false;
 
     std::vector<ShopItem*> items;
@@ -1065,7 +1071,7 @@ bool ShopWindow::findShopItem(const ShopItem *const shopItem,
     FOR_EACH (std::vector<ShopItem*>::const_iterator, it, items)
     {
         const ShopItem *const item = *(it);
-        if (!item)
+        if (item == nullptr)
             continue;
 
         if (item->getId() == shopItem->getId()
@@ -1081,18 +1087,18 @@ bool ShopWindow::findShopItem(const ShopItem *const shopItem,
 
 int ShopWindow::sumAmount(const Item *const shopItem)
 {
-    if (!localPlayer || !shopItem)
+    if ((localPlayer == nullptr) || (shopItem == nullptr))
         return 0;
 
     const Inventory *const inv = PlayerInfo::getInventory();
-    if (!inv)
+    if (inv == nullptr)
         return 0;
     int sum = 0;
 
     for (unsigned f = 0; f < inv->getSize(); f ++)
     {
         const Item *const item = inv->getItem(f);
-        if (item && item->getId() == shopItem->getId())
+        if ((item != nullptr) && item->getId() == shopItem->getId())
             sum += item->getQuantity();
     }
     return sum;
diff --git a/src/gui/windows/shortcutwindow.cpp b/src/gui/windows/shortcutwindow.cpp
index be96b6416..ffac3d320 100644
--- a/src/gui/windows/shortcutwindow.cpp
+++ b/src/gui/windows/shortcutwindow.cpp
@@ -70,15 +70,15 @@ ShortcutWindow::ShortcutWindow(const std::string &restrict title,
     mDragOffsetX = 0;
     mDragOffsetY = 0;
 
-    if (content)
+    if (content != nullptr)
         content->setWidget2(this);
-    if (setupWindow)
+    if (setupWindow != nullptr)
         setupWindow->registerWindowForReset(this);
 
     setMinWidth(32);
     setMinHeight(32);
     const int border = SCROLL_PADDING * 2 + getPadding() * 2;
-    if (mItems)
+    if (mItems != nullptr)
     {
         const int bw = mItems->getBoxWidth();
         const int bh = mItems->getBoxHeight();
@@ -130,10 +130,10 @@ ShortcutWindow::ShortcutWindow(const std::string &restrict title,
     mDragOffsetX = 0;
     mDragOffsetY = 0;
 
-    if (setupWindow)
+    if (setupWindow != nullptr)
         setupWindow->registerWindowForReset(this);
 
-    if (width && height)
+    if ((width != 0) && (height != 0))
         setDefaultSize(width, height, ImagePosition::LOWER_RIGHT);
 
     setMinWidth(32);
@@ -151,7 +151,7 @@ ShortcutWindow::ShortcutWindow(const std::string &restrict title,
 
 ShortcutWindow::~ShortcutWindow()
 {
-    if (mTabs)
+    if (mTabs != nullptr)
         mTabs->removeAll();
     delete2(mTabs);
     delete2(mItems);
@@ -168,7 +168,7 @@ void ShortcutWindow::addButton(const std::string &text,
 void ShortcutWindow::addTab(const std::string &name,
                             ShortcutContainer *const content)
 {
-    if (!content || !mTabs)
+    if ((content == nullptr) || (mTabs == nullptr))
         return;
     ScrollArea *const scroll = new ScrollArea(this, content, Opaque_false);
     scroll->setPosition(SCROLL_PADDING, SCROLL_PADDING);
@@ -181,7 +181,7 @@ void ShortcutWindow::addTab(const std::string &name,
 
 int ShortcutWindow::getTabIndex() const
 {
-    if (!mTabs)
+    if (mTabs == nullptr)
         return 0;
     return mTabs->getSelectedTabIndex();
 }
@@ -189,18 +189,18 @@ int ShortcutWindow::getTabIndex() const
 void ShortcutWindow::widgetHidden(const Event &event)
 {
     Window::widgetHidden(event);
-    if (mItems)
+    if (mItems != nullptr)
         mItems->widgetHidden(event);
-    if (mTabs)
+    if (mTabs != nullptr)
     {
         ScrollArea *const scroll = static_cast<ScrollArea *>(
             mTabs->getCurrentWidget());
-        if (scroll)
+        if (scroll != nullptr)
         {
             ShortcutContainer *const content = static_cast<ShortcutContainer*>(
                 scroll->getContent());
 
-            if (content)
+            if (content != nullptr)
                 content->widgetHidden(event);
         }
     }
@@ -240,7 +240,7 @@ void ShortcutWindow::mouseDragged(MouseEvent &event)
 void ShortcutWindow::widgetMoved(const Event& event)
 {
     Window::widgetMoved(event);
-    if (mItems)
+    if (mItems != nullptr)
         mItems->setRedraw(true);
     FOR_EACH (std::vector<ShortcutContainer*>::iterator, it, mPages)
         (*it)->setRedraw(true);
@@ -248,13 +248,13 @@ void ShortcutWindow::widgetMoved(const Event& event)
 
 void ShortcutWindow::nextTab()
 {
-    if (mTabs)
+    if (mTabs != nullptr)
         mTabs->selectNextTab();
 }
 
 void ShortcutWindow::prevTab()
 {
-    if (mTabs)
+    if (mTabs != nullptr)
         mTabs->selectPrevTab();
 }
 
diff --git a/src/gui/windows/skilldialog.cpp b/src/gui/windows/skilldialog.cpp
index 9a99c32ca..52dd067ea 100644
--- a/src/gui/windows/skilldialog.cpp
+++ b/src/gui/windows/skilldialog.cpp
@@ -102,7 +102,7 @@ SkillDialog::SkillDialog() :
     setSaveVisible(true);
     setStickyButtonLock(true);
     setDefaultSize(windowContainer->getWidth() - 280, 30, 275, 425);
-    if (setupWindow)
+    if (setupWindow != nullptr)
         setupWindow->registerWindowForReset(this);
 
     mUseButton->setEnabled(false);
@@ -156,11 +156,11 @@ void SkillDialog::action(const ActionEvent &event)
     const std::string &eventId = event.getId();
     if (eventId == "inc")
     {
-        if (!playerHandler)
+        if (playerHandler == nullptr)
             return;
         const SkillTab *const tab = static_cast<const SkillTab *>(
             mTabs->getSelectedTab());
-        if (tab)
+        if (tab != nullptr)
         {
             if (const SkillInfo *const info = tab->getSelectedInfo())
                 playerHandler->increaseSkill(CAST_U16(info->id));
@@ -170,7 +170,7 @@ void SkillDialog::action(const ActionEvent &event)
     {
         const SkillTab *const tab = static_cast<const SkillTab *>(
             mTabs->getSelectedTab());
-        if (tab)
+        if (tab != nullptr)
         {
             if (const SkillInfo *const info = tab->getSelectedInfo())
             {
@@ -179,7 +179,7 @@ void SkillDialog::action(const ActionEvent &event)
                 mIncreaseButton->setEnabled(info->id < SKILL_VAR_MIN_ID);
                 const int num = itemShortcutWindow->getTabIndex();
                 if (num >= 0 && num < CAST_S32(SHORTCUT_TABS)
-                    && itemShortcut[num])
+                    && (itemShortcut[num] != nullptr))
                 {
                     itemShortcut[num]->setItemSelected(
                         info->id + SKILL_MIN_ID);
@@ -198,7 +198,7 @@ void SkillDialog::action(const ActionEvent &event)
     {
         const SkillTab *const tab = static_cast<const SkillTab *>(
             mTabs->getSelectedTab());
-        if (tab)
+        if (tab != nullptr)
         {
             const SkillInfo *const info = tab->getSelectedInfo();
             useSkill(info,
@@ -224,7 +224,7 @@ std::string SkillDialog::update(const int id)
     if (i != mSkills.end())
     {
         SkillInfo *const info = i->second;
-        if (info)
+        if (info != nullptr)
         {
             info->update();
             return info->data->name;
@@ -244,7 +244,7 @@ void SkillDialog::update()
     FOR_EACH (SkillMap::const_iterator, it, mSkills)
     {
         SkillInfo *const info = (*it).second;
-        if (info && info->modifiable == Modifiable_true)
+        if ((info != nullptr) && info->modifiable == Modifiable_true)
             info->update();
     }
 
@@ -258,17 +258,17 @@ void SkillDialog::updateModels()
     FOR_EACH (SkillMap::const_iterator, it, mSkills)
     {
         SkillInfo *const info = (*it).second;
-        if (info)
+        if (info != nullptr)
         {
             SkillModel *const model = info->model;
-            if (model)
+            if (model != nullptr)
                 models.insert(model);
         }
     }
     FOR_EACH (std::set<SkillModel*>::iterator, it, models)
     {
         SkillModel *const model = *it;
-        if (model)
+        if (model != nullptr)
             model->updateVisibilities();
     }
 }
@@ -290,7 +290,7 @@ void SkillDialog::hideSkills(const SkillOwner::Type owner)
     FOR_EACH (SkillMap::iterator, it, mSkills)
     {
         SkillInfo *const info = (*it).second;
-        if (info && info->owner == owner)
+        if ((info != nullptr) && info->owner == owner)
         {
             PlayerInfo::setSkillLevel(info->id, 0);
             if (info->alwaysVisible == Visible_false)
@@ -322,7 +322,7 @@ void SkillDialog::loadXmlFile(const std::string &fileName,
 
     int setCount = 0;
 
-    if (!root || !xmlNameEqual(root, "skills"))
+    if ((root == nullptr) || !xmlNameEqual(root, "skills"))
     {
         logger->log("Error loading skills: " + fileName);
         return;
@@ -399,7 +399,7 @@ void SkillDialog::loadXmlFile(const std::string &fileName,
                         setTypeStr.c_str());
                     return;
             }
-            if (!mDefaultModel)
+            if (mDefaultModel == nullptr)
             {
                 mDefaultModel = model;
                 mDefaultTab = tab;
@@ -453,7 +453,7 @@ SkillInfo *SkillDialog::loadSkill(XmlNodeConstPtr node,
         strprintf(_("Skill %d"), id));
 
     SkillInfo *skill = getSkill(id);
-    if (!skill)
+    if (skill == nullptr)
     {
         skill = new SkillInfo;
         skill->id = CAST_U32(id);
@@ -495,12 +495,12 @@ SkillInfo *SkillDialog::loadSkill(XmlNodeConstPtr node,
 void SkillDialog::loadSkillData(XmlNodeConstPtr node,
                                 SkillInfo *const skill)
 {
-    if (!skill)
+    if (skill == nullptr)
         return;
     const int level = (skill->alwaysVisible == Visible_true) ?
         0 : XML::getProperty(node, "level", 0);
     SkillData *data = skill->getData(level);
-    if (!data)
+    if (data == nullptr)
         data = new SkillData;
 
     const std::string name = XML::langProperty(node, "name",
@@ -573,7 +573,7 @@ void SkillDialog::removeSkill(const int id)
     if (it != mSkills.end())
     {
         SkillInfo *const info = it->second;
-        if (info)
+        if (info != nullptr)
         {
             info->level = 0;
             info->update();
@@ -595,14 +595,14 @@ bool SkillDialog::updateSkill(const int id,
     if (it != mSkills.end())
     {
         SkillInfo *const info = it->second;
-        if (info)
+        if (info != nullptr)
         {
             info->modifiable = modifiable;
             info->range = range;
             info->type = type;
             info->sp = sp;
             info->update();
-            if (info->tab)
+            if (info->tab != nullptr)
             {
                 info->tab->setVisible(Visible_true);
                 mTabs->adjustTabPositions();
@@ -623,7 +623,7 @@ void SkillDialog::addSkill(const SkillOwner::Type owner,
                            const SkillType::SkillType type,
                            const int sp)
 {
-    if (mDefaultModel)
+    if (mDefaultModel != nullptr)
     {
         SkillInfo *const skill = new SkillInfo;
         skill->id = CAST_U32(id);
@@ -699,7 +699,7 @@ void SkillDialog::setSkillDuration(const SkillOwner::Type owner,
     {
         info = (*it).second;
     }
-    if (info)
+    if (info != nullptr)
     {
         info->duration = duration;
         info->durationTime = tick_time;
@@ -711,7 +711,7 @@ void SkillDialog::widgetResized(const Event &event)
 {
     Window::widgetResized(event);
 
-    if (mTabs)
+    if (mTabs != nullptr)
         mTabs->adjustSize();
 }
 
@@ -757,7 +757,7 @@ void SkillDialog::updateTabSelection()
 {
     const SkillTab *const tab = static_cast<SkillTab*>(
         mTabs->getSelectedTab());
-    if (tab)
+    if (tab != nullptr)
     {
         if (const SkillInfo *const info = tab->getSelectedInfo())
         {
@@ -786,7 +786,7 @@ void SkillDialog::updateQuest(const int var,
     if (it != mSkills.end())
     {
         SkillInfo *const info = it->second;
-        if (info)
+        if (info != nullptr)
         {
             PlayerInfo::setSkillLevel(id, val1);
             info->level = val1;
@@ -801,7 +801,7 @@ SkillData *SkillDialog::getSkillData(const int id) const
     if (it != mSkills.end())
     {
         SkillInfo *const info = it->second;
-        if (info)
+        if (info != nullptr)
             return info->data;
     }
     return nullptr;
@@ -814,7 +814,7 @@ SkillData *SkillDialog::getSkillDataByLevel(const int id,
     if (it != mSkills.end())
     {
         SkillInfo *const info = it->second;
-        if (info)
+        if (info != nullptr)
             return info->getData1(level);
     }
     return nullptr;
@@ -822,10 +822,10 @@ SkillData *SkillDialog::getSkillDataByLevel(const int id,
 
 void SkillDialog::playUpdateEffect(const int id) const
 {
-    if (!effectManager)
+    if (effectManager == nullptr)
         return;
     const SkillData *const data = getSkillData(id);
-    if (!data)
+    if (data == nullptr)
         return;
     effectManager->triggerDefault(data->updateEffectId,
         localPlayer,
@@ -834,10 +834,10 @@ void SkillDialog::playUpdateEffect(const int id) const
 
 void SkillDialog::playRemoveEffect(const int id) const
 {
-    if (!effectManager)
+    if (effectManager == nullptr)
         return;
     const SkillData *const data = getSkillData(id);
-    if (!data)
+    if (data == nullptr)
         return;
     effectManager->triggerDefault(data->removeEffectId,
         localPlayer,
@@ -850,10 +850,10 @@ void SkillDialog::playCastingDstTileEffect(const int id,
                                            const int y,
                                            const int delay) const
 {
-    if (!effectManager)
+    if (effectManager == nullptr)
         return;
     SkillData *const data = getSkillDataByLevel(id, level);
-    if (!data)
+    if (data == nullptr)
         return;
     effectManager->triggerDefault(data->castingGroundEffectId,
         x * 32,
@@ -872,7 +872,7 @@ void SkillDialog::useSkill(const int skillId,
                            const int offsetY)
 {
     SkillInfo *const info = skillDialog->getSkill(skillId);
-    if (!info)
+    if (info == nullptr)
         return;
     if (castType == CastType::Default)
         castType = info->customCastType;
@@ -895,13 +895,13 @@ void SkillDialog::useSkill(const SkillInfo *const info,
                            const int offsetX,
                            const int offsetY)
 {
-    if (!info || !localPlayer)
+    if ((info == nullptr) || (localPlayer == nullptr))
         return;
-    if (!level)
+    if (level == 0)
         level = info->level;
 
     const SkillData *data = info->getData1(level);
-    if (data)
+    if (data != nullptr)
     {
         const std::string cmd = data->invokeCmd;
         if (!cmd.empty())
@@ -973,15 +973,15 @@ void SkillDialog::useSkillTarget(const SkillInfo *const info,
     SkillType::SkillType type = info->type;
     if ((type & SkillType::Attack) != 0)
     {
-        if (!being && autoTarget == AutoTarget_true)
+        if ((being == nullptr) && autoTarget == AutoTarget_true)
         {
-            if (localPlayer)
+            if (localPlayer != nullptr)
             {
                 being = localPlayer->setNewTarget(ActorType::Monster,
                     AllowSort_true);
             }
         }
-        if (being)
+        if (being != nullptr)
         {
             skillHandler->useBeing(info->id,
                 level,
@@ -990,9 +990,9 @@ void SkillDialog::useSkillTarget(const SkillInfo *const info,
     }
     else if ((type & SkillType::Support) != 0)
     {
-        if (!being)
+        if (being == nullptr)
             being = localPlayer;
-        if (being)
+        if (being != nullptr)
         {
             skillHandler->useBeing(info->id,
                 level,
@@ -1007,7 +1007,7 @@ void SkillDialog::useSkillTarget(const SkillInfo *const info,
     }
     else if ((type & SkillType::Ground) != 0)
     {
-        if (!being)
+        if (being == nullptr)
             return;
         being->fixDirectionOffsets(offsetX, offsetY);
         const int x = being->getTileX() + offsetX;
@@ -1157,12 +1157,12 @@ void SkillDialog::useSkillDefault(const SkillInfo *const info,
     if ((type & SkillType::Attack) != 0)
     {
         const Being *being = localPlayer->getTarget();
-        if (!being && autoTarget == AutoTarget_true)
+        if ((being == nullptr) && autoTarget == AutoTarget_true)
         {
             being = localPlayer->setNewTarget(ActorType::Monster,
                 AllowSort_true);
         }
-        if (being)
+        if (being != nullptr)
         {
             skillHandler->useBeing(info->id,
                 level,
@@ -1172,9 +1172,9 @@ void SkillDialog::useSkillDefault(const SkillInfo *const info,
     else if ((type & SkillType::Support) != 0)
     {
         const Being *being = localPlayer->getTarget();
-        if (!being)
+        if (being == nullptr)
             being = localPlayer;
-        if (being)
+        if (being != nullptr)
         {
             skillHandler->useBeing(info->id,
                 level,
@@ -1247,7 +1247,7 @@ void SkillDialog::useSkillDefault(const SkillInfo *const info,
 
 void SkillDialog::addSkillDuration(SkillInfo *const skill)
 {
-    if (!skill)
+    if (skill == nullptr)
         return;
 
     FOR_EACH (std::vector<SkillInfo*>::const_iterator, it, mDurations)
@@ -1263,7 +1263,7 @@ void SkillDialog::slowLogic()
     FOR_EACH_SAFE (std::vector<SkillInfo*>::iterator, it, mDurations)
     {
         SkillInfo *const skill = *it;
-        if (skill)
+        if (skill != nullptr)
         {
             const int time = get_elapsed_time(skill->durationTime);
             if (time >= skill->duration)
@@ -1277,7 +1277,7 @@ void SkillDialog::slowLogic()
                 if (it != mDurations.begin())
                     -- it;
             }
-            else if (time)
+            else if (time != 0)
             {
                 skill->cooldown = skill->duration * 100 / time;
             }
@@ -1289,7 +1289,7 @@ void SkillDialog::selectSkillLevel(const int skillId,
                                    const int level)
 {
     SkillInfo *const info = getSkill(skillId);
-    if (!info)
+    if (info == nullptr)
         return;
     if (level > info->level)
         info->customSelectedLevel = info->level;
@@ -1302,7 +1302,7 @@ void SkillDialog::selectSkillCastType(const int skillId,
                                       const CastTypeT type)
 {
     SkillInfo *const info = getSkill(skillId);
-    if (!info)
+    if (info == nullptr)
         return;
     info->customCastType = type;
     info->update();
@@ -1312,7 +1312,7 @@ void SkillDialog::setSkillOffsetX(const int skillId,
                                   const int offset)
 {
     SkillInfo *const info = getSkill(skillId);
-    if (!info)
+    if (info == nullptr)
         return;
     info->customOffsetX = offset;
     info->update();
@@ -1322,7 +1322,7 @@ void SkillDialog::setSkillOffsetY(const int skillId,
                                   const int offset)
 {
     SkillInfo *const info = getSkill(skillId);
-    if (!info)
+    if (info == nullptr)
         return;
     info->customOffsetY = offset;
     info->update();
diff --git a/src/gui/windows/socialwindow.cpp b/src/gui/windows/socialwindow.cpp
index 78f7724ee..11207d47f 100644
--- a/src/gui/windows/socialwindow.cpp
+++ b/src/gui/windows/socialwindow.cpp
@@ -95,7 +95,7 @@ void SocialWindow::postInit()
     setMinWidth(120);
     setMinHeight(55);
     setDefaultSize(590, 200, 180, 300);
-    if (setupWindow)
+    if (setupWindow != nullptr)
         setupWindow->registerWindowForReset(this);
 
     place(0, 0, mMenuButton);
@@ -135,10 +135,10 @@ void SocialWindow::postInit()
         mPickupFilter = nullptr;
     }
 
-    if (localPlayer && localPlayer->getParty())
+    if ((localPlayer != nullptr) && (localPlayer->getParty() != nullptr))
         addTab(localPlayer->getParty());
 
-    if (localPlayer && localPlayer->getGuild())
+    if ((localPlayer != nullptr) && (localPlayer->getGuild() != nullptr))
         addTab(localPlayer->getGuild());
 
     enableVisibleSound(true);
@@ -149,7 +149,7 @@ void SocialWindow::postInit()
 SocialWindow::~SocialWindow()
 {
     player_relations.removeListener(this);
-    if (mGuildAcceptDialog)
+    if (mGuildAcceptDialog != nullptr)
     {
         mGuildAcceptDialog->close();
         mGuildAcceptDialog->scheduleDelete();
@@ -158,7 +158,7 @@ SocialWindow::~SocialWindow()
         mGuildInvited = 0;
     }
 
-    if (mPartyAcceptDialog)
+    if (mPartyAcceptDialog != nullptr)
     {
         mPartyAcceptDialog->close();
         mPartyAcceptDialog->scheduleDelete();
@@ -185,7 +185,7 @@ SocialWindow::~SocialWindow()
 
 bool SocialWindow::addTab(Guild *const guild)
 {
-    if (!guild)
+    if (guild == nullptr)
         return false;
 
     if (mGuilds.find(guild) != mGuilds.end())
@@ -230,7 +230,7 @@ bool SocialWindow::removeTab(Guild *const guild)
 
 bool SocialWindow::addTab(Party *const party)
 {
-    if (!party)
+    if (party == nullptr)
         return false;
 
     if (mParties.find(party) != mParties.end())
@@ -270,7 +270,7 @@ void SocialWindow::action(const ActionEvent &event)
     {
         if (eventId == "yes")
         {
-            if (localChatTab)
+            if (localChatTab != nullptr)
             {
                 localChatTab->chatLog(
                     // TRANSLATORS: chat message
@@ -282,7 +282,7 @@ void SocialWindow::action(const ActionEvent &event)
         }
         else if (eventId == "no")
         {
-            if (localChatTab)
+            if (localChatTab != nullptr)
             {
                 localChatTab->chatLog(
                     // TRANSLATORS: chat message
@@ -300,7 +300,7 @@ void SocialWindow::action(const ActionEvent &event)
     {
         if (eventId == "yes")
         {
-            if (localChatTab)
+            if (localChatTab != nullptr)
             {
                 localChatTab->chatLog(
                     // TRANSLATORS: chat message
@@ -309,7 +309,7 @@ void SocialWindow::action(const ActionEvent &event)
                     ChatMsgType::BY_SERVER);
             }
 #ifdef TMWA_SUPPORT
-            if (!guildManager || !GuildManager::getEnableGuildBot())
+            if (guildManager == nullptr || !GuildManager::getEnableGuildBot())
                 guildHandler->inviteResponse(mGuildInvited, true);
             else
                 guildManager->inviteResponse(true);
@@ -320,7 +320,7 @@ void SocialWindow::action(const ActionEvent &event)
         }
         else if (eventId == "no")
         {
-            if (localChatTab)
+            if (localChatTab != nullptr)
             {
                 localChatTab->chatLog(
                     // TRANSLATORS: chat message
@@ -329,7 +329,7 @@ void SocialWindow::action(const ActionEvent &event)
                     ChatMsgType::BY_SERVER);
             }
 #ifdef TMWA_SUPPORT
-            if (!guildManager || !GuildManager::getEnableGuildBot())
+            if (guildManager == nullptr || !GuildManager::getEnableGuildBot())
                 guildHandler->inviteResponse(mGuildInvited, false);
             else
                 guildManager->inviteResponse(false);
@@ -379,7 +379,7 @@ void SocialWindow::showGuildInvite(const std::string &restrict guildName,
     // check there isnt already an invite showing
     if (mGuildInvited != 0)
     {
-        if (localChatTab)
+        if (localChatTab != nullptr)
         {
             // TRANSLATORS: chat message
             localChatTab->chatLog(_("Received guild request, but one already "
@@ -394,7 +394,7 @@ void SocialWindow::showGuildInvite(const std::string &restrict guildName,
         _("%s has invited you to join the guild %s."),
         inviterName.c_str(), guildName.c_str());
 
-    if (localChatTab)
+    if (localChatTab != nullptr)
         localChatTab->chatLog(msg, ChatMsgType::BY_SERVER);
 
     CREATEWIDGETV(mGuildAcceptDialog, ConfirmDialog,
@@ -416,7 +416,7 @@ void SocialWindow::showPartyInvite(const std::string &restrict partyName,
     // check there isnt already an invite showing
     if (!mPartyInviter.empty())
     {
-        if (localChatTab)
+        if (localChatTab != nullptr)
         {
             // TRANSLATORS: chat message
             localChatTab->chatLog(_("Received party request, but one already "
@@ -457,7 +457,7 @@ void SocialWindow::showPartyInvite(const std::string &restrict partyName,
         }
     }
 
-    if (localChatTab)
+    if (localChatTab != nullptr)
         localChatTab->chatLog(msg, ChatMsgType::BY_SERVER);
 
     // show invite
@@ -519,25 +519,25 @@ void SocialWindow::updateButtons()
 
 void SocialWindow::updatePortals()
 {
-    if (mNavigation)
+    if (mNavigation != nullptr)
         mNavigation->updateList();
 }
 
 void SocialWindow::updatePortalNames()
 {
-    if (mNavigation)
+    if (mNavigation != nullptr)
         static_cast<SocialNavigationTab*>(mNavigation)->updateNames();
 }
 
 void SocialWindow::selectPortal(const unsigned num)
 {
-    if (mNavigation)
+    if (mNavigation != nullptr)
         mNavigation->selectIndex(num);
 }
 
 int SocialWindow::getPortalIndex(const int x, const int y)
 {
-    if (mNavigation)
+    if (mNavigation != nullptr)
     {
         return static_cast<SocialNavigationTab*>(
             mNavigation)->getPortalIndex(x, y);
@@ -550,47 +550,47 @@ int SocialWindow::getPortalIndex(const int x, const int y)
 
 void SocialWindow::addPortal(const int x, const int y)
 {
-    if (mNavigation)
+    if (mNavigation != nullptr)
         static_cast<SocialNavigationTab*>(mNavigation)->addPortal(x, y);
 }
 
 void SocialWindow::removePortal(const int x, const int y)
 {
-    if (mNavigation)
+    if (mNavigation != nullptr)
         static_cast<SocialNavigationTab*>(mNavigation)->removePortal(x, y);
 }
 
 void SocialWindow::nextTab()
 {
-    if (mTabs)
+    if (mTabs != nullptr)
         mTabs->selectNextTab();
 }
 
 void SocialWindow::prevTab()
 {
-    if (mTabs)
+    if (mTabs != nullptr)
         mTabs->selectPrevTab();
 }
 
 void SocialWindow::updateAttackFilter()
 {
-    if (mAttackFilter)
+    if (mAttackFilter != nullptr)
         mAttackFilter->updateList();
 }
 
 void SocialWindow::updatePickupFilter()
 {
-    if (mPickupFilter)
+    if (mPickupFilter != nullptr)
         mPickupFilter->updateList();
 }
 
 void SocialWindow::updateParty()
 {
-    if (!localPlayer)
+    if (localPlayer == nullptr)
         return;
 
     Party *const party = localPlayer->getParty();
-    if (party)
+    if (party != nullptr)
     {
         const PartyMap::iterator it = mParties.find(party);
         if (it != mParties.end())
@@ -604,7 +604,7 @@ void SocialWindow::updateParty()
 void SocialWindow::widgetResized(const Event &event)
 {
     Window::widgetResized(event);
-    if (mTabs)
+    if (mTabs != nullptr)
         mTabs->adjustSize();
 }
 
@@ -627,11 +627,11 @@ void SocialWindow::updateMenu(const SocialTab *const tab,
 
 void SocialWindow::updateGuildCounter(const int online, const int total)
 {
-    if (!localPlayer)
+    if (localPlayer == nullptr)
         return;
 
     Guild *const guild = localPlayer->getGuild();
-    if (guild)
+    if (guild != nullptr)
     {
         const GuildMap::iterator it = mGuilds.find(guild);
         if (it != mGuilds.end())
diff --git a/src/gui/windows/statuswindow.cpp b/src/gui/windows/statuswindow.cpp
index 9b1fa0770..3ec369b93 100644
--- a/src/gui/windows/statuswindow.cpp
+++ b/src/gui/windows/statuswindow.cpp
@@ -62,7 +62,7 @@
 StatusWindow *statusWindow = nullptr;
 
 StatusWindow::StatusWindow() :
-    Window(localPlayer ? localPlayer->getName() :
+    Window(localPlayer != nullptr ? localPlayer->getName() :
         "?", Modal_false, nullptr, "status.xml"),
     ActionListener(),
     AttributeListener(),
@@ -89,7 +89,7 @@ StatusWindow::StatusWindow() :
     mCopyButton(new Button(this, _("Copy to chat"), "copy", this))
 {
     setWindowName("Status");
-    if (setupWindow)
+    if (setupWindow != nullptr)
         setupWindow->registerWindowForReset(this);
     setResizable(true);
     setCloseButton(true);
@@ -102,14 +102,14 @@ StatusWindow::StatusWindow() :
     mTabs->getWidgetContainer()->setSelectable(false);
     mTabs->getTabContainer()->setSelectable(false);
 
-    if (localPlayer && !localPlayer->getRaceName().empty())
+    if ((localPlayer != nullptr) && !localPlayer->getRaceName().empty())
     {
         setCaption(strprintf("%s (%s)", localPlayer->getName().c_str(),
             localPlayer->getRaceName().c_str()));
     }
 
     int max = PlayerInfo::getAttribute(Attributes::PLAYER_MAX_HP);
-    if (!max)
+    if (max == 0)
         max = 1;
 
     mHpBar = new ProgressBar(this,
@@ -125,7 +125,7 @@ StatusWindow::StatusWindow() :
 
     max = PlayerInfo::getAttribute(Attributes::PLAYER_EXP_NEEDED);
     mXpBar = new ProgressBar(this,
-        max ?
+        max != 0 ?
         static_cast<float>(PlayerInfo::getAttribute(Attributes::PLAYER_EXP)) /
         static_cast<float>(max) : static_cast<float>(0),
         80,
@@ -143,7 +143,7 @@ StatusWindow::StatusWindow() :
     mMpLabel = new Label(this, _("MP:"));
     const bool useMagic = playerHandler->canUseMagic();
     mMpBar = new ProgressBar(this,
-        max ? static_cast<float>(PlayerInfo::getAttribute(
+        max != 0 ? static_cast<float>(PlayerInfo::getAttribute(
         Attributes::PLAYER_MAX_MP)) / static_cast<float>(max)
         : static_cast<float>(0),
         80,
@@ -258,7 +258,7 @@ void StatusWindow::addTabBasic(const std::string &name)
 
 void StatusWindow::updateLevelLabel()
 {
-    if (localPlayer && localPlayer->isGM())
+    if ((localPlayer != nullptr) && localPlayer->isGM())
     {
         // TRANSLATORS: status window label
         mLvlLabel->setCaption(strprintf(_("Level: %d (GM %d)"),
@@ -284,13 +284,13 @@ void StatusWindow::statChanged(const AttributesT id,
 
     if (id == Attributes::PLAYER_JOB)
     {
-        if (mJobLvlLabel)
+        if (mJobLvlLabel != nullptr)
         {
             int lvl = PlayerInfo::getStatBase(id);
             const int oldExp = oldVal1;
             const std::pair<int, int> exp = PlayerInfo::getStatExperience(id);
 
-            if (!lvl)
+            if (lvl == 0)
             {
                 // possible server broken and don't send job level,
                 // then we fixing it :)
@@ -381,7 +381,7 @@ void StatusWindow::setPointsNeeded(const AttributesT id,
 
 void StatusWindow::updateHPBar(ProgressBar *const bar, const bool showMax)
 {
-    if (!bar)
+    if (bar == nullptr)
         return;
 
     const int hp = PlayerInfo::getAttribute(Attributes::PLAYER_HP);
@@ -400,7 +400,7 @@ void StatusWindow::updateHPBar(ProgressBar *const bar, const bool showMax)
 void StatusWindow::updateMPBar(ProgressBar *const bar,
                                const bool showMax) const
 {
-    if (!bar)
+    if (bar == nullptr)
         return;
 
     const int mp = PlayerInfo::getAttribute(Attributes::PLAYER_MP);
@@ -435,7 +435,7 @@ void StatusWindow::updateProgressBar(ProgressBar *const bar,
                                      const int max,
                                      const bool percent)
 {
-    if (!bar)
+    if (bar == nullptr)
         return;
 
     if (max == 0)
@@ -464,7 +464,7 @@ void StatusWindow::updateProgressBar(ProgressBar *const bar,
 
 void StatusWindow::updateXPBar(ProgressBar *const bar, const bool percent)
 {
-    if (!bar)
+    if (bar == nullptr)
         return;
 
     updateProgressBar(bar, PlayerInfo::getAttribute(Attributes::PLAYER_EXP),
@@ -473,7 +473,7 @@ void StatusWindow::updateXPBar(ProgressBar *const bar, const bool percent)
 
 void StatusWindow::updateJobBar(ProgressBar *const bar, const bool percent)
 {
-    if (!bar)
+    if (bar == nullptr)
         return;
 
     const std::pair<int, int> exp =  PlayerInfo::getStatExperience(
@@ -491,7 +491,7 @@ void StatusWindow::updateProgressBar(ProgressBar *const bar,
 
 void StatusWindow::updateWeightBar(ProgressBar *const bar)
 {
-    if (!bar)
+    if (bar == nullptr)
         return;
 
     if (PlayerInfo::getAttribute(Attributes::MAX_WEIGHT) == 0)
@@ -506,7 +506,7 @@ void StatusWindow::updateWeightBar(ProgressBar *const bar)
             Attributes::TOTAL_WEIGHT);
         const int maxWeight = PlayerInfo::getAttribute(Attributes::MAX_WEIGHT);
         float progress = 1.0F;
-        if (maxWeight)
+        if (maxWeight != 0)
         {
             progress = static_cast<float>(totalWeight)
                 / static_cast<float>(maxWeight);
@@ -520,7 +520,7 @@ void StatusWindow::updateWeightBar(ProgressBar *const bar)
 
 void StatusWindow::updateMoneyBar(ProgressBar *const bar)
 {
-    if (!bar)
+    if (bar == nullptr)
         return;
 
     const int money = PlayerInfo::getAttribute(Attributes::MONEY);
@@ -539,13 +539,13 @@ void StatusWindow::updateMoneyBar(ProgressBar *const bar)
 
 void StatusWindow::updateArrowsBar(ProgressBar *const bar)
 {
-    if (!bar || !equipmentWindow)
+    if ((bar == nullptr) || (equipmentWindow == nullptr))
         return;
 
     const Item *const item = equipmentWindow->getEquipment(
         inventoryHandler->getProjectileSlot());
 
-    if (item && item->getQuantity() > 0)
+    if ((item != nullptr) && item->getQuantity() > 0)
         bar->setText(toString(item->getQuantity()));
     else
         bar->setText("0");
@@ -553,17 +553,17 @@ void StatusWindow::updateArrowsBar(ProgressBar *const bar)
 
 void StatusWindow::updateInvSlotsBar(ProgressBar *const bar)
 {
-    if (!bar)
+    if (bar == nullptr)
         return;
 
     const Inventory *const inv = PlayerInfo::getInventory();
-    if (!inv)
+    if (inv == nullptr)
         return;
 
     const int usedSlots = inv->getNumberOfSlotsUsed();
     const int maxSlots = inv->getSize();
 
-    if (maxSlots)
+    if (maxSlots != 0)
     {
         bar->setProgress(static_cast<float>(usedSlots)
             / static_cast<float>(maxSlots));
@@ -576,7 +576,7 @@ std::string StatusWindow::translateLetter(const char *const letters)
 {
     char buf[2];
     char *const str = gettext(letters);
-    if (!str || strlen(str) != 3)
+    if ((str == nullptr) || strlen(str) != 3)
         return letters;
 
     buf[0] = str[1];
@@ -595,7 +595,7 @@ std::string StatusWindow::translateLetter2(const std::string &letters)
 void StatusWindow::updateStatusBar(ProgressBar *const bar,
                                    const bool percent A_UNUSED) const
 {
-    if (!bar)
+    if (bar == nullptr)
         return;
     bar->setText(translateLetter2(GameModifiers::getMoveTypeString())
         .append(translateLetter2(GameModifiers::getCrazyMoveTypeString()))
@@ -626,7 +626,7 @@ void StatusWindow::updateStatusBar(ProgressBar *const bar,
 
 void StatusWindow::action(const ActionEvent &event)
 {
-    if (!chatWindow)
+    if (chatWindow == nullptr)
         return;
 
     if (event.getId() == "copy")
diff --git a/src/gui/windows/textcommandeditor.cpp b/src/gui/windows/textcommandeditor.cpp
index 4adeacbc6..5c8ee1357 100644
--- a/src/gui/windows/textcommandeditor.cpp
+++ b/src/gui/windows/textcommandeditor.cpp
@@ -52,7 +52,7 @@ TextCommandEditor::TextCommandEditor(TextCommand *const command) :
     Window(_("Command Editor"), Modal_false, nullptr, "commandeditor.xml"),
     ActionListener(),
 #ifdef TMWA_SUPPORT
-    mIsMagicCommand(command ?
+    mIsMagicCommand(command != nullptr ?
         (command->getCommandType() == TextCommandType::Magic) : false),
 #endif  // TMWA_SUPPORT
     mCommand(command),
@@ -136,14 +136,14 @@ TextCommandEditor::TextCommandEditor(TextCommand *const command) :
 
     mIconDropDown->setActionEventId("icon");
     mIconDropDown->addActionListener(this);
-    if (mCommand)
+    if (mCommand != nullptr)
         mIconDropDown->setSelectedString(mCommand->getIcon());
 
     mSaveButton->adjustSize();
     mCancelButton->adjustSize();
     mDeleteButton->adjustSize();
 
-    if (command)
+    if (command != nullptr)
     {
 #ifdef TMWA_SUPPORT
         if (command->getCommandType() == TextCommandType::Magic)
@@ -290,7 +290,7 @@ void TextCommandEditor::scheduleDelete()
 
 void TextCommandEditor::save()
 {
-    if (!mCommand)
+    if (mCommand == nullptr)
         return;
 #ifdef TMWA_SUPPORT
     if (mIsMagicCommand)
@@ -314,13 +314,13 @@ void TextCommandEditor::save()
     mCommand->setSchoolLvl(mSchoolLvlField->getValue());
 #endif  // TMWA_SUPPORT
 
-    if (spellManager)
+    if (spellManager != nullptr)
         spellManager->save();
 }
 
 void TextCommandEditor::deleteCommand()
 {
-    if (!mCommand)
+    if (mCommand == nullptr)
         return;
     mCommand->setSymbol("");
     mCommand->setCommand("");
@@ -335,6 +335,6 @@ void TextCommandEditor::deleteCommand()
     mCommand->setSchoolLvl(0);
 #endif  // TMWA_SUPPORT
 
-    if (spellManager)
+    if (spellManager != nullptr)
         spellManager->save();
 }
diff --git a/src/gui/windows/textdialog.cpp b/src/gui/windows/textdialog.cpp
index 17e3e90e4..87c9dcfa8 100644
--- a/src/gui/windows/textdialog.cpp
+++ b/src/gui/windows/textdialog.cpp
@@ -82,16 +82,16 @@ TextDialog::TextDialog(const std::string &restrict title,
 void TextDialog::postInit()
 {
     Window::postInit();
-    if (getParent())
+    if (getParent() != nullptr)
     {
         setLocationRelativeTo(getParent());
         getParent()->moveToTop(this);
     }
     setVisible(Visible_true);
     requestModalFocus();
-    if (mPasswordField)
+    if (mPasswordField != nullptr)
         mPasswordField->requestFocus();
-    else if (mTextField)
+    else if (mTextField != nullptr)
         mTextField->requestFocus();
 
     instances++;
@@ -113,18 +113,18 @@ void TextDialog::action(const ActionEvent &event)
 
 const std::string &TextDialog::getText() const
 {
-    if (mTextField)
+    if (mTextField != nullptr)
         return mTextField->getText();
-    else if (mPasswordField)
+    else if (mPasswordField != nullptr)
         return mPasswordField->getText();
     return emptyStr;
 }
 
 void TextDialog::setText(const std::string &text)
 {
-    if (mTextField)
+    if (mTextField != nullptr)
         mTextField->setText(text);
-    else if (mPasswordField)
+    else if (mPasswordField != nullptr)
         mPasswordField->setText(text);
 }
 
diff --git a/src/gui/windows/textdialog.h b/src/gui/windows/textdialog.h
index dbe4c0bb6..a2901e04e 100644
--- a/src/gui/windows/textdialog.h
+++ b/src/gui/windows/textdialog.h
@@ -69,7 +69,7 @@ class TextDialog final : public Window,
         void setText(const std::string &text);
 
         static bool isActive() noexcept2 A_WARN_UNUSED
-        { return instances; }
+        { return instances != 0; }
 
         void close() override final;
 
diff --git a/src/gui/windows/textselectdialog.cpp b/src/gui/windows/textselectdialog.cpp
index c99e09c74..f7a5afb22 100644
--- a/src/gui/windows/textselectdialog.cpp
+++ b/src/gui/windows/textselectdialog.cpp
@@ -69,7 +69,7 @@ void TextSelectDialog::postInit()
     setMinHeight(220);
     setDefaultSize(260, 230, ImagePosition::CENTER);
 
-    if (setupWindow)
+    if (setupWindow != nullptr)
         setupWindow->registerWindowForReset(this);
 
     setActionEventId("OK");
@@ -104,7 +104,7 @@ void TextSelectDialog::postInit()
     placer = getPlacer(0, 0);
 
     placer(0, 0, mScrollArea, 8, 5).setPadding(3);
-    if (mQuitButton)
+    if (mQuitButton != nullptr)
     {
         placer(6, 5, mSelectButton);
         placer(7, 5, mQuitButton);
@@ -174,7 +174,7 @@ void TextSelectDialog::setVisible(Visible visible)
 
     if (visible == Visible_true)
     {
-        if (mItemList)
+        if (mItemList != nullptr)
             mItemList->requestFocus();
     }
     else
diff --git a/src/gui/windows/tradewindow.cpp b/src/gui/windows/tradewindow.cpp
index de89eeca3..295f60a7d 100644
--- a/src/gui/windows/tradewindow.cpp
+++ b/src/gui/windows/tradewindow.cpp
@@ -107,7 +107,7 @@ TradeWindow::TradeWindow() :
     setMinWidth(310);
     setMinHeight(180);
 
-    if (setupWindow)
+    if (setupWindow != nullptr)
         setupWindow->registerWindowForReset(this);
 
     const Font *const fnt = mOkButton->getFont();
@@ -259,7 +259,7 @@ void TradeWindow::changeQuantity(const int index, const bool own,
         item = mMyInventory->getItem(index);
     else
         item = mPartnerInventory->getItem(index);
-    if (item)
+    if (item != nullptr)
         item->setQuantity(quantity);
 }
 
@@ -271,7 +271,7 @@ void TradeWindow::increaseQuantity(const int index, const bool own,
         item = mMyInventory->getItem(index);
     else
         item = mPartnerInventory->getItem(index);
-    if (item)
+    if (item != nullptr)
         item->increaseQuantity(quantity);
 }
 
@@ -324,18 +324,18 @@ void TradeWindow::tradeItem(const Item *const item, const int quantity,
 
 void TradeWindow::valueChanged(const SelectionEvent &event)
 {
-    if (!mMyItemContainer || !mPartnerItemContainer)
+    if ((mMyItemContainer == nullptr) || (mPartnerItemContainer == nullptr))
         return;
 
     /* If an item is selected in one container, make sure no item is selected
      * in the other container.
      */
     if (event.getSource() == mMyItemContainer &&
-        mMyItemContainer->getSelectedItem())
+        (mMyItemContainer->getSelectedItem() != nullptr))
     {
         mPartnerItemContainer->selectNone();
     }
-    else if (mPartnerItemContainer->getSelectedItem())
+    else if (mPartnerItemContainer->getSelectedItem() != nullptr)
     {
         mMyItemContainer->selectNone();
     }
@@ -374,7 +374,7 @@ void TradeWindow::setStatus(const Status s)
 
 void TradeWindow::action(const ActionEvent &event)
 {
-    if (!inventoryWindow)
+    if (inventoryWindow == nullptr)
         return;
 
     Item *const item = inventoryWindow->getSelectedItem();
@@ -391,7 +391,7 @@ void TradeWindow::action(const ActionEvent &event)
             return;
         }
 
-        if (!item)
+        if (item == nullptr)
             return;
 
         if (mMyInventory->getFreeSlot() == -1)
@@ -437,7 +437,7 @@ void TradeWindow::action(const ActionEvent &event)
         const int curMoney = PlayerInfo::getAttribute(Attributes::MONEY);
         if (v > curMoney)
         {
-            if (localChatTab)
+            if (localChatTab != nullptr)
             {
                 // TRANSLATORS: trade error
                 localChatTab->chatLog(_("You don't have enough money."),
@@ -485,23 +485,23 @@ void TradeWindow::addAutoMoney(const std::string &nick, const int money)
 
 void TradeWindow::initTrade(const std::string &nick)
 {
-    if (!localPlayer)
+    if (localPlayer == nullptr)
         return;
 
     if (!mAutoAddToNick.empty() && mAutoAddToNick == nick)
     {
-        if (mAutoAddItem && mAutoAddItem->getQuantity())
+        if ((mAutoAddItem != nullptr) && (mAutoAddItem->getQuantity() != 0))
         {
             const Inventory *const inv = PlayerInfo::getInventory();
-            if (inv)
+            if (inv != nullptr)
             {
                 const Item *const item = inv->findItem(mAutoAddItem->getId(),
                     mAutoAddItem->getColor());
-                if (item)
+                if (item != nullptr)
                     tradeItem(item, mAutoAddAmount);
             }
         }
-        if (mAutoMoney)
+        if (mAutoMoney != 0)
         {
             tradeHandler->setMoney(mAutoMoney);
             mMoneyField->setText(strprintf("%d", mAutoMoney));
@@ -514,7 +514,7 @@ void TradeWindow::initTrade(const std::string &nick)
 
 bool TradeWindow::checkItem(const Item *const item) const
 {
-    if (!item)
+    if (item == nullptr)
         return false;
 
     const int itemId = item->getId();
@@ -523,10 +523,10 @@ bool TradeWindow::checkItem(const Item *const item) const
     const Item *const tItem = mMyInventory->findItem(
         itemId, item->getColor());
 
-    if (tItem && (tItem->getQuantity() > 1
+    if ((tItem != nullptr) && (tItem->getQuantity() > 1
         || item->getQuantity() > 1))
     {
-        if (localChatTab)
+        if (localChatTab != nullptr)
         {
             // TRANSLATORS: trade error
             localChatTab->chatLog(_("Failed adding item. You can not "
@@ -538,7 +538,7 @@ bool TradeWindow::checkItem(const Item *const item) const
     if (Net::getNetworkType() != ServerType::TMWATHENA &&
         item->isEquipped() == Equipped_true)
     {
-        if (localChatTab)
+        if (localChatTab != nullptr)
         {
             localChatTab->chatLog(
                 // TRANSLATORS: trade error
@@ -552,5 +552,5 @@ bool TradeWindow::checkItem(const Item *const item) const
 
 bool TradeWindow::isInpupFocused() const
 {
-    return (mMoneyField && mMoneyField->isFocused());
+    return ((mMoneyField != nullptr) && mMoneyField->isFocused());
 }
diff --git a/src/gui/windows/updaterwindow.cpp b/src/gui/windows/updaterwindow.cpp
index a88aba197..3c63fb2ed 100644
--- a/src/gui/windows/updaterwindow.cpp
+++ b/src/gui/windows/updaterwindow.cpp
@@ -81,7 +81,7 @@ static std::vector<UpdateFile> loadXMLFile(const std::string &fileName,
     XML::Document doc(fileName, UseVirtFs_false, SkipError_false);
     XmlNodeConstPtrConst rootNode = doc.rootNode();
 
-    if (!rootNode || !xmlNameEqual(rootNode, "updates"))
+    if ((rootNode == nullptr) || !xmlNameEqual(rootNode, "updates"))
     {
         logger->log("Error loading update file: %s", fileName.c_str());
         return files;
@@ -265,7 +265,7 @@ UpdaterWindow::~UpdaterWindow()
     if (mLoadUpdates)
         loadUpdates();
 
-    if (mDownload)
+    if (mDownload != nullptr)
     {
         mDownload->cancel();
 
@@ -297,7 +297,7 @@ void UpdaterWindow::enable()
 
     if (client->getState() != State::GAME)
     {
-        if (mUpdateType & UpdateType::Close)
+        if ((mUpdateType & UpdateType::Close) != 0)
             client->setState(State::LOAD_DATA);
     }
     else
@@ -316,7 +316,7 @@ void UpdaterWindow::action(const ActionEvent &event)
         // Skip the updating process
         if (mDownloadStatus != UpdateDownloadStatus::UPDATE_COMPLETE)
         {
-            if (mDownload)
+            if (mDownload != nullptr)
                 mDownload->cancel();
             mDownloadStatus = UpdateDownloadStatus::UPDATE_ERROR;
         }
@@ -359,7 +359,7 @@ void UpdaterWindow::keyPressed(KeyEvent &event)
 
 void UpdaterWindow::loadNews()
 {
-    if (!mMemoryBuffer)
+    if (mMemoryBuffer == nullptr)
     {
         logger->log1("Couldn't load news");
         return;
@@ -368,7 +368,7 @@ void UpdaterWindow::loadNews()
     // Reallocate and include terminating 0 character
     mMemoryBuffer = static_cast<char*>(realloc(
         mMemoryBuffer, mDownloadedBytes + 1));
-    if (!mMemoryBuffer)
+    if (mMemoryBuffer == nullptr)
     {
         logger->log1("Couldn't load news");
         return;
@@ -392,7 +392,7 @@ void UpdaterWindow::loadNews()
         {
             firstLine = false;
             const size_t i = line.find("##9 Latest client version: ##6");
-            if (!i)
+            if (i == 0u)
                 continue;
 
             if (file.is_open())
@@ -427,7 +427,7 @@ void UpdaterWindow::loadNews()
 
 void UpdaterWindow::loadPatch()
 {
-    if (!mMemoryBuffer)
+    if (mMemoryBuffer == nullptr)
     {
         logger->log1("Couldn't load patch");
         return;
@@ -436,7 +436,7 @@ void UpdaterWindow::loadPatch()
     // Reallocate and include terminating 0 character
     mMemoryBuffer = static_cast<char*>(
         realloc(mMemoryBuffer, mDownloadedBytes + 1));
-    if (!mMemoryBuffer)
+    if (mMemoryBuffer == nullptr)
     {
         logger->log1("Couldn't load patch");
         return;
@@ -447,13 +447,13 @@ void UpdaterWindow::loadPatch()
 
     // Tokenize and add each line separately
     char *line = strtok(mMemoryBuffer, "\n");
-    if (line)
+    if (line != nullptr)
     {
         version = line;
         if (serverVersion < 1)
         {
             line = strtok(nullptr, "\n");
-            if (line)
+            if (line != nullptr)
             {
                 mBrowserBox->addRow(strprintf("##9 Latest client version: "
                     "##6ManaPlus %s##0", line), true);
@@ -500,7 +500,7 @@ int UpdaterWindow::updateProgress(void *ptr,
                                   const size_t dn)
 {
     UpdaterWindow *const uw = reinterpret_cast<UpdaterWindow *>(ptr);
-    if (!uw)
+    if (uw == nullptr)
         return -1;
 
     if (status == DownloadStatus::Complete)
@@ -524,7 +524,7 @@ int UpdaterWindow::updateProgress(void *ptr,
         }
     }
 
-    if (!dt)
+    if (dt == 0u)
         dt = 1;
 
     float progress = static_cast<float>(dn) /
@@ -559,11 +559,11 @@ size_t UpdaterWindow::memoryWrite(void *ptr, size_t size,
 {
     UpdaterWindow *const uw = reinterpret_cast<UpdaterWindow *>(stream);
     const size_t totalMem = size * nmemb;
-    if (!uw)
+    if (uw == nullptr)
         return 0;
     uw->mMemoryBuffer = static_cast<char*>(realloc(uw->mMemoryBuffer,
         CAST_SIZE(uw->mDownloadedBytes) + totalMem));
-    if (uw->mMemoryBuffer)
+    if (uw->mMemoryBuffer != nullptr)
     {
         memcpy(&(uw->mMemoryBuffer[uw->mDownloadedBytes]), ptr, totalMem);
         uw->mDownloadedBytes += CAST_S32(totalMem);
@@ -574,7 +574,7 @@ size_t UpdaterWindow::memoryWrite(void *ptr, size_t size,
 
 void UpdaterWindow::download()
 {
-    if (mDownload)
+    if (mDownload != nullptr)
     {
         mDownload->cancel();
         delete mDownload;
@@ -757,7 +757,7 @@ void UpdaterWindow::loadManaPlusUpdates(const std::string &dir)
             struct stat statbuf;
             std::string fileName = pathJoin(fixPath,
                 name);
-            if (!stat(fileName.c_str(), &statbuf))
+            if (stat(fileName.c_str(), &statbuf) == 0)
             {
                 VirtFs::mountZip(fileName,
                     Append_false);
@@ -784,7 +784,7 @@ void UpdaterWindow::unloadManaPlusUpdates(const std::string &dir)
             struct stat statbuf;
             const std::string file = pathJoin(
                 fixPath, name);
-            if (!stat(file.c_str(), &statbuf))
+            if (stat(file.c_str(), &statbuf) == 0)
                 VirtFs::unmountZip(file);
         }
     }
@@ -801,7 +801,7 @@ void UpdaterWindow::addUpdateFile(const std::string &restrict path,
 
     const std::string fixFile = pathJoin(fixPath, file);
     struct stat statbuf;
-    if (!stat(fixFile.c_str(), &statbuf))
+    if (stat(fixFile.c_str(), &statbuf) == 0)
         VirtFs::mountZip(fixFile, append);
 
     if (append == Append_true)
@@ -815,7 +815,7 @@ void UpdaterWindow::removeUpdateFile(const std::string &restrict path,
     VirtFs::unmountZip(pathJoin(path, file));
     const std::string fixFile = pathJoin(fixPath, file);
     struct stat statbuf;
-    if (!stat(fixFile.c_str(), &statbuf))
+    if (stat(fixFile.c_str(), &statbuf) == 0)
         VirtFs::unmountZip(fixFile);
 }
 
@@ -836,7 +836,7 @@ void UpdaterWindow::logic()
         }
 
         mProgressBar->setProgress(mDownloadProgress);
-        if (mUpdateFiles.size()
+        if ((mUpdateFiles.size() != 0u)
             && CAST_SIZE(mUpdateIndex) <= mUpdateFiles.size())
         {
             mProgressBar->setText(strprintf("%u/%u", mUpdateIndex
@@ -860,7 +860,7 @@ void UpdaterWindow::logic()
             mBrowserBox->addRow(_("##1  It is strongly recommended that"));
             // TRANSLATORS: Begins "It is strongly recommended that".
             mBrowserBox->addRow(_("##1  you try again later."));
-            if (mDownload)
+            if (mDownload != nullptr)
                 mBrowserBox->addRow(mDownload->getError());
             mScrollArea->setVerticalScrollAmount(
                     mScrollArea->getVerticalMaxScroll());
@@ -1063,7 +1063,7 @@ bool UpdaterWindow::validateFile(const std::string &filePath,
                                  const unsigned long hash)
 {
     FILE *const file = fopen(filePath.c_str(), "rb");
-    if (!file)
+    if (file == nullptr)
         return false;
 
     const unsigned long adler = Net::Download::fadler32(file);
@@ -1144,7 +1144,7 @@ void UpdaterWindow::loadMods(const std::string &dir,
                 struct stat statbuf;
                 std::string fileName = pathJoin(fixPath,
                     name);
-                if (!stat(fileName.c_str(), &statbuf))
+                if (stat(fileName.c_str(), &statbuf) == 0)
                 {
                     VirtFs::mountZip(fileName,
                         Append_false);
@@ -1171,7 +1171,7 @@ void UpdaterWindow::loadDirMods(const std::string &dir)
         if (modIt == mods.end())
             continue;
         const ModInfo *const mod = (*modIt).second;
-        if (mod)
+        if (mod != nullptr)
         {
             const std::string &localDir = mod->getLocalDir();
             if (!localDir.empty())
@@ -1196,7 +1196,7 @@ void UpdaterWindow::unloadMods(const std::string &dir)
         if (modIt == mods.end())
             continue;
         const ModInfo *const mod = (*modIt).second;
-        if (mod)
+        if (mod != nullptr)
         {
             const std::string &localDir = mod->getLocalDir();
             if (!localDir.empty())
diff --git a/src/gui/windows/whoisonline.cpp b/src/gui/windows/whoisonline.cpp
index 18e18a101..e5040077a 100644
--- a/src/gui/windows/whoisonline.cpp
+++ b/src/gui/windows/whoisonline.cpp
@@ -141,7 +141,7 @@ void WhoIsOnline::postInit()
     setStickyButtonLock(true);
     setSaveVisible(true);
 
-    if (setupWindow)
+    if (setupWindow != nullptr)
         setupWindow->registerWindowForReset(this);
 
     mUpdateButton->setEnabled(false);
@@ -174,7 +174,7 @@ WhoIsOnline::~WhoIsOnline()
     config.removeListeners(this);
     CHECKLISTENERS
 
-    if (mThread && SDL_GetThreadID(mThread))
+    if ((mThread != nullptr) && (SDL_GetThreadID(mThread) != 0u))
         SDL_WaitThread(mThread, nullptr);
 
     free(mMemoryBuffer);
@@ -191,9 +191,9 @@ WhoIsOnline::~WhoIsOnline()
 
 void WhoIsOnline::handleLink(const std::string& link, MouseEvent *event)
 {
-    if (!event || event->getButton() == MouseButton::LEFT)
+    if ((event == nullptr) || event->getButton() == MouseButton::LEFT)
     {
-        if (chatWindow)
+        if (chatWindow != nullptr)
         {
             const std::string text = decodeLinkText(link);
             if (config.getBoolValue("whispertab"))
@@ -209,18 +209,18 @@ void WhoIsOnline::handleLink(const std::string& link, MouseEvent *event)
     }
     else if (event->getButton() == MouseButton::RIGHT)
     {
-        if (localPlayer && link == localPlayer->getName())
+        if ((localPlayer != nullptr) && link == localPlayer->getName())
             return;
 
-        if (popupMenu)
+        if (popupMenu != nullptr)
         {
-            if (actorManager)
+            if (actorManager != nullptr)
             {
                 const std::string text = decodeLinkText(link);
                 Being *const being = actorManager->findBeingByName(
                     text, ActorType::Player);
 
-                if (being && popupManager)
+                if ((being != nullptr) && (popupManager != nullptr))
                 {
                     popupMenu->showPopup(viewport->mMouseX,
                         viewport->mMouseY,
@@ -286,7 +286,7 @@ void WhoIsOnline::updateWindow(size_t numOnline)
 void WhoIsOnline::handlerPlayerRelation(const std::string &nick,
                                         OnlinePlayer *const player)
 {
-    if (!player)
+    if (player == nullptr)
         return;
     switch (player_relations.getRelation(nick))
     {
@@ -350,11 +350,11 @@ void WhoIsOnline::loadList(const std::vector<OnlinePlayer*> &list)
     updateWindow(numOnline);
     if (!mOnlineNicks.empty())
     {
-        if (chatWindow)
+        if (chatWindow != nullptr)
             chatWindow->updateOnline(mOnlineNicks);
-        if (socialWindow)
+        if (socialWindow != nullptr)
             socialWindow->updateActiveList();
-        if (actorManager)
+        if (actorManager != nullptr)
             actorManager->updateSeenPlayers(mOnlineNicks);
     }
     updateSize();
@@ -367,13 +367,13 @@ void WhoIsOnline::loadList(const std::vector<OnlinePlayer*> &list)
 #ifdef TMWA_SUPPORT
 void WhoIsOnline::loadWebList()
 {
-    if (!mMemoryBuffer)
+    if (mMemoryBuffer == nullptr)
         return;
 
     // Reallocate and include terminating 0 character
     mMemoryBuffer = static_cast<char*>(
         realloc(mMemoryBuffer, mDownloadedBytes + 1));
-    if (!mMemoryBuffer)
+    if (mMemoryBuffer == nullptr)
         return;
 
     mMemoryBuffer[mDownloadedBytes] = '\0';
@@ -396,7 +396,7 @@ void WhoIsOnline::loadWebList()
 
     mShowLevel = config.getBoolValue("showlevel");
 
-    while (line)
+    while (line != nullptr)
     {
         std::string nick;
         lineStr = line;
@@ -444,11 +444,11 @@ void WhoIsOnline::loadWebList()
                 if (!lineStr.empty())
                     level = atoi(lineStr.c_str());
 
-                if (actorManager)
+                if (actorManager != nullptr)
                 {
                     Being *const being = actorManager->findBeingByName(
                         nick, ActorType::Player);
-                    if (being)
+                    if (being != nullptr)
                     {
                         if (level > 0)
                         {
@@ -503,7 +503,7 @@ size_t WhoIsOnline::memoryWrite(void *restrict ptr,
                                 size_t nmemb,
                                 FILE *restrict stream)
 {
-    if (!stream)
+    if (stream == nullptr)
         return 0;
 
     WhoIsOnline *restrict const wio =
@@ -511,7 +511,7 @@ size_t WhoIsOnline::memoryWrite(void *restrict ptr,
     const size_t totalMem = size * nmemb;
     wio->mMemoryBuffer = static_cast<char*>(realloc(wio->mMemoryBuffer,
         CAST_SIZE(wio->mDownloadedBytes) + totalMem));
-    if (wio->mMemoryBuffer)
+    if (wio->mMemoryBuffer != nullptr)
     {
         memcpy(&(wio->mMemoryBuffer[wio->mDownloadedBytes]), ptr, totalMem);
         wio->mDownloadedBytes += CAST_S32(totalMem);
@@ -524,7 +524,7 @@ int WhoIsOnline::downloadThread(void *ptr)
 {
     int attempts = 0;
     WhoIsOnline *const wio = reinterpret_cast<WhoIsOnline *>(ptr);
-    if (!wio)
+    if (wio == nullptr)
         return 0;
     CURLcode res;
     const std::string url(settings.onlineListUrl + "/online.txt");
@@ -532,7 +532,7 @@ int WhoIsOnline::downloadThread(void *ptr)
     while (attempts < 1 && !wio->mDownloadComplete)
     {
         CURL *curl = curl_easy_init();
-        if (curl)
+        if (curl != nullptr)
         {
             if (!wio->mAllowUpdate)
             {
@@ -625,7 +625,7 @@ void WhoIsOnline::download()
     else if (mWebList)
     {
         mDownloadComplete = true;
-        if (mThread && SDL_GetThreadID(mThread))
+        if (mThread != nullptr && SDL_GetThreadID(mThread) != 0U)
             SDL_WaitThread(mThread, nullptr);
 
         mDownloadComplete = false;
@@ -674,7 +674,7 @@ void WhoIsOnline::slowLogic()
     {
         case UPDATE_ERROR:
             logger->assertLog("Failed to fetch the online list:");
-            if (mCurlError)
+            if (mCurlError != nullptr)
                 logger->assertLog("%s", mCurlError);
             mDownloadStatus = UPDATE_COMPLETE;
             // TRANSLATORS: who is online window name
@@ -694,11 +694,11 @@ void WhoIsOnline::slowLogic()
                 updateSize();
                 if (!mOnlineNicks.empty())
                 {
-                    if (chatWindow)
+                    if (chatWindow != nullptr)
                         chatWindow->updateOnline(mOnlineNicks);
-                    if (socialWindow)
+                    if (socialWindow != nullptr)
                         socialWindow->updateActiveList();
-                    if (actorManager)
+                    if (actorManager != nullptr)
                         actorManager->updateSeenPlayers(mOnlineNicks);
                 }
             }
@@ -722,11 +722,11 @@ void WhoIsOnline::action(const ActionEvent &event)
             if (mDownloadStatus == UPDATE_COMPLETE)
             {
                 mUpdateTimer = cur_time - 20;
-                if (mUpdateButton)
+                if (mUpdateButton != nullptr)
                     mUpdateButton->setEnabled(false);
                 // TRANSLATORS: who is online window name
                 setCaption(_("Who Is Online - Update"));
-                if (mThread && SDL_GetThreadID(mThread))
+                if (mThread != nullptr && SDL_GetThreadID(mThread) != 0U)
                 {
                     SDL_WaitThread(mThread, nullptr);
                     mThread = nullptr;
@@ -755,12 +755,12 @@ void WhoIsOnline::widgetResized(const Event &event)
 void WhoIsOnline::updateSize()
 {
     const Rect area = getChildrenArea();
-    if (mUpdateButton)
+    if (mUpdateButton != nullptr)
         mUpdateButton->setWidth(area.width - 10);
 
-    if (mScrollArea)
+    if (mScrollArea != nullptr)
         mScrollArea->setSize(area.width - 10, area.height - 10 - 30);
-    if (mBrowserBox)
+    if (mBrowserBox != nullptr)
         mBrowserBox->setWidth(area.width - 10);
 }
 
@@ -792,10 +792,10 @@ void WhoIsOnline::optionChanged(const std::string &name)
 
 void WhoIsOnline::setNeutralColor(OnlinePlayer *const player)
 {
-    if (!player)
+    if (player == nullptr)
         return;
 
-    if (actorManager && localPlayer)
+    if ((actorManager != nullptr) && (localPlayer != nullptr))
     {
         const std::string &nick = player->getNick();
         if (nick == localPlayer->getName())
@@ -806,9 +806,9 @@ void WhoIsOnline::setNeutralColor(OnlinePlayer *const player)
         if (localPlayer->isInParty())
         {
             const Party *const party = localPlayer->getParty();
-            if (party)
+            if (party != nullptr)
             {
-                if (party->getMember(nick))
+                if (party->getMember(nick) != nullptr)
                 {
                     player->setText("P");
                     return;
@@ -817,16 +817,16 @@ void WhoIsOnline::setNeutralColor(OnlinePlayer *const player)
         }
 
         const Being *const being = actorManager->findBeingByName(nick);
-        if (being)
+        if (being != nullptr)
         {
             const Guild *const guild2 = localPlayer->getGuild();
-            if (guild2)
+            if (guild2 != nullptr)
             {
                 const Guild *const guild1 = being->getGuild();
-                if (guild1)
+                if (guild1 != nullptr)
                 {
                     if (guild1->getId() == guild2->getId()
-                        || guild2->getMember(nick))
+                        || (guild2->getMember(nick) != nullptr))
                     {
                         player->setText("U");
                         return;
@@ -840,7 +840,7 @@ void WhoIsOnline::setNeutralColor(OnlinePlayer *const player)
             }
         }
         const Guild *const guild3 = Guild::getGuild(1);
-        if (guild3 && guild3->isMember(nick))
+        if ((guild3 != nullptr) && guild3->isMember(nick))
         {
             player->setText("U");
             return;
@@ -860,11 +860,11 @@ void OnlinePlayer::setText(std::string color)
 {
     mText.clear();
 
-    if (mStatus != 255 && actorManager)
+    if (mStatus != 255 && (actorManager != nullptr))
     {
         Being *const being = actorManager->findBeingByName(
             mNick, ActorType::Player);
-        if (being)
+        if (being != nullptr)
         {
             being->setState(mStatus);
             // for now highlight versions > 3
@@ -873,7 +873,7 @@ void OnlinePlayer::setText(std::string color)
         }
     }
 
-    if ((mStatus != 255 && mStatus & BeingFlag::GM) || mIsGM)
+    if ((mStatus != 255 && ((mStatus & BeingFlag::GM) != 0)) || mIsGM)
         mText.append("(GM) ");
 
     if (mLevel > 0)
@@ -886,20 +886,20 @@ void OnlinePlayer::setText(std::string color)
 
     if (mStatus > 0 && mStatus != 255)
     {
-        if (mStatus & BeingFlag::SHOP)
+        if ((mStatus & BeingFlag::SHOP) != 0)
             mText.append("$");
-        if (mStatus & BeingFlag::AWAY)
+        if ((mStatus & BeingFlag::AWAY) != 0)
         {
             // TRANSLATORS: this away status writed in player nick
             mText.append(_("A"));
         }
-        if (mStatus & BeingFlag::INACTIVE)
+        if ((mStatus & BeingFlag::INACTIVE) != 0)
         {
             // TRANSLATORS: this inactive status writed in player nick
             mText.append(_("I"));
         }
 
-        if (mStatus & BeingFlag::GM && color == "0")
+        if (((mStatus & BeingFlag::GM) != 0) && color == "0")
             color = "2";
     }
     else if (mIsGM && color == "0")