Fix some warnings under gcc 4.7.

175 files changed, 946 insertions, 893 deletions

diff --git a/src/actorsprite.cpp b/src/actorsprite.cpp
index 6155bb7af..ea24513e1 100644
--- a/src/actorsprite.cpp
+++ b/src/actorsprite.cpp
@@ -186,7 +186,7 @@ static EffectDescription *getEffectDescription(int effectId)
         {
             logger->log1("Error loading being effects file: "
                     EFFECTS_FILE);
-            return NULL;
+            return nullptr;
         }
 
         for_each_xml_child_node(node, root)
diff --git a/src/actorsprite.h b/src/actorsprite.h
index 7ec5cc391..e130269bf 100644
--- a/src/actorsprite.h
+++ b/src/actorsprite.h
@@ -24,6 +24,7 @@
 
 #include "actor.h"
 #include "compoundsprite.h"
+#include "localconsts.h"
 #include "map.h"
 #include "particlecontainer.h"
 
@@ -122,7 +123,8 @@ public:
     /**
      * Untargets the actor.
      */
-    void untarget() { mUsedTargetCursor = NULL; }
+    void untarget()
+    { mUsedTargetCursor = nullptr; }
 
     /**
      * Triggers a visual effect, such as `level up'. Only draws the visual
diff --git a/src/actorspritemanager.cpp b/src/actorspritemanager.cpp
index cc18cfbee..f964a8b00 100644
--- a/src/actorspritemanager.cpp
+++ b/src/actorspritemanager.cpp
@@ -295,7 +295,7 @@ Being *ActorSpriteManager::findBeing(int id) const
         }
     }
 
-    return NULL;
+    return nullptr;
 }
 
 Being *ActorSpriteManager::findBeing(int x, int y,
@@ -308,14 +308,14 @@ Being *ActorSpriteManager::findBeing(int x, int y,
     ActorSpritesConstIterator it = find_if(mActors.begin(), mActors.end(),
                                            beingFinder);
 
-    return (it == mActors.end()) ? NULL : static_cast<Being*>(*it);
+    return (it == mActors.end()) ? nullptr : static_cast<Being*>(*it);
 }
 
 Being *ActorSpriteManager::findBeingByPixel(int x, int y,
                                             bool allPlayers) const
 {
     if (!mMap)
-        return NULL;
+        return nullptr;
 
     bool targetDead = mTargetDeadPlayers;
 
@@ -448,7 +448,7 @@ void ActorSpriteManager::findBeingsByPixel(std::vector<Being*> &beings,
 Being *ActorSpriteManager::findPortalByTile(int x, int y) const
 {
     if (!mMap)
-        return NULL;
+        return nullptr;
 
     for_actors
     {
@@ -464,7 +464,7 @@ Being *ActorSpriteManager::findPortalByTile(int x, int y) const
             return being;
     }
 
-    return NULL;
+    return nullptr;
 }
 
 FloorItem *ActorSpriteManager::findItem(int id) const
@@ -481,7 +481,7 @@ FloorItem *ActorSpriteManager::findItem(int id) const
         }
     }
 
-    return NULL;
+    return nullptr;
 }
 
 FloorItem *ActorSpriteManager::findItem(int x, int y) const
@@ -498,7 +498,7 @@ FloorItem *ActorSpriteManager::findItem(int x, int y) const
         }
     }
 
-    return NULL;
+    return nullptr;
 }
 
 bool ActorSpriteManager::pickUpAll(int x1, int y1, int x2, int y2,
@@ -563,7 +563,7 @@ bool ActorSpriteManager::pickUpNearest(int x, int y, int maxdist)
         return false;
 
     maxdist = maxdist * maxdist;
-    FloorItem *closestItem = NULL;
+    FloorItem *closestItem = nullptr;
     int dist = 0;
 
     for_actors
@@ -614,7 +614,7 @@ Being *ActorSpriteManager::findBeingByName(const std::string &name,
             return being;
         }
     }
-    return NULL;
+    return nullptr;
 }
 
 Being *ActorSpriteManager::findNearestByName(const std::string &name,
@@ -624,7 +624,7 @@ Being *ActorSpriteManager::findNearestByName(const std::string &name,
         return 0;
 
     int dist = 0;
-    Being* closestBeing = NULL;
+    Being* closestBeing = nullptr;
     int x, y;
 
     x = player_node->getTileX();
@@ -654,7 +654,7 @@ Being *ActorSpriteManager::findNearestByName(const std::string &name,
                         + (being->getTileY() - y) * (being->getTileY() - y);
 
                 if (validateBeing(0, being, type, 0, 50)
-                    && (d < dist || closestBeing == NULL))
+                    && (d < dist || closestBeing == nullptr))
                 {
                     dist = d;
                     closestBeing = being;
@@ -745,7 +745,7 @@ Being *ActorSpriteManager::findNearestLivingBeing(int x, int y,
 {
     const int maxDist = maxTileDist * 32;
 
-    return findNearestLivingBeing(NULL, maxDist, type, x, y, excluded);
+    return findNearestLivingBeing(nullptr, maxDist, type, x, y, excluded);
 }
 
 Being *ActorSpriteManager::findNearestLivingBeing(Being *aroundBeing,
@@ -884,7 +884,7 @@ Being *ActorSpriteManager::findNearestLivingBeing(Being *aroundBeing,
             beingSorter.priorityBeings = 0;
         }
 
-        if (player_node->getTarget() == NULL)
+        if (player_node->getTarget() == nullptr)
         {
             Being *target = sortedBeings.at(0);
 
diff --git a/src/being.cpp b/src/being.cpp
index 5e8d68041..d73684ba0 100644
--- a/src/being.cpp
+++ b/src/being.cpp
@@ -223,7 +223,7 @@ Being::Being(int id, Type type, Uint16 subtype, Map *map):
     mSpriteDirection(DIRECTION_DOWN),
     mDispName(0),
     mShowName(false),
-    mEquippedWeapon(NULL),
+    mEquippedWeapon(nullptr),
     mText(0),
     mLevel(0),
     mGender(GENDER_UNSPECIFIED),
@@ -1678,13 +1678,13 @@ void Being::setSprite(unsigned int slot, int id, std::string color,
         removeSprite(slot);
 
         if (isWeapon)
-            mEquippedWeapon = NULL;
+            mEquippedWeapon = nullptr;
     }
     else
     {
         const ItemInfo &info = ItemDB::get(id);
         std::string filename = info.getSprite(mGender);
-        AnimatedSprite *equipmentSprite = NULL;
+        AnimatedSprite *equipmentSprite = nullptr;
 
         if (!filename.empty())
         {
diff --git a/src/being.h b/src/being.h
index 9b38e1479..9ee60fcdf 100644
--- a/src/being.h
+++ b/src/being.h
@@ -354,7 +354,7 @@ class Being : public ActorSprite, public ConfigListener
         { return static_cast<short>(mGuilds.size()); }
 
         bool isInParty() const
-        { return mParty != NULL; }
+        { return mParty; }
 
         void setParty(Party *party);
 
@@ -761,10 +761,10 @@ class Being : public ActorSprite, public ConfigListener
         void setAttackRange(int range)
         { mAttackRange = range; }
 
-        void attack(Being *target = NULL, bool keep = false,
+        void attack(Being *target = nullptr, bool keep = false,
                     bool dontChangeEquipment = false);
 
-        void attack2(Being *target = NULL, bool keep = false,
+        void attack2(Being *target = nullptr, bool keep = false,
                      bool dontChangeEquipment = false);
 
     protected:
diff --git a/src/client.cpp b/src/client.cpp
index 642b967b1..966070d3a 100644
--- a/src/client.cpp
+++ b/src/client.cpp
@@ -341,7 +341,7 @@ Client::Client(const Options &options):
     SDL_EnableUNICODE(1);
     SDL_EnableKeyRepeat(SDL_DEFAULT_REPEAT_DELAY, SDL_DEFAULT_REPEAT_INTERVAL);
 
-    SDL_WM_SetCaption(branding.getValue("appName", "ManaPlus").c_str(), NULL);
+    SDL_WM_SetCaption(branding.getValue("appName", "ManaPlus").c_str(), nullptr);
 
     ResourceManager *resman = ResourceManager::getInstance();
 
@@ -440,12 +440,11 @@ Client::Client(const Options &options):
     static SDL_SysWMinfo pInfo;
     SDL_GetWMInfo(&pInfo);
     // Attempt to load icon from .ico file
-    HICON icon = (HICON) LoadImage(NULL,
-                                   iconFile.c_str(),
-                                   IMAGE_ICON, 64, 64, LR_LOADFROMFILE);
+    HICON icon = (HICON) LoadImage(nullptr, iconFile.c_str(),
+        IMAGE_ICON, 64, 64, LR_LOADFROMFILE);
     // If it's failing, we load the default resource file.
     if (!icon)
-        icon = LoadIcon(GetModuleHandle(NULL), "A");
+        icon = LoadIcon(GetModuleHandle(nullptr), "A");
 
     if (icon)
         SetClassLong(pInfo.window, GCL_HICON, (LONG) icon);
@@ -454,7 +453,7 @@ Client::Client(const Options &options):
     if (mIcon)
     {
         SDL_SetAlpha(mIcon, SDL_SRCALPHA, SDL_ALPHA_OPAQUE);
-        SDL_WM_SetIcon(mIcon, NULL);
+        SDL_WM_SetIcon(mIcon, nullptr);
     }
 #endif
 
@@ -601,8 +600,8 @@ Client::Client(const Options &options):
 
     // Initialize logic and seconds counters
     tick_time = 0;
-    mLogicCounterId = SDL_AddTimer(MILLISECONDS_IN_A_TICK, nextTick, NULL);
-    mSecondsCounterId = SDL_AddTimer(1000, nextSecond, NULL);
+    mLogicCounterId = SDL_AddTimer(MILLISECONDS_IN_A_TICK, nextTick, nullptr);
+    mSecondsCounterId = SDL_AddTimer(1000, nextSecond, nullptr);
 
     const int fpsLimit = config.getIntValue("fpslimit");
     mLimitFps = fpsLimit > 0;
@@ -625,7 +624,7 @@ Client::Client(const Options &options):
 
     optionChanged("fpslimit");
 
-    start_time = static_cast<int>(time(NULL));
+    start_time = static_cast<int>(time(nullptr));
 
     // Initialize PlayerInfo
     PlayerInfo::init();
@@ -1197,7 +1196,7 @@ int Client::exec()
                     delete mDesktop;
                     mDesktop = 0;
 
-                    mCurrentDialog = NULL;
+                    mCurrentDialog = nullptr;
 
                     logger->log1("State: GAME");
                     if (Net::getGeneralHandler())
@@ -1209,14 +1208,14 @@ int Client::exec()
                     logger->log1("State: LOGIN ERROR");
                     mCurrentDialog = new OkDialog(_("Error"), errorMessage);
                     mCurrentDialog->addActionListener(&loginListener);
-                    mCurrentDialog = NULL; // OkDialog deletes itself
+                    mCurrentDialog = nullptr; // OkDialog deletes itself
                     break;
 
                 case STATE_ACCOUNTCHANGE_ERROR:
                     logger->log1("State: ACCOUNT CHANGE ERROR");
                     mCurrentDialog = new OkDialog(_("Error"), errorMessage);
                     mCurrentDialog->addActionListener(&accountListener);
-                    mCurrentDialog = NULL; // OkDialog deletes itself
+                    mCurrentDialog = nullptr; // OkDialog deletes itself
                     break;
 
                 case STATE_REGISTER_PREP:
@@ -1252,7 +1251,7 @@ int Client::exec()
                     mCurrentDialog = new OkDialog(_("Password Change"),
                             _("Password changed successfully!"));
                     mCurrentDialog->addActionListener(&accountListener);
-                    mCurrentDialog = NULL; // OkDialog deletes itself
+                    mCurrentDialog = nullptr; // OkDialog deletes itself
                     loginData.password = loginData.newPassword;
                     loginData.newPassword = "";
                     break;
@@ -1272,7 +1271,7 @@ int Client::exec()
                     mCurrentDialog = new OkDialog(_("Email Change"),
                             _("Email changed successfully!"));
                     mCurrentDialog->addActionListener(&accountListener);
-                    mCurrentDialog = NULL; // OkDialog deletes itself
+                    mCurrentDialog = nullptr; // OkDialog deletes itself
                     break;
 
                 case STATE_UNREGISTER:
@@ -1295,7 +1294,7 @@ int Client::exec()
                     loginData.clear();
                     //The errorlistener sets the state to STATE_CHOOSE_SERVER
                     mCurrentDialog->addActionListener(&errorListener);
-                    mCurrentDialog = NULL; // OkDialog deletes itself
+                    mCurrentDialog = nullptr; // OkDialog deletes itself
                     break;
 
                 case STATE_SWITCH_SERVER:
@@ -1350,7 +1349,7 @@ int Client::exec()
                     logger->log("Error: %s\n", errorMessage.c_str());
                     mCurrentDialog = new OkDialog(_("Error"), errorMessage);
                     mCurrentDialog->addActionListener(&errorListener);
-                    mCurrentDialog = NULL; // OkDialog deletes itself
+                    mCurrentDialog = nullptr; // OkDialog deletes itself
                     Net::getGameHandler()->disconnect();
                     break;
 
@@ -1796,7 +1795,7 @@ bool Client::copyFile(std::string &configPath, std::string &oldConfigPath)
 
     configFile = fopen(oldConfigPath.c_str(), "r");
 
-    if (configFile != NULL)
+    if (configFile)
     {
         fclose(configFile);
 
diff --git a/src/compoundsprite.cpp b/src/compoundsprite.cpp
index ceab9a149..cda178aeb 100644
--- a/src/compoundsprite.cpp
+++ b/src/compoundsprite.cpp
@@ -166,7 +166,7 @@ void CompoundSprite::drawSpritesSDL(Graphics* graphics,
 
 int CompoundSprite::getWidth() const
 {
-    Sprite *base = NULL;
+    Sprite *base = nullptr;
 
     SpriteConstIterator it, it_end;
     for (it = begin(), it_end = end(); it != it_end; ++it)
@@ -183,7 +183,7 @@ int CompoundSprite::getWidth() const
 
 int CompoundSprite::getHeight() const
 {
-    Sprite *base = NULL;
+    Sprite *base = nullptr;
 
     SpriteConstIterator it, it_end;
     for (it = begin(), it_end = end(); it != it_end; ++it)
@@ -271,7 +271,7 @@ void CompoundSprite::setSprite(int layer, Sprite* sprite)
 void CompoundSprite::removeSprite(int layer)
 {
     // Skip if it won't change anything
-    if (at(layer) == NULL)
+    if (at(layer) == nullptr)
         return;
 
     delete at(layer);
@@ -299,7 +299,7 @@ void CompoundSprite::ensureSize(size_t layerCount)
     if (size() >= layerCount)
         return;
 
-    resize(layerCount, NULL);
+    resize(layerCount, nullptr);
 }
 
 /**
@@ -387,7 +387,7 @@ void CompoundSprite::redraw() const
         BUFFER_WIDTH, BUFFER_HEIGHT, 32, rmask, gmask, bmask, amask);
 
     SDL_SetAlpha(surface, 0, SDL_ALPHA_OPAQUE);
-    SDL_BlitSurface(surface, NULL, surfaceA, NULL);
+    SDL_BlitSurface(surface, nullptr, surfaceA, nullptr);
 
     delete mImage;
     delete mAlphaImage;
diff --git a/src/configuration.cpp b/src/configuration.cpp
index a0167b9b0..814b0ce65 100644
--- a/src/configuration.cpp
+++ b/src/configuration.cpp
@@ -565,8 +565,8 @@ void Configuration::write()
     logger->log1("Configuration::write() writing configuration...");
 
     xmlTextWriterSetIndent(writer, 1);
-    xmlTextWriterStartDocument(writer, NULL, NULL, NULL);
-//    xmlTextWriterStartDocument(writer, NULL, "utf8", NULL);
+    xmlTextWriterStartDocument(writer, nullptr, nullptr, nullptr);
+//    xmlTextWriterStartDocument(writer, nullptr, "utf8", nullptr);
     xmlTextWriterStartElement(writer, BAD_CAST "configuration");
 
     writeToXML(writer);
diff --git a/src/debug.h b/src/debug.h
index 81a2e0526..3c509152d 100644
--- a/src/debug.h
+++ b/src/debug.h
@@ -18,6 +18,8 @@
  *  along with this program.  If not, see <http://www.gnu.org/licenses/>.
  */
 
+#include "localconsts.h"
+
 #ifdef ENABLE_MEM_DEBUG
 //define _DEBUG_NEW_EMULATE_MALLOC 1
 #include "debug/debug_new.h"
diff --git a/src/equipment.h b/src/equipment.h
index 71b4b8593..2b6dae3ce 100644
--- a/src/equipment.h
+++ b/src/equipment.h
@@ -25,6 +25,8 @@
 
 #define EQUIPMENT_SIZE 13
 
+#include "localconsts.h"
+
 class Item;
 
 class Equipment
@@ -33,14 +35,14 @@ class Equipment
         /**
          * Constructor.
          */
-        Equipment(): mBackend(0)
+        Equipment(): mBackend(nullptr)
         { }
 
         /**
          * Destructor.
          */
         ~Equipment()
-        { mBackend = 0; }
+        { mBackend = nullptr; }
 
         enum Slot
         {
@@ -72,7 +74,7 @@ class Equipment
          * Get equipment at the given slot.
          */
         Item *getEquipment(int index) const
-        { return mBackend ? mBackend->getEquipment(index) : 0; }
+        { return mBackend ? mBackend->getEquipment(index) : nullptr; }
 
         /**
          * Clears equipment.
diff --git a/src/game.cpp b/src/game.cpp
index a9fa318f7..6b595e8e1 100644
--- a/src/game.cpp
+++ b/src/game.cpp
@@ -117,54 +117,54 @@
 
 #include "debug.h"
 
-Joystick *joystick = NULL;
+Joystick *joystick = nullptr;
 
-OkDialog *weightNotice = NULL;
+OkDialog *weightNotice = nullptr;
 int weightNoticeTime = 0;
-OkDialog *deathNotice = NULL;
-QuitDialog *quitDialog = NULL;
-OkDialog *disconnectedDialog = NULL;
-
-ChatWindow *chatWindow = NULL;
-StatusWindow *statusWindow = NULL;
-MiniStatusWindow *miniStatusWindow = NULL;
-InventoryWindow *inventoryWindow = NULL;
-ShopWindow *shopWindow = NULL;
-SkillDialog *skillDialog = NULL;
-Minimap *minimap = NULL;
-EquipmentWindow *equipmentWindow = NULL;
-EquipmentWindow *beingEquipmentWindow = NULL;
-TradeWindow *tradeWindow = NULL;
-HelpWindow *helpWindow = NULL;
-DebugWindow *debugWindow = NULL;
-ShortcutWindow *itemShortcutWindow = NULL;
-ShortcutWindow *emoteShortcutWindow = NULL;
-OutfitWindow *outfitWindow = NULL;
-SpecialsWindow *specialsWindow = NULL;
-ShortcutWindow *dropShortcutWindow = NULL;
-ShortcutWindow *spellShortcutWindow = NULL;
-WhoIsOnline *whoIsOnline = NULL;
-DidYouKnowWindow *didYouKnowWindow = NULL;
-KillStats *killStats = NULL;
-BotCheckerWindow *botCheckerWindow = NULL;
-SocialWindow *socialWindow = NULL;
-WindowMenu *windowMenu = NULL;
-
-ActorSpriteManager *actorSpriteManager = NULL;
-ChannelManager *channelManager = NULL;
-CommandHandler *commandHandler = NULL;
-MumbleManager *mumbleManager = NULL;
-Particle *particleEngine = NULL;
-EffectManager *effectManager = NULL;
-SpellManager *spellManager = NULL;
-Viewport *viewport = NULL;                    /**< Viewport on the map. */
-GuildManager *guildManager = NULL;
-AuctionManager *auctionManager = NULL;
-
-ChatTab *localChatTab = NULL;
-ChatTab *debugChatTab = NULL;
-TradeTab *tradeChatTab = NULL;
-BattleTab *battleChatTab = NULL;
+OkDialog *deathNotice = nullptr;
+QuitDialog *quitDialog = nullptr;
+OkDialog *disconnectedDialog = nullptr;
+
+ChatWindow *chatWindow = nullptr;
+StatusWindow *statusWindow = nullptr;
+MiniStatusWindow *miniStatusWindow = nullptr;
+InventoryWindow *inventoryWindow = nullptr;
+ShopWindow *shopWindow = nullptr;
+SkillDialog *skillDialog = nullptr;
+Minimap *minimap = nullptr;
+EquipmentWindow *equipmentWindow = nullptr;
+EquipmentWindow *beingEquipmentWindow = nullptr;
+TradeWindow *tradeWindow = nullptr;
+HelpWindow *helpWindow = nullptr;
+DebugWindow *debugWindow = nullptr;
+ShortcutWindow *itemShortcutWindow = nullptr;
+ShortcutWindow *emoteShortcutWindow = nullptr;
+OutfitWindow *outfitWindow = nullptr;
+SpecialsWindow *specialsWindow = nullptr;
+ShortcutWindow *dropShortcutWindow = nullptr;
+ShortcutWindow *spellShortcutWindow = nullptr;
+WhoIsOnline *whoIsOnline = nullptr;
+DidYouKnowWindow *didYouKnowWindow = nullptr;
+KillStats *killStats = nullptr;
+BotCheckerWindow *botCheckerWindow = nullptr;
+SocialWindow *socialWindow = nullptr;
+WindowMenu *windowMenu = nullptr;
+
+ActorSpriteManager *actorSpriteManager = nullptr;
+ChannelManager *channelManager = nullptr;
+CommandHandler *commandHandler = nullptr;
+MumbleManager *mumbleManager = nullptr;
+Particle *particleEngine = nullptr;
+EffectManager *effectManager = nullptr;
+SpellManager *spellManager = nullptr;
+Viewport *viewport = nullptr;                    /**< Viewport on the map. */
+GuildManager *guildManager = nullptr;
+AuctionManager *auctionManager = nullptr;
+
+ChatTab *localChatTab = nullptr;
+ChatTab *debugChatTab = nullptr;
+TradeTab *tradeChatTab = nullptr;
+BattleTab *battleChatTab = nullptr;
 
 const unsigned adjustDelay = 10;
 
@@ -182,7 +182,7 @@ static void initEngines()
     AuctionManager::init();
     GuildManager::init();
 
-    particleEngine = new Particle(NULL);
+    particleEngine = new Particle(nullptr);
     particleEngine->setupEngine();
 
     Mana::Event::trigger(CHANNEL_GAME, Mana::Event(EVENT_ENGINESINITALIZED));
@@ -297,7 +297,7 @@ static void destroyGuiWindows()
 {
     Mana::Event::trigger(CHANNEL_GAME, Mana::Event(EVENT_GUIWINDOWSUNLOADING));
 
-    logger->setChatWindow(NULL);
+    logger->setChatWindow(nullptr);
     if (whoIsOnline)
         whoIsOnline->setAllowUpdate(false);
 
@@ -365,7 +365,7 @@ Game::Game():
     assert(!mInstance);
     mInstance = this;
 
-    disconnectedDialog = NULL;
+    disconnectedDialog = nullptr;
 
     mAdjustPerfomance = config.getBoolValue("adjustPerfomance");
 
@@ -729,7 +729,7 @@ void Game::handleInput()
         // Keyboard events (for discontinuous keys)
         if (event.type == SDL_KEYDOWN)
         {
-            gcn::Window *requestedWindow = NULL;
+            gcn::Window *requestedWindow = nullptr;
 
             if (setupWindow && setupWindow->isVisible() &&
                 keyboard.getNewKeyIndex() > keyboard.KEY_NO_VALUE)
@@ -846,9 +846,9 @@ void Game::handleInput()
                         helpWindow->setVisible(false);
                     // Close the config window, cancelling changes if opened
                     else if (setupWindow->isVisible())
-                        setupWindow->action(gcn::ActionEvent(NULL, "cancel"));
+                        setupWindow->action(gcn::ActionEvent(nullptr, "cancel"));
                     else if (dialog)
-                        dialog->action(gcn::ActionEvent(NULL, "ok"));
+                        dialog->action(gcn::ActionEvent(nullptr, "ok"));
                 }
                 if (chatWindow && keyboard.isKeyActive(
                     keyboard.KEY_TOGGLE_CHAT))
diff --git a/src/game.h b/src/game.h
index 24ca7f0fc..2205e30de 100644
--- a/src/game.h
+++ b/src/game.h
@@ -26,6 +26,8 @@
 #include <string>
 #include "gui/sdlinput.h"
 
+#include "localconsts.h"
+
 #define MAX_LASTKEYS 10
 
 extern volatile int cur_time;
@@ -66,7 +68,7 @@ class Game
         { return mInstance; }
 
         static void clearInstance()
-        { mInstance = 0; }
+        { mInstance = nullptr; }
 
         /**
          * This method takes the game a small step further. It is called 100
diff --git a/src/graphics.cpp b/src/graphics.cpp
index d914b0b00..47b0cae3d 100644
--- a/src/graphics.cpp
+++ b/src/graphics.cpp
@@ -645,7 +645,7 @@ SDL_Surface *Graphics::getScreenshot()
             mTarget->h, 24, rmask, gmask, bmask, amask);
 
     if (screenshot)
-        SDL_BlitSurface(mTarget, NULL, screenshot, NULL);
+        SDL_BlitSurface(mTarget, nullptr, screenshot, nullptr);
 
     return screenshot;
 }
@@ -684,8 +684,8 @@ int Graphics::SDL_FakeUpperBlit(SDL_Surface *src, SDL_Rect *srcrect,
     if (src->locked || dst->locked)
         return(-1);
 
-    /* If the destination rectangle is NULL, use the entire dest surface */
-    if (dstrect == NULL)
+    /* If the destination rectangle is nullptr, use the entire dest surface */
+    if (!dstrect)
     {
         fulldst.x = 0;
         fulldst.y = 0;
diff --git a/src/graphicsvertexes.h b/src/graphicsvertexes.h
index 5b39dfb08..13b7bf0c8 100644
--- a/src/graphicsvertexes.h
+++ b/src/graphicsvertexes.h
@@ -25,6 +25,7 @@
 #include "main.h"
 
 #include "graphics.h"
+#include "localconsts.h"
 
 #ifdef USE_OPENGL
 #define NO_SDL_GLEXT
@@ -122,7 +123,7 @@ class ImageVertexes
 {
     public:
         ImageVertexes() :
-            image(0)
+            image(nullptr)
         {
             sdl.reserve(30);
 #ifdef USE_OPENGL
diff --git a/src/gui/beingpopup.cpp b/src/gui/beingpopup.cpp
index 98df1ca9a..759d4c245 100644
--- a/src/gui/beingpopup.cpp
+++ b/src/gui/beingpopup.cpp
@@ -130,7 +130,7 @@ void BeingPopup::show(int x, int y, Being *b)
         label4 = label3;
         label3 = label2;
         label2 = label1;
-        label1 = 0;
+        label1 = nullptr;
     }
 
     if (!(b->getGuildName().empty()))
@@ -143,7 +143,7 @@ void BeingPopup::show(int x, int y, Being *b)
     {
         label4 = label3;
         label3 = label2;
-        label2 = 0;
+        label2 = nullptr;
     }
 
     if (b->getPvpRank() > 0)
@@ -154,7 +154,7 @@ void BeingPopup::show(int x, int y, Being *b)
     else
     {
         label4 = label3;
-        label3 = 0;
+        label3 = nullptr;
     }
 
     if (!b->getComment().empty())
@@ -165,7 +165,7 @@ void BeingPopup::show(int x, int y, Being *b)
     }
     else
     {
-        label4 = 0;
+        label4 = nullptr;
     }
 
     int minWidth = mBeingName->getWidth();
diff --git a/src/gui/botcheckerwindow.cpp b/src/gui/botcheckerwindow.cpp
index 88bc65a78..bff9ad31a 100644
--- a/src/gui/botcheckerwindow.cpp
+++ b/src/gui/botcheckerwindow.cpp
@@ -263,7 +263,7 @@ protected:
 
 
 BotCheckerWindow::BotCheckerWindow():
-    Window(_("Bot Checker"), false, 0, "botchecker.xml"),
+    Window(_("Bot Checker"), false, nullptr, "botchecker.xml"),
     mEnabled(false)
 {
     int w = 500;
diff --git a/src/gui/changeemaildialog.cpp b/src/gui/changeemaildialog.cpp
index 384ebf07f..3c412b424 100644
--- a/src/gui/changeemaildialog.cpp
+++ b/src/gui/changeemaildialog.cpp
@@ -45,7 +45,7 @@
 #include "debug.h"
 
 ChangeEmailDialog::ChangeEmailDialog(LoginData *data):
-    Window(_("Change Email Address"), true, 0, "changeemail.xml"),
+    Window(_("Change Email Address"), true, nullptr, "changeemail.xml"),
     mWrongDataNoticeListener(new WrongDataNoticeListener),
     mLoginData(data)
 {
@@ -102,7 +102,7 @@ ChangeEmailDialog::ChangeEmailDialog(LoginData *data):
 ChangeEmailDialog::~ChangeEmailDialog()
 {
     delete mWrongDataNoticeListener;
-    mWrongDataNoticeListener = 0;
+    mWrongDataNoticeListener = nullptr;
 }
 
 void ChangeEmailDialog::action(const gcn::ActionEvent &event)
diff --git a/src/gui/changepassworddialog.cpp b/src/gui/changepassworddialog.cpp
index 7a67279b6..a7ebaebca 100644
--- a/src/gui/changepassworddialog.cpp
+++ b/src/gui/changepassworddialog.cpp
@@ -47,7 +47,7 @@
 #include "debug.h"
 
 ChangePasswordDialog::ChangePasswordDialog(LoginData *data):
-    Window(_("Change Password"), true, 0, "changepassword.xml"),
+    Window(_("Change Password"), true, nullptr, "changepassword.xml"),
     mWrongDataNoticeListener(new WrongDataNoticeListener),
     mLoginData(data)
 {
@@ -82,7 +82,7 @@ ChangePasswordDialog::ChangePasswordDialog(LoginData *data):
 ChangePasswordDialog::~ChangePasswordDialog()
 {
     delete mWrongDataNoticeListener;
-    mWrongDataNoticeListener = 0;
+    mWrongDataNoticeListener = nullptr;
 }
 
 void ChangePasswordDialog::action(const gcn::ActionEvent &event)
diff --git a/src/gui/charcreatedialog.cpp b/src/gui/charcreatedialog.cpp
index efe7e804f..0cde69386 100644
--- a/src/gui/charcreatedialog.cpp
+++ b/src/gui/charcreatedialog.cpp
@@ -63,7 +63,7 @@ CharCreateDialog::CharCreateDialog(CharSelectDialog *parent, int slot):
     setStickyButtonLock(true);
     setSticky(true);
 
-    mPlayer = new Being(0, ActorSprite::PLAYER, mRace, NULL);
+    mPlayer = new Being(0, ActorSprite::PLAYER, mRace, nullptr);
     mPlayer->setGender(GENDER_MALE);
 
     int numberOfHairColors = ColorDB::getHairSize();
diff --git a/src/gui/charselectdialog.cpp b/src/gui/charselectdialog.cpp
index 00cae41e6..93302e0ff 100644
--- a/src/gui/charselectdialog.cpp
+++ b/src/gui/charselectdialog.cpp
@@ -122,14 +122,14 @@ class CharacterDisplay : public Container
 };
 
 CharSelectDialog::CharSelectDialog(LoginData *data):
-    Window(_("Account and Character Management"), false, 0, "char.xml"),
+    Window(_("Account and Character Management"), false, nullptr, "char.xml"),
     mLocked(false),
-    mUnregisterButton(0),
-    mChangeEmailButton(0),
+    mUnregisterButton(nullptr),
+    mChangeEmailButton(nullptr),
     mCharacterEntries(0),
     mLoginData(data),
     mCharHandler(Net::getCharHandler()),
-    mDeleteDialog(0),
+    mDeleteDialog(nullptr),
     mDeleteIndex(-1)
 {
     setCloseButton(false);
@@ -246,7 +246,7 @@ void CharSelectDialog::action(const gcn::ActionEvent &event)
             == LoginDialog::savedPassword)
         {
             attemptCharacterDelete(mDeleteIndex);
-            mDeleteDialog = 0;
+            mDeleteDialog = nullptr;
         }
         else
         {
@@ -313,7 +313,7 @@ void CharSelectDialog::setCharacters(const Net::Characters &characters)
     for (iter = mCharacterEntries.begin(), iter_end = mCharacterEntries.end();
          iter != iter_end; ++iter)
     {
-        (*iter)->setCharacter(0);
+        (*iter)->setCharacter(nullptr);
     }
 
     Net::Characters::const_iterator i, i_end = characters.end();
@@ -399,7 +399,7 @@ bool CharSelectDialog::selectByName(const std::string &name,
 
 
 CharacterDisplay::CharacterDisplay(CharSelectDialog *charSelectDialog):
-    mCharacter(0),
+    mCharacter(nullptr),
     mPlayerBox(new PlayerBox)
 {
     mButton = new Button("wwwwwwwww", "go", charSelectDialog);
@@ -445,7 +445,7 @@ void CharacterDisplay::setCharacter(Net::Character *character)
         return;
 
     mCharacter = character;
-    mPlayerBox->setPlayer(character ? character->dummy : 0);
+    mPlayerBox->setPlayer(character ? character->dummy : nullptr);
     update();
 }
 
diff --git a/src/gui/chatwindow.cpp b/src/gui/chatwindow.cpp
index cdcd02bc3..35b89b839 100644
--- a/src/gui/chatwindow.cpp
+++ b/src/gui/chatwindow.cpp
@@ -149,7 +149,7 @@ public:
 
 
 ChatWindow::ChatWindow():
-    Window(_("Chat"), false, 0, "chat.xml"),
+    Window(_("Chat"), false, nullptr, "chat.xml"),
     mTmpVisible(false),
     mChatHistoryIndex(0)
 {
@@ -222,11 +222,11 @@ ChatWindow::~ChatWindow()
     config.setValue("ReturnToggles", mReturnToggles);
     removeAllWhispers();
     delete mItemLinkHandler;
-    mItemLinkHandler = 0;
+    mItemLinkHandler = nullptr;
     delete mColorPicker;
-    mColorPicker = 0;
+    mColorPicker = nullptr;
     delete mColorListModel;
-    mColorListModel = 0;
+    mColorListModel = nullptr;
 }
 
 void ChatWindow::fillCommands()
@@ -557,13 +557,13 @@ void ChatWindow::ignoreAllWhispers()
         }
 
         delete(iter->second);
-        iter->second = 0;
+        iter->second = nullptr;
     }
 }
 
 void ChatWindow::chatInput(const std::string &message)
 {
-    ChatTab *tab = NULL;
+    ChatTab *tab = nullptr;
     std::string msg = message;
     trim(msg);
 
@@ -939,7 +939,7 @@ void ChatWindow::addWhisper(const std::string &nick,
     if (tempNick.compare(playerName) == 0)
         return;
 
-    ChatTab *tab = 0;
+    ChatTab *tab = nullptr;
     TabMap::const_iterator i = mWhispers.find(tempNick);
 
     if (i != mWhispers.end())
@@ -1006,7 +1006,7 @@ void ChatWindow::addWhisper(const std::string &nick,
         {
             localChatTab->chatLog(nick + " : " + mes, ACT_WHISPER, false);
             if (player_node)
-                player_node->afkRespond(0, nick);
+                player_node->afkRespond(nullptr, nick);
         }
     }
 }
@@ -1014,7 +1014,7 @@ void ChatWindow::addWhisper(const std::string &nick,
 ChatTab *ChatWindow::addWhisperTab(const std::string &nick, bool switchTo)
 {
     if (!player_node)
-        return NULL;
+        return nullptr;
 
     std::string playerName = player_node->getName();
     std::string tempNick = nick;
@@ -1026,7 +1026,7 @@ ChatTab *ChatWindow::addWhisperTab(const std::string &nick, bool switchTo)
     ChatTab *ret;
 
     if (tempNick.compare(playerName) == 0)
-        return NULL;
+        return nullptr;
 
     if (i != mWhispers.end())
     {
@@ -1051,7 +1051,7 @@ ChatTab *ChatWindow::addWhisperTab(const std::string &nick, bool switchTo)
 ChatTab *ChatWindow::getWhisperTab(const std::string &nick) const
 {
     if (!player_node)
-        return NULL;
+        return nullptr;
 
     std::string playerName = player_node->getName();
     std::string tempNick = nick;
@@ -1060,10 +1060,10 @@ ChatTab *ChatWindow::getWhisperTab(const std::string &nick) const
     toLower(tempNick);
 
     TabMap::const_iterator i = mWhispers.find(tempNick);
-    ChatTab *ret = 0;
+    ChatTab *ret = nullptr;
 
     if (tempNick.compare(playerName) == 0)
-        return NULL;
+        return nullptr;
 
     if (i != mWhispers.end())
         ret = i->second;
@@ -1350,8 +1350,8 @@ void ChatWindow::initTradeFilter()
 void ChatWindow::updateOnline(std::set<std::string> &onlinePlayers)
 {
     TabMap::const_iterator iter;
-    const Party *party = 0;
-    const Guild *guild = 0;
+    const Party *party = nullptr;
+    const Guild *guild = nullptr;
     if (player_node)
     {
         party = player_node->getParty();
diff --git a/src/gui/confirmdialog.cpp b/src/gui/confirmdialog.cpp
index f7f81bd2f..298855563 100644
--- a/src/gui/confirmdialog.cpp
+++ b/src/gui/confirmdialog.cpp
@@ -46,7 +46,7 @@ ConfirmDialog::ConfirmDialog(const std::string &title, const std::string &msg,
 
     gcn::Button *yesButton = new Button(_("Yes"), "yes", this);
     gcn::Button *noButton = new Button(_("No"), "no", this);
-    gcn::Button *ignoreButton = NULL;
+    gcn::Button *ignoreButton = nullptr;
 
     if (ignore)
         ignoreButton = new Button(_("Ignore"), "ignore", this);
diff --git a/src/gui/confirmdialog.h b/src/gui/confirmdialog.h
index 214aaba60..2b5febed0 100644
--- a/src/gui/confirmdialog.h
+++ b/src/gui/confirmdialog.h
@@ -23,6 +23,8 @@
 #ifndef OPTION_DIALOG_H
 #define OPTION_DIALOG_H
 
+#include "localconsts.h"
+
 #include "gui/widgets/window.h"
 
 #include <guichan/actionlistener.hpp>
@@ -44,7 +46,7 @@ class ConfirmDialog : public Window, public gcn::ActionListener
          */
         ConfirmDialog(const std::string &title, const std::string &msg,
                       bool ignore = false, bool modal = false,
-                      Window *parent = NULL);
+                      Window *parent = nullptr);
 
         /**
          * Called when receiving actions from the widgets.
diff --git a/src/gui/debugwindow.cpp b/src/gui/debugwindow.cpp
index 83e9791ef..56a63c72d 100644
--- a/src/gui/debugwindow.cpp
+++ b/src/gui/debugwindow.cpp
@@ -51,7 +51,7 @@
 #include "debug.h"
 
 DebugWindow::DebugWindow():
-    Window(_("Debug"), false, 0, "debug.xml")
+    Window(_("Debug"), false, nullptr, "debug.xml")
 {
     setWindowName("Debug");
     if (setupWindow)
@@ -85,11 +85,11 @@ DebugWindow::DebugWindow():
 DebugWindow::~DebugWindow()
 {
     delete mMapWidget;
-    mMapWidget = 0;
+    mMapWidget = nullptr;
     delete mTargetWidget;
-    mTargetWidget = 0;
+    mTargetWidget = nullptr;
     delete mNetWidget;
-    mNetWidget = 0;
+    mNetWidget = nullptr;
 }
 
 void DebugWindow::logic()
@@ -139,7 +139,7 @@ void DebugWindow::widgetResized(const gcn::Event &event)
 }
 
 MapDebugTab::MapDebugTab() :
-    mTexturesLabel(0)
+    mTexturesLabel(nullptr)
 {
     LayoutHelper h(this);
     ContainerPlacer place = h.getPlacer(0, 0);
diff --git a/src/gui/didyouknowwindow.cpp b/src/gui/didyouknowwindow.cpp
index df15e6ebd..9a913a305 100644
--- a/src/gui/didyouknowwindow.cpp
+++ b/src/gui/didyouknowwindow.cpp
@@ -44,7 +44,7 @@ static const int minTip = 1;
 static const int maxTip = 14;
 
 DidYouKnowWindow::DidYouKnowWindow():
-    Window(_("Did You Know?"), false, 0, "didyouknow.xml")
+    Window(_("Did You Know?"), false, nullptr, "didyouknow.xml")
 {
     setMinWidth(300);
     setMinHeight(250);
diff --git a/src/gui/editdialog.h b/src/gui/editdialog.h
index dc0d1cc63..69f86edca 100644
--- a/src/gui/editdialog.h
+++ b/src/gui/editdialog.h
@@ -24,6 +24,8 @@
 #ifndef EDIT_DIALOG_H
 #define EDIT_DIALOG_H
 
+#include "localconsts.h"
+
 #include "gui/widgets/window.h"
 #include "gui/widgets/textfield.h"
 
@@ -48,7 +50,7 @@ class EditDialog : public Window, public gcn::ActionListener
          */
         EditDialog(const std::string &title, const std::string &msg,
                    std::string eventOk = ACTION_EDIT_OK, int width = 300,
-                   Window *parent = NULL, bool modal = true);
+                   Window *parent = nullptr, bool modal = true);
 
         /**
          * Called when receiving actions from the widgets.
diff --git a/src/gui/emotepopup.cpp b/src/gui/emotepopup.cpp
index 6d2bf7be2..a8c92ed47 100644
--- a/src/gui/emotepopup.cpp
+++ b/src/gui/emotepopup.cpp
@@ -80,7 +80,7 @@ EmotePopup::~EmotePopup()
     if (mSelectionImage)
     {
         mSelectionImage->decRef();
-        mSelectionImage = 0;
+        mSelectionImage = nullptr;
     }
 }
 
diff --git a/src/gui/equipmentwindow.cpp b/src/gui/equipmentwindow.cpp
index f423cddf0..d3d230922 100644
--- a/src/gui/equipmentwindow.cpp
+++ b/src/gui/equipmentwindow.cpp
@@ -58,7 +58,7 @@ static const int BOX_HEIGHT = 36;
 
 EquipmentWindow::EquipmentWindow(Equipment *equipment, Being *being,
                                  bool foring):
-    Window(_("Equipment"), false, 0, "equipment.xml"),
+    Window(_("Equipment"), false, nullptr, "equipment.xml"),
     mEquipment(equipment),
     mSelected(-1),
     mForing(foring)
@@ -86,7 +86,7 @@ EquipmentWindow::EquipmentWindow(Equipment *equipment, Being *being,
 
     mBoxes.reserve(13);
     for (int f = 0; f < 13; f ++)
-        mBoxes.push_back(0);
+        mBoxes.push_back(nullptr);
 
     fillBoxes();
 
@@ -109,13 +109,13 @@ EquipmentWindow::EquipmentWindow(Equipment *equipment, Being *being,
 EquipmentWindow::~EquipmentWindow()
 {
     delete mItemPopup;
-    mItemPopup = 0;
+    mItemPopup = nullptr;
     if (this == beingEquipmentWindow)
     {
         if (mEquipment)
             delete mEquipment->getBackend();
         delete mEquipment;
-        mEquipment = 0;
+        mEquipment = nullptr;
     }
     delete_all(mBoxes);
     mBoxes.clear();
@@ -198,7 +198,7 @@ void EquipmentWindow::action(const gcn::ActionEvent &event)
 Item *EquipmentWindow::getItem(int x, int y) const
 {
     if (!mEquipment)
-        return 0;
+        return nullptr;
 
     std::vector<std::pair<int, int>*>::const_iterator it;
     std::vector<std::pair<int, int>*>::const_iterator it_end = mBoxes.end();
@@ -215,7 +215,7 @@ Item *EquipmentWindow::getItem(int x, int y) const
         if (tRect.isPointInRect(x, y))
             return mEquipment->getEquipment(i);
     }
-    return NULL;
+    return nullptr;
 }
 
 void EquipmentWindow::mousePressed(gcn::MouseEvent& mouseEvent)
@@ -322,7 +322,7 @@ void EquipmentWindow::setBeing(Being *being)
     delete mEquipment;
     if (!being)
     {
-        mEquipment = 0;
+        mEquipment = nullptr;
         return;
     }
     mEquipment = being->getEquipment();
@@ -337,7 +337,7 @@ void EquipmentWindow::updateBeing(Being *being)
 void EquipmentWindow::resetBeing(Being *being)
 {
     if (being == mBeing)
-        setBeing(0);
+        setBeing(nullptr);
 }
 
 void EquipmentWindow::fillBoxes()
diff --git a/src/gui/focushandler.cpp b/src/gui/focushandler.cpp
index ec854cf87..40fa2f4ed 100644
--- a/src/gui/focushandler.cpp
+++ b/src/gui/focushandler.cpp
@@ -34,7 +34,7 @@ void FocusHandler::requestModalFocus(gcn::Widget *widget)
     if (mModalFocusedWidget && mModalFocusedWidget != widget)
     {
         mModalStack.push_front(mModalFocusedWidget);
-        mModalFocusedWidget = NULL;
+        mModalFocusedWidget = nullptr;
     }
 
     gcn::FocusHandler::requestModalFocus(widget);
diff --git a/src/gui/gui.cpp b/src/gui/gui.cpp
index 658d65769..b3154fb25 100644
--- a/src/gui/gui.cpp
+++ b/src/gui/gui.cpp
@@ -48,11 +48,11 @@
 #include "debug.h"
 
 // Guichan stuff
-Gui *gui = 0;
-SDLInput *guiInput = 0;
+Gui *gui = nullptr;
+SDLInput *guiInput = nullptr;
 
 // Bolded font
-gcn::Font *boldFont = 0;
+gcn::Font *boldFont = nullptr;
 
 class GuiConfigListener : public ConfigListener
 {
@@ -75,7 +75,7 @@ class GuiConfigListener : public ConfigListener
 
 Gui::Gui(Graphics *graphics):
     mCustomCursor(false),
-    mMouseCursors(NULL),
+    mMouseCursors(nullptr),
     mMouseCursorAlpha(1.0f),
     mMouseInactivityTimer(0),
     mCursorType(CURSOR_POINTER)
@@ -205,28 +205,28 @@ Gui::~Gui()
 {
     config.removeListener("customcursor", mConfigListener);
     delete mConfigListener;
-    mConfigListener = 0;
+    mConfigListener = nullptr;
 
     if (mMouseCursors)
     {
         mMouseCursors->decRef();
-        mMouseCursors = 0;
+        mMouseCursors = nullptr;
     }
 
     delete mGuiFont;
-    mGuiFont = 0;
+    mGuiFont = nullptr;
     delete boldFont;
-    boldFont = 0;
+    boldFont = nullptr;
     delete mHelpFont;
-    mHelpFont = 0;
+    mHelpFont = nullptr;
     delete mSecureFont;
-    mSecureFont = 0;
+    mSecureFont = nullptr;
     delete mInfoParticleFont;
-    mInfoParticleFont = 0;
+    mInfoParticleFont = nullptr;
     delete getTop();
 
     delete guiInput;
-    guiInput = 0;
+    guiInput = nullptr;
 
     Theme::deleteInstance();
 }
@@ -306,7 +306,7 @@ void Gui::setUseCustomCursor(bool customCursor)
             if (mMouseCursors)
             {
                 mMouseCursors->decRef();
-                mMouseCursors = NULL;
+                mMouseCursors = nullptr;
             }
         }
     }
@@ -357,13 +357,13 @@ void Gui::distributeMouseEvent(gcn::Widget* source, int type, int button,
     gcn::Widget* parent = source;
     gcn::Widget* widget = source;
 
-    if (!force && mFocusHandler->getModalFocused() != NULL
+    if (!force && mFocusHandler->getModalFocused() != nullptr
         && !widget->isModalFocused())
     {
         return;
     }
 
-    if (!force && mFocusHandler->getModalMouseInputFocused() != NULL
+    if (!force && mFocusHandler->getModalMouseInputFocused() != nullptr
         && !widget->isModalMouseInputFocused())
     {
         return;
@@ -373,7 +373,7 @@ void Gui::distributeMouseEvent(gcn::Widget* source, int type, int button,
         mAltPressed, mMetaPressed, type, button,
         x, y, mClickCount);
 
-    while (parent != NULL)
+    while (parent)
     {
         // If the widget has been removed due to input
         // cancel the distribution.
@@ -443,7 +443,7 @@ void Gui::distributeMouseEvent(gcn::Widget* source, int type, int button,
 
         // If a non modal focused widget has been reach
         // and we have modal focus cancel the distribution.
-        if (mFocusHandler->getModalFocused() != NULL
+        if (mFocusHandler->getModalFocused()
             && !widget->isModalFocused())
         {
             break;
@@ -451,7 +451,7 @@ void Gui::distributeMouseEvent(gcn::Widget* source, int type, int button,
 
         // If a non modal mouse input focused widget has been reach
         // and we have modal mouse input focus cancel the distribution.
-        if (mFocusHandler->getModalMouseInputFocused() != NULL
+        if (mFocusHandler->getModalMouseInputFocused()
             && !widget->isModalMouseInputFocused())
         {
             break;
diff --git a/src/gui/helpwindow.cpp b/src/gui/helpwindow.cpp
index 019baf503..49f309bca 100644
--- a/src/gui/helpwindow.cpp
+++ b/src/gui/helpwindow.cpp
@@ -40,7 +40,7 @@
 #include "debug.h"
 
 HelpWindow::HelpWindow():
-    Window(_("Help"), false, 0, "help.xml")
+    Window(_("Help"), false, nullptr, "help.xml")
 {
     setMinWidth(300);
     setMinHeight(250);
diff --git a/src/gui/inventorywindow.cpp b/src/gui/inventorywindow.cpp
index f52151698..8ffebebff 100644
--- a/src/gui/inventorywindow.cpp
+++ b/src/gui/inventorywindow.cpp
@@ -96,7 +96,7 @@ public:
 InventoryWindow::WindowList InventoryWindow::instances;
 
 InventoryWindow::InventoryWindow(Inventory *inventory):
-    Window("Inventory", false, 0, "inventory.xml"),
+    Window("Inventory", false, nullptr, "inventory.xml"),
     mInventory(inventory),
     mDropButton(0),
     mSplit(false),
@@ -238,7 +238,7 @@ InventoryWindow::InventoryWindow(Inventory *inventory):
     loadWindowState();
     slotsChanged(mInventory);
 
-    widgetResized(0);
+    widgetResized(nullptr);
     if (!isMainInventory())
         setVisible(true);
 }
@@ -250,7 +250,7 @@ InventoryWindow::~InventoryWindow()
     if (!instances.empty())
         instances.front()->updateDropButton();
     delete mSortModel;
-    mSortModel = 0;
+    mSortModel = nullptr;
 }
 
 void InventoryWindow::action(const gcn::ActionEvent &event)
@@ -644,7 +644,7 @@ void InventoryWindow::updateDropButton()
     }
     else
     {
-        Item *item = 0;
+        Item *item = nullptr;
         if (mItems)
             item = mItems->getSelectedItem();
 
diff --git a/src/gui/itemamountwindow.cpp b/src/gui/itemamountwindow.cpp
index 7c5b19415..a80434ac0 100644
--- a/src/gui/itemamountwindow.cpp
+++ b/src/gui/itemamountwindow.cpp
@@ -138,13 +138,13 @@ void ItemAmountWindow::finish(Item *item, int amount, int price, Usage usage)
 ItemAmountWindow::ItemAmountWindow(Usage usage, Window *parent, Item *item,
                                    int maxRange):
     Window("", true, parent, "amount.xml"),
-    mItemPriceTextField(0),
-    mGPLabel(0),
+    mItemPriceTextField(nullptr),
+    mGPLabel(nullptr),
     mItem(item),
     mMax(maxRange),
     mUsage(usage),
-    mItemPriceSlide(0),
-    mItemsModal(0),
+    mItemPriceSlide(nullptr),
+    mItemsModal(nullptr),
     mPrice(0)
 {
     if (!mItem)
@@ -293,7 +293,7 @@ ItemAmountWindow::ItemAmountWindow(Usage usage, Window *parent, Item *item,
 ItemAmountWindow::~ItemAmountWindow()
 {
     delete mItemPopup;
-    mItemPopup = 0;
+    mItemPopup = nullptr;
 }
 
 // Show ItemTooltip
diff --git a/src/gui/itempopup.cpp b/src/gui/itempopup.cpp
index b05d7fe28..2e87cd544 100644
--- a/src/gui/itempopup.cpp
+++ b/src/gui/itempopup.cpp
@@ -50,7 +50,7 @@
 
 ItemPopup::ItemPopup():
     Popup("ItemPopup", "itempopup.xml"),
-    mIcon(0),
+    mIcon(nullptr),
     mLastName(""),
     mLastColor(1)
 {
@@ -76,7 +76,7 @@ ItemPopup::ItemPopup():
     mItemWeight->setEditable(false);
     mItemWeight->setPosition(getPadding(), 3 * fontHeight + 4 * getPadding());
 
-    mIcon = new Icon(0);
+    mIcon = new Icon(nullptr);
 
     add(mItemName);
     add(mItemDesc);
@@ -95,7 +95,7 @@ ItemPopup::~ItemPopup()
         if (image)
         {
             image->decRef();
-            image = 0;
+            image = nullptr;
         }
     }
 }
@@ -164,7 +164,7 @@ void ItemPopup::setItem(const ItemInfo &item, unsigned char color,
     }
     else
     {
-        mIcon->setImage(0);
+        mIcon->setImage(nullptr);
     }
 
     mItemType = item.getType();
diff --git a/src/gui/killstats.cpp b/src/gui/killstats.cpp
index 4bcab0a09..fa6241ef6 100644
--- a/src/gui/killstats.cpp
+++ b/src/gui/killstats.cpp
@@ -43,7 +43,7 @@
 #include "debug.h"
 
 KillStats::KillStats():
-    Window(_("Kill stats"), false, 0, "killstats.xml"),
+    Window(_("Kill stats"), false, nullptr, "killstats.xml"),
     mKillCounter(0), mExpCounter(0),
     mKillTCounter(0), mExpTCounter(0), mKillTimer(0),
     m1minExpTime(0), m1minExpNum(0), m1minSpeed(0),
diff --git a/src/gui/logindialog.cpp b/src/gui/logindialog.cpp
index 136a01b37..86b3dc28b 100644
--- a/src/gui/logindialog.cpp
+++ b/src/gui/logindialog.cpp
@@ -83,7 +83,7 @@ public:
 
 LoginDialog::LoginDialog(LoginData *data, std::string serverName,
                          std::string *updateHost):
-    Window(_("Login"), false, 0, "login.xml"),
+    Window(_("Login"), false, nullptr, "login.xml"),
     mLoginData(data),
     mUpdateHost(updateHost),
     mServerName(serverName)
@@ -166,7 +166,7 @@ LoginDialog::LoginDialog(LoginData *data, std::string serverName,
 LoginDialog::~LoginDialog()
 {
     delete mUpdateTypeModel;
-    mUpdateTypeModel = 0;
+    mUpdateTypeModel = nullptr;
 }
 
 void LoginDialog::action(const gcn::ActionEvent &event)
@@ -226,9 +226,9 @@ void LoginDialog::keyPressed(gcn::KeyEvent &keyEvent)
     gcn::Key key = keyEvent.getKey();
 
     if (key.getValue() == Key::ESCAPE)
-        action(gcn::ActionEvent(NULL, mServerButton->getActionEventId()));
+        action(gcn::ActionEvent(nullptr, mServerButton->getActionEventId()));
     else if (key.getValue() == Key::ENTER)
-        action(gcn::ActionEvent(NULL, mLoginButton->getActionEventId()));
+        action(gcn::ActionEvent(nullptr, mLoginButton->getActionEventId()));
     else
         mLoginButton->setEnabled(canSubmit());
 }
diff --git a/src/gui/minimap.cpp b/src/gui/minimap.cpp
index e42f12336..d890a462f 100644
--- a/src/gui/minimap.cpp
+++ b/src/gui/minimap.cpp
@@ -47,8 +47,8 @@
 bool Minimap::mShow = true;
 
 Minimap::Minimap():
-    Window(_("Map"), false, 0, "map.xml"),
-    mMapImage(0),
+    Window(_("Map"), false, nullptr, "map.xml"),
+    mMapImage(nullptr),
     mWidthProportion(0.5),
     mHeightProportion(0.5),
     mCustomMapImage(false),
@@ -83,7 +83,7 @@ Minimap::~Minimap()
             delete mMapImage;
         else
             mMapImage->decRef();
-        mMapImage = 0;
+        mMapImage = nullptr;
     }
 }
 
@@ -107,7 +107,7 @@ void Minimap::setMap(Map *map)
             delete mMapImage;
         else
             mMapImage->decRef();
-        mMapImage = 0;
+        mMapImage = nullptr;
     }
 
     if (map)
diff --git a/src/gui/ministatuswindow.cpp b/src/gui/ministatuswindow.cpp
index d307dfed0..665d2b61b 100644
--- a/src/gui/ministatuswindow.cpp
+++ b/src/gui/ministatuswindow.cpp
@@ -67,7 +67,7 @@ MiniStatusWindow::MiniStatusWindow():
     }
     else
     {
-        mMpBar = 0;
+        mMpBar = nullptr;
     }
 
     int job = Net::getPlayerHandler()->getJobLocation()
@@ -85,7 +85,7 @@ MiniStatusWindow::MiniStatusWindow():
     }
     else
     {
-        mJobBar = 0;
+        mJobBar = nullptr;
     }
 
     mWeightBar = createBar(0, 140, 20, Theme::PROG_WEIGHT,
@@ -124,9 +124,9 @@ MiniStatusWindow::MiniStatusWindow():
 MiniStatusWindow::~MiniStatusWindow()
 {
     delete mTextPopup;
-    mTextPopup = 0;
+    mTextPopup = nullptr;
     delete mStatusPopup;
-    mStatusPopup = 0;
+    mStatusPopup = nullptr;
     delete_all(mIcons);
     mIcons.clear();
 
@@ -161,7 +161,7 @@ void MiniStatusWindow::updateBars()
 {
     int x = 0;
     std::vector <ProgressBar*>::const_iterator it, it_end;
-    ProgressBar* lastBar = 0;
+    ProgressBar* lastBar = nullptr;
     for (it = mBars.begin(), it_end = mBars.end(); it != it_end; ++it)
         safeRemove(*it);
     for (it = mBars.begin(), it_end = mBars.end(); it != it_end; ++it)
diff --git a/src/gui/npcdialog.cpp b/src/gui/npcdialog.cpp
index b926d260e..66a30c8a7 100644
--- a/src/gui/npcdialog.cpp
+++ b/src/gui/npcdialog.cpp
@@ -55,14 +55,14 @@
 
 NpcDialog::DialogList NpcDialog::instances;
 
-NpcDialog::NpcDialog(int npcId)
-    : Window(_("NPC"), false, 0, "npc.xml"),
-      mNpcId(npcId),
-      mLogInteraction(config.getBoolValue("logNpcInGui")),
-      mDefaultInt(0),
-      mInputState(NPC_INPUT_NONE),
-      mActionState(NPC_ACTION_WAIT),
-      mLastNextTime(0)
+NpcDialog::NpcDialog(int npcId) :
+    Window(_("NPC"), false, nullptr, "npc.xml"),
+    mNpcId(npcId),
+    mLogInteraction(config.getBoolValue("logNpcInGui")),
+    mDefaultInt(0),
+    mInputState(NPC_INPUT_NONE),
+    mActionState(NPC_ACTION_WAIT),
+    mLastNextTime(0)
 {
     // Basic Window Setup
     setWindowName("NpcText");
@@ -143,32 +143,32 @@ NpcDialog::~NpcDialog()
     clearLayout();
 
     delete mTextBox;
-    mTextBox = 0;
+    mTextBox = nullptr;
     delete mClearButton;
-    mClearButton = 0;
+    mClearButton = nullptr;
     delete mButton;
-    mButton = 0;
+    mButton = nullptr;
 
     // These might not actually be in the layout, so lets be safe
     delete mScrollArea;
-    mScrollArea = 0;
+    mScrollArea = nullptr;
     delete mItemList;
-    mItemList = 0;
+    mItemList = nullptr;
     delete mTextField;
-    mTextField = 0;
+    mTextField = nullptr;
     delete mIntField;
-    mIntField = 0;
+    mIntField = nullptr;
     delete mResetButton;
-    mResetButton = 0;
+    mResetButton = nullptr;
     delete mPlusButton;
-    mPlusButton = 0;
+    mPlusButton = nullptr;
     delete mMinusButton;
-    mMinusButton = 0;
+    mMinusButton = nullptr;
     delete mItemLinkHandler;
-    mItemLinkHandler = 0;
+    mItemLinkHandler = nullptr;
 
     delete mListScrollArea;
-    mListScrollArea = 0;
+    mListScrollArea = nullptr;
 
     instances.remove(this);
 }
@@ -432,7 +432,7 @@ NpcDialog *NpcDialog::getActive()
             return (*it);
     }
 
-    return 0;
+    return nullptr;
 }
 
 void NpcDialog::closeAll()
diff --git a/src/gui/npcpostdialog.cpp b/src/gui/npcpostdialog.cpp
index 67fc57ba9..ada48e832 100644
--- a/src/gui/npcpostdialog.cpp
+++ b/src/gui/npcpostdialog.cpp
@@ -39,7 +39,7 @@
 NpcPostDialog::DialogList NpcPostDialog::instances;
 
 NpcPostDialog::NpcPostDialog(int npcId):
-    Window(_("NPC"), false, 0, "npcpost.xml"),
+    Window(_("NPC"), false, nullptr, "npcpost.xml"),
     mNpcId(npcId)
 {
     setContentSize(400, 180);
diff --git a/src/gui/okdialog.h b/src/gui/okdialog.h
index 2ee8653ec..2f32d0d65 100644
--- a/src/gui/okdialog.h
+++ b/src/gui/okdialog.h
@@ -23,6 +23,8 @@
 #ifndef OK_DIALOG_H
 #define OK_DIALOG_H
 
+#include "localconsts.h"
+
 #include "gui/widgets/window.h"
 
 #include <guichan/actionlistener.hpp>
@@ -44,7 +46,7 @@ class OkDialog : public Window, public gcn::ActionListener
          */
         OkDialog(const std::string &title, const std::string &msg,
                  bool modal = true, bool showCenter = true,
-                 Window *parent = NULL);
+                 Window *parent = nullptr);
 
         /**
          * Called when receiving actions from the widgets.
diff --git a/src/gui/outfitwindow.cpp b/src/gui/outfitwindow.cpp
index 8e0791af1..c33c753bc 100644
--- a/src/gui/outfitwindow.cpp
+++ b/src/gui/outfitwindow.cpp
@@ -57,13 +57,13 @@
 float OutfitWindow::mAlpha = 1.0;
 
 OutfitWindow::OutfitWindow():
-    Window(_("Outfits"), false, 0, "outfits.xml"),
+    Window(_("Outfits"), false, nullptr, "outfits.xml"),
     mBoxWidth(33),
     mBoxHeight(33),
     mGridWidth(4),
     mGridHeight(3),
     mItemClicked(false),
-    mItemMoved(NULL),
+    mItemMoved(nullptr),
     mItemSelected(-1),
     mItemColorSelected(1),
     mCurrentOutfit(0),
@@ -383,7 +383,7 @@ void OutfitWindow::mouseDragged(gcn::MouseEvent &event)
                 if (item)
                     mItemMoved = item;
                 else
-                    mItemMoved = 0;
+                    mItemMoved = nullptr;
                 mItems[mCurrentOutfit][index] = -1;
             }
         }
@@ -433,7 +433,7 @@ void OutfitWindow::mouseReleased(gcn::MouseEvent &event)
         const int index = getIndexFromGrid(event.getX(), event.getY());
         if (index == -1)
         {
-            mItemMoved = NULL;
+            mItemMoved = nullptr;
             Window::mouseReleased(event);
             return;
         }
@@ -443,7 +443,7 @@ void OutfitWindow::mouseReleased(gcn::MouseEvent &event)
         {
             mItems[mCurrentOutfit][index] = mItemMoved->getId();
             mItemColors[mCurrentOutfit][index] = mItemMoved->getColor();
-            mItemMoved = NULL;
+            mItemMoved = nullptr;
         }
         if (mItemClicked)
             mItemClicked = false;
diff --git a/src/gui/popupmenu.cpp b/src/gui/popupmenu.cpp
index a457573ce..b133f66fc 100644
--- a/src/gui/popupmenu.cpp
+++ b/src/gui/popupmenu.cpp
@@ -85,15 +85,15 @@ std::string tradePartnerName("");
 PopupMenu::PopupMenu():
     Popup("PopupMenu", "popupmenu.xml"),
     mBeingId(0),
-    mFloorItem(0),
-    mItem(0),
+    mFloorItem(nullptr),
+    mItem(nullptr),
     mItemId(0),
     mItemColor(1),
-    mMapItem(0),
-    mTab(0),
-    mSpell(0),
-    mDialog(0),
-    mButton(0),
+    mMapItem(nullptr),
+    mTab(nullptr),
+    mSpell(nullptr),
+    mDialog(nullptr),
+    mButton(nullptr),
     mNick(""),
     mType(Being::UNKNOWN)
 {
@@ -102,10 +102,10 @@ PopupMenu::PopupMenu():
     mBrowserBox->setHighlightMode(BrowserBox::BACKGROUND);
     mBrowserBox->setOpaque(false);
     mBrowserBox->setLinkHandler(this);
-    mRenameListener.setMapItem(0);
-    mRenameListener.setDialog(0);
+    mRenameListener.setMapItem(nullptr);
+    mRenameListener.setDialog(nullptr);
     mPlayerListener.setNick("");
-    mPlayerListener.setDialog(0);
+    mPlayerListener.setDialog(nullptr);
     mPlayerListener.setType(Being::UNKNOWN);
 
     add(mBrowserBox);
@@ -833,9 +833,9 @@ void PopupMenu::showChangePos(int x, int y)
     else
     {
         mBeingId = 0;
-        mFloorItem = 0;
-        mItem = 0;
-        mMapItem = 0;
+        mFloorItem = nullptr;
+        mItem = nullptr;
+        mMapItem = nullptr;
         mNick = "";
         mType = Being::UNKNOWN;
         setVisible(false);
@@ -1683,11 +1683,11 @@ void PopupMenu::handleLink(const std::string &link,
     setVisible(false);
 
     mBeingId = 0;
-    mFloorItem = 0;
-    mItem = 0;
+    mFloorItem = nullptr;
+    mItem = nullptr;
     mItemId = 0;
     mItemColor = 1;
-    mMapItem = 0;
+    mMapItem = nullptr;
     mNick = "";
     mType = Being::UNKNOWN;
 }
@@ -1790,7 +1790,7 @@ void PopupMenu::showItemPopup(int x, int y, int itemId, unsigned char color)
     }
     else
     {
-        mItem = 0;
+        mItem = nullptr;
         mItemId = itemId;
         mItemColor = color;
         mBrowserBox->clearRows();
@@ -2066,8 +2066,8 @@ void PopupMenu::showPopup(int x, int y)
 }
 
 RenameListener::RenameListener() :
-    mMapItem(0),
-    mDialog(0)
+    mMapItem(nullptr),
+    mDialog(nullptr)
 {
 }
 
@@ -2080,7 +2080,7 @@ void RenameListener::action(const gcn::ActionEvent &event)
             return;
 
         SpecialLayer *sl = map->getSpecialLayer();
-        MapItem *item = 0;
+        MapItem *item = nullptr;
         if (sl)
         {
             item = sl->getTile(mMapItem->getX(), mMapItem->getY());
@@ -2099,12 +2099,12 @@ void RenameListener::action(const gcn::ActionEvent &event)
         if (socialWindow)
             socialWindow->updatePortalNames();
     }
-    mDialog = 0;
+    mDialog = nullptr;
 }
 
 PlayerListener::PlayerListener() :
     mNick(""),
-    mDialog(0),
+    mDialog(nullptr),
     mType(Being::UNKNOWN)
 {
 }
@@ -2120,5 +2120,5 @@ void PlayerListener::action(const gcn::ActionEvent &event)
             being->setComment(comment);
         Being::saveComment(mNick, comment, mType);
     }
-    mDialog = 0;
+    mDialog = nullptr;
 }
diff --git a/src/gui/quitdialog.cpp b/src/gui/quitdialog.cpp
index 1307e198f..0f4d7f6f7 100644
--- a/src/gui/quitdialog.cpp
+++ b/src/gui/quitdialog.cpp
@@ -44,7 +44,7 @@
 #include "debug.h"
 
 QuitDialog::QuitDialog(QuitDialog** pointerToMe):
-    Window(_("Quit"), true, 0, "quit.xml"),
+    Window(_("Quit"), true, nullptr, "quit.xml"),
     mMyPointer(pointerToMe)
 {
     mForceQuit = new RadioButton(_("Quit"), "quitdialog");
@@ -98,16 +98,16 @@ QuitDialog::QuitDialog(QuitDialog** pointerToMe):
 QuitDialog::~QuitDialog()
 {
     if (mMyPointer)
-        *mMyPointer = 0;
+        *mMyPointer = nullptr;
     // Optional widgets, so delete them by hand.
     delete mForceQuit;
-    mForceQuit = 0;
+    mForceQuit = nullptr;
     delete mLogoutQuit;
-    mLogoutQuit = 0;
+    mLogoutQuit = nullptr;
     delete mSwitchAccountServer;
-    mSwitchAccountServer = 0;
+    mSwitchAccountServer = nullptr;
     delete mSwitchCharacter;
-    mSwitchCharacter = 0;
+    mSwitchCharacter = nullptr;
 }
 
 void QuitDialog::placeOption(ContainerPlacer &placer, gcn::RadioButton *option)
@@ -162,10 +162,10 @@ void QuitDialog::keyPressed(gcn::KeyEvent &keyEvent)
     switch (key.getValue())
     {
         case Key::ENTER:
-            action(gcn::ActionEvent(NULL, mOkButton->getActionEventId()));
+            action(gcn::ActionEvent(nullptr, mOkButton->getActionEventId()));
             break;
         case Key::ESCAPE:
-            action(gcn::ActionEvent(NULL, mCancelButton->getActionEventId()));
+            action(gcn::ActionEvent(nullptr, mCancelButton->getActionEventId()));
             break;
         case Key::UP:
             dir = -1;
diff --git a/src/gui/register.cpp b/src/gui/register.cpp
index 062275b80..29030aa72 100644
--- a/src/gui/register.cpp
+++ b/src/gui/register.cpp
@@ -47,7 +47,7 @@
 #include "debug.h"
 
 WrongDataNoticeListener::WrongDataNoticeListener():
-    mTarget(0)
+    mTarget(nullptr)
 {
 }
 
@@ -63,10 +63,10 @@ void WrongDataNoticeListener::action(const gcn::ActionEvent &event)
 }
 
 RegisterDialog::RegisterDialog(LoginData *data):
-    Window(_("Register"), false, 0, "register.xml"),
-    mEmailField(0),
-    mMaleButton(0),
-    mFemaleButton(0),
+    Window(_("Register"), false, nullptr, "register.xml"),
+    mEmailField(nullptr),
+    mMaleButton(nullptr),
+    mFemaleButton(nullptr),
     mWrongDataNoticeListener(new WrongDataNoticeListener),
     mLoginData(data)
 {
@@ -147,7 +147,7 @@ RegisterDialog::RegisterDialog(LoginData *data):
 RegisterDialog::~RegisterDialog()
 {
     delete mWrongDataNoticeListener;
-    mWrongDataNoticeListener = 0;
+    mWrongDataNoticeListener = nullptr;
 }
 
 void RegisterDialog::action(const gcn::ActionEvent &event)
diff --git a/src/gui/sdlfont.cpp b/src/gui/sdlfont.cpp
index b196ae4e4..001a8671a 100644
--- a/src/gui/sdlfont.cpp
+++ b/src/gui/sdlfont.cpp
@@ -49,14 +49,14 @@ class SDLTextChunk
 {
     public:
         SDLTextChunk(const std::string &text0, const gcn::Color &color0) :
-            img(0), text(text0), color(color0)
+            img(nullptr), text(text0), color(color0)
         {
         }
 
         ~SDLTextChunk()
         {
             delete img;
-            img = 0;
+            img = nullptr;
         }
 
         bool operator==(const SDLTextChunk &chunk) const
@@ -79,7 +79,7 @@ class SDLTextChunk
 
             if (!surface)
             {
-                img = 0;
+                img = nullptr;
                 return;
             }
 
@@ -138,7 +138,7 @@ SDLFont::SDLFont(const std::string &filename, int size, int style) :
 SDLFont::~SDLFont()
 {
     TTF_CloseFont(mFont);
-    mFont = 0;
+    mFont = nullptr;
     --fontCounter;
 
     if (fontCounter == 0)
diff --git a/src/gui/selldialog.cpp b/src/gui/selldialog.cpp
index bbd0a71c1..e1a77f6c9 100644
--- a/src/gui/selldialog.cpp
+++ b/src/gui/selldialog.cpp
@@ -50,14 +50,14 @@
 SellDialog::DialogList SellDialog::instances;
 
 SellDialog::SellDialog(int npcId):
-    Window(_("Sell"), false, 0, "sell.xml"),
+    Window(_("Sell"), false, nullptr, "sell.xml"),
     mNpcId(npcId), mMaxItems(0), mAmountItems(0), mNick("")
 {
     init();
 }
 
 SellDialog::SellDialog(std::string nick):
-    Window(_("Sell"), false, 0, "sell.xml"),
+    Window(_("Sell"), false, nullptr, "sell.xml"),
     mNpcId(-1), mMaxItems(0), mAmountItems(0), mNick(nick)
 {
     init();
@@ -133,7 +133,7 @@ void SellDialog::init()
 SellDialog::~SellDialog()
 {
     delete mShopItems;
-    mShopItems = 0;
+    mShopItems = nullptr;
 
     instances.remove(this);
 }
@@ -290,7 +290,7 @@ void SellDialog::updateButtonsAndLabels()
 {
     int selectedItem = mShopItemList->getSelected();
     int income = 0;
-    ShopItem *item = 0;
+    ShopItem *item = nullptr;
 
     if (selectedItem > -1 && mShopItems->at(selectedItem))
     {
diff --git a/src/gui/serverdialog.cpp b/src/gui/serverdialog.cpp
index 5a00d4a76..3fd298159 100644
--- a/src/gui/serverdialog.cpp
+++ b/src/gui/serverdialog.cpp
@@ -234,15 +234,15 @@ private:
 
 
 ServerDialog::ServerDialog(ServerInfo *serverInfo, const std::string &dir):
-    Window(_("Choose Your Server"), false, 0, "server.xml"),
+    Window(_("Choose Your Server"), false, nullptr, "server.xml"),
     mDir(dir),
 //    mDownloadStatus(DOWNLOADING_PREPARING),
     mDownloadStatus(DOWNLOADING_UNKNOWN),
-    mDownload(0),
+    mDownload(nullptr),
     mDownloadProgress(-1.0f),
     mServers(ServerInfos()),
     mServerInfo(serverInfo),
-    mPersistentIPCheckBox(0)
+    mPersistentIPCheckBox(nullptr)
 {
     if (isSafeMode)
         setCaption(_("Choose Your Server  *** SAFE MODE ***"));
@@ -377,12 +377,12 @@ ServerDialog::~ServerDialog()
     {
         mDownload->cancel();
         delete mDownload;
-        mDownload = 0;
+        mDownload = nullptr;
     }
     delete mServersListModel;
-    mServersListModel = 0;
+    mServersListModel = nullptr;
     delete mTypeListModel;
-    mTypeListModel = 0;
+    mTypeListModel = nullptr;
 }
 
 void ServerDialog::action(const gcn::ActionEvent &event)
@@ -489,7 +489,7 @@ void ServerDialog::keyPressed(gcn::KeyEvent &keyEvent)
     if (key.getValue() == Key::ESCAPE)
         Client::setState(STATE_EXIT);
     else if (key.getValue() == Key::ENTER)
-        action(gcn::ActionEvent(NULL, mConnectButton->getActionEventId()));
+        action(gcn::ActionEvent(nullptr, mConnectButton->getActionEventId()));
 }
 
 void ServerDialog::valueChanged(const gcn::SelectionEvent &)
@@ -617,7 +617,7 @@ void ServerDialog::downloadServerList()
     {
         mDownload->cancel();
         delete mDownload;
-        mDownload = 0;
+        mDownload = nullptr;
     }
 
     mDownload = new Net::Download(this, listFile, &downloadUpdate);
diff --git a/src/gui/setup.cpp b/src/gui/setup.cpp
index ae7a3109c..d305824d5 100644
--- a/src/gui/setup.cpp
+++ b/src/gui/setup.cpp
@@ -51,7 +51,7 @@
 extern Window *statusWindow;
 
 Setup::Setup():
-    Window(_("Setup"), false, 0, "setup.xml")
+    Window(_("Setup"), false, nullptr, "setup.xml")
 {
     setCloseButton(true);
     setResizable(true);
@@ -72,7 +72,7 @@ Setup::Setup():
         N_("Cancel"),
         N_("Store"),
         N_("Reset Windows"),
-        0
+        nullptr
     };
     int x = width;
     for (const char **curBtn = buttonNames; *curBtn; ++curBtn)
diff --git a/src/gui/setup_colors.cpp b/src/gui/setup_colors.cpp
index 7c0306f8f..6f1a4afce 100644
--- a/src/gui/setup_colors.cpp
+++ b/src/gui/setup_colors.cpp
@@ -65,7 +65,7 @@ Setup_Colors::Setup_Colors() :
     mPreview->setOpaque(false);
 
     // don't do anything with links
-    mPreview->setLinkHandler(NULL);
+    mPreview->setLinkHandler(nullptr);
 
     mPreviewBox = new ScrollArea(mPreview);
     mPreviewBox->setHeight(20);
@@ -188,12 +188,12 @@ Setup_Colors::~Setup_Colors()
     if (mPreviewBox && mPreviewBox->getContent() == mPreview)
     {
         delete mTextPreview;
-        mTextPreview = 0;
+        mTextPreview = nullptr;
     }
     else
     {
         delete mPreview;
-        mPreview = 0;
+        mPreview = nullptr;
     }
 }
 
@@ -251,7 +251,7 @@ void Setup_Colors::valueChanged(const gcn::SelectionEvent &event A_UNUSED)
     mPreviewBox->setContent(mTextPreview);
     mTextPreview->setFont(boldFont);
     mTextPreview->setTextColor(col);
-    mTextPreview->setTextBGColor(NULL);
+    mTextPreview->setTextBGColor(nullptr);
     mTextPreview->setOpaque(false);
     mTextPreview->setShadow(true);
     mTextPreview->setOutline(true);
diff --git a/src/gui/setup_keyboard.cpp b/src/gui/setup_keyboard.cpp
index 922d9797b..fa7a63b8c 100644
--- a/src/gui/setup_keyboard.cpp
+++ b/src/gui/setup_keyboard.cpp
@@ -112,16 +112,16 @@ Setup_Keyboard::Setup_Keyboard():
 Setup_Keyboard::~Setup_Keyboard()
 {
     delete mKeyList;
-    mKeyList = 0;
+    mKeyList = nullptr;
     delete mKeyListModel;
-    mKeyListModel = 0;
+    mKeyListModel = nullptr;
 
     delete mAssignKeyButton;
-    mAssignKeyButton = 0;
+    mAssignKeyButton = nullptr;
     delete mUnassignKeyButton;
-    mUnassignKeyButton = 0;
+    mUnassignKeyButton = nullptr;
     delete mMakeDefaultButton;
-    mMakeDefaultButton = 0;
+    mMakeDefaultButton = nullptr;
 }
 
 void Setup_Keyboard::apply()
diff --git a/src/gui/setup_relations.cpp b/src/gui/setup_relations.cpp
index 73fd34e27..1921ee267 100644
--- a/src/gui/setup_relations.cpp
+++ b/src/gui/setup_relations.cpp
@@ -98,7 +98,7 @@ class PlayerTableModel : public TableModel
 {
 public:
     PlayerTableModel() :
-        mPlayers(NULL),
+        mPlayers(nullptr),
         mListModel(new PlayerRelationListModel)
     {
         playerRelationsUpdated();
diff --git a/src/gui/setup_theme.cpp b/src/gui/setup_theme.cpp
index 04d4c5412..3b1c1d932 100644
--- a/src/gui/setup_theme.cpp
+++ b/src/gui/setup_theme.cpp
@@ -155,7 +155,7 @@ const Language LANG_NAME[langs_count] =
     {N_("Portuguese"), "pt_PT"},
     {N_("Portuguese (Brazilian)"), "pt_BR"},
     {N_("Russian"), "ru_RU"},
-    {N_("Spanish (Castilian)"), "es_ES"},
+    {N_("Spanish (Castilian)"), "es_ES"}
 };
 
 class LangListModel : public gcn::ListModel
@@ -302,16 +302,16 @@ Setup_Theme::Setup_Theme():
 Setup_Theme::~Setup_Theme()
 {
     delete mThemesModel;
-    mThemesModel = 0;
+    mThemesModel = nullptr;
 
     delete mFontsModel;
-    mFontsModel = 0;
+    mFontsModel = nullptr;
 
     delete mFontSizeListModel;
-    mFontSizeListModel = 0;
+    mFontSizeListModel = nullptr;
 
     delete mLangListModel;
-    mLangListModel = 0;
+    mLangListModel = nullptr;
 }
 
 void Setup_Theme::action(const gcn::ActionEvent &event)
diff --git a/src/gui/setup_video.cpp b/src/gui/setup_video.cpp
index d3c1163dc..ea181ea14 100644
--- a/src/gui/setup_video.cpp
+++ b/src/gui/setup_video.cpp
@@ -130,7 +130,7 @@ bool modeSorter(std::string mode1, std::string mode2)
 ModeListModel::ModeListModel()
 {
     /* Get available fullscreen/hardware modes */
-    SDL_Rect **modes = SDL_ListModes(NULL, SDL_FULLSCREEN | SDL_HWSURFACE);
+    SDL_Rect **modes = SDL_ListModes(nullptr, SDL_FULLSCREEN | SDL_HWSURFACE);
 
     /* Check which modes are available */
     if (modes == static_cast<SDL_Rect **>(0))
diff --git a/src/gui/shortcutwindow.cpp b/src/gui/shortcutwindow.cpp
index 6d48da197..eff28def7 100644
--- a/src/gui/shortcutwindow.cpp
+++ b/src/gui/shortcutwindow.cpp
@@ -54,7 +54,7 @@ ShortcutWindow::ShortcutWindow(const std::string &title,
                                ShortcutContainer *content,
                                std::string skinFile,
                                int width, int height) :
-    Window("Window", false, 0, skinFile)
+    Window("Window", false, nullptr, skinFile)
 {
     setWindowName(title);
     // no title presented, title bar is padding so window can be moved.
@@ -66,7 +66,7 @@ ShortcutWindow::ShortcutWindow(const std::string &title,
 
     setupWindow->registerWindowForReset(this);
 
-    mTabs = 0;
+    mTabs = nullptr;
     mItems = content;
 
     const int border = SCROLL_PADDING * 2 + getPadding() * 2;
@@ -100,7 +100,7 @@ ShortcutWindow::ShortcutWindow(const std::string &title,
 
 ShortcutWindow::ShortcutWindow(const std::string &title, std::string skinFile,
                                int width, int height) :
-    Window("Window", false, 0, skinFile)
+    Window("Window", false, nullptr, skinFile)
 {
     setWindowName(title);
     // no title presented, title bar is padding so window can be moved.
@@ -114,7 +114,7 @@ ShortcutWindow::ShortcutWindow(const std::string &title, std::string skinFile,
 
     mTabs = new TabbedArea;
 
-    mItems = 0;
+    mItems = nullptr;
 
     const int border = SCROLL_PADDING * 2 + getPadding() * 2;
 
@@ -138,9 +138,9 @@ ShortcutWindow::~ShortcutWindow()
     if (mTabs)
         mTabs->removeAll();
     delete mTabs;
-    mTabs = 0;
+    mTabs = nullptr;
     delete mItems;
-    mItems = 0;
+    mItems = nullptr;
 }
 
 void ShortcutWindow::addTab(std::string name, ShortcutContainer *content)
diff --git a/src/gui/socialwindow.cpp b/src/gui/socialwindow.cpp
index a728d4051..6b07e109f 100644
--- a/src/gui/socialwindow.cpp
+++ b/src/gui/socialwindow.cpp
@@ -79,14 +79,14 @@ protected:
         {
             mInviteDialog->close();
             mInviteDialog->scheduleDelete();
-            mInviteDialog = NULL;
+            mInviteDialog = nullptr;
         }
 
         if (mConfirmDialog)
         {
             mConfirmDialog->close();
             mConfirmDialog->scheduleDelete();
-            mConfirmDialog = NULL;
+            mConfirmDialog = nullptr;
         }
     }
 
@@ -347,11 +347,11 @@ public:
                 localChatTab->chatLog(strprintf(_("Invited user %s to party."),
                                       name.c_str()), BY_SERVER);
             }
-            mInviteDialog = NULL;
+            mInviteDialog = nullptr;
         }
         else if (event.getId() == "~do invite")
         {
-            mInviteDialog = NULL;
+            mInviteDialog = nullptr;
         }
         else if (event.getId() == "yes")
         {
@@ -361,11 +361,11 @@ public:
                 localChatTab->chatLog(strprintf(_("Party %s quit requested."),
                                       mParty->getName().c_str()), BY_SERVER);
             }
-            mConfirmDialog = NULL;
+            mConfirmDialog = nullptr;
         }
         else if (event.getId() == "~yes")
         {
-            mConfirmDialog = NULL;
+            mConfirmDialog = nullptr;
         }
     }
 
@@ -1146,7 +1146,7 @@ SocialWindow::SocialWindow() :
     place(2, 0, mLeaveButton);
     place(0, 1, mTabs, 4, 4);
 
-    widgetResized(NULL);
+    widgetResized(nullptr);
 
     mCreatePopup = new CreatePopup();
 
@@ -1184,7 +1184,7 @@ SocialWindow::~SocialWindow()
     {
         mGuildAcceptDialog->close();
         mGuildAcceptDialog->scheduleDelete();
-        mGuildAcceptDialog = NULL;
+        mGuildAcceptDialog = nullptr;
 
         mGuildInvited = 0;
     }
@@ -1193,7 +1193,7 @@ SocialWindow::~SocialWindow()
     {
         mPartyAcceptDialog->close();
         mPartyAcceptDialog->scheduleDelete();
-        mPartyAcceptDialog = NULL;
+        mPartyAcceptDialog = nullptr;
 
         mPartyInviter = "";
     }
@@ -1300,7 +1300,7 @@ void SocialWindow::action(const gcn::ActionEvent &event)
         }
 
         mPartyInviter = "";
-        mPartyAcceptDialog = NULL;
+        mPartyAcceptDialog = nullptr;
     }
     else if (event.getSource() == mGuildAcceptDialog)
     {
@@ -1333,7 +1333,7 @@ void SocialWindow::action(const gcn::ActionEvent &event)
         }
 
         mGuildInvited = 0;
-        mGuildAcceptDialog = NULL;
+        mGuildAcceptDialog = nullptr;
     }
     else if (event.getId() == "create")
     {
@@ -1374,11 +1374,11 @@ void SocialWindow::action(const gcn::ActionEvent &event)
                                   name.c_str()), BY_SERVER);
         }
 
-        mGuildCreateDialog = NULL;
+        mGuildCreateDialog = nullptr;
     }
     else if (event.getId() == "~create guild")
     {
-        mGuildCreateDialog = NULL;
+        mGuildCreateDialog = nullptr;
     }
     else if (event.getId() == "create party")
     {
@@ -1397,11 +1397,11 @@ void SocialWindow::action(const gcn::ActionEvent &event)
                                   name.c_str()), BY_SERVER);
         }
 
-        mPartyCreateDialog = NULL;
+        mPartyCreateDialog = nullptr;
     }
     else if (event.getId() == "~create party")
     {
-        mPartyCreateDialog = NULL;
+        mPartyCreateDialog = nullptr;
     }
 }
 
diff --git a/src/gui/specialswindow.cpp b/src/gui/specialswindow.cpp
index c464b83b5..a52b30c62 100644
--- a/src/gui/specialswindow.cpp
+++ b/src/gui/specialswindow.cpp
@@ -194,10 +194,10 @@ void SpecialsWindow::rebuild(const std::map<int, Special> &specialData)
 
 SpecialEntry::SpecialEntry(SpecialInfo *info) :
     mInfo(info),
-    mIcon(NULL),
-    mLevelLabel(NULL),
-    mUse(NULL),
-    mRechargeBar(NULL)
+    mIcon(nullptr),
+    mLevelLabel(nullptr),
+    mUse(nullptr),
+    mRechargeBar(nullptr)
 {
     setFrameSize(1);
     setOpaque(false);
diff --git a/src/gui/textcommandeditor.cpp b/src/gui/textcommandeditor.cpp
index 6512f8465..7d97549f3 100644
--- a/src/gui/textcommandeditor.cpp
+++ b/src/gui/textcommandeditor.cpp
@@ -165,7 +165,7 @@ public:
 
 
 TextCommandEditor::TextCommandEditor(TextCommand *command):
-    Window(_("Command Editor"), false, 0, "commandeditor.xml")
+    Window(_("Command Editor"), false, nullptr, "commandeditor.xml")
 {
     int w = 350;
     int h = 370;
@@ -302,11 +302,11 @@ TextCommandEditor::TextCommandEditor(TextCommand *command):
 TextCommandEditor::~TextCommandEditor()
 {
     delete mIconsModal;
-    mIconsModal = 0;
+    mIconsModal = nullptr;
     delete mTargetTypeModel;
-    mTargetTypeModel = 0;
+    mTargetTypeModel = nullptr;
     delete mMagicSchoolModel;
-    mMagicSchoolModel = 0;
+    mMagicSchoolModel = nullptr;
 }
 
 void TextCommandEditor::action(const gcn::ActionEvent &event)
diff --git a/src/gui/updaterwindow.cpp b/src/gui/updaterwindow.cpp
index 2efe82199..b605d30df 100644
--- a/src/gui/updaterwindow.cpp
+++ b/src/gui/updaterwindow.cpp
@@ -147,8 +147,8 @@ UpdaterWindow::UpdaterWindow(const std::string &updateHost,
     mDownloadComplete(true),
     mUserCancel(false),
     mDownloadedBytes(0),
-    mMemoryBuffer(NULL),
-    mDownload(NULL),
+    mMemoryBuffer(nullptr),
+    mDownload(nullptr),
     mUpdateIndex(0),
     mUpdateIndexOffset(0),
     mLoadUpdates(applyUpdates),
@@ -256,7 +256,7 @@ void UpdaterWindow::keyPressed(gcn::KeyEvent &keyEvent)
 
     if (key.getValue() == Key::ESCAPE)
     {
-        action(gcn::ActionEvent(NULL, mCancelButton->getActionEventId()));
+        action(gcn::ActionEvent(nullptr, mCancelButton->getActionEventId()));
         Client::setState(STATE_WORLD_SELECT);
     }
     else if (key.getValue() == Key::ENTER)
@@ -264,11 +264,11 @@ void UpdaterWindow::keyPressed(gcn::KeyEvent &keyEvent)
         if (mDownloadStatus == UPDATE_COMPLETE ||
             mDownloadStatus == UPDATE_ERROR)
         {
-            action(gcn::ActionEvent(NULL, mPlayButton->getActionEventId()));
+            action(gcn::ActionEvent(nullptr, mPlayButton->getActionEventId()));
         }
         else
         {
-            action(gcn::ActionEvent(NULL, mCancelButton->getActionEventId()));
+            action(gcn::ActionEvent(nullptr, mCancelButton->getActionEventId()));
         }
     }
 }
@@ -294,12 +294,12 @@ void UpdaterWindow::loadNews()
     while (line)
     {
         mBrowserBox->addRow(line);
-        line = strtok(NULL, "\n");
+        line = strtok(nullptr, "\n");
     }
 
     // Free the memory buffer now that we don't need it anymore
     free(mMemoryBuffer);
-    mMemoryBuffer = NULL;
+    mMemoryBuffer = nullptr;
     mDownloadedBytes = 0;
 
     mScrollArea->setVerticalScrollAmount(0);
@@ -340,7 +340,7 @@ void UpdaterWindow::loadPatch()
 
     // Free the memory buffer now that we don't need it anymore
     free(mMemoryBuffer);
-    mMemoryBuffer = NULL;
+    mMemoryBuffer = nullptr;
     mDownloadedBytes = 0;
 
     mScrollArea->setVerticalScrollAmount(0);
@@ -365,7 +365,7 @@ int UpdaterWindow::updateProgress(void *ptr, DownloadStatus status,
             uw->mDownloadStatus = UPDATE_COMPLETE;
             uw->mDownloadComplete = true;
             free(uw->mMemoryBuffer);
-            uw->mMemoryBuffer = NULL;
+            uw->mMemoryBuffer = nullptr;
         }
         else
         {
diff --git a/src/gui/viewport.cpp b/src/gui/viewport.cpp
index 97a467add..13c0a8cc0 100644
--- a/src/gui/viewport.cpp
+++ b/src/gui/viewport.cpp
@@ -298,8 +298,8 @@ void Viewport::_followMouse()
     if (mPlayerFollowMouse && button & SDL_BUTTON(1))
     {
         // We create a mouse event and send it to mouseDragged.
-        Uint8 *keys = SDL_GetKeyState(NULL);
-        gcn::MouseEvent mouseEvent(NULL,
+        Uint8 *keys = SDL_GetKeyState(nullptr);
+        gcn::MouseEvent mouseEvent(nullptr,
                       (keys[SDLK_LSHIFT] || keys[SDLK_RSHIFT]),
                       false,
                       false,
diff --git a/src/gui/whoisonline.cpp b/src/gui/whoisonline.cpp
index 3fb63a105..b6d67fa83 100644
--- a/src/gui/whoisonline.cpp
+++ b/src/gui/whoisonline.cpp
@@ -83,11 +83,11 @@ class NameFunctuator
 
 WhoIsOnline::WhoIsOnline():
     Window(_("Who Is Online - Updating"), false, 0, "whoisonline.xml"),
-    mThread(NULL),
+    mThread(nullptr),
     mDownloadStatus(UPDATE_LIST),
     mDownloadComplete(true),
     mDownloadedBytes(0),
-    mMemoryBuffer(NULL),
+    mMemoryBuffer(nullptr),
     mCurlError(new char[CURL_ERROR_SIZE]),
     mAllowUpdate(true),
     mShowLevel(false)
@@ -137,7 +137,7 @@ WhoIsOnline::~WhoIsOnline()
     config.removeListener("updateOnlineList", this);
 
     if (mThread && SDL_GetThreadID(mThread))
-        SDL_WaitThread(mThread, NULL);
+        SDL_WaitThread(mThread, nullptr);
 
     free(mMemoryBuffer);
     mMemoryBuffer = 0;
@@ -206,7 +206,7 @@ void WhoIsOnline::loadList()
 
     mShowLevel = config.getBoolValue("showlevel");
 
-    while (line != NULL)
+    while (line)
     {
         std::string nick;
         lineStr = line;
@@ -295,7 +295,7 @@ void WhoIsOnline::loadList()
         {
             listStarted = true;
         }
-        line = strtok(NULL, "\n");
+        line = strtok(nullptr, "\n");
     }
 
     //Set window caption
@@ -448,12 +448,12 @@ void WhoIsOnline::download()
 {
     mDownloadComplete = true;
     if (mThread && SDL_GetThreadID(mThread))
-        SDL_WaitThread(mThread, NULL);
+        SDL_WaitThread(mThread, nullptr);
 
     mDownloadComplete = false;
     mThread = SDL_CreateThread(WhoIsOnline::downloadThread, this);
 
-    if (mThread == NULL)
+    if (mThread == nullptr)
         mDownloadStatus = UPDATE_ERROR;
 }
 
@@ -525,8 +525,8 @@ void WhoIsOnline::action(const gcn::ActionEvent &event)
             setCaption(_("Who Is Online - Update"));
             if (mThread && SDL_GetThreadID(mThread))
             {
-                SDL_WaitThread(mThread, NULL);
-                mThread = NULL;
+                SDL_WaitThread(mThread, nullptr);
+                mThread = nullptr;
             }
             mDownloadComplete = true;
         }
diff --git a/src/gui/widgets/avatarlistbox.cpp b/src/gui/widgets/avatarlistbox.cpp
index 18dc48417..8264f0fb9 100644
--- a/src/gui/widgets/avatarlistbox.cpp
+++ b/src/gui/widgets/avatarlistbox.cpp
@@ -43,8 +43,8 @@
 #include "debug.h"
 
 int AvatarListBox::instances = 0;
-Image *AvatarListBox::onlineIcon = 0;
-Image *AvatarListBox::offlineIcon = 0;
+Image *AvatarListBox::onlineIcon = nullptr;
+Image *AvatarListBox::offlineIcon = nullptr;
 
 AvatarListBox::AvatarListBox(AvatarListModel *model):
     ListBox(model),
@@ -83,12 +83,12 @@ AvatarListBox::~AvatarListBox()
         if (onlineIcon)
         {
             onlineIcon->decRef();
-            onlineIcon = 0;
+            onlineIcon = nullptr;
         }
         if (offlineIcon)
         {
             offlineIcon->decRef();
-            offlineIcon = 0;
+            offlineIcon = nullptr;
         }
     }
 }
diff --git a/src/gui/widgets/browserbox.cpp b/src/gui/widgets/browserbox.cpp
index 5b862d16c..5ded29c55 100644
--- a/src/gui/widgets/browserbox.cpp
+++ b/src/gui/widgets/browserbox.cpp
@@ -49,8 +49,9 @@
 
 BrowserBox::BrowserBox(unsigned int mode, bool opaque):
     gcn::Widget(),
-    mLinkHandler(0),
-    mMode(mode), mHighMode(UNDERLINE | BACKGROUND),
+    mLinkHandler(nullptr),
+    mMode(mode),
+    mHighMode(UNDERLINE | BACKGROUND),
     mOpaque(opaque),
     mUseLinksAndUserColors(true),
     mSelectedLink(-1),
@@ -648,5 +649,5 @@ LinePart::~LinePart()
 {
     if (mImage)
         mImage->decRef();
-    mImage = 0;
+    mImage = nullptr;
 }
diff --git a/src/gui/widgets/browserbox.h b/src/gui/widgets/browserbox.h
index cf2f9c1f1..06609b318 100644
--- a/src/gui/widgets/browserbox.h
+++ b/src/gui/widgets/browserbox.h
@@ -30,6 +30,8 @@
 #include <list>
 #include <vector>
 
+#include "localconsts.h"
+
 class Image;
 class Resource;
 class LinkHandler;
@@ -46,7 +48,7 @@ class LinePart
     public:
         LinePart(int x, int y, gcn::Color color, std::string text, bool bold) :
             mX(x), mY(y), mColor(color), mText(text), mType(0),
-            mImage(0), mBold(bold)
+            mImage(nullptr), mBold(bold)
         {
         }
 
diff --git a/src/gui/widgets/button.cpp b/src/gui/widgets/button.cpp
index 7c46ae9df..85e4eca17 100644
--- a/src/gui/widgets/button.cpp
+++ b/src/gui/widgets/button.cpp
@@ -146,7 +146,7 @@ Button::~Button()
     mInstances--;
 
     delete mVertexes;
-    mVertexes = 0;
+    mVertexes = nullptr;
     if (mInstances == 0)
     {
         for (int mode = 0; mode < BUTTON_COUNT; mode++)
diff --git a/src/gui/widgets/chattab.cpp b/src/gui/widgets/chattab.cpp
index 9a29ae204..0a224605a 100644
--- a/src/gui/widgets/chattab.cpp
+++ b/src/gui/widgets/chattab.cpp
@@ -82,9 +82,9 @@ ChatTab::~ChatTab()
         chatWindow->removeTab(this);
 
     delete mTextOutput;
-    mTextOutput = 0;
+    mTextOutput = nullptr;
     delete mScrollArea;
-    mScrollArea = 0;
+    mScrollArea = nullptr;
 }
 
 void ChatTab::chatLog(std::string line, Own own,
diff --git a/src/gui/widgets/checkbox.cpp b/src/gui/widgets/checkbox.cpp
index 65d26e196..dcedc8951 100644
--- a/src/gui/widgets/checkbox.cpp
+++ b/src/gui/widgets/checkbox.cpp
@@ -70,12 +70,12 @@ CheckBox::CheckBox(const std::string &caption, bool selected,
         }
         else
         {
-            checkBoxNormal = 0;
-            checkBoxChecked = 0;
-            checkBoxDisabled = 0;
-            checkBoxDisabledChecked = 0;
-            checkBoxNormalHi = 0;
-            checkBoxCheckedHi = 0;
+            checkBoxNormal = nullptr;
+            checkBoxChecked = nullptr;
+            checkBoxDisabled = nullptr;
+            checkBoxDisabledChecked = nullptr;
+            checkBoxNormalHi = nullptr;
+            checkBoxCheckedHi = nullptr;
         }
     }
 
@@ -97,17 +97,17 @@ CheckBox::~CheckBox()
     if (instances == 0)
     {
         delete checkBoxNormal;
-        checkBoxNormal = 0;
+        checkBoxNormal = nullptr;
         delete checkBoxChecked;
-        checkBoxChecked = 0;
+        checkBoxChecked = nullptr;
         delete checkBoxDisabled;
-        checkBoxDisabled = 0;
+        checkBoxDisabled = nullptr;
         delete checkBoxDisabledChecked;
-        checkBoxDisabledChecked = 0;
+        checkBoxDisabledChecked = nullptr;
         delete checkBoxNormalHi;
-        checkBoxNormalHi = 0;
+        checkBoxNormalHi = nullptr;
         delete checkBoxCheckedHi;
-        checkBoxCheckedHi = 0;
+        checkBoxCheckedHi = nullptr;
     }
 }
 
diff --git a/src/gui/widgets/checkbox.h b/src/gui/widgets/checkbox.h
index a16ab242c..4e293aad6 100644
--- a/src/gui/widgets/checkbox.h
+++ b/src/gui/widgets/checkbox.h
@@ -25,6 +25,8 @@
 
 #include <guichan/widgets/checkbox.hpp>
 
+#include "localconsts.h"
+
 #ifdef __GNUC__
 #define A_UNUSED  __attribute__ ((unused))
 #else
@@ -45,7 +47,7 @@ class CheckBox : public gcn::CheckBox
          * Constructor.
          */
         CheckBox(const std::string &caption, bool selected = false,
-                 gcn::ActionListener* listener = NULL,
+                 gcn::ActionListener* listener = nullptr,
                  std::string eventId = "");
 
         /**
diff --git a/src/gui/widgets/desktop.cpp b/src/gui/widgets/desktop.cpp
index 46240f76d..beb232fb2 100644
--- a/src/gui/widgets/desktop.cpp
+++ b/src/gui/widgets/desktop.cpp
@@ -39,7 +39,7 @@
 #include "debug.h"
 
 Desktop::Desktop() :
-    mWallpaper(0)
+    mWallpaper(nullptr)
 {
     addWidgetListener(this);
 
@@ -66,7 +66,7 @@ Desktop::~Desktop()
     if (mWallpaper)
     {
         mWallpaper->decRef();
-        mWallpaper = 0;
+        mWallpaper = nullptr;
     }
 }
 
diff --git a/src/gui/widgets/dropdown.cpp b/src/gui/widgets/dropdown.cpp
index 687d7dc6d..2a17320de 100644
--- a/src/gui/widgets/dropdown.cpp
+++ b/src/gui/widgets/dropdown.cpp
@@ -133,7 +133,7 @@ DropDown::~DropDown()
     }
 
     delete mScrollArea;
-    mScrollArea = 0;
+    mScrollArea = nullptr;
 }
 
 void DropDown::updateAlpha()
diff --git a/src/gui/widgets/dropdown.h b/src/gui/widgets/dropdown.h
index 4cbd23314..3559b634a 100644
--- a/src/gui/widgets/dropdown.h
+++ b/src/gui/widgets/dropdown.h
@@ -25,6 +25,8 @@
 
 #include <guichan/widgets/dropdown.hpp>
 
+#include "localconsts.h"
+
 class Image;
 class ImageRect;
 
@@ -47,7 +49,7 @@ class DropDown : public gcn::DropDown
          * @see ListModel, ScrollArea, ListBox.
          */
         DropDown(gcn::ListModel *listModel = 0,
-                 gcn::ActionListener* listener = NULL,
+                 gcn::ActionListener* listener = nullptr,
                  std::string eventId = "");
 
         ~DropDown();
diff --git a/src/gui/widgets/dropshortcutcontainer.cpp b/src/gui/widgets/dropshortcutcontainer.cpp
index 1fa272448..8335a61bc 100644
--- a/src/gui/widgets/dropshortcutcontainer.cpp
+++ b/src/gui/widgets/dropshortcutcontainer.cpp
@@ -49,7 +49,7 @@
 DropShortcutContainer::DropShortcutContainer():
     ShortcutContainer(),
     mItemClicked(false),
-    mItemMoved(NULL)
+    mItemMoved(nullptr)
 {
     addMouseListener(this);
     addWidgetListener(this);
@@ -82,10 +82,10 @@ DropShortcutContainer::~DropShortcutContainer()
     if (mBackgroundImg)
     {
         mBackgroundImg->decRef();
-        mBackgroundImg = 0;
+        mBackgroundImg = nullptr;
     }
     delete mItemPopup;
-    mItemPopup = 0;
+    mItemPopup = nullptr;
 }
 
 void DropShortcutContainer::draw(gcn::Graphics *graphics)
@@ -254,14 +254,14 @@ void DropShortcutContainer::mouseReleased(gcn::MouseEvent &event)
         const int index = getIndexFromGrid(event.getX(), event.getY());
         if (index == -1)
         {
-            mItemMoved = NULL;
+            mItemMoved = nullptr;
             return;
         }
         if (mItemMoved)
         {
             dropShortcut->setItems(index, mItemMoved->getId(),
                 mItemMoved->getColor());
-            mItemMoved = NULL;
+            mItemMoved = nullptr;
         }
 
         if (mItemClicked)
diff --git a/src/gui/widgets/emoteshortcutcontainer.cpp b/src/gui/widgets/emoteshortcutcontainer.cpp
index cc9e8badf..e8d7bb7e3 100644
--- a/src/gui/widgets/emoteshortcutcontainer.cpp
+++ b/src/gui/widgets/emoteshortcutcontainer.cpp
@@ -90,7 +90,7 @@ EmoteShortcutContainer::~EmoteShortcutContainer()
     if (mBackgroundImg)
     {
         mBackgroundImg->decRef();
-        mBackgroundImg = 0;
+        mBackgroundImg = nullptr;
     }
 }
 
diff --git a/src/gui/widgets/flowcontainer.cpp b/src/gui/widgets/flowcontainer.cpp
index 0a64a7142..7d3ddc0b4 100644
--- a/src/gui/widgets/flowcontainer.cpp
+++ b/src/gui/widgets/flowcontainer.cpp
@@ -87,5 +87,5 @@ void FlowContainer::add(gcn::Widget *widget)
 
     Container::add(widget);
     widget->setSize(mBoxWidth, mBoxHeight);
-    widgetResized(NULL);
+    widgetResized(nullptr);
 }
diff --git a/src/gui/widgets/guitable.cpp b/src/gui/widgets/guitable.cpp
index e02eda88c..78ce14e56 100644
--- a/src/gui/widgets/guitable.cpp
+++ b/src/gui/widgets/guitable.cpp
@@ -76,7 +76,7 @@ GuiTableActionListener::~GuiTableActionListener()
     if (mWidget)
     {
         mWidget->removeActionListener(this);
-        mWidget->_setParent(NULL);
+        mWidget->_setParent(nullptr);
     }
 }
 
@@ -92,10 +92,10 @@ GuiTable::GuiTable(TableModel *initial_model, bool opacity) :
     mLinewiseMode(false),
     mWrappingEnabled(false),
     mOpaque(opacity),
-    mModel(NULL),
+    mModel(nullptr),
     mSelectedRow(0),
     mSelectedColumn(0),
-    mTopWidget(NULL)
+    mTopWidget(nullptr)
 {
     mBackgroundColor = Theme::getThemeColor(Theme::BACKGROUND);
     mHighlightColor = Theme::getThemeColor(Theme::HIGHLIGHT);
@@ -110,7 +110,7 @@ GuiTable::~GuiTable()
 {
     uninstallActionListeners();
     delete mModel;
-    mModel = 0;
+    mModel = nullptr;
 }
 
 TableModel *GuiTable::getModel() const
@@ -391,7 +391,7 @@ void GuiTable::moveToBottom(gcn::Widget *widget)
 {
     gcn::Widget::moveToBottom(widget);
     if (widget == mTopWidget)
-        mTopWidget = NULL;
+        mTopWidget = nullptr;
 }
 
 gcn::Rectangle GuiTable::getChildrenArea()
@@ -512,7 +512,7 @@ void GuiTable::modelUpdated(bool completed)
     }
     else
     { // before the update?
-        mTopWidget = NULL; // No longer valid in general
+        mTopWidget = nullptr; // No longer valid in general
         uninstallActionListeners();
     }
 }
@@ -531,10 +531,10 @@ gcn::Widget *GuiTable::getWidgetAt(int x, int y)
         if (w && w->isFocusable())
             return w;
         else
-            return NULL; // Grab the event locally
+            return nullptr; // Grab the event locally
     }
     else
-        return NULL;
+        return nullptr;
 }
 
 int GuiTable::getRowForY(int y) const
diff --git a/src/gui/widgets/guitable.h b/src/gui/widgets/guitable.h
index d248c4820..cf3cb8ad8 100644
--- a/src/gui/widgets/guitable.h
+++ b/src/gui/widgets/guitable.h
@@ -23,6 +23,8 @@
 #ifndef TABLE_H
 #define TABLE_H
 
+#include "localconsts.h"
+
 #include "gui/widgets/tablemodel.h"
 
 #include <guichan/keylistener.hpp>
@@ -57,7 +59,7 @@ class GuiTable : public gcn::Widget,
     friend class GuiTableActionListener;
 
 public:
-    GuiTable(TableModel * initial_model = NULL,
+    GuiTable(TableModel * initial_model = nullptr,
              bool opacity = true);
 
     virtual ~GuiTable();
diff --git a/src/gui/widgets/icon.cpp b/src/gui/widgets/icon.cpp
index 3e9c7dd24..b8cc2ac3a 100644
--- a/src/gui/widgets/icon.cpp
+++ b/src/gui/widgets/icon.cpp
@@ -30,7 +30,7 @@
 #include "debug.h"
 
 Icon::Icon(const std::string &file)
-    : mImage(0)
+    : mImage(nullptr)
 {
     mImage = ResourceManager::getInstance()->getImage(file);
     if (mImage)
diff --git a/src/gui/widgets/itemcontainer.cpp b/src/gui/widgets/itemcontainer.cpp
index 9a17d81cd..57c64093b 100644
--- a/src/gui/widgets/itemcontainer.cpp
+++ b/src/gui/widgets/itemcontainer.cpp
@@ -166,7 +166,7 @@ ItemContainer::ItemContainer(Inventory *inventory, bool forceQuantity):
     mDescItems(false),
     mTag(0),
     mSortType(0),
-    mShowMatrix(0)
+    mShowMatrix(nullptr)
 {
     mItemPopup = new ItemPopup;
     setFocusable(true);
@@ -188,10 +188,10 @@ ItemContainer::~ItemContainer()
     if (mSelImg)
     {
         mSelImg->decRef();
-        mSelImg = 0;
+        mSelImg = nullptr;
     }
     delete mItemPopup;
-    mItemPopup = 0;
+    mItemPopup = nullptr;
     delete []mShowMatrix;
 }
 
@@ -309,7 +309,7 @@ Item *ItemContainer::getSelectedItem() const
     if (mInventory)
         return mInventory->getItem(mSelectedIndex);
     else
-        return 0;
+        return nullptr;
 }
 
 void ItemContainer::distributeValueChangedEvent()
diff --git a/src/gui/widgets/itemlinkhandler.cpp b/src/gui/widgets/itemlinkhandler.cpp
index 6ae0f6b5b..549aa1616 100644
--- a/src/gui/widgets/itemlinkhandler.cpp
+++ b/src/gui/widgets/itemlinkhandler.cpp
@@ -42,7 +42,7 @@ ItemLinkHandler::ItemLinkHandler()
 ItemLinkHandler::~ItemLinkHandler()
 {
     delete mItemPopup;
-    mItemPopup = 0;
+    mItemPopup = nullptr;
 }
 
 void ItemLinkHandler::handleLink(const std::string &link,
diff --git a/src/gui/widgets/itemshortcutcontainer.cpp b/src/gui/widgets/itemshortcutcontainer.cpp
index 560045a29..3682ec448 100644
--- a/src/gui/widgets/itemshortcutcontainer.cpp
+++ b/src/gui/widgets/itemshortcutcontainer.cpp
@@ -51,7 +51,7 @@
 ItemShortcutContainer::ItemShortcutContainer(unsigned number):
     ShortcutContainer(),
     mItemClicked(false),
-    mItemMoved(NULL),
+    mItemMoved(nullptr),
     mNumber(number)
 {
     addMouseListener(this);
@@ -87,12 +87,12 @@ ItemShortcutContainer::~ItemShortcutContainer()
     if (mBackgroundImg)
     {
         mBackgroundImg->decRef();
-        mBackgroundImg = 0;
+        mBackgroundImg = nullptr;
     }
     delete mItemPopup;
-    mItemPopup = 0;
+    mItemPopup = nullptr;
     delete mSpellPopup;
-    mSpellPopup = 0;
+    mSpellPopup = nullptr;
 }
 
 void ItemShortcutContainer::draw(gcn::Graphics *graphics)
@@ -304,14 +304,14 @@ void ItemShortcutContainer::mouseReleased(gcn::MouseEvent &event)
         const int index = getIndexFromGrid(event.getX(), event.getY());
         if (index == -1)
         {
-            mItemMoved = NULL;
+            mItemMoved = nullptr;
             return;
         }
         if (mItemMoved)
         {
             itemShortcut[mNumber]->setItems(index,
                 mItemMoved->getId(), mItemMoved->getColor());
-            mItemMoved = NULL;
+            mItemMoved = nullptr;
         }
         else if (itemShortcut[mNumber]->getItem(index) && mItemClicked)
         {
diff --git a/src/gui/widgets/layout.cpp b/src/gui/widgets/layout.cpp
index 52b92d0bc..7f2f1f621 100644
--- a/src/gui/widgets/layout.cpp
+++ b/src/gui/widgets/layout.cpp
@@ -45,7 +45,7 @@ LayoutCell::~LayoutCell()
     if (mType == ARRAY)
     {
         delete mArray;
-        mArray = 0;
+        mArray = nullptr;
     }
 }
 
@@ -159,7 +159,7 @@ void LayoutArray::resizeGrid(int w, int h)
         i = mCells.begin();
     while (i != mCells.end())
     {
-        i->resize(w, 0);
+        i->resize(w, nullptr);
         ++i;
     }
 }
diff --git a/src/gui/widgets/layout.h b/src/gui/widgets/layout.h
index 5e3ac4532..c4c703644 100644
--- a/src/gui/widgets/layout.h
+++ b/src/gui/widgets/layout.h
@@ -23,6 +23,8 @@
 #ifndef WIDGET_LAYOUT_H
 #define WIDGET_LAYOUT_H
 
+#include "localconsts.h"
+
 #include <guichan/widgets/container.hpp>
 
 #include <vector>
@@ -35,7 +37,7 @@ class LayoutCell;
 class ContainerPlacer
 {
     public:
-        ContainerPlacer(gcn::Container *c = NULL, LayoutCell *l = NULL):
+        ContainerPlacer(gcn::Container *c = nullptr, LayoutCell *l = nullptr):
             mContainer(c), mCell(l)
         {}
 
@@ -172,7 +174,7 @@ class LayoutCell
         };
 
         LayoutCell():
-            mWidget(0),
+            mWidget(nullptr),
             mHPadding(0),
             mVPadding(0),
             mType(NONE)
diff --git a/src/gui/widgets/playerbox.cpp b/src/gui/widgets/playerbox.cpp
index 2efaa2088..fb72176bd 100644
--- a/src/gui/widgets/playerbox.cpp
+++ b/src/gui/widgets/playerbox.cpp
@@ -68,7 +68,7 @@ PlayerBox::PlayerBox(const Being *being):
                 }
                 else
                 {
-                    background.grid[a] = 0;
+                    background.grid[a] = nullptr;
                 }
                 a++;
             }
@@ -85,7 +85,7 @@ PlayerBox::~PlayerBox()
 {
     instances--;
 
-    mBeing = 0;
+    mBeing = nullptr;
 
     if (instances == 0)
         for_each(background.grid, background.grid + 9, dtor<Image*>());
diff --git a/src/gui/widgets/playerbox.h b/src/gui/widgets/playerbox.h
index 1b1a237d8..2bf010618 100644
--- a/src/gui/widgets/playerbox.h
+++ b/src/gui/widgets/playerbox.h
@@ -52,7 +52,8 @@ class PlayerBox : public gcn::ScrollArea
          * player to <code>NULL</code> causes the box not to draw any
          * character.
          */
-        void setPlayer(const Being *being) { mBeing = being; }
+        void setPlayer(const Being *being)
+        { mBeing = being; }
 
         /**
          * Draws the scroll area.
diff --git a/src/gui/widgets/popup.cpp b/src/gui/widgets/popup.cpp
index ac282b088..78557d481 100644
--- a/src/gui/widgets/popup.cpp
+++ b/src/gui/widgets/popup.cpp
@@ -70,7 +70,7 @@ Popup::Popup(const std::string &name, std::string skin):
     }
     else
     {
-        mSkin = 0;
+        mSkin = nullptr;
     }
 
     // Add this window to the window container
@@ -85,13 +85,13 @@ Popup::~Popup()
     logger->log("Popup::~Popup(\"%s\")", mPopupName.c_str());
 
     delete mVertexes;
-    mVertexes = 0;
+    mVertexes = nullptr;
 
     if (mSkin)
     {
         if (Theme::instance())
             Theme::instance()->unload(mSkin);
-        mSkin = 0;
+        mSkin = nullptr;
     }
 }
 
diff --git a/src/gui/widgets/progressbar.cpp b/src/gui/widgets/progressbar.cpp
index 7324fc9ad..f9b6da153 100644
--- a/src/gui/widgets/progressbar.cpp
+++ b/src/gui/widgets/progressbar.cpp
@@ -93,7 +93,7 @@ ProgressBar::ProgressBar(float progress,
         else
         {
             for (int f = 0; f < 9; f ++)
-                mBorder.grid[f] = 0;
+                mBorder.grid[f] = nullptr;
         }
 
     }
@@ -108,7 +108,7 @@ ProgressBar::~ProgressBar()
     if (mInstances == 0)
         for_each(mBorder.grid, mBorder.grid + 9, dtor<Image*>());
     delete mVertexes;
-    mVertexes = 0;
+    mVertexes = nullptr;
 }
 
 void ProgressBar::logic()
diff --git a/src/gui/widgets/radiobutton.cpp b/src/gui/widgets/radiobutton.cpp
index feedeae7b..7d344b09d 100644
--- a/src/gui/widgets/radiobutton.cpp
+++ b/src/gui/widgets/radiobutton.cpp
@@ -112,7 +112,7 @@ void RadioButton::drawBox(gcn::Graphics* graphics)
             radioCheckedHi->setAlpha(mAlpha);
     }
 
-    Image *box = NULL;
+    Image *box = nullptr;
 
     if (isEnabled())
     {
diff --git a/src/gui/widgets/resizegrip.cpp b/src/gui/widgets/resizegrip.cpp
index 861dde29e..c8822eea9 100644
--- a/src/gui/widgets/resizegrip.cpp
+++ b/src/gui/widgets/resizegrip.cpp
@@ -34,7 +34,7 @@
 
 #include "debug.h"
 
-Image *ResizeGrip::gripImage = 0;
+Image *ResizeGrip::gripImage = nullptr;
 int ResizeGrip::mInstances = 0;
 float ResizeGrip::mAlpha = 1.0;
 
@@ -69,7 +69,7 @@ ResizeGrip::~ResizeGrip()
     if (mInstances == 0 && gripImage)
     {
         gripImage->decRef();
-        gripImage = 0;
+        gripImage = nullptr;
     }
 }
 
diff --git a/src/gui/widgets/scrollarea.cpp b/src/gui/widgets/scrollarea.cpp
index 3204028dc..0ec4a2027 100644
--- a/src/gui/widgets/scrollarea.cpp
+++ b/src/gui/widgets/scrollarea.cpp
@@ -111,7 +111,7 @@ ScrollArea::~ScrollArea()
             buttons[RIGHT][1]->decRef();
     }
     delete mVertexes;
-    mVertexes = 0;
+    mVertexes = nullptr;
 }
 
 void ScrollArea::init()
@@ -147,7 +147,7 @@ void ScrollArea::init()
                 }
                 else
                 {
-                    background.grid[a] = 0;
+                    background.grid[a] = nullptr;
                 }
                 a++;
             }
@@ -179,7 +179,7 @@ void ScrollArea::init()
                 }
                 else
                 {
-                    vMarker.grid[a] = 0;
+                    vMarker.grid[a] = nullptr;
                 }
                 if (vscrollHi)
                 {
@@ -192,7 +192,7 @@ void ScrollArea::init()
                 }
                 else
                 {
-                    vMarkerHi.grid[a] = 0;
+                    vMarkerHi.grid[a] = nullptr;
                 }
                 a++;
             }
diff --git a/src/gui/widgets/setupitem.cpp b/src/gui/widgets/setupitem.cpp
index 698e133dd..8081f5d7b 100644
--- a/src/gui/widgets/setupitem.cpp
+++ b/src/gui/widgets/setupitem.cpp
@@ -53,7 +53,7 @@ SetupItem::SetupItem(std::string text, std::string description,
     mUseDefault(false),
     mValue(""),
     mDefault(""),
-    mWidget(0),
+    mWidget(nullptr),
     mValueType(VBOOL)
 {
 }
@@ -70,7 +70,7 @@ SetupItem::SetupItem(std::string text, std::string description,
     mUseDefault(true),
     mValue(""),
     mDefault(def),
-    mWidget(0),
+    mWidget(nullptr),
     mValueType(VBOOL)
 {
 }
@@ -184,7 +184,7 @@ SetupItemCheckBox::SetupItemCheckBox(std::string text, std::string description,
 
 SetupItemCheckBox::~SetupItemCheckBox()
 {
-    mWidget = 0;
+    mWidget = nullptr;
 }
 
 void SetupItemCheckBox::createControls()
@@ -225,11 +225,11 @@ SetupItemTextField::SetupItemTextField(std::string text,
                                        std::string eventName,
                                        bool mainConfig) :
     SetupItem(text, description, keyName, parent, eventName, mainConfig),
-    mHorizont(0),
-    mLabel(0),
-    mTextField(0),
-    mButton(0),
-    mEditDialog(0)
+    mHorizont(nullptr),
+    mLabel(nullptr),
+    mTextField(nullptr),
+    mButton(nullptr),
+    mEditDialog(nullptr)
 {
     mValueType = VSTR;
     createControls();
@@ -242,11 +242,11 @@ SetupItemTextField::SetupItemTextField(std::string text,
                                        std::string eventName, std::string def,
                                        bool mainConfig) :
     SetupItem(text, description, keyName, parent, eventName, def, mainConfig),
-    mHorizont(0),
-    mLabel(0),
-    mTextField(0),
-    mButton(0),
-    mEditDialog(0)
+    mHorizont(nullptr),
+    mLabel(nullptr),
+    mTextField(nullptr),
+    mButton(nullptr),
+    mEditDialog(nullptr)
 {
     mValueType = VSTR;
     createControls();
@@ -254,11 +254,11 @@ SetupItemTextField::SetupItemTextField(std::string text,
 
 SetupItemTextField::~SetupItemTextField()
 {
-    mHorizont = 0;
-    mWidget = 0;
-    mTextField = 0;
-    mLabel = 0;
-    mButton = 0;
+    mHorizont = nullptr;
+    mWidget = nullptr;
+    mTextField = nullptr;
+    mLabel = nullptr;
+    mButton = nullptr;
 }
 
 void SetupItemTextField::createControls()
@@ -318,7 +318,7 @@ void SetupItemTextField::action(const gcn::ActionEvent &event)
     else if (event.getId() == mEventName + "_EDIT_OK")
     {
         mTextField->setText(mEditDialog->getMsg());
-        mEditDialog = 0;
+        mEditDialog = nullptr;
     }
 }
 
@@ -339,13 +339,13 @@ SetupItemIntTextField::SetupItemIntTextField(std::string text,
                                              int min, int max,
                                              bool mainConfig) :
     SetupItem(text, description, keyName, parent, eventName, mainConfig),
-    mHorizont(0),
-    mLabel(0),
-    mTextField(0),
-    mButton(0),
+    mHorizont(nullptr),
+    mLabel(nullptr),
+    mTextField(nullptr),
+    mButton(nullptr),
     mMin(min),
     mMax(max),
-    mEditDialog(0)
+    mEditDialog(nullptr)
 {
     mValueType = VSTR;
     createControls();
@@ -360,13 +360,13 @@ SetupItemIntTextField::SetupItemIntTextField(std::string text,
                                              std::string def,
                                              bool mainConfig) :
     SetupItem(text, description, keyName, parent, eventName, def, mainConfig),
-    mHorizont(0),
-    mLabel(0),
-    mTextField(0),
-    mButton(0),
+    mHorizont(nullptr),
+    mLabel(nullptr),
+    mTextField(nullptr),
+    mButton(nullptr),
     mMin(min),
     mMax(max),
-    mEditDialog(0)
+    mEditDialog(nullptr)
 {
     mValueType = VSTR;
     createControls();
@@ -374,11 +374,11 @@ SetupItemIntTextField::SetupItemIntTextField(std::string text,
 
 SetupItemIntTextField::~SetupItemIntTextField()
 {
-    mHorizont = 0;
-    mWidget = 0;
-    mTextField = 0;
-    mLabel = 0;
-    mButton = 0;
+    mHorizont = nullptr;
+    mWidget = nullptr;
+    mTextField = nullptr;
+    mLabel = nullptr;
+    mButton = nullptr;
 }
 
 void SetupItemIntTextField::createControls()
@@ -441,7 +441,7 @@ void SetupItemIntTextField::action(const gcn::ActionEvent &event)
     else if (event.getId() == mEventName + "_EDIT_OK")
     {
         mTextField->setValue(atoi(mEditDialog->getMsg().c_str()));
-        mEditDialog = 0;
+        mEditDialog = nullptr;
     }
 }
 
@@ -459,7 +459,7 @@ void SetupItemIntTextField::apply(std::string eventName)
 SetupItemLabel::SetupItemLabel(std::string text, std::string description,
                                SetupTabScroll *parent, bool separator) :
     SetupItem(text, description, "", parent, "", "", true),
-    mLabel(0),
+    mLabel(nullptr),
     mIsSeparator(separator)
 {
     mValueType = VNONE;
@@ -468,8 +468,8 @@ SetupItemLabel::SetupItemLabel(std::string text, std::string description,
 
 SetupItemLabel::~SetupItemLabel()
 {
-    mWidget = 0;
-    mLabel = 0;
+    mWidget = nullptr;
+    mLabel = nullptr;
 }
 
 void SetupItemLabel::createControls()
@@ -517,10 +517,10 @@ SetupItemDropDown::SetupItemDropDown(std::string text,
                                      gcn::ListModel *model,
                                      bool mainConfig) :
     SetupItem(text, description, keyName, parent, eventName, mainConfig),
-    mHorizont(0),
-    mLabel(0),
+    mHorizont(nullptr),
+    mLabel(nullptr),
     mModel(model),
-    mDropDown(0)
+    mDropDown(nullptr)
 {
     mValueType = VSTR;
     createControls();
@@ -535,10 +535,10 @@ SetupItemDropDown::SetupItemDropDown(std::string text,
                                      std::string def,
                                      bool mainConfig) :
     SetupItem(text, description, keyName, parent, eventName, def, mainConfig),
-    mHorizont(0),
-    mLabel(0),
+    mHorizont(nullptr),
+    mLabel(nullptr),
     mModel(model),
-    mDropDown(0)
+    mDropDown(nullptr)
 {
     mValueType = VSTR;
     createControls();
@@ -546,11 +546,11 @@ SetupItemDropDown::SetupItemDropDown(std::string text,
 
 SetupItemDropDown::~SetupItemDropDown()
 {
-    mHorizont = 0;
-    mWidget = 0;
-    mModel = 0;
-    mDropDown = 0;
-    mLabel = 0;
+    mHorizont = nullptr;
+    mWidget = nullptr;
+    mModel = nullptr;
+    mDropDown = nullptr;
+    mLabel = nullptr;
 }
 
 void SetupItemDropDown::createControls()
diff --git a/src/gui/widgets/setuptabscroll.cpp b/src/gui/widgets/setuptabscroll.cpp
index e9917b090..4fb092070 100644
--- a/src/gui/widgets/setuptabscroll.cpp
+++ b/src/gui/widgets/setuptabscroll.cpp
@@ -43,10 +43,10 @@ SetupTabScroll::SetupTabScroll() :
 
 SetupTabScroll::~SetupTabScroll()
 {
-    mScroll = 0;
+    mScroll = nullptr;
 
     delete mContainer;
-    mContainer = 0;
+    mContainer = nullptr;
 
     std::set<SetupItem*>::iterator it = mAllItems.begin();
     std::set<SetupItem*>::iterator it_end = mAllItems.end();
diff --git a/src/gui/widgets/shopitems.cpp b/src/gui/widgets/shopitems.cpp
index e15445b77..d3aac5c56 100644
--- a/src/gui/widgets/shopitems.cpp
+++ b/src/gui/widgets/shopitems.cpp
@@ -75,7 +75,7 @@ void ShopItems::addItemNoDup(int id, unsigned char color,
 void ShopItems::addItem2(int inventoryIndex, int id, unsigned char color,
                          int quantity, int price)
 {
-    ShopItem *item = 0;
+    ShopItem *item = nullptr;
     if (mMergeDuplicates)
         item = findItem(id, color);
 
@@ -93,7 +93,7 @@ void ShopItems::addItem2(int inventoryIndex, int id, unsigned char color,
 ShopItem *ShopItems::at(unsigned int i) const
 {
     if (i >= mShopItems.size())
-        return 0;
+        return nullptr;
 
     return mShopItems.at(i);
 }
@@ -137,5 +137,5 @@ ShopItem *ShopItems::findItem(int id, unsigned char color) const
         ++it;
     }
 
-    return 0;
+    return nullptr;
 }
diff --git a/src/gui/widgets/shoplistbox.cpp b/src/gui/widgets/shoplistbox.cpp
index 793491808..b649a81ef 100644
--- a/src/gui/widgets/shoplistbox.cpp
+++ b/src/gui/widgets/shoplistbox.cpp
@@ -47,7 +47,7 @@ float ShopListBox::mAlpha = 1.0;
 ShopListBox::ShopListBox(gcn::ListModel *listModel):
     ListBox(listModel),
     mPlayerMoney(0),
-    mShopItems(0)
+    mShopItems(nullptr)
 {
     mRowHeight = getFont()->getHeight();
     init();
diff --git a/src/gui/widgets/shortcutcontainer.cpp b/src/gui/widgets/shortcutcontainer.cpp
index 9fd9b26c6..36f88da08 100644
--- a/src/gui/widgets/shortcutcontainer.cpp
+++ b/src/gui/widgets/shortcutcontainer.cpp
@@ -33,7 +33,7 @@
 float ShortcutContainer::mAlpha = 1.0;
 
 ShortcutContainer::ShortcutContainer():
-    mBackgroundImg(0),
+    mBackgroundImg(nullptr),
     mMaxItems(0),
     mBoxWidth(1),
     mBoxHeight(1),
diff --git a/src/gui/widgets/slider.cpp b/src/gui/widgets/slider.cpp
index d29c2211f..3822d40c9 100644
--- a/src/gui/widgets/slider.cpp
+++ b/src/gui/widgets/slider.cpp
@@ -101,9 +101,9 @@ void Slider::init()
         }
         else
         {
-            hStart = 0;
-            hMid = 0;
-            hEnd = 0;
+            hStart = nullptr;
+            hMid = nullptr;
+            hEnd = nullptr;
         }
         if (sliderHi)
         {
@@ -113,9 +113,9 @@ void Slider::init()
         }
         else
         {
-            hStartHi = 0;
-            hMidHi = 0;
-            hEndHi = 0;
+            hStartHi = nullptr;
+            hMidHi = nullptr;
+            hEndHi = nullptr;
         }
 
         x = 6; y = 8;
@@ -123,11 +123,11 @@ void Slider::init()
         if (slider)
             hGrip = slider->getSubImage(x, y, w, h);
         else
-            hGrip = 0;
+            hGrip = nullptr;
         if (sliderHi)
             hGripHi = sliderHi->getSubImage(x, y, w, h);
         else
-            hGripHi = 0;
+            hGripHi = nullptr;
 
         x = 0; y = 6;
         w = 6; h = 21;
@@ -140,9 +140,9 @@ void Slider::init()
         }
         else
         {
-            vStart = 0;
-            vMid = 0;
-            vEnd = 0;
+            vStart = nullptr;
+            vMid = nullptr;
+            vEnd = nullptr;
         }
         if (sliderHi)
         {
@@ -152,9 +152,9 @@ void Slider::init()
         }
         else
         {
-            vStartHi = 0;
-            vMidHi = 0;
-            vEndHi = 0;
+            vStartHi = nullptr;
+            vMidHi = nullptr;
+            vEndHi = nullptr;
         }
 
         x = 6; y = 8;
@@ -162,12 +162,12 @@ void Slider::init()
         if (slider)
             vGrip = slider->getSubImage(x, y, w, h);
         else
-            vGrip = 0;
+            vGrip = nullptr;
 
         if (sliderHi)
             vGripHi = sliderHi->getSubImage(x, y, w, h);
         else
-            vGripHi = 0;
+            vGripHi = nullptr;
 
         if (slider)
             slider->decRef();
diff --git a/src/gui/widgets/spellshortcutcontainer.cpp b/src/gui/widgets/spellshortcutcontainer.cpp
index 6317dd56f..5c4dbc9a1 100644
--- a/src/gui/widgets/spellshortcutcontainer.cpp
+++ b/src/gui/widgets/spellshortcutcontainer.cpp
@@ -54,7 +54,7 @@
 SpellShortcutContainer::SpellShortcutContainer(unsigned number):
     ShortcutContainer(),
     mSpellClicked(false),
-    mSpellMoved(NULL),
+    mSpellMoved(nullptr),
     mNumber(number)
 {
     mBoxWidth = mBoxWidth;
@@ -88,9 +88,9 @@ SpellShortcutContainer::~SpellShortcutContainer()
 {
     if (mBackgroundImg)
         mBackgroundImg->decRef();
-    mBackgroundImg = 0;
+    mBackgroundImg = nullptr;
     delete mSpellPopup;
-    mSpellPopup = 0;
+    mSpellPopup = nullptr;
 }
 
 void SpellShortcutContainer::draw(gcn::Graphics *graphics)
@@ -251,7 +251,7 @@ void SpellShortcutContainer::mouseReleased(gcn::MouseEvent &event)
     }
     else if (event.getButton() == gcn::MouseEvent::RIGHT)
     {
-        TextCommand *spell = NULL;
+        TextCommand *spell = nullptr;
         if (itemId >= 0)
             spell = spellManager->getSpell(itemId);
 
diff --git a/src/gui/widgets/tab.cpp b/src/gui/widgets/tab.cpp
index 530f1ac82..8e4b1fe6f 100644
--- a/src/gui/widgets/tab.cpp
+++ b/src/gui/widgets/tab.cpp
@@ -91,7 +91,7 @@ Tab::~Tab()
             for_each(tabImg[mode].grid, tabImg[mode].grid + 9, dtor<Image*>());
     }
     delete mVertexes;
-    mVertexes = 0;
+    mVertexes = nullptr;
 }
 
 void Tab::init()
diff --git a/src/gui/widgets/tabbedarea.cpp b/src/gui/widgets/tabbedarea.cpp
index 47b02c925..fb9279343 100644
--- a/src/gui/widgets/tabbedarea.cpp
+++ b/src/gui/widgets/tabbedarea.cpp
@@ -46,15 +46,15 @@ TabbedArea::TabbedArea()
     mArrowButton[0] = new Button("<", "shift_left", this);
     mArrowButton[1] = new Button(">", "shift_right", this);
 
-    widgetResized(NULL);
+    widgetResized(nullptr);
 }
 
 TabbedArea::~TabbedArea()
 {
     delete mArrowButton[0];
-    mArrowButton[0] = 0;
+    mArrowButton[0] = nullptr;
     delete mArrowButton[1];
-    mArrowButton[1] = 0;
+    mArrowButton[1] = nullptr;
 }
 
 void TabbedArea::enableScrollButtons(bool enable)
@@ -90,7 +90,7 @@ Tab *TabbedArea::getTab(const std::string &name) const
 
         ++itr;
     }
-    return NULL;
+    return nullptr;
 }
 
 void TabbedArea::draw(gcn::Graphics *graphics)
@@ -112,7 +112,7 @@ gcn::Widget *TabbedArea::getWidget(const std::string &name) const
         ++itr;
     }
 
-    return NULL;
+    return nullptr;
 }
 
 gcn::Widget *TabbedArea::getCurrentWidget()
@@ -122,7 +122,7 @@ gcn::Widget *TabbedArea::getCurrentWidget()
     if (tab)
         return getWidget(tab->getCaption());
     else
-        return NULL;
+        return nullptr;
 }
 
 void TabbedArea::addTab(gcn::Tab* tab, gcn::Widget* widget)
@@ -192,7 +192,7 @@ void TabbedArea::removeTab(gcn::Tab *tab)
 
     if (tabIndexToBeSelected == -1)
     {
-        mSelectedTab = 0;
+        mSelectedTab = nullptr;
         mWidgetContainer->clear();
     }
     else
@@ -238,7 +238,7 @@ void TabbedArea::setSelectedTab(gcn::Tab *tab)
     if (newTab)
         newTab->setCurrent();
 
-    widgetResized(NULL);
+    widgetResized(nullptr);
 }
 
 void TabbedArea::setSelectedTab(const std::string &name)
@@ -266,7 +266,7 @@ void TabbedArea::widgetResized(const gcn::Event &event A_UNUSED)
     if (w)
     {
         int newScroll = 0;
-        ScrollArea* scr = 0;
+        ScrollArea* scr = nullptr;
         if (mFollowDownScroll && height != 0)
         {
             gcn::Rectangle rect = w->getDimension();
@@ -444,14 +444,14 @@ void TabbedArea::updateArrowEnableState()
 Tab *TabbedArea::getTabByIndex(int index) const
 {
     if (index < 0 || index >= static_cast<int>(mTabs.size()))
-        return 0;
+        return nullptr;
     return static_cast<Tab*>(mTabs[index].first);
 }
 
 gcn::Widget *TabbedArea::getWidgetByIndex(int index) const
 {
     if (index < 0 || index >= static_cast<int>(mTabs.size()))
-        return 0;
+        return nullptr;
     return mTabs[index].second;
 }
 
diff --git a/src/gui/widgets/tablemodel.cpp b/src/gui/widgets/tablemodel.cpp
index 6c932a411..f54b4281a 100644
--- a/src/gui/widgets/tablemodel.cpp
+++ b/src/gui/widgets/tablemodel.cpp
@@ -68,7 +68,7 @@ StaticTableModel::StaticTableModel(int row, int column) :
     mColumns(column),
     mHeight(1)
 {
-    mTableModel.resize(row * column, NULL);
+    mTableModel.resize(row * column, nullptr);
     mWidths.resize(column, 1);
 }
 
@@ -82,7 +82,7 @@ void StaticTableModel::resize()
 {
     mRows = getRows();
     mColumns = getColumns();
-    mTableModel.resize(mRows * mColumns, NULL);
+    mTableModel.resize(mRows * mColumns, nullptr);
 }
 
 void StaticTableModel::set(int row, int column, gcn::Widget *widget)
diff --git a/src/gui/widgets/textfield.cpp b/src/gui/widgets/textfield.cpp
index 6ce4cbf3b..b4584947a 100644
--- a/src/gui/widgets/textfield.cpp
+++ b/src/gui/widgets/textfield.cpp
@@ -86,7 +86,7 @@ TextField::TextField(const std::string &text, bool loseFocusOnTab,
                 }
                 else
                 {
-                    skin.grid[a] = 0;
+                    skin.grid[a] = nullptr;
                 }
                 a++;
             }
diff --git a/src/gui/widgets/textfield.h b/src/gui/widgets/textfield.h
index 93f970168..e530cfef2 100644
--- a/src/gui/widgets/textfield.h
+++ b/src/gui/widgets/textfield.h
@@ -25,6 +25,8 @@
 
 #include <guichan/widgets/textfield.hpp>
 
+#include "localconsts.h"
+
 class ImageRect;
 class TextField;
 
@@ -40,7 +42,7 @@ class TextField : public gcn::TextField
          * Constructor, initializes the text field with the given string.
          */
         TextField(const std::string &text = "", bool loseFocusOnTab = true,
-                  gcn::ActionListener* listener = NULL,
+                  gcn::ActionListener* listener = nullptr,
                   std::string eventId = "", bool sendAlwaysEvents = false);
 
         ~TextField();
diff --git a/src/gui/widgets/textpreview.cpp b/src/gui/widgets/textpreview.cpp
index 07cf19b61..9be2d5b3f 100644
--- a/src/gui/widgets/textpreview.cpp
+++ b/src/gui/widgets/textpreview.cpp
@@ -44,7 +44,7 @@ TextPreview::TextPreview(const std::string &text):
     mTextAlpha = false;
     mFont = gui->getFont();
     mTextColor = &Theme::getThemeColor(Theme::TEXT);
-    mTextBGColor = NULL;
+    mTextBGColor = nullptr;
     mBGColor = &Theme::getThemeColor(Theme::BACKGROUND);
     mOpaque = false;
 }
diff --git a/src/gui/widgets/window.cpp b/src/gui/widgets/window.cpp
index c52bf744e..273695a1a 100644
--- a/src/gui/widgets/window.cpp
+++ b/src/gui/widgets/window.cpp
@@ -49,9 +49,9 @@ int Window::mouseResize = 0;
 Window::Window(const std::string &caption, bool modal, Window *parent,
                std::string skin):
     gcn::Window(caption),
-    mGrip(0),
+    mGrip(nullptr),
     mParent(parent),
-    mLayout(NULL),
+    mLayout(nullptr),
     mWindowName("window"),
     mShowTitle(true),
     mModal(modal),
@@ -91,7 +91,7 @@ Window::Window(const std::string &caption, bool modal, Window *parent,
     }
     else
     {
-        mSkin = 0;
+        mSkin = nullptr;
     }
 
     // Add this window to the window container
@@ -118,7 +118,7 @@ Window::~Window()
     saveWindowState();
 
     delete mLayout;
-    mLayout = 0;
+    mLayout = nullptr;
 
     while (!mWidgets.empty())
         delete mWidgets.front();
@@ -127,7 +127,7 @@ Window::~Window()
 
     removeWidgetListener(this);
     delete mVertexes;
-    mVertexes = 0;
+    mVertexes = nullptr;
 
     instances--;
 
@@ -135,7 +135,7 @@ Window::~Window()
     {
         if (Theme::instance())
             Theme::instance()->unload(mSkin);
-        mSkin = 0;
+        mSkin = nullptr;
     }
 }
 
@@ -348,7 +348,7 @@ void Window::setResizable(bool r)
     {
         remove(mGrip);
         delete mGrip;
-        mGrip = 0;
+        mGrip = nullptr;
     }
 }
 
@@ -947,7 +947,7 @@ void Window::reflowLayout(int w, int h)
 
     mLayout->reflow(w, h);
     delete mLayout;
-    mLayout = 0;
+    mLayout = nullptr;
     setContentSize(w, h);
 }
 
diff --git a/src/gui/widgets/window.h b/src/gui/widgets/window.h
index ffc27ab10..5ace2328e 100644
--- a/src/gui/widgets/window.h
+++ b/src/gui/widgets/window.h
@@ -25,6 +25,7 @@
 
 #include "graphics.h"
 #include "guichanfwd.h"
+#include "localconsts.h"
 
 #include <guichan/widgetlistener.hpp>
 
@@ -65,7 +66,7 @@ class Window : public gcn::Window, gcn::WidgetListener
          * @param skin    The location where the window's skin XML can be found.
          */
         Window(const std::string &caption = "Window", bool modal = false,
-               Window *parent = NULL, std::string skin = "");
+               Window *parent = nullptr, std::string skin = "");
 
         /**
          * Destructor. Deletes all the added widgets.
diff --git a/src/gui/widgets/windowcontainer.cpp b/src/gui/widgets/windowcontainer.cpp
index 5a3c16037..34a6b68c7 100644
--- a/src/gui/widgets/windowcontainer.cpp
+++ b/src/gui/widgets/windowcontainer.cpp
@@ -26,7 +26,7 @@
 
 #include "debug.h"
 
-WindowContainer *windowContainer = NULL;
+WindowContainer *windowContainer = nullptr;
 
 void WindowContainer::logic()
 {
diff --git a/src/gui/worldselectdialog.cpp b/src/gui/worldselectdialog.cpp
index b4f697ba3..3749049fe 100644
--- a/src/gui/worldselectdialog.cpp
+++ b/src/gui/worldselectdialog.cpp
@@ -140,7 +140,7 @@ void WorldSelectDialog::keyPressed(gcn::KeyEvent &keyEvent)
     gcn::Key key = keyEvent.getKey();
 
     if (key.getValue() == Key::ESCAPE)
-        action(gcn::ActionEvent(NULL, mChangeLoginButton->getActionEventId()));
+        action(gcn::ActionEvent(nullptr, mChangeLoginButton->getActionEventId()));
     else if (key.getValue() == Key::ENTER)
-        action(gcn::ActionEvent(NULL, mChooseWorld->getActionEventId()));
+        action(gcn::ActionEvent(nullptr, mChooseWorld->getActionEventId()));
 }
diff --git a/src/guichan/basiccontainer.cpp b/src/guichan/basiccontainer.cpp
index 439535c9a..a36ab5f9b 100644
--- a/src/guichan/basiccontainer.cpp
+++ b/src/guichan/basiccontainer.cpp
@@ -173,7 +173,7 @@ namespace gcn
         Rectangle r = getChildrenArea();
 
         if (!r.isPointInRect(x, y))
-            return NULL;
+            return nullptr;
 
         x -= r.x;
         y -= r.y;
@@ -188,7 +188,7 @@ namespace gcn
             }
         }
 
-        return NULL;
+        return nullptr;
     }
 
     void BasicContainer::logic()
@@ -200,7 +200,7 @@ namespace gcn
     {
         Widget::_setFocusHandler(focusHandler);
 
-        if (mInternalFocusHandler != NULL)
+        if (mInternalFocusHandler)
             return;
 
         WidgetListConstIterator iter;
@@ -214,7 +214,7 @@ namespace gcn
     {
         mWidgets.push_back(widget);
 
-        if (mInternalFocusHandler == NULL)
+        if (!mInternalFocusHandler)
             widget->_setFocusHandler(_getFocusHandler());
         else
             widget->_setFocusHandler(mInternalFocusHandler);
@@ -231,8 +231,8 @@ namespace gcn
             if (*iter == widget)
             {
                 mWidgets.erase(iter);
-                widget->_setFocusHandler(NULL);
-                widget->_setParent(NULL);
+                widget->_setFocusHandler(nullptr);
+                widget->_setParent(nullptr);
                 widget->removeDeathListener(this);
                 return;
             }
@@ -247,8 +247,8 @@ namespace gcn
 
         for (iter = mWidgets.begin(); iter != mWidgets.end(); ++ iter)
         {
-            (*iter)->_setFocusHandler(NULL);
-            (*iter)->_setParent(NULL);
+            (*iter)->_setFocusHandler(nullptr);
+            (*iter)->_setParent(nullptr);
             (*iter)->removeDeathListener(this);
         }
 
@@ -327,7 +327,7 @@ namespace gcn
         WidgetListConstIterator iter;
         for (iter = mWidgets.begin(); iter != mWidgets.end(); ++ iter)
         {
-            if (mInternalFocusHandler == NULL)
+            if (!mInternalFocusHandler)
                 (*iter)->_setFocusHandler(_getFocusHandler());
             else
                 (*iter)->_setFocusHandler(mInternalFocusHandler);
@@ -345,15 +345,15 @@ namespace gcn
             BasicContainer *basicContainer
                 = dynamic_cast<BasicContainer*>(*iter);
 
-            if (basicContainer != NULL)
+            if (basicContainer)
             {
                 Widget *widget = basicContainer->findWidgetById(id);
 
-                if (widget != NULL)
+                if (widget)
                     return widget;
             }
         }
 
-        return NULL;
+        return nullptr;
     }
 }
diff --git a/src/guichan/focushandler.cpp b/src/guichan/focushandler.cpp
index 367eed6b1..b1da9e77e 100644
--- a/src/guichan/focushandler.cpp
+++ b/src/guichan/focushandler.cpp
@@ -56,24 +56,21 @@
 namespace gcn
 {
     FocusHandler::FocusHandler() :
-        mFocusedWidget(NULL),
-        mModalFocusedWidget(NULL),
-        mModalMouseInputFocusedWidget(NULL),
-        mDraggedWidget(NULL),
-        mLastWidgetWithMouse(NULL),
-        mLastWidgetWithModalFocus(NULL),
-        mLastWidgetWithModalMouseInputFocus(NULL),
-        mLastWidgetPressed(NULL)
+        mFocusedWidget(nullptr),
+        mModalFocusedWidget(nullptr),
+        mModalMouseInputFocusedWidget(nullptr),
+        mDraggedWidget(nullptr),
+        mLastWidgetWithMouse(nullptr),
+        mLastWidgetWithModalFocus(nullptr),
+        mLastWidgetWithModalMouseInputFocus(nullptr),
+        mLastWidgetPressed(nullptr)
     {
     }
 
     void FocusHandler::requestFocus(Widget* widget)
     {
-        if (widget == NULL
-            || widget == mFocusedWidget)
-        {
+        if (!widget || widget == mFocusedWidget)
             return;
-        }
 
         unsigned int i = 0;
         int toBeFocusedIndex = -1;
@@ -95,7 +92,7 @@ namespace gcn
         {
             mFocusedWidget = mWidgets.at(toBeFocusedIndex);
 
-            if (oldFocused != NULL)
+            if (oldFocused)
             {
                 Event focusEvent(oldFocused);
                 distributeFocusLostEvent(focusEvent);
@@ -108,21 +105,18 @@ namespace gcn
 
     void FocusHandler::requestModalFocus(Widget* widget)
     {
-        if (mModalFocusedWidget != NULL && mModalFocusedWidget != widget)
+        if (mModalFocusedWidget && mModalFocusedWidget != widget)
             throw GCN_EXCEPTION("Another widget already has modal focus.");
 
         mModalFocusedWidget = widget;
 
-        if (mFocusedWidget != NULL 
-            && !mFocusedWidget->isModalFocused())
-        {
+        if (mFocusedWidget && !mFocusedWidget->isModalFocused())
             focusNone();
-        }
     }
 
     void FocusHandler::requestModalMouseInputFocus(Widget* widget)
     {
-        if (mModalMouseInputFocusedWidget != NULL
+        if (mModalMouseInputFocusedWidget
             && mModalMouseInputFocusedWidget != widget)
         {
             throw GCN_EXCEPTION("Another widget already has "
@@ -135,13 +129,13 @@ namespace gcn
     void FocusHandler::releaseModalFocus(Widget* widget)
     {
         if (mModalFocusedWidget == widget)
-            mModalFocusedWidget = NULL;
+            mModalFocusedWidget = nullptr;
     }
 
     void FocusHandler::releaseModalMouseInputFocus(Widget* widget)
     {
         if (mModalMouseInputFocusedWidget == widget)
-            mModalMouseInputFocusedWidget = NULL;
+            mModalMouseInputFocusedWidget = nullptr;
     }
 
     Widget* FocusHandler::getFocused() const
@@ -212,7 +206,7 @@ namespace gcn
     {
         if (mWidgets.empty())
         {
-            mFocusedWidget = NULL;
+            mFocusedWidget = nullptr;
             return;
         }
 
@@ -275,9 +269,7 @@ namespace gcn
     void FocusHandler::remove(Widget* widget)
     {
         if (isFocused(widget))
-        {
-            mFocusedWidget = NULL;
-        }
+            mFocusedWidget = nullptr;
 
         WidgetIterator iter;
 
@@ -292,41 +284,41 @@ namespace gcn
 
         if (mDraggedWidget == widget)
         {
-            mDraggedWidget = NULL;
+            mDraggedWidget = nullptr;
             return;
         }
 
         if (mLastWidgetWithMouse == widget)
         {
-            mLastWidgetWithMouse = NULL;
+            mLastWidgetWithMouse = nullptr;
             return;
         }
 
         if (mLastWidgetWithModalFocus == widget)
         {
-            mLastWidgetWithModalFocus = NULL;
+            mLastWidgetWithModalFocus = nullptr;
             return;
         }
 
         if (mLastWidgetWithModalMouseInputFocus == widget)
         {
-            mLastWidgetWithModalMouseInputFocus = NULL;
+            mLastWidgetWithModalMouseInputFocus = nullptr;
             return;
         }
 
         if (mLastWidgetPressed == widget)
         {
-            mLastWidgetPressed = NULL;
+            mLastWidgetPressed = nullptr;
             return;
         }
     }
 
     void FocusHandler::focusNone()
     {
-        if (mFocusedWidget != NULL)
+        if (mFocusedWidget)
         {
             Widget* focused = mFocusedWidget;
-            mFocusedWidget = NULL;
+            mFocusedWidget = nullptr;
 
             Event focusEvent(focused);
             distributeFocusLostEvent(focusEvent);
@@ -335,7 +327,7 @@ namespace gcn
 
     void FocusHandler::tabNext()
     {
-        if (mFocusedWidget != NULL)
+        if (mFocusedWidget)
         {
             if (!mFocusedWidget->isTabOutEnabled())
                 return;
@@ -343,7 +335,7 @@ namespace gcn
 
         if (mWidgets.empty())
         {
-            mFocusedWidget = NULL;
+            mFocusedWidget = nullptr;
             return;
         }
 
@@ -380,7 +372,7 @@ namespace gcn
 
             if (mWidgets.at(focusedWidget)->isFocusable() &&
                 mWidgets.at(focusedWidget)->isTabInEnabled() &&
-                (mModalFocusedWidget == NULL ||
+                (!mModalFocusedWidget ||
                 mWidgets.at(focusedWidget)->isModalFocused()))
             {
                 done = true;
@@ -404,7 +396,7 @@ namespace gcn
 
     void FocusHandler::tabPrevious()
     {
-        if (mFocusedWidget != NULL)
+        if (mFocusedWidget)
         {
             if (!mFocusedWidget->isTabOutEnabled())
                 return;
@@ -412,7 +404,7 @@ namespace gcn
 
         if (mWidgets.empty())
         {
-            mFocusedWidget = NULL;
+            mFocusedWidget = nullptr;
             return;
         }
 
@@ -449,7 +441,7 @@ namespace gcn
 
             if (mWidgets.at(focusedWidget)->isFocusable() &&
                 mWidgets.at(focusedWidget)->isTabInEnabled() &&
-                (mModalFocusedWidget == NULL ||
+                (!mModalFocusedWidget ||
                 mWidgets.at(focusedWidget)->isModalFocused()))
             {
                 done = true;
diff --git a/src/guichan/graphics.cpp b/src/guichan/graphics.cpp
index d09050a10..c57b5d5c0 100644
--- a/src/guichan/graphics.cpp
+++ b/src/guichan/graphics.cpp
@@ -57,7 +57,7 @@ namespace gcn
 {
 
     Graphics::Graphics() :
-        mFont(NULL)
+        mFont(nullptr)
     {
     }
 
@@ -155,7 +155,7 @@ namespace gcn
     void Graphics::drawText(const std::string& text, int x, int y,
                             Alignment alignment)
     {
-        if (mFont == NULL)
+        if (!mFont)
             throw GCN_EXCEPTION("No font set.");
 
         switch (alignment)
diff --git a/src/guichan/gui.cpp b/src/guichan/gui.cpp
index 0c81182ea..810a983c4 100644
--- a/src/guichan/gui.cpp
+++ b/src/guichan/gui.cpp
@@ -63,9 +63,9 @@
 namespace gcn
 {
     Gui::Gui() :
-        mTop(NULL),
-        mGraphics(NULL),
-        mInput(NULL),
+        mTop(nullptr),
+        mGraphics(nullptr),
+        mInput(nullptr),
         mTabbing(true),
         mShiftPressed(false),
         mMetaPressed(false),
@@ -84,17 +84,17 @@ namespace gcn
     Gui::~Gui()
     {
         if (Widget::widgetExists(mTop))
-            setTop(NULL);
+            setTop(nullptr);
 
         delete mFocusHandler;
-        mFocusHandler = 0;
+        mFocusHandler = nullptr;
     }
 
     void Gui::setTop(Widget* top)
     {
-        if (mTop != NULL)
-            mTop->_setFocusHandler(NULL);
-        if (top != NULL)
+        if (mTop)
+            mTop->_setFocusHandler(nullptr);
+        if (top)
             top->_setFocusHandler(mFocusHandler);
 
         mTop = top;
@@ -127,13 +127,13 @@ namespace gcn
 
     void Gui::logic()
     {
-        if (mTop == NULL)
+        if (!mTop)
             throw GCN_EXCEPTION("No top widget set");
 
         handleModalFocus();
         handleModalMouseInputFocus();
 
-        if (mInput != NULL)
+        if (mInput)
         {
             mInput->_pollInput();
 
@@ -147,9 +147,9 @@ namespace gcn
 
     void Gui::draw()
     {
-        if (mTop == NULL)
+        if (!mTop)
             throw GCN_EXCEPTION("No top widget set");
-        if (mGraphics == NULL)
+        if (!mGraphics)
             throw GCN_EXCEPTION("No graphics set");
 
         if (!mTop->isVisible())
@@ -250,7 +250,7 @@ namespace gcn
             mControlPressed = keyInput.isControlPressed();
             mAltPressed = keyInput.isAltPressed();
 
-            KeyEvent keyEventToGlobalKeyListeners(NULL,
+            KeyEvent keyEventToGlobalKeyListeners(nullptr,
                                                   mShiftPressed,
                                                   mControlPressed,
                                                   mAltPressed,
@@ -270,7 +270,7 @@ namespace gcn
             bool keyEventConsumed = false;
 
             // Send key inputs to the focused widgets
-            if (mFocusHandler->getFocused() != NULL)
+            if (mFocusHandler->getFocused())
             {
                 KeyEvent keyEvent(getKeyEventSource(),
                                   mShiftPressed,
@@ -400,7 +400,7 @@ namespace gcn
         // 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() != NULL
+        if (mFocusHandler->getModalMouseInputFocused()
             && widget == mFocusHandler->getModalMouseInputFocused()
             && Widget::widgetExists(widget))
         {
@@ -411,11 +411,11 @@ namespace gcn
                 || x + widget->getWidth() <= mouseInput.getX()
                 || y + widget->getHeight() <= mouseInput.getY())
             {
-                parent = NULL;
+                parent = nullptr;
             }
         }
 
-        while (parent != NULL)
+        while (parent)
         {
             parent = (Widget*)widget->getParent();
 
@@ -453,7 +453,7 @@ namespace gcn
             parent = (Widget*)swap->getParent();
         }
 
-        if (mFocusHandler->getDraggedWidget() != NULL)
+        if (mFocusHandler->getDraggedWidget())
         {
             distributeMouseEvent(mFocusHandler->getDraggedWidget(),
                                  MouseEvent::DRAGGED,
@@ -479,15 +479,15 @@ namespace gcn
         Widget* sourceWidget = getMouseEventSource(
             mouseInput.getX(), mouseInput.getY());
 
-        if (mFocusHandler->getDraggedWidget() != NULL)
+        if (mFocusHandler->getDraggedWidget())
             sourceWidget = mFocusHandler->getDraggedWidget();
 
         int sourceWidgetX, sourceWidgetY;
         sourceWidget->getAbsolutePosition(sourceWidgetX, sourceWidgetY);
 
-        if ((mFocusHandler->getModalFocused() != NULL
+        if ((mFocusHandler->getModalFocused()
             && sourceWidget->isModalFocused())
-            || mFocusHandler->getModalFocused() == NULL)
+            || !mFocusHandler->getModalFocused())
         {
             sourceWidget->requestFocus();
         }
@@ -522,7 +522,7 @@ namespace gcn
         Widget* sourceWidget = getMouseEventSource(
             mouseInput.getX(), mouseInput.getY());
 
-        if (mFocusHandler->getDraggedWidget() != NULL)
+        if (mFocusHandler->getDraggedWidget())
             sourceWidget = mFocusHandler->getDraggedWidget();
 
         int sourceWidgetX, sourceWidgetY;
@@ -540,7 +540,7 @@ namespace gcn
         Widget* sourceWidget = getMouseEventSource(
             mouseInput.getX(), mouseInput.getY());
 
-        if (mFocusHandler->getDraggedWidget() != NULL)
+        if (mFocusHandler->getDraggedWidget())
             sourceWidget = mFocusHandler->getDraggedWidget();
 
         int sourceWidgetX, sourceWidgetY;
@@ -558,10 +558,10 @@ namespace gcn
         Widget* sourceWidget = getMouseEventSource(
             mouseInput.getX(), mouseInput.getY());
 
-        if (mFocusHandler->getDraggedWidget() != NULL)
+        if (mFocusHandler->getDraggedWidget())
         {
             if (sourceWidget != mFocusHandler->getLastWidgetPressed())
-                mFocusHandler->setLastWidgetPressed(NULL);
+                mFocusHandler->setLastWidgetPressed(nullptr);
 
             sourceWidget = mFocusHandler->getDraggedWidget();
         }
@@ -584,7 +584,7 @@ namespace gcn
                                  mouseInput.getX(),
                                  mouseInput.getY());
 
-            mFocusHandler->setLastWidgetPressed(NULL);
+            mFocusHandler->setLastWidgetPressed(nullptr);
         }
         else
         {
@@ -592,8 +592,8 @@ namespace gcn
             mClickCount = 0;
         }
 
-        if (mFocusHandler->getDraggedWidget() != NULL)
-            mFocusHandler->setDraggedWidget(NULL);
+        if (mFocusHandler->getDraggedWidget())
+            mFocusHandler->setDraggedWidget(nullptr);
     }
 
     Widget* Gui::getWidgetAt(int x, int y)
@@ -602,7 +602,7 @@ namespace gcn
         Widget* parent = mTop;
         Widget* child = mTop;
 
-        while (child != NULL)
+        while (child)
         {
             Widget* swap = child;
             int parentX, parentY;
@@ -618,7 +618,7 @@ namespace gcn
     {
         Widget* widget = getWidgetAt(x, y);
 
-        if (mFocusHandler->getModalMouseInputFocused() != NULL
+        if (mFocusHandler->getModalMouseInputFocused()
             && !widget->isModalMouseInputFocused())
         {
             return mFocusHandler->getModalMouseInputFocused();
@@ -631,8 +631,8 @@ namespace gcn
     {
         Widget* widget = mFocusHandler->getFocused();
 
-        while (widget->_getInternalFocusHandler() != NULL
-               && widget->_getInternalFocusHandler()->getFocused() != NULL)
+        while (widget->_getInternalFocusHandler()
+               && widget->_getInternalFocusHandler()->getFocused())
         {
             widget = widget->_getInternalFocusHandler()->getFocused();
         }
@@ -651,14 +651,14 @@ namespace gcn
         Widget* parent = source;
         Widget* widget = source;
 
-        if (mFocusHandler->getModalFocused() != NULL
+        if (mFocusHandler->getModalFocused()
             && !widget->isModalFocused()
             && !force)
         {
             return;
         }
 
-        if (mFocusHandler->getModalMouseInputFocused() != NULL
+        if (mFocusHandler->getModalMouseInputFocused()
             && !widget->isModalMouseInputFocused()
             && !force)
         {
@@ -676,7 +676,7 @@ namespace gcn
                               y,
                               mClickCount);
 
-        while (parent != NULL)
+        while (parent)
         {
             // If the widget has been removed due to input
             // cancel the distribution.
@@ -746,7 +746,7 @@ namespace gcn
 
             // If a non modal focused widget has been reach
             // and we have modal focus cancel the distribution.
-            if (mFocusHandler->getModalFocused() != NULL
+            if (mFocusHandler->getModalFocused()
                 && !widget->isModalFocused())
             {
                 break;
@@ -754,7 +754,7 @@ namespace gcn
 
             // If a non modal mouse input focused widget has been reach
             // and we have modal mouse input focus cancel the distribution.
-            if (mFocusHandler->getModalMouseInputFocused() != NULL
+            if (mFocusHandler->getModalMouseInputFocused()
                 && !widget->isModalMouseInputFocused())
             {
                 break;
@@ -767,26 +767,24 @@ namespace gcn
         Widget* parent = keyEvent.getSource();
         Widget* widget = keyEvent.getSource();
 
-        if (mFocusHandler->getModalFocused() != NULL
+        if (mFocusHandler->getModalFocused()
             && !widget->isModalFocused())
         {
             return;
         }
 
-        if (mFocusHandler->getModalMouseInputFocused() != NULL
+        if (mFocusHandler->getModalMouseInputFocused()
             && !widget->isModalMouseInputFocused())
         {
             return;
         }
 
-        while (parent != NULL)
+        while (parent)
         {
             // If the widget has been removed due to input
             // cancel the distribution.
             if (!Widget::widgetExists(widget))
-            {
                 break;
-            }
 
             parent = (Widget*)widget->getParent();
 
@@ -821,7 +819,7 @@ namespace gcn
 
             // If a non modal focused widget has been reach
             // and we have modal focus cancel the distribution.
-            if (mFocusHandler->getModalFocused() != NULL
+            if (mFocusHandler->getModalFocused()
                 && !widget->isModalFocused())
             {
                 break;
@@ -857,8 +855,7 @@ namespace gcn
         // Check if modal mouse input focus has been gained by a widget.
         if ((mFocusHandler->getLastWidgetWithModalMouseInputFocus() 
             != mFocusHandler->getModalMouseInputFocused())
-            && (mFocusHandler->getLastWidgetWithModalMouseInputFocus()
-            == NULL))
+            && (!mFocusHandler->getLastWidgetWithModalMouseInputFocus()))
         {
             handleModalFocusGained();
             mFocusHandler->setLastWidgetWithModalMouseInputFocus(
@@ -867,11 +864,10 @@ namespace gcn
         // Check if modal mouse input focus has been released.
         else if ((mFocusHandler->getLastWidgetWithModalMouseInputFocus()
                  != mFocusHandler->getModalMouseInputFocused())
-                 && (mFocusHandler->getLastWidgetWithModalMouseInputFocus()
-                 != NULL))
+                 && (mFocusHandler->getLastWidgetWithModalMouseInputFocus()))
         {
             handleModalFocusReleased();
-            mFocusHandler->setLastWidgetWithModalMouseInputFocus(NULL);
+            mFocusHandler->setLastWidgetWithModalMouseInputFocus(nullptr);
         }
     }
 
@@ -880,7 +876,7 @@ namespace gcn
         // Check if modal focus has been gained by a widget.
         if ((mFocusHandler->getLastWidgetWithModalFocus() 
             != mFocusHandler->getModalFocused())
-            && (mFocusHandler->getLastWidgetWithModalFocus() == NULL))
+            && (!mFocusHandler->getLastWidgetWithModalFocus()))
         {
             handleModalFocusGained();
             mFocusHandler->setLastWidgetWithModalFocus(
@@ -889,10 +885,10 @@ namespace gcn
         // Check if modal focus has been released.
         else if ((mFocusHandler->getLastWidgetWithModalFocus()
                  != mFocusHandler->getModalFocused())
-                 && (mFocusHandler->getLastWidgetWithModalFocus() != NULL))
+                 && (mFocusHandler->getLastWidgetWithModalFocus()))
         {
             handleModalFocusReleased();
-            mFocusHandler->setLastWidgetWithModalFocus(NULL);
+            mFocusHandler->setLastWidgetWithModalFocus(nullptr);
         }
     }
 
@@ -930,7 +926,7 @@ namespace gcn
         Widget* widget = getMouseEventSource(mLastMouseX, mLastMouseY);
         Widget* parent = widget;
 
-        while (parent != NULL)
+        while (parent)
         {
             parent = (Widget*)widget->getParent();
 
diff --git a/src/guichan/image.cpp b/src/guichan/image.cpp
index 2c15151a2..837840435 100644
--- a/src/guichan/image.cpp
+++ b/src/guichan/image.cpp
@@ -55,7 +55,7 @@
 namespace gcn
 {
 
-    ImageLoader* Image::mImageLoader = NULL;
+    ImageLoader* Image::mImageLoader = nullptr;
 
     Image::Image()
     {
@@ -78,7 +78,7 @@ namespace gcn
     Image* Image::load(const std::string& filename,
                        bool convertToDisplayFormat)
     {
-        if (mImageLoader == NULL)
+        if (!mImageLoader)
         {
             throw GCN_EXCEPTION("Trying to load an image but "
                 "no image loader is set.");
diff --git a/src/guichan/sdl/sdlgraphics.cpp b/src/guichan/sdl/sdlgraphics.cpp
index 28aface0e..67aa657cd 100644
--- a/src/guichan/sdl/sdlgraphics.cpp
+++ b/src/guichan/sdl/sdlgraphics.cpp
@@ -65,7 +65,7 @@ namespace gcn
 {
 
     SDLGraphics::SDLGraphics() :
-        mTarget(0),
+        mTarget(nullptr),
         mAlpha(false)
     {
     }
@@ -155,7 +155,7 @@ namespace gcn
 
         const SDLImage* srcImage = dynamic_cast<const SDLImage*>(image);
 
-        if (srcImage == NULL)
+        if (!srcImage)
         {
             throw GCN_EXCEPTION("Trying to draw an image of unknown format,"
                 " must be an SDLImage.");
diff --git a/src/guichan/sdl/sdlimage.cpp b/src/guichan/sdl/sdlimage.cpp
index 12c5571cf..156b399b3 100644
--- a/src/guichan/sdl/sdlimage.cpp
+++ b/src/guichan/sdl/sdlimage.cpp
@@ -50,6 +50,8 @@
 #include "guichan/exception.hpp"
 #include "guichan/sdl/sdlpixel.hpp"
 
+#include "debug.h"
+
 namespace gcn
 {
     SDLImage::SDLImage(SDL_Surface* surface, bool autoFree)
@@ -71,7 +73,7 @@ namespace gcn
 
     int SDLImage::getWidth() const
     {
-        if (mSurface == NULL)
+        if (!mSurface)
         {
             throw GCN_EXCEPTION("Trying to get the width of "
                 "a non loaded image.");
@@ -82,7 +84,7 @@ namespace gcn
 
     int SDLImage::getHeight() const
     {
-        if (mSurface == NULL)
+        if (!mSurface)
         {
             throw GCN_EXCEPTION("Trying to get the height of "
                 "a non loaded image.");
@@ -93,7 +95,7 @@ namespace gcn
 
     Color SDLImage::getPixel(int x, int y)
     {
-        if (mSurface == NULL)
+        if (!mSurface)
         {
             throw GCN_EXCEPTION("Trying to get a pixel from a "
                 "non loaded image.");
@@ -104,7 +106,7 @@ namespace gcn
 
     void SDLImage::putPixel(int x, int y, const Color& color)
     {
-        if (mSurface == NULL)
+        if (!mSurface)
         {
             throw GCN_EXCEPTION("Trying to put a pixel in a "
                 "non loaded image.");
@@ -115,7 +117,7 @@ namespace gcn
 
     void SDLImage::convertToDisplayFormat()
     {
-        if (mSurface == NULL)
+        if (!mSurface)
         {
             throw GCN_EXCEPTION("Trying to convert a non loaded image "
                 "to display format.");
@@ -155,16 +157,16 @@ namespace gcn
         {
             tmp = SDL_DisplayFormatAlpha(mSurface);
             SDL_FreeSurface(mSurface);
-            mSurface = NULL;
+            mSurface = nullptr;
         }
         else
         {
             tmp = SDL_DisplayFormat(mSurface);
             SDL_FreeSurface(mSurface);
-            mSurface = NULL;
+            mSurface = nullptr;
         }
 
-        if (tmp == NULL)
+        if (!tmp)
             throw GCN_EXCEPTION("Unable to convert image to display format.");
 
         if (hasPink)
diff --git a/src/guichan/widget.cpp b/src/guichan/widget.cpp
index 1b2b3295b..571644aa4 100644
--- a/src/guichan/widget.cpp
+++ b/src/guichan/widget.cpp
@@ -66,7 +66,7 @@
 
 namespace gcn
 {
-    Font* Widget::mGlobalFont = NULL;
+    Font* Widget::mGlobalFont = nullptr;
     DefaultFont Widget::mDefaultFont;
     std::list<Widget*> Widget::mWidgets;
     std::set<Widget*> Widget::mWidgetsSet;
@@ -76,16 +76,16 @@ namespace gcn
         mBackgroundColor(0xffffff),
         mBaseColor(0x808090),
         mSelectionColor(0xc3d9ff),
-        mFocusHandler(NULL),
-        mInternalFocusHandler(NULL),
-        mParent(NULL),
+        mFocusHandler(nullptr),
+        mInternalFocusHandler(nullptr),
+        mParent(nullptr),
         mFrameSize(0),
         mFocusable(false),
         mVisible(true),
         mTabIn(true),
         mTabOut(true),
         mEnabled(true),
-        mCurrentFont(NULL)
+        mCurrentFont(nullptr)
     {
         mWidgets.push_back(this);
         mWidgetsSet.insert(this);
@@ -103,7 +103,7 @@ namespace gcn
             (*iter)->death(event);
         }
 
-        _setFocusHandler(NULL);
+        _setFocusHandler(nullptr);
 
         mWidgets.remove(this);
         mWidgetsSet.erase(this);
@@ -272,7 +272,7 @@ namespace gcn
 
     void Widget::requestFocus()
     {
-        if (mFocusHandler == NULL)
+        if (!mFocusHandler)
         {
             throw GCN_EXCEPTION("No focushandler set (did you add "
                 "the widget to the gui?).");
@@ -455,9 +455,9 @@ namespace gcn
 
     Font* Widget::getFont() const
     {
-        if (mCurrentFont == NULL)
+        if (!mCurrentFont)
         {
-            if (mGlobalFont == NULL)
+            if (!mGlobalFont)
                 return &mDefaultFont;
 
             return mGlobalFont;
@@ -473,7 +473,7 @@ namespace gcn
         std::list<Widget*>::const_iterator iter;
         for (iter = mWidgets.begin(); iter != mWidgets.end(); ++iter)
         {
-            if ((*iter)->mCurrentFont == NULL)
+            if (!(*iter)->mCurrentFont)
                 (*iter)->fontChanged();
         }
     }
@@ -531,7 +531,7 @@ namespace gcn
 
     void Widget::requestModalFocus()
     {
-        if (mFocusHandler == NULL)
+        if (!mFocusHandler)
         {
             throw GCN_EXCEPTION("No focushandler set (did you add "
                 "the widget to the gui?).");
@@ -542,7 +542,7 @@ namespace gcn
 
     void Widget::requestModalMouseInputFocus()
     {
-        if (mFocusHandler == NULL)
+        if (!mFocusHandler)
         {
             throw GCN_EXCEPTION("No focushandler set (did you add "
                 "the widget to the gui?).");
@@ -553,7 +553,7 @@ namespace gcn
 
     void Widget::releaseModalFocus()
     {
-        if (mFocusHandler == NULL)
+        if (!mFocusHandler)
             return;
 
         mFocusHandler->releaseModalFocus(this);
@@ -561,7 +561,7 @@ namespace gcn
 
     void Widget::releaseModalMouseInputFocus()
     {
-        if (mFocusHandler == NULL)
+        if (!mFocusHandler)
             return;
 
         mFocusHandler->releaseModalMouseInputFocus(this);
@@ -569,7 +569,7 @@ namespace gcn
 
     bool Widget::isModalFocused() const
     {
-        if (mFocusHandler == NULL)
+        if (!mFocusHandler)
         {
             throw GCN_EXCEPTION("No focushandler set (did you add "
                 "the widget to the gui?).");
@@ -586,7 +586,7 @@ namespace gcn
 
     bool Widget::isModalMouseInputFocused() const
     {
-        if (mFocusHandler == NULL)
+        if (!mFocusHandler)
         {
             throw GCN_EXCEPTION("No focushandler set (did you add "
                 "the widget to the gui?).");
@@ -603,7 +603,7 @@ namespace gcn
 
     Widget *Widget::getWidgetAt(int x A_UNUSED, int y A_UNUSED)
     {
-        return NULL;
+        return nullptr;
     }
 
     const std::list<MouseListener*>& Widget::_getMouseListeners()
@@ -712,7 +712,7 @@ namespace gcn
 
     void Widget::showPart(Rectangle rectangle)
     {
-        if (mParent != NULL)
+        if (mParent)
             mParent->showWidgetPart(this, rectangle);
     }
 }
diff --git a/src/guichan/widgets/dropdown.cpp b/src/guichan/widgets/dropdown.cpp
index 3ecbd75d8..17513931f 100644
--- a/src/guichan/widgets/dropdown.cpp
+++ b/src/guichan/widgets/dropdown.cpp
@@ -68,8 +68,8 @@ namespace gcn
 
         setInternalFocusHandler(&mInternalFocusHandler);
 
-        mInternalScrollArea = (scrollArea == NULL);
-        mInternalListBox = (listBox == NULL);
+        mInternalScrollArea = (!scrollArea);
+        mInternalListBox = (!listBox);
 
         if (mInternalScrollArea)
             mScrollArea = new ScrollArea();
@@ -110,16 +110,16 @@ namespace gcn
         if (mInternalScrollArea)
         {
             delete mScrollArea;
-            mScrollArea = 0;
+            mScrollArea = nullptr;
         }
 
         if (mInternalListBox)
         {
             delete mListBox;
-            mListBox = 0;
+            mListBox = nullptr;
         }
 
-        setInternalFocusHandler(NULL);
+        setInternalFocusHandler(nullptr);
     }
 
     int DropDown::getSelected() const
@@ -223,10 +223,10 @@ namespace gcn
 
     void DropDown::adjustHeight()
     {
-        if (mScrollArea == NULL)
+        if (!mScrollArea)
             throw GCN_EXCEPTION("Scroll area has been deleted.");
 
-        if (mListBox == NULL)
+        if (!mListBox)
             throw GCN_EXCEPTION("List box has been deleted.");
 
         int listBoxHeight = mListBox->getHeight();
@@ -296,7 +296,7 @@ namespace gcn
     void DropDown::death(const Event& event)
     {
         if (event.getSource() == mScrollArea)
-            mScrollArea = NULL;
+            mScrollArea = nullptr;
 
         BasicContainer::death(event);
     }
diff --git a/src/guichan/widgets/icon.cpp b/src/guichan/widgets/icon.cpp
index 2983c7c29..13a9f1309 100644
--- a/src/guichan/widgets/icon.cpp
+++ b/src/guichan/widgets/icon.cpp
@@ -56,14 +56,14 @@
 namespace gcn
 {
     Icon::Icon()
-        : mImage(0)
+        : mImage(nullptr)
         , mInternalImage(false)
     {
         setSize(0, 0);
     }
 
     Icon::Icon(const std::string& filename)
-        : mImage(0),
+        : mImage(nullptr),
           mInternalImage(false)
     {
         mImage = Image::load(filename);
@@ -85,7 +85,7 @@ namespace gcn
         if (mInternalImage)
         {
             delete mImage;
-            mImage = 0;
+            mImage = nullptr;
         }
     }
 
@@ -107,7 +107,7 @@ namespace gcn
 
     void Icon::draw(Graphics* graphics)
     {
-        if (mImage != NULL)
+        if (mImage)
         {
             const int x = (getWidth() - mImage->getWidth()) / 2;
             const int y = (getHeight() - mImage->getHeight()) / 2;
diff --git a/src/guichan/widgets/imagebutton.cpp b/src/guichan/widgets/imagebutton.cpp
index 2f4c5dcde..feeed795d 100644
--- a/src/guichan/widgets/imagebutton.cpp
+++ b/src/guichan/widgets/imagebutton.cpp
@@ -55,7 +55,7 @@
 namespace gcn
 {
     ImageButton::ImageButton() :
-        mImage(0), 
+        mImage(nullptr), 
         mInternalImage(false)
     {
         setWidth(0);
@@ -63,7 +63,7 @@ namespace gcn
     }
 
     ImageButton::ImageButton(const std::string& filename) :
-        mImage(0), 
+        mImage(nullptr), 
         mInternalImage(false)
     {
         mImage = Image::load(filename);
@@ -85,7 +85,7 @@ namespace gcn
         if (mInternalImage)
         {
             delete mImage;
-            mImage = 0;
+            mImage = nullptr;
         }
     }
 
@@ -94,7 +94,7 @@ namespace gcn
         if (mInternalImage)
         {
             delete mImage;
-            mImage = 0;
+            mImage = nullptr;
         }
 
         mImage = image;
diff --git a/src/guichan/widgets/listbox.cpp b/src/guichan/widgets/listbox.cpp
index 95f04fc68..80989cc72 100644
--- a/src/guichan/widgets/listbox.cpp
+++ b/src/guichan/widgets/listbox.cpp
@@ -61,7 +61,7 @@ namespace gcn
 {
     ListBox::ListBox() :
         mSelected(-1),
-        mListModel(NULL),
+        mListModel(nullptr),
         mWrappingEnabled(false)
     {
         setWidth(100);
@@ -88,7 +88,7 @@ namespace gcn
         graphics->setColor(getBackgroundColor());
         graphics->fillRectangle(Rectangle(0, 0, getWidth(), getHeight()));
 
-        if (mListModel == NULL)
+        if (!mListModel)
             return;
 
         graphics->setColor(getForegroundColor());
@@ -161,7 +161,7 @@ namespace gcn
 
     void ListBox::setSelected(int selected)
     {
-        if (mListModel == NULL)
+        if (!mListModel)
         {
             mSelected = -1;
         }
@@ -286,7 +286,7 @@ namespace gcn
 
     void ListBox::adjustSize()
     {
-        if (mListModel != NULL)
+        if (mListModel)
             setHeight(getRowHeight() * mListModel->getNumberOfElements());
     }
 
diff --git a/src/guichan/widgets/scrollarea.cpp b/src/guichan/widgets/scrollarea.cpp
index 7dc7566c0..574308b7c 100644
--- a/src/guichan/widgets/scrollarea.cpp
+++ b/src/guichan/widgets/scrollarea.cpp
@@ -138,12 +138,12 @@ namespace gcn
 
     ScrollArea::~ScrollArea()
     {
-        setContent(NULL);
+        setContent(nullptr);
     }
 
     void ScrollArea::setContent(Widget* widget)
     {
-        if (widget != NULL)
+        if (widget)
         {
             clear();
             add(widget);
@@ -162,7 +162,7 @@ namespace gcn
         if (!mWidgets.empty())
             return *mWidgets.begin();
 
-        return NULL;
+        return nullptr;
     }
 
     void ScrollArea::setHorizontalScrollPolicy(ScrollPolicy hPolicy)
@@ -240,7 +240,7 @@ namespace gcn
     {
         checkPolicies();
 
-        if (getContent() == NULL)
+        if (!getContent())
             return 0;
 
         int value = getContent()->getWidth() - getChildrenArea().width +
@@ -256,7 +256,7 @@ namespace gcn
     {
         checkPolicies();
 
-        if (getContent() == NULL)
+        if (!getContent())
             return 0;
 
         int value;
@@ -790,7 +790,7 @@ namespace gcn
         setVerticalScrollAmount(getVerticalScrollAmount());
         setHorizontalScrollAmount(getHorizontalScrollAmount());
 
-        if (getContent() != NULL)
+        if (getContent())
         {
             getContent()->setPosition(-mHScroll + getContent()->getFrameSize(),
                 -mVScroll + getContent()->getFrameSize());
@@ -1126,7 +1126,7 @@ namespace gcn
         if (getChildrenArea().isPointInRect(x, y))
             return getContent();
 
-        return NULL;
+        return nullptr;
     }
 
     void ScrollArea::mouseWheelMovedUp(MouseEvent& mouseEvent)
diff --git a/src/guichan/widgets/tab.cpp b/src/guichan/widgets/tab.cpp
index 9b7424748..768e2c695 100644
--- a/src/guichan/widgets/tab.cpp
+++ b/src/guichan/widgets/tab.cpp
@@ -59,7 +59,7 @@ namespace gcn
 {
     Tab::Tab() :
         mHasMouse(false),
-        mTabbedArea(NULL)
+        mTabbedArea(nullptr)
     {
         mLabel = new Label();
         mLabel->setPosition(4, 4);
@@ -71,7 +71,7 @@ namespace gcn
     Tab::~Tab()
     {
         delete mLabel;
-        mLabel = 0;
+        mLabel = nullptr;
     }
 
     void Tab::adjustSize()
@@ -79,7 +79,7 @@ namespace gcn
         setSize(mLabel->getWidth() + 8,
                 mLabel->getHeight() + 8);
 
-        if (mTabbedArea != NULL)
+        if (mTabbedArea)
             mTabbedArea->adjustTabPositions();
     }
 
diff --git a/src/guichan/widgets/tabbedarea.cpp b/src/guichan/widgets/tabbedarea.cpp
index 3c556eeca..4ee164778 100644
--- a/src/guichan/widgets/tabbedarea.cpp
+++ b/src/guichan/widgets/tabbedarea.cpp
@@ -62,7 +62,7 @@
 namespace gcn
 {
     TabbedArea::TabbedArea() :
-        mSelectedTab(NULL),
+        mSelectedTab(nullptr),
         mOpaque(false)
     {
         setFocusable(true);
@@ -83,14 +83,14 @@ namespace gcn
         remove(mWidgetContainer);
 
         delete mTabContainer;
-        mTabContainer = 0;
+        mTabContainer = nullptr;
         delete mWidgetContainer;
-        mWidgetContainer = 0;
+        mWidgetContainer = nullptr;
 
         for (unsigned int i = 0; i < mTabsToDelete.size(); i++)
         {
             delete mTabsToDelete[i];
-            mTabsToDelete[i] = 0;
+            mTabsToDelete[i] = nullptr;
         }
     }
 
@@ -102,7 +102,7 @@ namespace gcn
         mTabContainer->add(tab);
         mTabs.push_back(std::pair<Tab*, Widget*>(tab, widget));
 
-        if (mSelectedTab == NULL)
+        if (!mSelectedTab)
             setSelectedTab(tab);
 
         adjustTabPositions();
@@ -224,7 +224,7 @@ namespace gcn
 
         // If a tab is selected, remove the line right underneath
         // the selected tab.
-        if (mSelectedTab != NULL)
+        if (mSelectedTab)
         {
             graphics->setColor(getBaseColor());
             graphics->drawLine(mSelectedTab->getX() + 1,
@@ -332,7 +332,7 @@ namespace gcn
     {
         Tab* tab = dynamic_cast<Tab*>(event.getSource());
 
-        if (tab != NULL)
+        if (tab)
             removeTab(tab);
         else
             BasicContainer::death(event);
@@ -343,7 +343,7 @@ namespace gcn
         Widget* source = actionEvent.getSource();
         Tab* tab = dynamic_cast<Tab*>(source);
 
-        if (tab == NULL)
+        if (!tab)
         {
             throw GCN_EXCEPTION("Received an action from a "
                 "widget that's not a tab!");
diff --git a/src/guichan/widgets/textbox.cpp b/src/guichan/widgets/textbox.cpp
index 35fbf5437..7b5b03ab8 100644
--- a/src/guichan/widgets/textbox.cpp
+++ b/src/guichan/widgets/textbox.cpp
@@ -270,7 +270,7 @@ namespace gcn
         {
             Widget* par = getParent();
 
-            if (par != NULL)
+            if (par)
             {
                 int rowsPerPage = par->getChildrenArea().height
                     / getFont()->getHeight();
@@ -284,7 +284,7 @@ namespace gcn
         {
             Widget* par = getParent();
 
-            if (par != NULL)
+            if (par)
             {
                 int rowsPerPage = par->getChildrenArea().height
                     / getFont()->getHeight();
diff --git a/src/guichan/widgets/window.cpp b/src/guichan/widgets/window.cpp
index 550b23749..1c46b2283 100644
--- a/src/guichan/widgets/window.cpp
+++ b/src/guichan/widgets/window.cpp
@@ -130,7 +130,7 @@ namespace gcn
         if (mouseEvent.getSource() != this)
             return;
 
-        if (getParent() != NULL)
+        if (getParent())
             getParent()->moveToTop(this);
 
         mDragOffsetX = mouseEvent.getX();
diff --git a/src/guild.cpp b/src/guild.cpp
index a2b85b6c1..0e629e2be 100644
--- a/src/guild.cpp
+++ b/src/guild.cpp
@@ -129,7 +129,7 @@ GuildMember *Guild::getMember(int id) const
         ++itr;
     }
 
-    return NULL;
+    return nullptr;
 }
 
 GuildMember *Guild::getMember(int accountId, int charId) const
@@ -143,7 +143,7 @@ GuildMember *Guild::getMember(int accountId, int charId) const
         ++itr;
     }
 
-    return NULL;
+    return nullptr;
 }
 
 GuildMember *Guild::getMember(const std::string &name) const
@@ -157,7 +157,7 @@ GuildMember *Guild::getMember(const std::string &name) const
         ++itr;
     }
 
-    return NULL;
+    return nullptr;
 }
 
 void Guild::removeMember(GuildMember *member)
diff --git a/src/keyboardconfig.cpp b/src/keyboardconfig.cpp
index 3e387ba64..0079ee2ee 100644
--- a/src/keyboardconfig.cpp
+++ b/src/keyboardconfig.cpp
@@ -477,7 +477,7 @@ bool KeyboardConfig::isKeyActive(int index) const
 
 void KeyboardConfig::refreshActiveKeys()
 {
-    mActiveKeys = SDL_GetKeyState(NULL);
+    mActiveKeys = SDL_GetKeyState(nullptr);
 }
 
 std::string KeyboardConfig::getKeyValueString(int index) const
diff --git a/src/localconsts.h b/src/localconsts.h
new file mode 100644
index 000000000..cd7fcd955
--- /dev/null
+++ b/src/localconsts.h
@@ -0,0 +1,24 @@
+/*
+ *  The ManaPlus Client
+ *  Copyright (C) 2011  The ManaPlus Developers
+ *
+ *  This file is part of The ManaPlus Client.
+ *
+ *  This program is free software; you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License as published by
+ *  the Free Software Foundation; either version 2 of the License, or
+ *  any later version.
+ *
+ *  This program is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *  GNU General Public License for more details.
+ *
+ *  You should have received a copy of the GNU General Public License
+ *  along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#ifndef __GXX_EXPERIMENTAL_CXX0X__
+#undef nullptr
+#define nullptr 0
+#endif
diff --git a/src/localplayer.cpp b/src/localplayer.cpp
index a776f0165..a6289d9bb 100644
--- a/src/localplayer.cpp
+++ b/src/localplayer.cpp
@@ -89,7 +89,7 @@
 const short walkingKeyboardDelay = 1000;
 const short awayLimitTimer = 60;
 
-LocalPlayer *player_node = NULL;
+LocalPlayer *player_node = nullptr;
 
 extern std::list<BeingCacheEntry*> beingInfoCache;
 extern OkDialog *weightNotice;
@@ -101,10 +101,10 @@ LocalPlayer::LocalPlayer(int id, int subtype):
     Being(id, PLAYER, subtype, 0),
     mTargetTime(-1),
     mLastTarget(-1),
-    mTarget(NULL),
+    mTarget(nullptr),
     mPlayerFollowed(""),
     mPlayerImitated(""),
-    mPickUpTarget(NULL),
+    mPickUpTarget(nullptr),
     mGoingToTarget(false), mKeepAttacking(false),
     mLastAction(-1),
     mWalkingDir(0),
@@ -305,7 +305,7 @@ void LocalPlayer::logic()
     if (get_elapsed_time(mTargetTime) >= 60000)
     {
         mTargetTime = tick_time;
-//        setTarget(NULL);
+//        setTarget(nullptr);
         mLastTarget = -1;
     }
 
@@ -384,7 +384,7 @@ void LocalPlayer::setAction(Action action, int attackType)
             debugMsg(_("You were killed by ") + mLastHitFrom);
             mLastHitFrom = "";
         }
-        setTarget(NULL);
+        setTarget(nullptr);
     }
 
     Being::setAction(action, attackType);
@@ -942,7 +942,7 @@ bool LocalPlayer::pickUp(FloorItem *item)
     if (dx * dx + dy * dy < dist)
     {
         Net::getPlayerHandler()->pickUp(item);
-        mPickUpTarget = NULL;
+        mPickUpTarget = nullptr;
     }
     else if (mPickUpType >= 4 && mPickUpType <= 6)
     {
@@ -1408,7 +1408,7 @@ void LocalPlayer::untarget()
         setAction(STAND);
 
     if (mTarget)
-        setTarget(NULL);
+        setTarget(nullptr);
 
     mKeepAttacking = false;
     mLastTarget = -1;
@@ -1948,7 +1948,7 @@ void LocalPlayer::changeEquipmentBeforeAttack(Being* target)
     bool allowSword = false;
     int dx = target->getTileX() - mX;
     int dy = target->getTileY() - mY;
-    Item *item = NULL;
+    Item *item = nullptr;
 
     if (dx * dx + dy * dy > 80)
         return;
diff --git a/src/localplayer.h b/src/localplayer.h
index 4183f2d1b..08ebbe841 100644
--- a/src/localplayer.h
+++ b/src/localplayer.h
@@ -28,6 +28,7 @@
 #include "client.h"
 #include "game.h"
 #include "listener.h"
+#include "localconsts.h"
 
 #include "gui/userpalette.h"
 
@@ -136,10 +137,10 @@ class LocalPlayer : public Being, public ActorSpriteListener,
 
         int getAttackRange2();
 
-        void attack(Being *target = NULL, bool keep = false,
+        void attack(Being *target = nullptr, bool keep = false,
                     bool dontChangeEquipment = false);
 
-        void attack2(Being *target = NULL, bool keep = false,
+        void attack2(Being *target = nullptr, bool keep = false,
                      bool dontChangeEquipment = false);
 
         void setGMLevel(int level);
@@ -422,7 +423,7 @@ class LocalPlayer : public Being, public ActorSpriteListener,
         { return mPickUpTarget; }
 
         void unSetPickUpTarget()
-        { mPickUpTarget = 0; }
+        { mPickUpTarget = nullptr; }
 
         /**
          * Stop following a player.
diff --git a/src/logger.cpp b/src/logger.cpp
index 8ce92c6d6..129a8a884 100644
--- a/src/logger.cpp
+++ b/src/logger.cpp
@@ -43,7 +43,7 @@
 
 Logger::Logger():
     mLogToStandardOut(true),
-    mChatWindow(NULL),
+    mChatWindow(nullptr),
     mDebugLog(false)
 {
 }
@@ -80,7 +80,7 @@ void Logger::dlog(std::string str)
 
     // Get the current system time
     timeval tv;
-    gettimeofday(&tv, NULL);
+    gettimeofday(&tv, nullptr);
 
     // Print the log entry
     std::stringstream timeStr;
@@ -112,7 +112,7 @@ void Logger::log1(const char *buf)
 {
     // Get the current system time
     timeval tv;
-    gettimeofday(&tv, NULL);
+    gettimeofday(&tv, nullptr);
 
     // Print the log entry
     std::stringstream timeStr;
@@ -158,7 +158,7 @@ void Logger::log(const char *log_text, ...)
 
     // Get the current system time
     timeval tv;
-    gettimeofday(&tv, NULL);
+    gettimeofday(&tv, nullptr);
 
     // Print the log entry
     std::stringstream timeStr;
@@ -193,17 +193,17 @@ void Logger::error(const std::string &error_text)
 {
     log("Error: %s", error_text.c_str());
 #ifdef WIN32
-    MessageBox(NULL, error_text.c_str(), "Error", MB_ICONERROR | MB_OK);
+    MessageBox(nullptr, error_text.c_str(), "Error", MB_ICONERROR | MB_OK);
 #elif defined __APPLE__
 //    Str255 msg;
 //    CFStringRef error;
-//    error = CFStringCreateWithCString(NULL,
+//    error = CFStringCreateWithCString(nullptr,
 //                                      error_text.c_str(),
 //                                      kCFStringEncodingMacRoman);
 //    CFStringGetPascalString(error, msg, 255, kCFStringEncodingMacRoman);
 //    StandardAlert(kAlertStopAlert,
 //                  (const unsigned char*)"\pError",
-//                  (ConstStr255Param) msg, NULL, NULL);
+//                  (ConstStr255Param) msg, nullptr, nullptr);
 #elif defined __linux__ || __linux
     std::cerr << "Error: " << error_text << std::endl;
     std::string msg = "xmessage \"" + error_text + "\"";
diff --git a/src/main.cpp b/src/main.cpp
index be3140c99..166aab2b1 100644
--- a/src/main.cpp
+++ b/src/main.cpp
@@ -112,7 +112,7 @@ static void parseOptions(int argc, char *argv[], Client::Options &options)
 
     while (optind < argc)
     {
-        int result = getopt_long(argc, argv, optstring, long_options, NULL);
+        int result = getopt_long(argc, argv, optstring, long_options, nullptr);
 
         if (result == -1)
             break;
@@ -204,7 +204,7 @@ static void initXML()
     LIBXML_TEST_VERSION;
 
     // Suppress libxml2 error messages
-    xmlSetGenericErrorFunc(NULL, xmlNullLogger);
+    xmlSetGenericErrorFunc(nullptr, xmlNullLogger);
 }
 
 
diff --git a/src/map.cpp b/src/map.cpp
index dc742d6bb..676c01a48 100644
--- a/src/map.cpp
+++ b/src/map.cpp
@@ -90,7 +90,7 @@ class ActorFunctuator
 } actorCompare;
 
 TileAnimation::TileAnimation(Animation *ani):
-    mLastImage(NULL)
+    mLastImage(nullptr)
 {
     mAnimation = new SimpleAnimation(ani);
 }
@@ -1807,7 +1807,7 @@ TileAnimation *Map::getAnimationForGid(int gid) const
 
     std::map<int, TileAnimation*>::const_iterator
         i = mTileAnimations.find(gid);
-    return (i == mTileAnimations.end()) ? NULL : i->second;
+    return (i == mTileAnimations.end()) ? nullptr : i->second;
 }
 
 void Map::setPvpMode(int mode)
diff --git a/src/mumblemanager.cpp b/src/mumblemanager.cpp
index 2b3f15afa..fd95a67f9 100644
--- a/src/mumblemanager.cpp
+++ b/src/mumblemanager.cpp
@@ -86,7 +86,7 @@ void MumbleManager::init()
 #ifdef WIN32
     HANDLE hMapObject = OpenFileMappingW(FILE_MAP_ALL_ACCESS,
                                          FALSE, L"MumbleLink");
-    if (hMapObject == NULL)
+    if (!hMapObject)
     {
         logger->log1("MumbleManager::init can't open MumbleLink");
         return;
@@ -95,10 +95,10 @@ void MumbleManager::init()
     mLinkedMem = (LinkedMem *) MapViewOfFile(hMapObject,
         FILE_MAP_ALL_ACCESS, 0, 0, sizeof(LinkedMem));
 
-    if (mLinkedMem == NULL)
+    if (!mLinkedMem)
     {
         CloseHandle(hMapObject);
-        hMapObject = NULL;
+        hMapObject = nullptr;
         logger->log1("MumbleManager::init can't map MumbleLink");
         return;
     }
@@ -116,12 +116,12 @@ void MumbleManager::init()
         return;
     }
 
-    mLinkedMem = static_cast<LinkedMem *>(mmap(NULL, sizeof(struct LinkedMem),
+    mLinkedMem = static_cast<LinkedMem *>(mmap(nullptr, sizeof(struct LinkedMem),
         PROT_READ | PROT_WRITE, MAP_SHARED, shmfd, 0));
 
     if (mLinkedMem == reinterpret_cast<void *>(-1))
     {
-        mLinkedMem = NULL;
+        mLinkedMem = nullptr;
         logger->log1("MumbleManager::init can't map MumbleLink");
         return;
     }
diff --git a/src/net/download.cpp b/src/net/download.cpp
index 969318b19..dcce218a9 100644
--- a/src/net/download.cpp
+++ b/src/net/download.cpp
@@ -53,12 +53,12 @@ Download::Download(void *ptr, const std::string &url,
     mPtr(ptr),
     mUrl(url),
     mFileName(""),
-    mWriteFunction(NULL),
+    mWriteFunction(nullptr),
     mAdler(0),
     mUpdateFunction(updateFunction),
-    mThread(NULL),
-    mCurl(NULL),
-    mHeaders(NULL),
+    mThread(nullptr),
+    mCurl(nullptr),
+    mHeaders(nullptr),
     mIgnoreError(ignoreError)
 {
     mError = static_cast<char*>(calloc(CURL_ERROR_SIZE + 1, 1));
@@ -158,9 +158,9 @@ void Download::cancel()
 
     mOptions.cancel = true;
     if (mThread && SDL_GetThreadID(mThread))
-        SDL_WaitThread(mThread, NULL);
+        SDL_WaitThread(mThread, nullptr);
 
-    mThread = NULL;
+    mThread = nullptr;
 }
 
 char *Download::getError()
@@ -204,14 +204,14 @@ int Download::downloadThread(void *ptr)
 
     while (attempts < 3 && !complete && !d->mOptions.cancel)
     {
-        FILE *file = NULL;
+        FILE *file = nullptr;
 
         d->mUpdateFunction(d->mPtr, DOWNLOAD_STATUS_STARTING, 0, 0);
 
         if (d->mOptions.cancel)
         {
             //need terminate thread?
-            d->mThread = NULL;
+            d->mThread = nullptr;
             return 0;
         }
 
@@ -335,7 +335,7 @@ int Download::downloadThread(void *ptr)
         if (d->mOptions.cancel)
         {
             //need ternibate thread?
-            d->mThread = NULL;
+            d->mThread = nullptr;
             return 0;
         }
         attempts++;
@@ -354,7 +354,7 @@ int Download::downloadThread(void *ptr)
         d->mUpdateFunction(d->mPtr, DOWNLOAD_STATUS_COMPLETE, 0, 0);
     }
 
-    d->mThread = NULL;
+    d->mThread = nullptr;
     return 0;
 }
 
diff --git a/src/net/ea/gamehandler.cpp b/src/net/ea/gamehandler.cpp
index a202cbc86..b74f2384d 100644
--- a/src/net/ea/gamehandler.cpp
+++ b/src/net/ea/gamehandler.cpp
@@ -96,7 +96,7 @@ void GameHandler::processCharSwitchResponse(Net::MessageIn &msg)
 void GameHandler::processMapQuitResponse(Net::MessageIn &msg)
 {
     if (msg.readInt8())
-        new OkDialog(_("Game"), _("Request to quit denied!"), NULL);
+        new OkDialog(_("Game"), _("Request to quit denied!"), nullptr);
 }
 
 } // namespace Ea
diff --git a/src/net/ea/inventoryhandler.h b/src/net/ea/inventoryhandler.h
index 3a99bc47f..72b993c4b 100644
--- a/src/net/ea/inventoryhandler.h
+++ b/src/net/ea/inventoryhandler.h
@@ -25,6 +25,7 @@
 
 #include "equipment.h"
 #include "inventory.h"
+#include "localconsts.h"
 #include "logger.h"
 #include "playerinfo.h"
 
@@ -58,7 +59,7 @@ class EquipBackend : public Equipment::Backend
         {
             int invyIndex = mEquipment[index];
             if (invyIndex == -1)
-                return NULL;
+                return nullptr;
 
             if (PlayerInfo::getInventory())
                 return PlayerInfo::getInventory()->getItem(invyIndex);
diff --git a/src/net/ea/playerhandler.cpp b/src/net/ea/playerhandler.cpp
index 3009426ae..02af3dbb4 100644
--- a/src/net/ea/playerhandler.cpp
+++ b/src/net/ea/playerhandler.cpp
@@ -59,7 +59,7 @@ namespace
     {
         void action(const gcn::ActionEvent &event A_UNUSED)
         {
-            weightNotice = NULL;
+            weightNotice = nullptr;
         }
     } weightListener;
 
@@ -72,7 +72,7 @@ namespace
         {
             if (Net::getPlayerHandler())
                 Net::getPlayerHandler()->respawn();
-            deathNotice = NULL;
+            deathNotice = nullptr;
 
             Game::closeDialogs();
 
diff --git a/src/net/manaserv/network.cpp b/src/net/manaserv/network.cpp
index b83bc5748..3303934bd 100644
--- a/src/net/manaserv/network.cpp
+++ b/src/net/manaserv/network.cpp
@@ -56,9 +56,9 @@ void initialize()
     }
 
 #if defined(ENET_VERSION) && ENET_VERSION >= ENET_CUTOFF
-    client = enet_host_create(NULL, 3, 0, 0, 0);
+    client = enet_host_create(nullptr, 3, 0, 0, 0);
 #else
-    client = enet_host_create(NULL, 3, 0, 0);
+    client = enet_host_create(nullptr, 3, 0, 0);
 #endif
 
     if (!client)
diff --git a/src/net/manaserv/partyhandler.cpp b/src/net/manaserv/partyhandler.cpp
index 987a40dc5..660657f44 100644
--- a/src/net/manaserv/partyhandler.cpp
+++ b/src/net/manaserv/partyhandler.cpp
@@ -96,7 +96,7 @@ void PartyHandler::handleMessage(Net::MessageIn &msg)
             if (msg.readInt8() == ERRMSG_OK)
             {
                 mParty->clearMembers();
-                player_node->setParty(NULL);
+                player_node->setParty(nullptr);
             }
         } break;
 
diff --git a/src/net/net.cpp b/src/net/net.cpp
index 49bb58903..933f7686b 100644
--- a/src/net/net.cpp
+++ b/src/net/net.cpp
@@ -48,21 +48,21 @@
 
 #include "debug.h"
 
-Net::AdminHandler *adminHandler = NULL;
-Net::CharHandler *charHandler = NULL;
-Net::ChatHandler *chatHandler = NULL;
-Net::GeneralHandler *generalHandler = NULL;
-Net::InventoryHandler *inventoryHandler = NULL;
-Net::LoginHandler *loginHandler = NULL;
-Net::GameHandler *gameHandler = NULL;
-Net::GuildHandler *guildHandler = NULL;
-Net::NpcHandler *npcHandler = NULL;
-Net::PartyHandler *partyHandler = NULL;
-Net::PlayerHandler *playerHandler = NULL;
-Net::SpecialHandler *specialHandler = NULL;
-Net::TradeHandler *tradeHandler = NULL;
-Net::BeingHandler *beingHandler = NULL;
-Net::BuySellHandler *buySellHandler = NULL;
+Net::AdminHandler *adminHandler = nullptr;
+Net::CharHandler *charHandler = nullptr;
+Net::ChatHandler *chatHandler = nullptr;
+Net::GeneralHandler *generalHandler = nullptr;
+Net::InventoryHandler *inventoryHandler = nullptr;
+Net::LoginHandler *loginHandler = nullptr;
+Net::GameHandler *gameHandler = nullptr;
+Net::GuildHandler *guildHandler = nullptr;
+Net::NpcHandler *npcHandler = nullptr;
+Net::PartyHandler *partyHandler = nullptr;
+Net::PlayerHandler *playerHandler = nullptr;
+Net::SpecialHandler *specialHandler = nullptr;
+Net::TradeHandler *tradeHandler = nullptr;
+Net::BeingHandler *beingHandler = nullptr;
+Net::BuySellHandler *buySellHandler = nullptr;
 
 Net::AdminHandler *Net::getAdminHandler()
 {
@@ -151,13 +151,13 @@ void connectToServer(const ServerInfo &server)
         // that
     }
 
-    if (networkType == server.type && getGeneralHandler() != NULL)
+    if (networkType == server.type && getGeneralHandler())
     {
         getGeneralHandler()->reload();
     }
     else
     {
-        if (networkType != ServerInfo::UNKNOWN && getGeneralHandler() != NULL)
+        if (networkType != ServerInfo::UNKNOWN && getGeneralHandler())
             getGeneralHandler()->unload();
 
         switch (server.type)
diff --git a/src/net/tmwa/messagehandler.cpp b/src/net/tmwa/messagehandler.cpp
index 843339718..830b3bc4f 100644
--- a/src/net/tmwa/messagehandler.cpp
+++ b/src/net/tmwa/messagehandler.cpp
@@ -32,7 +32,7 @@ namespace TmwAthena
 {
 
 MessageHandler::MessageHandler()
-    : mNetwork(NULL)
+    : mNetwork(nullptr)
 {
 }
 
diff --git a/src/net/tmwa/network.cpp b/src/net/tmwa/network.cpp
index e26f48324..6f26035be 100644
--- a/src/net/tmwa/network.cpp
+++ b/src/net/tmwa/network.cpp
@@ -181,8 +181,8 @@ void Network::disconnect()
 
     if (mWorkerThread && SDL_GetThreadID(mWorkerThread))
     {
-        SDL_WaitThread(mWorkerThread, NULL);
-        mWorkerThread = NULL;
+        SDL_WaitThread(mWorkerThread, nullptr);
+        mWorkerThread = nullptr;
     }
 
     if (mSocket)
diff --git a/src/particle.cpp b/src/particle.cpp
index 874e49d9a..e71791ce8 100644
--- a/src/particle.cpp
+++ b/src/particle.cpp
@@ -73,7 +73,7 @@ Particle::Particle(Map *map):
     mRandomness(0),
     mBounce(0.0f),
     mFollow(false),
-    mTarget(NULL),
+    mTarget(nullptr),
     mAcceleration(0.0f),
     mInvDieDistance(-1.0f),
     mMomentum(1.0f)
@@ -283,7 +283,7 @@ Particle *Particle::createChild()
 Particle *Particle::addEffect(const std::string &particleEffectFile,
                               int pixelX, int pixelY, int rotation)
 {
-    Particle *newParticle = NULL;
+    Particle *newParticle = nullptr;
 
     std::string::size_type pos = particleEffectFile.find('|');
     std::string dyePalettes;
@@ -296,7 +296,7 @@ Particle *Particle::addEffect(const std::string &particleEffectFile,
     if (!rootNode || !xmlStrEqual(rootNode->name, BAD_CAST "effect"))
     {
         logger->log("Error loading particle: %s", particleEffectFile.c_str());
-        return NULL;
+        return nullptr;
     }
 
     ResourceManager *resman = ResourceManager::getInstance();
diff --git a/src/particle.h b/src/particle.h
index 7220ad258..0a4a2253d 100644
--- a/src/particle.h
+++ b/src/particle.h
@@ -76,7 +76,7 @@ class Particle : public Actor
         /**
          * Constructor.
          *
-         * @param map the map this particle will add itself to, may be NULL
+         * @param map the map this particle will add itself to, may be nullptr
          */
         Particle(Map *map);
 
diff --git a/src/particlecontainer.cpp b/src/particlecontainer.cpp
index 5f5b1b257..c839e3c8d 100644
--- a/src/particlecontainer.cpp
+++ b/src/particlecontainer.cpp
@@ -139,7 +139,7 @@ void ParticleVector::setLocally(int index, Particle *particle)
     delLocally(index);
 
     if (mIndexedElements.size() <= static_cast<unsigned>(index))
-        mIndexedElements.resize(index + 1, NULL);
+        mIndexedElements.resize(index + 1, nullptr);
 
     if (particle)
         particle->disableAutoDelete();
@@ -157,7 +157,7 @@ void ParticleVector::delLocally(int index)
     Particle *p = mIndexedElements[index];
     if (p)
     {
-        mIndexedElements[index] = NULL;
+        mIndexedElements[index] = nullptr;
         p->kill();
     }
 }
@@ -182,7 +182,7 @@ void ParticleVector::moveTo(float x, float y)
             if ((*it)->isExtinct())
             {
                 (*it)->kill();
-                *it = NULL;
+                *it = nullptr;
             }
         }
     }
diff --git a/src/particlecontainer.h b/src/particlecontainer.h
index 27b52f592..75cda83fc 100644
--- a/src/particlecontainer.h
+++ b/src/particlecontainer.h
@@ -26,6 +26,8 @@
 #include <list>
 #include <vector>
 
+#include "localconsts.h"
+
 class Particle;
 
 /**
@@ -42,7 +44,7 @@ public:
      *
      * delParent means that the destructor should also free the parent.
      */
-    ParticleContainer(ParticleContainer *parent = NULL, bool delParent = true);
+    ParticleContainer(ParticleContainer *parent = nullptr, bool delParent = true);
     virtual ~ParticleContainer();
 
     /**
@@ -71,7 +73,7 @@ protected:
 class ParticleList : public ParticleContainer
 {
 public:
-    ParticleList(ParticleContainer *parent = NULL, bool delParent = true);
+    ParticleList(ParticleContainer *parent = nullptr, bool delParent = true);
     virtual ~ParticleList();
 
     /**
@@ -98,7 +100,7 @@ protected:
 class ParticleVector : public ParticleContainer
 {
 public:
-    ParticleVector(ParticleContainer *parent = NULL, bool delParent = true);
+    ParticleVector(ParticleContainer *parent = nullptr, bool delParent = true);
     virtual ~ParticleVector();
 
     /**
diff --git a/src/party.cpp b/src/party.cpp
index cb45fa355..6546391cd 100644
--- a/src/party.cpp
+++ b/src/party.cpp
@@ -95,7 +95,7 @@ PartyMember *Party::getMember(int id) const
         ++itr;
     }
 
-    return NULL;
+    return nullptr;
 }
 
 PartyMember *Party::getMember(const std::string &name) const
@@ -110,7 +110,7 @@ PartyMember *Party::getMember(const std::string &name) const
         ++itr;
     }
 
-    return NULL;
+    return nullptr;
 }
 
 void Party::removeMember(PartyMember *member)
diff --git a/src/playerrelations.cpp b/src/playerrelations.cpp
index 8facfdefb..69be97898 100644
--- a/src/playerrelations.cpp
+++ b/src/playerrelations.cpp
@@ -69,7 +69,7 @@ class PlayerConfSerialiser :
         ConfigurationObject *cobj)
     {
         if (!cobj || !value.second)
-            return NULL;
+            return nullptr;
         cobj->setValue(NAME, value.first);
         cobj->setValue(RELATION, toString(
                 static_cast<int>(value.second->mRelation)));
diff --git a/src/playerrelations.h b/src/playerrelations.h
index 6cb175ec2..5fabb3d0e 100644
--- a/src/playerrelations.h
+++ b/src/playerrelations.h
@@ -182,7 +182,7 @@ class PlayerRelationsManager
         /**
          * Return the current player ignore strategy.
          *
-         * \return A player ignore strategy, or NULL
+         * \return A player ignore strategy, or nullptr
          */
         PlayerIgnoreStrategy *getPlayerIgnoreStrategy() const
         { return mIgnoreStrategy; }
diff --git a/src/resources/action.cpp b/src/resources/action.cpp
index a95ebc5e3..c2af3ff9b 100644
--- a/src/resources/action.cpp
+++ b/src/resources/action.cpp
@@ -61,7 +61,7 @@ Animation *Action::getAnimation(int direction) const
             i = mAnimations.begin();
     }
 
-    return (i == mAnimations.end()) ? NULL : i->second;
+    return (i == mAnimations.end()) ? nullptr : i->second;
 }
 
 void Action::setAnimation(int direction, Animation *animation)
diff --git a/src/resources/animation.cpp b/src/resources/animation.cpp
index 32b57b3b1..363e9b2ac 100644
--- a/src/resources/animation.cpp
+++ b/src/resources/animation.cpp
@@ -44,12 +44,12 @@ void Animation::addFrame(Image *image, int delay, int offsetX, int offsetY,
 
 void Animation::addTerminator(int rand)
 {
-    addFrame(NULL, 0, 0, 0, rand);
+    addFrame(nullptr, 0, 0, 0, rand);
 }
 
 bool Animation::isTerminator(const Frame &candidate)
 {
-    return (candidate.image == NULL && candidate.type == Frame::ANIMATION);
+    return (!candidate.image && candidate.type == Frame::ANIMATION);
 }
 
 void Animation::addJump(std::string name, int rand)
diff --git a/src/resources/emotedb.cpp b/src/resources/emotedb.cpp
index b7f7d7901..c456c49e4 100644
--- a/src/resources/emotedb.cpp
+++ b/src/resources/emotedb.cpp
@@ -199,7 +199,7 @@ const EmoteInfo *EmoteDB::get(int id, bool allowNull)
     if (i == mEmoteInfos.end())
     {
         if (allowNull)
-            return NULL;
+            return nullptr;
         logger->log("EmoteDB: Warning, unknown emote ID %d requested", id);
         return &mUnknown;
     }
@@ -213,7 +213,7 @@ const AnimatedSprite *EmoteDB::getAnimation(int id, bool allowNull)
 {
     const EmoteInfo *info = get(id, allowNull);
     if (!info)
-        return NULL;
+        return nullptr;
 
     return info->sprites.front()->sprite;
 }
@@ -222,7 +222,7 @@ const EmoteSprite *EmoteDB::getSprite(int id, bool allowNull)
 {
     const EmoteInfo *info = get(id, allowNull);
     if (!info)
-        return NULL;
+        return nullptr;
 
     return info->sprites.front();
 }
diff --git a/src/resources/image.cpp b/src/resources/image.cpp
index 8f5ee1d2d..537630a2c 100644
--- a/src/resources/image.cpp
+++ b/src/resources/image.cpp
@@ -128,7 +128,7 @@ Resource *Image::load(void *buffer, unsigned bufferSize)
     if (!tmpImage)
     {
         logger->log("Error, image load failed: %s", IMG_GetError());
-        return NULL;
+        return nullptr;
     }
 
     Image *image = load(tmpImage);
@@ -145,11 +145,11 @@ Resource *Image::load(void *buffer, unsigned bufferSize, Dye const &dye)
     if (!tmpImage)
     {
         logger->log("Error, image load failed: %s", IMG_GetError());
-        return NULL;
+        return nullptr;
     }
 
     SDL_PixelFormat rgba;
-    rgba.palette = NULL;
+    rgba.palette = nullptr;
     rgba.BitsPerPixel = 32;
     rgba.BytesPerPixel = 4;
     rgba.Rmask = 0xFF000000; rgba.Rloss = 0; rgba.Rshift = 24;
@@ -195,7 +195,7 @@ Image *Image::load(SDL_Surface *tmpImage)
 Image *Image::createTextSurface(SDL_Surface *tmpImage, float alpha)
 {
     if (!tmpImage)
-        return NULL;
+        return nullptr;
 
     Image *img;
 #ifdef USE_OPENGL
@@ -293,10 +293,10 @@ void Image::unload()
         SDLCleanCache();
         // Free the image surface.
         SDL_FreeSurface(mSDLSurface);
-        mSDLSurface = NULL;
+        mSDLSurface = nullptr;
 
         delete[] mAlphaChannel;
-        mAlphaChannel = NULL;
+        mAlphaChannel = nullptr;
     }
 
 #ifdef USE_OPENGL
@@ -451,7 +451,7 @@ void Image::setAlpha(float alpha)
 Image* Image::SDLmerge(Image *image, int x, int y)
 {
     if (!mSDLSurface || !image || !image->mSDLSurface)
-        return NULL;
+        return nullptr;
 
     SDL_Surface* surface = new SDL_Surface(*(image->mSDLSurface));
 
@@ -543,14 +543,14 @@ Image* Image::SDLgetScaledImage(int width, int height)
 {
     // No scaling on incorrect new values.
     if (width == 0 || height == 0)
-        return NULL;
+        return nullptr;
 
     // No scaling when there is ... no different given size ...
     if (width == getWidth() && height == getHeight())
-        return NULL;
+        return nullptr;
 
-    Image* scaledImage = NULL;
-    SDL_Surface* scaledSurface = NULL;
+    Image* scaledImage = nullptr;
+    SDL_Surface* scaledSurface = nullptr;
 
     if (mSDLSurface)
     {
@@ -573,7 +573,7 @@ Image* Image::SDLgetScaledImage(int width, int height)
 SDL_Surface* Image::convertTo32Bit(SDL_Surface* tmpImage)
 {
     if (!tmpImage)
-        return NULL;
+        return nullptr;
     SDL_PixelFormat RGBAFormat;
     RGBAFormat.palette = 0;
     RGBAFormat.colorkey = 0;
@@ -613,7 +613,7 @@ SDL_Surface* Image::convertTo32Bit(SDL_Surface* tmpImage)
 SDL_Surface* Image::SDLDuplicateSurface(SDL_Surface* tmpImage)
 {
     if (!tmpImage || !tmpImage->format)
-        return NULL;
+        return nullptr;
 
     return SDL_ConvertSurface(tmpImage, tmpImage->format, SDL_SWSURFACE);
 }
@@ -621,7 +621,7 @@ SDL_Surface* Image::SDLDuplicateSurface(SDL_Surface* tmpImage)
 Image *Image::_SDLload(SDL_Surface *tmpImage)
 {
     if (!tmpImage)
-        return NULL;
+        return nullptr;
 
     bool hasAlpha = false;
     bool converted = false;
@@ -636,14 +636,14 @@ Image *Image::_SDLload(SDL_Surface *tmpImage)
         if (!tmpImage)
         {
             delete[] alphaChannel;
-            return NULL;
+            return nullptr;
         }
         converted = true;
     }
 
     const int sz = tmpImage->w * tmpImage->h;
     // Figure out whether the image uses its alpha layer
-    if (tmpImage->format->palette == NULL)
+    if (!tmpImage->format->palette)
     {
         const SDL_PixelFormat * const fmt = tmpImage->format;
         if (fmt->Amask)
@@ -713,7 +713,7 @@ Image *Image::_SDLload(SDL_Surface *tmpImage)
 Image *Image::_GLload(SDL_Surface *tmpImage)
 {
     if (!tmpImage)
-        return NULL;
+        return nullptr;
 
     // Flush current error flag.
     glGetError();
@@ -753,10 +753,10 @@ Image *Image::_GLload(SDL_Surface *tmpImage)
     if (!tmpImage)
     {
         logger->log("Error, image convert failed: out of memory");
-        return NULL;
+        return nullptr;
     }
 
-    SDL_BlitSurface(oldImage, NULL, tmpImage, NULL);
+    SDL_BlitSurface(oldImage, nullptr, tmpImage, nullptr);
 
     GLuint texture;
     glGenTextures(1, &texture);
@@ -811,7 +811,7 @@ Image *Image::_GLload(SDL_Surface *tmpImage)
                 break;
         }
         logger->log("Error: Image GL import failed: %s", errmsg.c_str());
-        return NULL;
+        return nullptr;
     }
 
     return new Image(texture, width, height, realWidth, realHeight);
@@ -939,5 +939,5 @@ Image *SubImage::getSubImage(int x, int y, int w, int h)
     if (mParent)
         return mParent->getSubImage(mBounds.x + x, mBounds.y + y, w, h);
     else
-        return NULL;
+        return nullptr;
 }
diff --git a/src/resources/image.h b/src/resources/image.h
index 941b34465..333dc63f9 100644
--- a/src/resources/image.h
+++ b/src/resources/image.h
@@ -23,6 +23,7 @@
 #ifndef IMAGE_H
 #define IMAGE_H
 
+#include "localconsts.h"
 #include "main.h"
 
 #include "resources/resource.h"
@@ -252,7 +253,7 @@ class Image : public Resource
 
         /** SDL Constructor */
         Image(SDL_Surface *image, bool hasAlphaChannel = false,
-              Uint8 *alphaChannel = NULL);
+              Uint8 *alphaChannel = nullptr);
 
         /** SDL_Surface to SDL_Surface Image loader */
         static Image *_SDLload(SDL_Surface *tmpImage);
diff --git a/src/resources/imageloader.cpp b/src/resources/imageloader.cpp
index 72a839573..d88e633be 100644
--- a/src/resources/imageloader.cpp
+++ b/src/resources/imageloader.cpp
@@ -36,7 +36,8 @@
 #endif
 
 ProxyImage::ProxyImage(SDL_Surface *s):
-    mImage(NULL), mSDLImage(s)
+    mImage(nullptr),
+    mSDLImage(s)
 {
 }
 
@@ -103,7 +104,7 @@ void ProxyImage::convertToDisplayFormat()
                     SDL_MapRGB(mSDLImage->format, 255, 0, 255));
     mImage = ::Image::load(mSDLImage);
     SDL_FreeSurface(mSDLImage);
-    mSDLImage = NULL;
+    mSDLImage = nullptr;
 }
 
 gcn::Image *ImageLoader::load(const std::string &filename, bool convert)
diff --git a/src/resources/imageset.cpp b/src/resources/imageset.cpp
index 5cf3e7d82..09b57be28 100644
--- a/src/resources/imageset.cpp
+++ b/src/resources/imageset.cpp
@@ -62,7 +62,7 @@ Image* ImageSet::get(size_type i) const
     {
         logger->log("Warning: No sprite %d in this image set",
             static_cast<int>(i));
-        return NULL;
+        return nullptr;
     }
     else
     {
diff --git a/src/resources/imagewriter.cpp b/src/resources/imagewriter.cpp
index e6f3c8c27..2498f9c31 100644
--- a/src/resources/imagewriter.cpp
+++ b/src/resources/imagewriter.cpp
@@ -60,14 +60,14 @@ bool ImageWriter::writePNG(SDL_Surface *surface, const std::string &filename)
     info_ptr = png_create_info_struct(png_ptr);
     if (!info_ptr)
     {
-        png_destroy_write_struct(&png_ptr, static_cast<png_infopp>(NULL));
+        png_destroy_write_struct(&png_ptr, static_cast<png_infopp>(nullptr));
         logger->log1("Could not create png_info");
         return false;
     }
 
     if (setjmp(png_jmpbuf(png_ptr)))
     {
-        png_destroy_write_struct(&png_ptr, static_cast<png_infopp>(NULL));
+        png_destroy_write_struct(&png_ptr, static_cast<png_infopp>(nullptr));
         logger->log("problem writing to %s", filename.c_str());
         return false;
     }
@@ -113,7 +113,7 @@ bool ImageWriter::writePNG(SDL_Surface *surface, const std::string &filename)
 
     delete [] row_pointers;
 
-    png_destroy_write_struct(&png_ptr, static_cast<png_infopp>(NULL));
+    png_destroy_write_struct(&png_ptr, static_cast<png_infopp>(nullptr));
 
     if (SDL_MUSTLOCK(surface))
         SDL_UnlockSurface(surface);
diff --git a/src/resources/mapreader.cpp b/src/resources/mapreader.cpp
index f702864ea..a6e1074f3 100644
--- a/src/resources/mapreader.cpp
+++ b/src/resources/mapreader.cpp
@@ -102,7 +102,7 @@ int inflateMemory(unsigned char *in, unsigned int inLength,
 
     do
     {
-        if (strm.next_out == NULL)
+        if (!strm.next_out)
         {
             inflateEnd(&strm);
             return Z_MEM_ERROR;
@@ -128,7 +128,7 @@ int inflateMemory(unsigned char *in, unsigned int inLength,
         {
             out = static_cast<unsigned char*>(realloc(out, bufferSize * 2));
 
-            if (out == NULL)
+            if (!out)
             {
                 inflateEnd(&strm);
                 return Z_MEM_ERROR;
@@ -153,7 +153,7 @@ int inflateMemory(unsigned char *in, unsigned int inLength,
     unsigned int outLength = 0;
     int ret = inflateMemory(in, inLength, out, outLength);
 
-    if (ret != Z_OK || out == NULL)
+    if (ret != Z_OK || !out)
     {
         if (ret == Z_MEM_ERROR)
         {
@@ -173,7 +173,7 @@ int inflateMemory(unsigned char *in, unsigned int inLength,
         }
 
         free(out);
-        out = NULL;
+        out = nullptr;
         outLength = 0;
     }
 
@@ -188,12 +188,12 @@ Map *MapReader::readMap(const std::string &filename,
     ResourceManager *resman = ResourceManager::getInstance();
     int fileSize;
     void *buffer = resman->loadFile(realFilename, fileSize);
-    Map *map = NULL;
+    Map *map = nullptr;
 
-    if (buffer == NULL)
+    if (!buffer)
     {
         logger->log("Map file not found (%s)", realFilename.c_str());
-        return NULL;
+        return nullptr;
     }
 
     unsigned char *inflated;
@@ -207,11 +207,11 @@ Map *MapReader::readMap(const std::string &filename,
             fileSize, inflated);
         free(buffer);
 
-        if (inflated == NULL)
+        if (!inflated)
         {
             logger->log("Could not decompress map file (%s)",
                         realFilename.c_str());
-            return NULL;
+            return nullptr;
         }
     }
     else
@@ -651,13 +651,13 @@ Tileset *MapReader::readTileset(xmlNodePtr node, const std::string &path,
                                 Map *map)
 {
     if (!map)
-        return NULL;
+        return nullptr;
 
     int firstGid = XML::getProperty(node, "firstgid", 0);
     int margin = XML::getProperty(node, "margin", 0);
     int spacing = XML::getProperty(node, "spacing", 0);
-    XML::Document* doc = NULL;
-    Tileset *set = NULL;
+    XML::Document* doc = nullptr;
+    Tileset *set = nullptr;
     std::string pathDir(path);
 
     if (xmlHasProp(node, BAD_CAST "source"))
diff --git a/src/resources/music.cpp b/src/resources/music.cpp
index 5ae9a2202..099d030b0 100644
--- a/src/resources/music.cpp
+++ b/src/resources/music.cpp
@@ -54,7 +54,7 @@ Resource *Music::load(void *buffer, unsigned bufferSize)
     else
     {
         logger->log("Error, failed to load music: %s", Mix_GetError());
-        return NULL;
+        return nullptr;
     }
 }
 
diff --git a/src/resources/resourcemanager.cpp b/src/resources/resourcemanager.cpp
index fcba17812..af9f664d4 100644
--- a/src/resources/resourcemanager.cpp
+++ b/src/resources/resourcemanager.cpp
@@ -48,7 +48,7 @@
 
 #include "debug.h"
 
-ResourceManager *ResourceManager::instance = NULL;
+ResourceManager *ResourceManager::instance = nullptr;
 
 ResourceManager::ResourceManager() :
     mOldestOrphan(0),
@@ -177,7 +177,7 @@ void ResourceManager::cleanUp(Resource *res)
 void ResourceManager::cleanOrphans(bool always)
 {
     timeval tv;
-    gettimeofday(&tv, NULL);
+    gettimeofday(&tv, nullptr);
     // Delete orphaned resources after 30 seconds.
     time_t oldest = tv.tv_sec, threshold = oldest - 30;
 
@@ -324,7 +324,7 @@ std::string ResourceManager::getPath(const std::string &file)
     const char* tmp = PHYSFS_getRealDir(file.c_str());
     std::string path;
 
-    // if the file is not in the search path, then its NULL
+    // if the file is not in the search path, then its nullptr
     if (tmp)
     {
         path = std::string(tmp) + "/" + file;
@@ -388,7 +388,7 @@ Resource *ResourceManager::get(const std::string &idPath, generator fun,
         logger->log("Error loaging image: " + idPath);
     }
 
-    // Returns NULL if the object could not be created.
+    // Returns nullptr if the object could not be created.
     return resource;
 }
 
@@ -400,14 +400,14 @@ struct ResourceLoader
     static Resource *load(void *v)
     {
         if (!v)
-            return NULL;
+            return nullptr;
         ResourceLoader *l = static_cast< ResourceLoader * >(v);
         int fileSize;
         if (!l->manager)
-            return NULL;
+            return nullptr;
         void *buffer = l->manager->loadFile(l->path, fileSize);
         if (!buffer)
-            return NULL;
+            return nullptr;
         Resource *res = l->fun(buffer, fileSize);
         free(buffer);
         return res;
@@ -437,15 +437,15 @@ struct DyedImageLoader
     static Resource *load(void *v)
     {
         if (!v)
-            return NULL;
+            return nullptr;
 
         DyedImageLoader *l = static_cast< DyedImageLoader * >(v);
         if (!l->manager)
-            return NULL;
+            return nullptr;
 
         std::string path = l->path;
         std::string::size_type p = path.find('|');
-        Dye *d = NULL;
+        Dye *d = nullptr;
         if (p != std::string::npos)
         {
             d = new Dye(path.substr(p + 1));
@@ -495,15 +495,15 @@ struct ImageSetLoader
     static Resource *load(void *v)
     {
         if (!v)
-            return NULL;
+            return nullptr;
 
         ImageSetLoader *l = static_cast< ImageSetLoader * >(v);
         if (!l->manager)
-            return NULL;
+            return nullptr;
 
         Image *img = l->manager->getImage(l->path);
         if (!img)
-            return NULL;
+            return nullptr;
         ImageSet *res = new ImageSet(img, l->w, l->h);
         img->decRef();
         return res;
@@ -526,7 +526,7 @@ struct SpriteDefLoader
     static Resource *load(void *v)
     {
         if (!v)
-            return NULL;
+            return nullptr;
 
         SpriteDefLoader *l = static_cast< SpriteDefLoader * >(v);
         return SpriteDef::load(l->path, l->variant);
@@ -552,7 +552,7 @@ void ResourceManager::release(Resource *res)
     assert(resIter != mResources.end() && resIter->second == res);
 
     timeval tv;
-    gettimeofday(&tv, NULL);
+    gettimeofday(&tv, nullptr);
     time_t timestamp = tv.tv_sec;
 
     res->mTimeStamp = timestamp;
@@ -583,11 +583,11 @@ void *ResourceManager::loadFile(const std::string &fileName, int &fileSize)
     PHYSFS_file *file = PHYSFS_openRead(fileName.c_str());
 
     // If the handler is an invalid pointer indicate failure
-    if (file == NULL)
+    if (!file)
     {
         logger->log("Warning: Failed to load %s: %s",
                     fileName.c_str(), PHYSFS_getLastError());
-        return NULL;
+        return nullptr;
     }
 
     // Log the real dir of the file
@@ -698,7 +698,7 @@ SDL_Surface *ResourceManager::loadSDLSurface(const std::string &filename)
 {
     int fileSize;
     void *buffer = loadFile(filename, fileSize);
-    SDL_Surface *tmp = NULL;
+    SDL_Surface *tmp = nullptr;
 
     if (buffer)
     {
@@ -734,13 +734,13 @@ struct RescaledLoader
     static Resource *load(void *v)
     {
         if (!v)
-            return NULL;
+            return nullptr;
         RescaledLoader *l = static_cast< RescaledLoader * >(v);
         if (!l->manager)
-            return NULL;
+            return nullptr;
         Image *rescaled = l->image->SDLgetScaledImage(l->width, l->height);
         if (!rescaled)
-            return NULL;
+            return nullptr;
         return rescaled;
     }
 };
diff --git a/src/resources/soundeffect.cpp b/src/resources/soundeffect.cpp
index e8e5d3dbb..a8da8dd80 100644
--- a/src/resources/soundeffect.cpp
+++ b/src/resources/soundeffect.cpp
@@ -34,7 +34,7 @@ SoundEffect::~SoundEffect()
 Resource *SoundEffect::load(void *buffer, unsigned bufferSize)
 {
     if (!buffer)
-        return NULL;
+        return nullptr;
 
     // Load the raw file data from the buffer in an RWops structure
     SDL_RWops *rw = SDL_RWFromMem(buffer, bufferSize);
@@ -49,7 +49,7 @@ Resource *SoundEffect::load(void *buffer, unsigned bufferSize)
     else
     {
         logger->log("Error, failed to load sound effect: %s", Mix_GetError());
-        return NULL;
+        return nullptr;
     }
 }
 
diff --git a/src/resources/specialdb.cpp b/src/resources/specialdb.cpp
index 2463da06a..51ba4bc74 100644
--- a/src/resources/specialdb.cpp
+++ b/src/resources/specialdb.cpp
@@ -126,9 +126,9 @@ SpecialInfo *SpecialDB::get(int id)
     SpecialInfos::const_iterator i = mSpecialInfos.find(id);
 
     if (i == mSpecialInfos.end())
-        return NULL;
+        return nullptr;
     else
         return i->second;
-    return NULL;
+    return nullptr;
 }
 
diff --git a/src/resources/spritedef.cpp b/src/resources/spritedef.cpp
index 2e32f6c5f..2d49e8cd1 100644
--- a/src/resources/spritedef.cpp
+++ b/src/resources/spritedef.cpp
@@ -48,7 +48,7 @@ Action *SpriteDef::getAction(std::string action) const
     if (i == mActions.end())
     {
         logger->log("Warning: no action \"%s\" defined!", action.c_str());
-        return NULL;
+        return nullptr;
     }
 
     return i->second;
@@ -73,7 +73,7 @@ SpriteDef *SpriteDef::load(const std::string &animationFile, int variant)
         if (animationFile != errorFile)
             return load(errorFile, 0);
         else
-            return NULL;
+            return nullptr;
     }
 
     SpriteDef *def = new SpriteDef;
diff --git a/src/resources/wallpaper.cpp b/src/resources/wallpaper.cpp
index 5cfec3b84..93eb8a40f 100644
--- a/src/resources/wallpaper.cpp
+++ b/src/resources/wallpaper.cpp
@@ -94,7 +94,7 @@ void Wallpaper::loadWallpapers()
 
     char **imgs = PHYSFS_enumerateFiles(wallpaperPath.c_str());
 
-    for (char **i = imgs; *i != NULL; i++)
+    for (char **i = imgs; *i; i++)
     {
         int width;
         int height;
diff --git a/src/rotationalparticle.cpp b/src/rotationalparticle.cpp
index 60d818cd9..c1bb6ab45 100644
--- a/src/rotationalparticle.cpp
+++ b/src/rotationalparticle.cpp
@@ -29,7 +29,7 @@
 #define PI 3.14159265
 
 RotationalParticle::RotationalParticle(Map *map, Animation *animation):
-    ImageParticle(map, NULL),
+    ImageParticle(map, nullptr),
     mAnimation(new SimpleAnimation(animation))
 {
 }
diff --git a/src/simpleanimation.cpp b/src/simpleanimation.cpp
index 4736b2e57..d0c7b7e39 100644
--- a/src/simpleanimation.cpp
+++ b/src/simpleanimation.cpp
@@ -133,7 +133,7 @@ Image *SimpleAnimation::getCurrentImage() const
     if (mCurrentFrame)
         return mCurrentFrame->image;
     else
-        return NULL;
+        return nullptr;
 }
 
 void SimpleAnimation::initializeAnimation(xmlNodePtr animationNode,
diff --git a/src/sound.cpp b/src/sound.cpp
index 40c929824..39c5a72aa 100644
--- a/src/sound.cpp
+++ b/src/sound.cpp
@@ -70,7 +70,7 @@ Sound::~Sound()
     config.removeListener("playMusic", this);
 
     // Unlink the callback function.
-    Mix_HookMusicFinished(NULL);
+    Mix_HookMusicFinished(nullptr);
 }
 
 void Sound::optionChanged(const std::string &value)
diff --git a/src/spellmanager.cpp b/src/spellmanager.cpp
index 9f7aaaa8b..d80090396 100644
--- a/src/spellmanager.cpp
+++ b/src/spellmanager.cpp
@@ -54,7 +54,7 @@ SpellManager::~SpellManager()
 TextCommand* SpellManager::getSpell(int spellId)
 {
     if (spellId < 0 || static_cast<unsigned int>(spellId) >= mSpells.size())
-        return NULL;
+        return nullptr;
 
     return mSpells[spellId];
 }
@@ -353,7 +353,7 @@ std::string SpellManager::autoComplete(std::string partName)
 {
     std::vector<TextCommand*>::const_iterator i = mSpellsVector.begin();
     std::string newName = "";
-    TextCommand *newCommand = NULL;
+    TextCommand *newCommand = nullptr;
 
     while (i != mSpellsVector.end())
     {
@@ -368,7 +368,7 @@ std::string SpellManager::autoComplete(std::string partName)
                 if (newName != "")
                 {
                     newName = findSameSubstring(line, newName);
-                    newCommand = NULL;
+                    newCommand = nullptr;
                 }
                 else
                 {
diff --git a/src/sprite.h b/src/sprite.h
index 20f38bef0..52752619b 100644
--- a/src/sprite.h
+++ b/src/sprite.h
@@ -24,6 +24,8 @@
 
 #include "resources/spritedef.h"
 
+#include "localconsts.h"
+
 class Graphics;
 class Image;
 
@@ -105,7 +107,7 @@ class Sprite
         virtual unsigned int getFrameCount() const = 0;
 
         virtual void *getHash()
-        { return 0; }
+        { return nullptr; }
 
         virtual void *getHash2()
         { return this; }
diff --git a/src/statuseffect.cpp b/src/statuseffect.cpp
index dccf21f46..f7bffc31f 100644
--- a/src/statuseffect.cpp
+++ b/src/statuseffect.cpp
@@ -65,7 +65,7 @@ void StatusEffect::deliverMessage()
 Particle *StatusEffect::getParticle()
 {
     if (!particleEngine || mParticleEffect.empty())
-        return NULL;
+        return nullptr;
     else
         return particleEngine->addEffect(mParticleEffect, 0, 0);
 }
@@ -74,7 +74,7 @@ AnimatedSprite *StatusEffect::getIcon()
 {
     if (mIcon.empty())
     {
-        return NULL;
+        return nullptr;
     }
     else
     {
@@ -141,7 +141,7 @@ void StatusEffect::load()
 
     for_each_xml_child_node(node, rootNode)
     {
-        status_effect_map *the_map = NULL;
+        status_effect_map *the_map = nullptr;
 
         int index = atoi(XML::getProperty(node, "id", "-1").c_str());
 
diff --git a/src/utils/base64.cpp b/src/utils/base64.cpp
index 14876d878..3906efc76 100644
--- a/src/utils/base64.cpp
+++ b/src/utils/base64.cpp
@@ -102,8 +102,8 @@ unsigned char *php3_base64_decode(const unsigned char *string,
     unsigned char *result = static_cast<unsigned char *>(
         calloc(length + 1, 1));
 
-    if (result == NULL)
-        return NULL;
+    if (result == nullptr)
+        return nullptr;
 
     /* run through the whole string, converting as we go */
     while ((ch = *current++) != '\0')
diff --git a/src/utils/copynpaste.cpp b/src/utils/copynpaste.cpp
index ed9f0f641..7bf7e59d4 100644
--- a/src/utils/copynpaste.cpp
+++ b/src/utils/copynpaste.cpp
@@ -43,7 +43,7 @@ bool retrieveBuffer(std::string& text, std::string::size_type& pos)
 {
     bool  ret = false;
 
-    if (!OpenClipboard(NULL))
+    if (!OpenClipboard(nullptr))
         return false;
 
     HANDLE  h = GetClipboardData(CF_UNICODETEXT);
@@ -54,13 +54,13 @@ bool retrieveBuffer(std::string& text, std::string::size_type& pos)
         if (data)
         {
             int len = WideCharToMultiByte(CP_UTF8, 0, data, -1,
-                NULL, 0, NULL, NULL);
+                nullptr, 0, nullptr, nullptr);
             if (len > 0)
             {
                 // Convert from UTF-16 to UTF-8
                 void *temp = calloc(len, 1);
                 if (WideCharToMultiByte(CP_UTF8, 0, data, -1,
-                    (LPSTR)temp, len, NULL, NULL))
+                    (LPSTR)temp, len, nullptr, nullptr))
                 {
                     text.insert(pos, (char*)temp);
                     pos += len-1;
@@ -94,7 +94,7 @@ bool retrieveBuffer(std::string& text, std::string::size_type& pos)
 
 bool sendBuffer(std::string& text)
 {
-    int wCharsLen = MultiByteToWideChar(CP_UTF8, 0, text.c_str(), -1, NULL, 0);
+    int wCharsLen = MultiByteToWideChar(CP_UTF8, 0, text.c_str(), -1, nullptr, 0);
     if (!wCharsLen)
         return false;
 
@@ -298,7 +298,7 @@ static char* getSelection2(Display *dpy, Window us, Atom selection,
     if (owner == None)
     {
         //printf("No owner\n");
-        return NULL;
+        return nullptr;
     }
     XConvertSelection(dpy, selection, request_target,
         XA_PRIMARY, us, CurrentTime);
@@ -317,13 +317,13 @@ static char* getSelection2(Display *dpy, Window us, Atom selection,
             if (e.xselection.property == None)
             {
                 //printf("Couldn't convert\n");
-                return NULL;
+                return nullptr;
             }
 
             long unsigned len, left, dummy;
             int format;
             Atom type;
-            unsigned char *data = NULL;
+            unsigned char *data = nullptr;
 
             ret = XGetWindowProperty(dpy, us, e.xselection.property, 0, 0,
                 False, AnyPropertyType, &type, &format, &len, &left, &data);
@@ -331,7 +331,7 @@ static char* getSelection2(Display *dpy, Window us, Atom selection,
             {
                 if (ret == Success)
                 XFree(data);
-                return NULL;
+                return nullptr;
             }
 
             ret = XGetWindowProperty(dpy, us, e.xselection.property, 0,
@@ -341,7 +341,7 @@ static char* getSelection2(Display *dpy, Window us, Atom selection,
             if (ret != Success)
             {
                 //printf("Failed to get property: %p on %lu\n", data, len);
-                return NULL;
+                return nullptr;
             }
 
             //printf(">>>  Got %s: len=%lu left=%lu (event %i)\n", data,
@@ -349,14 +349,14 @@ static char* getSelection2(Display *dpy, Window us, Atom selection,
             return reinterpret_cast<char*>(data);
         }
     }
-    return NULL;
+    return nullptr;
 }
 
 static Atom requestAtom;
 
 static char* getSelection(Display *dpy, Window us, Atom selection)
 {
-    char *data = NULL;
+    char *data = nullptr;
     if (requestAtom != None)
         data = getSelection2(dpy, us, selection, requestAtom);
     if (!data)
@@ -374,7 +374,7 @@ bool retrieveBuffer(std::string& text, std::string::size_type& pos)
     {
         Display *dpy = info.info.x11.display;
         Window us = info.info.x11.window;
-        char *data = NULL;
+        char *data = nullptr;
 
         requestAtom = XInternAtom (dpy, "UTF8_STRING", true);
 
diff --git a/src/utils/dtor.h b/src/utils/dtor.h
index 11583709f..fbe903ced 100644
--- a/src/utils/dtor.h
+++ b/src/utils/dtor.h
@@ -30,14 +30,16 @@
 template<typename T>
 struct dtor : public std::unary_function <T, void>
 {
-    void operator()(T &ptr) { delete ptr; }
+    void operator()(T &ptr)
+    { delete ptr; }
 };
 
 template<typename T1, typename T2>
 struct dtor<std::pair<T1, T2> > :
 public std::unary_function <std::pair<T1, T2>, void>
 {
-    void operator()(std::pair<T1, T2> &pair) { delete pair.second; }
+    void operator()(std::pair<T1, T2> &pair)
+    { delete pair.second; }
 };
 
 template<class Cont>
diff --git a/src/utils/paths.cpp b/src/utils/paths.cpp
index b42caf9b5..3cc35cb55 100644
--- a/src/utils/paths.cpp
+++ b/src/utils/paths.cpp
@@ -41,7 +41,7 @@ std::string getRealPath(const std::string &str)
     char *realPath = (char*)calloc(PATH_MAX, sizeof(char));
     realpath(str.c_str(), realPath);
 #else
-    char *realPath = realpath(str.c_str(), NULL);
+    char *realPath = realpath(str.c_str(), nullptr);
 #endif
     path = realPath;
     free(realPath);
diff --git a/src/utils/specialfolder.cpp b/src/utils/specialfolder.cpp
index 31eaec687..fae0fbf47 100644
--- a/src/utils/specialfolder.cpp
+++ b/src/utils/specialfolder.cpp
@@ -45,7 +45,7 @@ std::string getSpecialFolderLocation(int folderId)
     char szPath[_MAX_PATH];
 
     // get the item ID list for folderId
-    HRESULT hr = SHGetSpecialFolderLocation(NULL, folderId, &pItemIdList);
+    HRESULT hr = SHGetSpecialFolderLocation(nullptr, folderId, &pItemIdList);
     if (hr != S_OK)
         return ret;
 
diff --git a/src/utils/xml.cpp b/src/utils/xml.cpp
index 89457a4e8..56aa44ce3 100644
--- a/src/utils/xml.cpp
+++ b/src/utils/xml.cpp
@@ -38,7 +38,7 @@ namespace XML
         mDoc(0)
     {
         int size;
-        char *data = NULL;
+        char *data = nullptr;
         if (useResman)
         {
             ResourceManager *resman = ResourceManager::getInstance();
@@ -162,7 +162,7 @@ namespace XML
                 return child;
         }
 
-        return NULL;
+        return nullptr;
     }
 
 } // namespace XML