Add A_NONNULL attribute to all parameters with class Graphics.

67 files changed, 198 insertions, 156 deletions

diff --git a/src/animatedsprite.h b/src/animatedsprite.h
index d2a43fff4..5e0f58c76 100644
--- a/src/animatedsprite.h
+++ b/src/animatedsprite.h
@@ -68,7 +68,8 @@ class AnimatedSprite final : public Sprite
         bool update(const int time) override final;
 
         void draw(Graphics *const graphics,
-                  const int posX, const int posY) const override final;
+                  const int posX, const int posY)
+                  const override final A_NONNULL(2);
 
         int getWidth() const override final A_WARN_UNUSED;
 
diff --git a/src/being/actor.h b/src/being/actor.h
index a36c3560e..f76f7ba09 100644
--- a/src/being/actor.h
+++ b/src/being/actor.h
@@ -50,7 +50,8 @@ class Actor notfinal
          * partly with the clipping rectangle support.
          */
         virtual void draw(Graphics *const graphics,
-                          const int offsetX, const int offsetY) const = 0;
+                          const int offsetX,
+                          const int offsetY) const A_NONNULL(2) = 0;
 
         /**
          * Returns the horizontal size of the actors graphical representation
diff --git a/src/being/being.h b/src/being/being.h
index e957228c2..bf389c324 100644
--- a/src/being/being.h
+++ b/src/being/being.h
@@ -355,8 +355,9 @@ class Being notfinal : public ActorSprite,
         /**
          * Draws the emotion picture above the being.
          */
-        void drawEmotion(Graphics *const graphics, const int offsetX,
-                         const int offsetY) const;
+        void drawEmotion(Graphics *const graphics,
+                         const int offsetX,
+                         const int offsetY) const A_NONNULL(2);
 
         BeingTypeId getSubType() const
         { return mSubType; }
@@ -530,10 +531,13 @@ class Being notfinal : public ActorSprite,
         void setState(const uint8_t state);
 
         virtual void drawSprites(Graphics *const  graphics,
-                                 int posX, int posY) const override final;
+                                 int posX,
+                                 int posY) const override final A_NONNULL(2);
 
         virtual void drawSpritesSDL(Graphics *const graphics,
-                                    int posX, int posY) const override final;
+                                    int posX,
+                                    int posY) const override final
+                                    A_NONNULL(2);
 
         void drawHpBar(Graphics *const graphics,
                        const int maxHP,
@@ -544,7 +548,7 @@ class Being notfinal : public ActorSprite,
                        const int x,
                        const int y,
                        const int width,
-                       const int height) const;
+                       const int height) const A_NONNULL(2);
 
         static void load();
 
@@ -622,10 +626,11 @@ class Being notfinal : public ActorSprite,
         void talkTo() const;
 
         void draw(Graphics *const graphics,
-                  const int offsetX, const int offsetY) const override final;
+                  const int offsetX,
+                  const int offsetY) const override final A_NONNULL(2);
 
         void drawSpriteAt(Graphics *const graphics,
-                          const int x, const int y) const;
+                          const int x, const int y) const A_NONNULL(2);
 
         void setMoveTime()
         { mMoveTime = cur_time; }
diff --git a/src/being/compoundsprite.h b/src/being/compoundsprite.h
index 3e48ffdf7..25dee6b65 100644
--- a/src/being/compoundsprite.h
+++ b/src/being/compoundsprite.h
@@ -52,7 +52,7 @@ class CompoundSprite notfinal : public Sprite
 
         void draw(Graphics *const graphics,
                   const int posX,
-                  const int posY) const override;
+                  const int posY) const override A_NONNULL(2);
 
         /**
          * Gets the width in pixels of the first sprite in the list.
diff --git a/src/flooritem.h b/src/flooritem.h
index 9e9b95050..33c95c062 100644
--- a/src/flooritem.h
+++ b/src/flooritem.h
@@ -59,7 +59,8 @@ class FloorItem final : public ActorSprite
         { return ActorType::FloorItem; }
 
         void draw(Graphics *const graphics,
-                  const int offsetX, const int offsetY) const override final;
+                  const int offsetX, const int offsetY)
+                  const override final A_NONNULL(2);
 
         /**
          * Returns the item ID.
diff --git a/src/gui/fonts/font.h b/src/gui/fonts/font.h
index 3da6d9c7d..0188586b3 100644
--- a/src/gui/fonts/font.h
+++ b/src/gui/fonts/font.h
@@ -110,7 +110,8 @@ class Font final
                         Color col,
                         const Color &col2,
                         const std::string &text,
-                        const int x, const int y);
+                        const int x,
+                        const int y) A_NONNULL(2);
 
         void clear();
 
diff --git a/src/gui/gui.h b/src/gui/gui.h
index 8a2935208..a8b862f63 100644
--- a/src/gui/gui.h
+++ b/src/gui/gui.h
@@ -127,7 +127,7 @@ class Gui final
          */
         ~Gui();
 
-        void postInit(Graphics *const graphics);
+        void postInit(Graphics *const graphics) A_NONNULL(2);
 
         /**
          * Performs logic of the GUI. Overridden to track mouse pointer
diff --git a/src/gui/viewport.h b/src/gui/viewport.h
index e459afcae..0963bd394 100644
--- a/src/gui/viewport.h
+++ b/src/gui/viewport.h
@@ -74,9 +74,9 @@ class Viewport final : public WindowContainer,
         /**
          * Draws the viewport.
          */
-        void draw(Graphics *graphics) override final;
+        void draw(Graphics *graphics) override final A_NONNULL(2);
 
-        void safeDraw(Graphics *graphics) override final;
+        void safeDraw(Graphics *graphics) override final A_NONNULL(2);
 
         /**
          * Implements player to keep following mouse.
@@ -183,14 +183,15 @@ class Viewport final : public WindowContainer,
          * Finds a path from the player to the mouse, and draws it. This is for
          * debug purposes.
          */
-        void drawDebugPath(Graphics *const graphics);
+        void drawDebugPath(Graphics *const graphics) A_NONNULL(2);
 
         /**
          * Draws the given path.
          */
         void drawPath(Graphics *const graphics,
                       const Path &path,
-                      const Color &color = Color(255, 0, 0)) const;
+                      const Color &color = Color(255, 0, 0))
+                      const A_NONNULL(2);
 
         bool leftMouseAction();
 
diff --git a/src/gui/widgets/avatarlistbox.h b/src/gui/widgets/avatarlistbox.h
index 7c59f0924..3040b3261 100644
--- a/src/gui/widgets/avatarlistbox.h
+++ b/src/gui/widgets/avatarlistbox.h
@@ -41,9 +41,9 @@ class AvatarListBox final : public ListBox,
         /**
          * Draws the list box.
          */
-        void draw(Graphics *gcnGraphics) override final;
+        void draw(Graphics *gcnGraphics) override final A_NONNULL(2);
 
-        void safeDraw(Graphics *gcnGraphics) override final;
+        void safeDraw(Graphics *gcnGraphics) override final A_NONNULL(2);
 
         void mousePressed(MouseEvent &event) override final;
 
diff --git a/src/gui/widgets/basiccontainer2.h b/src/gui/widgets/basiccontainer2.h
index 7243e68d3..dc5a65234 100644
--- a/src/gui/widgets/basiccontainer2.h
+++ b/src/gui/widgets/basiccontainer2.h
@@ -137,9 +137,9 @@ class BasicContainer2: public BasicContainer
 
         // Inherited from Widget
 
-        void draw(Graphics* graphics) override;
+        void draw(Graphics* graphics) override A_NONNULL(2);
 
-        void safeDraw(Graphics* graphics) override;
+        void safeDraw(Graphics* graphics) override A_NONNULL(2);
 
     protected:
         /**
diff --git a/src/gui/widgets/browserbox.h b/src/gui/widgets/browserbox.h
index 012c04dd7..a3e7ad7f2 100644
--- a/src/gui/widgets/browserbox.h
+++ b/src/gui/widgets/browserbox.h
@@ -122,9 +122,9 @@ class BrowserBox final : public Widget,
         /**
          * Draws the browser box.
          */
-        void draw(Graphics *graphics) override final;
+        void draw(Graphics *graphics) override final A_NONNULL(2);
 
-        void safeDraw(Graphics *graphics) override final;
+        void safeDraw(Graphics *graphics) override final A_NONNULL(2);
 
         void updateHeight();
 
diff --git a/src/gui/widgets/button.h b/src/gui/widgets/button.h
index 233906d06..a4222c395 100644
--- a/src/gui/widgets/button.h
+++ b/src/gui/widgets/button.h
@@ -151,9 +151,9 @@ class Button final : public Widget,
         /**
          * Draws the button.
          */
-        void draw(Graphics *graphics) override final;
+        void draw(Graphics *graphics) override final A_NONNULL(2);
 
-        void safeDraw(Graphics *graphics) override final;
+        void safeDraw(Graphics *graphics) override final A_NONNULL(2);
 
         /**
          * Update the alpha value to the button components.
diff --git a/src/gui/widgets/checkbox.h b/src/gui/widgets/checkbox.h
index 2f2fe812d..23b75ddae 100644
--- a/src/gui/widgets/checkbox.h
+++ b/src/gui/widgets/checkbox.h
@@ -109,9 +109,9 @@ class CheckBox final : public Widget,
         /**
          * Draws the caption, then calls drawBox to draw the check box.
          */
-        void draw(Graphics *const graphics) override final;
+        void draw(Graphics *const graphics) override final A_NONNULL(2);
 
-        void safeDraw(Graphics *const graphics) override final;
+        void safeDraw(Graphics *const graphics) override final A_NONNULL(2);
 
         /**
          * Update the alpha value to the checkbox components.
@@ -121,7 +121,7 @@ class CheckBox final : public Widget,
         /**
          * Draws the check box, not the caption.
          */
-        void drawBox(Graphics *const graphics);
+        void drawBox(Graphics *const graphics) A_NONNULL(2);
 
         /**
          * Called when the mouse enteres the widget area.
diff --git a/src/gui/widgets/colorpage.h b/src/gui/widgets/colorpage.h
index 4863aaa60..7049ef2bc 100644
--- a/src/gui/widgets/colorpage.h
+++ b/src/gui/widgets/colorpage.h
@@ -36,9 +36,9 @@ class ColorPage final : public ListBox
 
         ~ColorPage();
 
-        void draw(Graphics *graphics) override final;
+        void draw(Graphics *graphics) override final A_NONNULL(2);
 
-        void safeDraw(Graphics *graphics) override final;
+        void safeDraw(Graphics *graphics) override final A_NONNULL(2);
 
         void resetAction();
 
diff --git a/src/gui/widgets/desktop.h b/src/gui/widgets/desktop.h
index 21da974cd..ec75c588d 100644
--- a/src/gui/widgets/desktop.h
+++ b/src/gui/widgets/desktop.h
@@ -65,9 +65,9 @@ class Desktop final : public Container,
 
         void widgetResized(const Event &event) override final;
 
-        void draw(Graphics *graphics) override final;
+        void draw(Graphics *graphics) override final A_NONNULL(2);
 
-        void safeDraw(Graphics *graphics) override final;
+        void safeDraw(Graphics *graphics) override final A_NONNULL(2);
 
         void postInit() override final;
 
diff --git a/src/gui/widgets/dropdown.h b/src/gui/widgets/dropdown.h
index aea2752d0..df8e93d49 100644
--- a/src/gui/widgets/dropdown.h
+++ b/src/gui/widgets/dropdown.h
@@ -79,13 +79,13 @@ class DropDown final : public ActionListener,
          */
         void updateAlpha();
 
-        void draw(Graphics *graphics) override final;
+        void draw(Graphics *graphics) override final A_NONNULL(2);
 
-        void safeDraw(Graphics *graphics) override final;
+        void safeDraw(Graphics *graphics) override final A_NONNULL(2);
 
-        void drawFrame(Graphics *graphics) override final;
+        void drawFrame(Graphics *graphics) override final A_NONNULL(2);
 
-        void safeDrawFrame(Graphics *graphics) override final;
+        void safeDrawFrame(Graphics *graphics) override final A_NONNULL(2);
 
         // Inherited from KeyListener
 
diff --git a/src/gui/widgets/emotepage.h b/src/gui/widgets/emotepage.h
index 24d166750..74829c13e 100644
--- a/src/gui/widgets/emotepage.h
+++ b/src/gui/widgets/emotepage.h
@@ -39,9 +39,9 @@ class EmotePage final : public Widget,
 
         ~EmotePage();
 
-        void draw(Graphics *graphics) override final;
+        void draw(Graphics *graphics) override final A_NONNULL(2);
 
-        void safeDraw(Graphics *graphics) override final;
+        void safeDraw(Graphics *graphics) override final A_NONNULL(2);
 
         void mousePressed(MouseEvent &event) override final;
 
diff --git a/src/gui/widgets/emoteshortcutcontainer.h b/src/gui/widgets/emoteshortcutcontainer.h
index c1ba76b2b..9dba54e5f 100644
--- a/src/gui/widgets/emoteshortcutcontainer.h
+++ b/src/gui/widgets/emoteshortcutcontainer.h
@@ -49,9 +49,9 @@ class EmoteShortcutContainer final : public ShortcutContainer
         /**
          * Draws the items.
          */
-        void draw(Graphics *graphics) override final;
+        void draw(Graphics *graphics) override final A_NONNULL(2);
 
-        void safeDraw(Graphics *graphics) override final;
+        void safeDraw(Graphics *graphics) override final A_NONNULL(2);
 
         /**
          * Handles mouse when dragged.
diff --git a/src/gui/widgets/extendedlistbox.h b/src/gui/widgets/extendedlistbox.h
index aca0ba8a8..3f2e30af4 100644
--- a/src/gui/widgets/extendedlistbox.h
+++ b/src/gui/widgets/extendedlistbox.h
@@ -42,9 +42,9 @@ class ExtendedListBox final : public ListBox
         /**
          * Draws the list box.
          */
-        void draw(Graphics *graphics) override final;
+        void draw(Graphics *graphics) override final A_NONNULL(2);
 
-        void safeDraw(Graphics *graphics) override final;
+        void safeDraw(Graphics *graphics) override final A_NONNULL(2);
 
         void adjustSize() override;
 
diff --git a/src/gui/widgets/guitable.h b/src/gui/widgets/guitable.h
index af94c4ec9..ff9342661 100644
--- a/src/gui/widgets/guitable.h
+++ b/src/gui/widgets/guitable.h
@@ -110,9 +110,9 @@ class GuiTable final : public Widget,
         { mLinewiseMode = linewise; }
 
         // Inherited from Widget
-        void draw(Graphics* graphics) override final;
+        void draw(Graphics* graphics) override final A_NONNULL(2);
 
-        void safeDraw(Graphics* graphics) override final;
+        void safeDraw(Graphics* graphics) override final A_NONNULL(2);
 
         Widget *getWidgetAt(int x, int y) override final A_WARN_UNUSED;
 
diff --git a/src/gui/widgets/itemcontainer.h b/src/gui/widgets/itemcontainer.h
index 8b30e5f8b..243104ead 100644
--- a/src/gui/widgets/itemcontainer.h
+++ b/src/gui/widgets/itemcontainer.h
@@ -74,9 +74,9 @@ class ItemContainer final : public Widget,
         /**
          * Draws the items.
          */
-        void draw(Graphics *graphics) override final;
+        void draw(Graphics *graphics) override final A_NONNULL(2);
 
-        void safeDraw(Graphics *graphics) override final;
+        void safeDraw(Graphics *graphics) override final A_NONNULL(2);
 
         // KeyListener
         void keyPressed(KeyEvent &event) override final;
diff --git a/src/gui/widgets/itemshortcutcontainer.h b/src/gui/widgets/itemshortcutcontainer.h
index a211941c2..424db2ac3 100644
--- a/src/gui/widgets/itemshortcutcontainer.h
+++ b/src/gui/widgets/itemshortcutcontainer.h
@@ -49,9 +49,9 @@ class ItemShortcutContainer final : public ShortcutContainer
         /**
          * Draws the items.
          */
-        void draw(Graphics *graphics) override final;
+        void draw(Graphics *graphics) override final A_NONNULL(2);
 
-        void safeDraw(Graphics *graphics) override final;
+        void safeDraw(Graphics *graphics) override final A_NONNULL(2);
 
         /**
          * Handles mouse when dragged.
diff --git a/src/gui/widgets/label.h b/src/gui/widgets/label.h
index bbe49a1e0..fd7e144e0 100644
--- a/src/gui/widgets/label.h
+++ b/src/gui/widgets/label.h
@@ -108,9 +108,9 @@ class Label final : public Widget,
         /**
          * Draws the label.
          */
-        void draw(Graphics *graphics) override final;
+        void draw(Graphics *graphics) override final A_NONNULL(2);
 
-        void safeDraw(Graphics *graphics) override final;
+        void safeDraw(Graphics *graphics) override final A_NONNULL(2);
 
         void adjustSize();
 
diff --git a/src/gui/widgets/listbox.h b/src/gui/widgets/listbox.h
index 9dff11e09..382f56dfe 100644
--- a/src/gui/widgets/listbox.h
+++ b/src/gui/widgets/listbox.h
@@ -108,9 +108,9 @@ class ListBox notfinal : public Widget,
         /**
          * Draws the list box.
          */
-        void draw(Graphics *graphics) override;
+        void draw(Graphics *graphics) override A_NONNULL(2);
 
-        void safeDraw(Graphics *graphics) override;
+        void safeDraw(Graphics *graphics) override A_NONNULL(2);
 
         /**
          * Update the alpha value to the graphic components.
diff --git a/src/gui/widgets/passwordfield.h b/src/gui/widgets/passwordfield.h
index 0efce0dcf..6b3da5e50 100644
--- a/src/gui/widgets/passwordfield.h
+++ b/src/gui/widgets/passwordfield.h
@@ -44,9 +44,9 @@ class PasswordField final : public TextField
         /**
          * Draws the password field.
          */
-        void draw(Graphics *graphics) override final;
+        void draw(Graphics *graphics) override final A_NONNULL(2);
 
-        void safeDraw(Graphics *graphics) override final;
+        void safeDraw(Graphics *graphics) override final A_NONNULL(2);
 
     protected:
         unsigned char mPasswordChar;
diff --git a/src/gui/widgets/playerbox.h b/src/gui/widgets/playerbox.h
index b331b7a1b..ee15f32ba 100644
--- a/src/gui/widgets/playerbox.h
+++ b/src/gui/widgets/playerbox.h
@@ -76,9 +76,9 @@ class PlayerBox final : public Widget,
         /**
          * Draws the scroll area.
          */
-        void draw(Graphics *graphics) override final;
+        void draw(Graphics *graphics) override final A_NONNULL(2);
 
-        void safeDraw(Graphics *graphics) override final;
+        void safeDraw(Graphics *graphics) override final A_NONNULL(2);
 
         /**
          * Draws the background and border of the scroll area.
diff --git a/src/gui/widgets/popup.h b/src/gui/widgets/popup.h
index a784990ec..9f043114e 100644
--- a/src/gui/widgets/popup.h
+++ b/src/gui/widgets/popup.h
@@ -76,9 +76,9 @@ class Popup notfinal : public Container,
         /**
          * Draws the popup.
          */
-        void draw(Graphics *graphics) override;
+        void draw(Graphics *graphics) override A_NONNULL(2);
 
-        void safeDraw(Graphics *graphics) override;
+        void safeDraw(Graphics *graphics) override A_NONNULL(2);
 
         /**
          * Sets the size of this popup.
diff --git a/src/gui/widgets/progressbar.h b/src/gui/widgets/progressbar.h
index 89ee13e85..4b45f1aab 100644
--- a/src/gui/widgets/progressbar.h
+++ b/src/gui/widgets/progressbar.h
@@ -71,9 +71,9 @@ class ProgressBar final : public Widget,
         /**
          * Draws the progress bar.
          */
-        void draw(Graphics *graphics) override final;
+        void draw(Graphics *graphics) override final A_NONNULL(2);
 
-        void safeDraw(Graphics *graphics) override final;
+        void safeDraw(Graphics *graphics) override final A_NONNULL(2);
 
         /**
          * Sets the current progress.
diff --git a/src/gui/widgets/progressindicator.h b/src/gui/widgets/progressindicator.h
index cc278e8a2..6957b6993 100644
--- a/src/gui/widgets/progressindicator.h
+++ b/src/gui/widgets/progressindicator.h
@@ -43,9 +43,9 @@ class ProgressIndicator final : public Widget
 
         void logic() override final;
 
-        void draw(Graphics *graphics) override final;
+        void draw(Graphics *graphics) override final A_NONNULL(2);
 
-        void safeDraw(Graphics *graphics) override final;
+        void safeDraw(Graphics *graphics) override final A_NONNULL(2);
 
     private:
         SimpleAnimation *mIndicator;
diff --git a/src/gui/widgets/radiobutton.h b/src/gui/widgets/radiobutton.h
index f1e4748e1..50b000f31 100644
--- a/src/gui/widgets/radiobutton.h
+++ b/src/gui/widgets/radiobutton.h
@@ -112,9 +112,9 @@ class RadioButton final : public Widget,
          * Implementation of the draw methods.
          * Thus, avoiding the rhomb around the radio button.
          */
-        void draw(Graphics* graphics) override final;
+        void draw(Graphics* graphics) override final A_NONNULL(2);
 
-        void safeDraw(Graphics* graphics) override final;
+        void safeDraw(Graphics* graphics) override final A_NONNULL(2);
 
         /**
          * Called when the mouse enteres the widget area.
diff --git a/src/gui/widgets/scrollarea.h b/src/gui/widgets/scrollarea.h
index deb24ff79..5d9b2e70b 100644
--- a/src/gui/widgets/scrollarea.h
+++ b/src/gui/widgets/scrollarea.h
@@ -137,9 +137,9 @@ class ScrollArea final : public BasicContainer,
         /**
          * Draws the scroll area.
          */
-        void draw(Graphics *graphics) override final;
+        void draw(Graphics *graphics) override final A_NONNULL(2);
 
-        void safeDraw(Graphics *graphics) override final;
+        void safeDraw(Graphics *graphics) override final A_NONNULL(2);
 
         /**
          * Draws the background and border of the scroll area.
@@ -449,21 +449,23 @@ class ScrollArea final : public BasicContainer,
          */
         void checkPolicies();
 
-        void drawButton(Graphics *const graphics, const BUTTON_DIR dir);
-        void calcButton(Graphics *const graphics, const BUTTON_DIR dir);
-        void drawVBar(Graphics *const graphics) const;
-        void drawHBar(Graphics *const graphics) const;
-        void drawVMarker(Graphics *const graphics);
-        void drawHMarker(Graphics *const graphics);
+        void drawButton(Graphics *const graphics,
+                        const BUTTON_DIR dir) A_NONNULL(2);
+        void calcButton(Graphics *const graphics,
+                        const BUTTON_DIR dir) A_NONNULL(2);
+        void drawVBar(Graphics *const graphics) const A_NONNULL(2);
+        void drawHBar(Graphics *const graphics) const A_NONNULL(2);
+        void drawVMarker(Graphics *const graphics) A_NONNULL(2);
+        void drawHMarker(Graphics *const graphics) A_NONNULL(2);
 
-        void calcVBar(const Graphics *const graphics);
-        void calcHBar(const Graphics *const graphics);
-        void calcVMarker(Graphics *const graphics);
-        void calcHMarker(Graphics *const graphics);
+        void calcVBar(const Graphics *const graphics) A_NONNULL(2);
+        void calcHBar(const Graphics *const graphics) A_NONNULL(2);
+        void calcVMarker(Graphics *const graphics) A_NONNULL(2);
+        void calcHMarker(Graphics *const graphics) A_NONNULL(2);
 
         Image *getImageByState(Rect &dim, const BUTTON_DIR dir);
 
-        void updateCalcFlag(Graphics *const graphics);
+        void updateCalcFlag(Graphics *const graphics) A_NONNULL(2);
 
         static int instances;
         static float mAlpha;
diff --git a/src/gui/widgets/serverslistbox.h b/src/gui/widgets/serverslistbox.h
index 5586cf1d1..e15bebb41 100644
--- a/src/gui/widgets/serverslistbox.h
+++ b/src/gui/widgets/serverslistbox.h
@@ -43,7 +43,7 @@ class ServersListBox final : public ListBox
             mHighlightColor = getThemeColor(ThemeColorId::HIGHLIGHT);
         }
 
-        void draw(Graphics *graphics) override final
+        void draw(Graphics *graphics) override final A_NONNULL(2)
         {
             if (!mListModel)
                 return;
diff --git a/src/gui/widgets/shoplistbox.h b/src/gui/widgets/shoplistbox.h
index ff7835dd0..d0c230f9d 100644
--- a/src/gui/widgets/shoplistbox.h
+++ b/src/gui/widgets/shoplistbox.h
@@ -55,9 +55,9 @@ class ShopListBox final : public ListBox
         /**
          * Draws the list box.
          */
-        void draw(Graphics *graphics) override final;
+        void draw(Graphics *graphics) override final A_NONNULL(2);
 
-        void safeDraw(Graphics *graphics) override final;
+        void safeDraw(Graphics *graphics) override final A_NONNULL(2);
 
         /**
          * gives information about the current player's money
diff --git a/src/gui/widgets/skilllistbox.h b/src/gui/widgets/skilllistbox.h
index 4eda139a5..a27c57147 100644
--- a/src/gui/widgets/skilllistbox.h
+++ b/src/gui/widgets/skilllistbox.h
@@ -90,7 +90,7 @@ class SkillListBox final : public ListBox
             return static_cast<SkillModel*>(mListModel)->getSkillAt(selected);
         }
 
-        void draw(Graphics *graphics) override final
+        void draw(Graphics *graphics) override final A_NONNULL(2)
         {
             if (!mListModel)
                 return;
diff --git a/src/gui/widgets/slider.h b/src/gui/widgets/slider.h
index d31c9e9fc..256c64819 100644
--- a/src/gui/widgets/slider.h
+++ b/src/gui/widgets/slider.h
@@ -125,9 +125,9 @@ class Slider final : public Widget,
         /**
          * Draws the slider.
          */
-        void draw(Graphics *graphics) override final;
+        void draw(Graphics *graphics) override final A_NONNULL(2);
 
-        void safeDraw(Graphics *graphics) override final;
+        void safeDraw(Graphics *graphics) override final A_NONNULL(2);
 
         /**
          * Called when the mouse enteres the widget area.
diff --git a/src/gui/widgets/sliderlist.h b/src/gui/widgets/sliderlist.h
index a48ffeb4a..525fd3c92 100644
--- a/src/gui/widgets/sliderlist.h
+++ b/src/gui/widgets/sliderlist.h
@@ -55,9 +55,9 @@ class SliderList final : public Container,
 
         void resize();
 
-        void draw(Graphics *graphics) override final;
+        void draw(Graphics *graphics) override final A_NONNULL(2);
 
-        void safeDraw(Graphics *graphics) override final;
+        void safeDraw(Graphics *graphics) override final A_NONNULL(2);
 
         void action(const ActionEvent &event) override final;
 
diff --git a/src/gui/widgets/spellshortcutcontainer.h b/src/gui/widgets/spellshortcutcontainer.h
index eb2dbec49..21fc0d5b9 100644
--- a/src/gui/widgets/spellshortcutcontainer.h
+++ b/src/gui/widgets/spellshortcutcontainer.h
@@ -49,9 +49,9 @@ class SpellShortcutContainer final : public ShortcutContainer
         /**
          * Draws the items.
          */
-        void draw(Graphics *graphics) override final;
+        void draw(Graphics *graphics) override final A_NONNULL(2);
 
-        void safeDraw(Graphics *graphics) override final;
+        void safeDraw(Graphics *graphics) override final A_NONNULL(2);
 
         /**
          * Handles mouse when dragged.
diff --git a/src/gui/widgets/tabbedarea.h b/src/gui/widgets/tabbedarea.h
index 3d123f2ec..40ac05753 100644
--- a/src/gui/widgets/tabbedarea.h
+++ b/src/gui/widgets/tabbedarea.h
@@ -102,9 +102,9 @@ class TabbedArea final : public ActionListener,
         /**
          * Draw the tabbed area.
          */
-        void draw(Graphics *graphics) override final;
+        void draw(Graphics *graphics) override final A_NONNULL(2);
 
-        void safeDraw(Graphics *graphics) override final;
+        void safeDraw(Graphics *graphics) override final A_NONNULL(2);
 
         /**
          * Return how many tabs have been created.
diff --git a/src/gui/widgets/tabs/tab.h b/src/gui/widgets/tabs/tab.h
index 65ebc57b7..ded1e6709 100644
--- a/src/gui/widgets/tabs/tab.h
+++ b/src/gui/widgets/tabs/tab.h
@@ -109,9 +109,9 @@ class Tab notfinal : public BasicContainer,
         /**
          * Draw the tabbed area.
          */
-        void draw(Graphics *graphics) override final;
+        void draw(Graphics *graphics) override final A_NONNULL(2);
 
-        void safeDraw(Graphics *graphics) override final;
+        void safeDraw(Graphics *graphics) override final A_NONNULL(2);
 
         /**
          * Set the normal color for the tab's text.
diff --git a/src/gui/widgets/textbox.h b/src/gui/widgets/textbox.h
index 611efd4a0..6fe3aefd9 100644
--- a/src/gui/widgets/textbox.h
+++ b/src/gui/widgets/textbox.h
@@ -107,9 +107,9 @@ class TextBox final : public Widget,
 
         void keyPressed(KeyEvent& event) override final;
 
-        void draw(Graphics* graphics) override final;
+        void draw(Graphics* graphics) override final A_NONNULL(2);
 
-        void safeDraw(Graphics* graphics) override final;
+        void safeDraw(Graphics* graphics) override final A_NONNULL(2);
 
         void setForegroundColor(const Color &color);
 
@@ -287,7 +287,9 @@ class TextBox final : public Widget,
          * @param x the x position.
          * @param y the y position.
          */
-        void drawCaret(Graphics *const graphics, const int x, const int y);
+        void drawCaret(Graphics *const graphics,
+                       const int x,
+                       const int y) A_NONNULL(2);
 
         /**
          * Adjusts the text box's size to fit the text.
diff --git a/src/gui/widgets/textfield.h b/src/gui/widgets/textfield.h
index 0c5335143..75c3d9253 100644
--- a/src/gui/widgets/textfield.h
+++ b/src/gui/widgets/textfield.h
@@ -107,9 +107,9 @@ class TextField notfinal : public Widget,
         /**
          * Draws the text field.
          */
-        void draw(Graphics *graphics) override;
+        void draw(Graphics *graphics) override A_NONNULL(2);
 
-        void safeDraw(Graphics *graphics) override;
+        void safeDraw(Graphics *graphics) override A_NONNULL(2);
 
         /**
          * Update the alpha value to the graphic components.
diff --git a/src/gui/widgets/textpreview.h b/src/gui/widgets/textpreview.h
index 62e3d1cd1..f56eac5bb 100644
--- a/src/gui/widgets/textpreview.h
+++ b/src/gui/widgets/textpreview.h
@@ -100,9 +100,9 @@ class TextPreview final : public Widget
          *
          * @param graphics graphics to draw into
          */
-        void draw(Graphics *graphics) override final;
+        void draw(Graphics *graphics) override final A_NONNULL(2);
 
-        void safeDraw(Graphics *graphics) override final;
+        void safeDraw(Graphics *graphics) override final A_NONNULL(2);
 
         /**
          * Set opacity for this widget (whether or not to show the background
diff --git a/src/gui/widgets/virtshortcutcontainer.h b/src/gui/widgets/virtshortcutcontainer.h
index 96aea1012..5405c2046 100644
--- a/src/gui/widgets/virtshortcutcontainer.h
+++ b/src/gui/widgets/virtshortcutcontainer.h
@@ -51,9 +51,9 @@ class VirtShortcutContainer final : public ShortcutContainer
         /**
          * Draws the items.
          */
-        void draw(Graphics *graphics) override final;
+        void draw(Graphics *graphics) override final A_NONNULL(2);
 
-        void safeDraw(Graphics *graphics) override final;
+        void safeDraw(Graphics *graphics) override final A_NONNULL(2);
 
         /**
          * Handles mouse when dragged.
diff --git a/src/gui/widgets/widget.h b/src/gui/widgets/widget.h
index 416782dc2..c5573b404 100644
--- a/src/gui/widgets/widget.h
+++ b/src/gui/widgets/widget.h
@@ -121,9 +121,9 @@ class Widget notfinal : public Widget2
           * @param graphics aA graphics object to draw with.
           * @since 0.1.0
           */
-        virtual void draw(Graphics* graphics) = 0;
+        virtual void draw(Graphics* graphics) A_NONNULL(2) = 0;
 
-        virtual void safeDraw(Graphics* graphics) = 0;
+        virtual void safeDraw(Graphics* graphics) A_NONNULL(2) = 0;
 
         /**
           * Called when a widget is given a chance to draw a frame around itself.
@@ -145,10 +145,10 @@ class Widget notfinal : public Widget2
           * @see setFrameSize, getFrameSize
           * @since 0.8.0
           */
-        virtual void drawFrame(Graphics* graphics A_UNUSED)
+        virtual void drawFrame(Graphics* graphics A_UNUSED) A_NONNULL(2)
         { }
 
-        virtual void safeDrawFrame(Graphics* graphics A_UNUSED)
+        virtual void safeDrawFrame(Graphics* graphics A_UNUSED) A_NONNULL(2)
         { }
 
         /**
diff --git a/src/gui/widgets/window.h b/src/gui/widgets/window.h
index e062de671..ae1e922c9 100644
--- a/src/gui/widgets/window.h
+++ b/src/gui/widgets/window.h
@@ -128,9 +128,9 @@ class Window notfinal : public BasicContainer2,
         /**
          * Draws the window.
          */
-        void draw(Graphics *graphics) override;
+        void draw(Graphics *graphics) override A_NONNULL(2);
 
-        void safeDraw(Graphics *graphics) override;
+        void safeDraw(Graphics *graphics) override A_NONNULL(2);
 
         /**
          * Sets the size of this window.
diff --git a/src/gui/widgets/windowcontainer.h b/src/gui/widgets/windowcontainer.h
index 59fd54af1..6188777d2 100644
--- a/src/gui/widgets/windowcontainer.h
+++ b/src/gui/widgets/windowcontainer.h
@@ -55,7 +55,7 @@ class WindowContainer notfinal : public Container
                              Widget *const widget);
 
 #ifdef USE_PROFILER
-        void draw(Graphics* graphics) override;
+        void draw(Graphics* graphics) override A_NONNULL(2);
 #endif
 
     private:
diff --git a/src/gui/windows/chatwindow.h b/src/gui/windows/chatwindow.h
index c5b5aea1a..ea71e4716 100644
--- a/src/gui/windows/chatwindow.h
+++ b/src/gui/windows/chatwindow.h
@@ -280,9 +280,9 @@ class ChatWindow final : public Window,
 
         void mouseExited(MouseEvent& event A_UNUSED) override final;
 
-        void draw(Graphics* graphics) override final;
+        void draw(Graphics* graphics) override final A_NONNULL(2);
 
-        void safeDraw(Graphics* graphics) override final;
+        void safeDraw(Graphics* graphics) override final A_NONNULL(2);
 
         void updateVisibility();
 
diff --git a/src/gui/windows/connectiondialog.h b/src/gui/windows/connectiondialog.h
index 6fdeeff00..b7318d79f 100644
--- a/src/gui/windows/connectiondialog.h
+++ b/src/gui/windows/connectiondialog.h
@@ -58,9 +58,9 @@ class ConnectionDialog final : public Window,
          */
         void action(const ActionEvent &) override final;
 
-        void draw(Graphics *graphics) override final;
+        void draw(Graphics *graphics) override final A_NONNULL(2);
 
-        void safeDraw(Graphics *graphics) override final;
+        void safeDraw(Graphics *graphics) override final A_NONNULL(2);
 
     private:
         State mCancelState;
diff --git a/src/gui/windows/debugwindow.h b/src/gui/windows/debugwindow.h
index 5496852f6..0ccbae3a1 100644
--- a/src/gui/windows/debugwindow.h
+++ b/src/gui/windows/debugwindow.h
@@ -54,9 +54,9 @@ class DebugWindow final : public Window
          */
         void slowLogic();
 
-        void draw(Graphics *g) override final;
+        void draw(Graphics *g) override final A_NONNULL(2);
 
-        void safeDraw(Graphics *g) override final;
+        void safeDraw(Graphics *g) override final A_NONNULL(2);
 
         void setPing(int pingTime);
 
diff --git a/src/gui/windows/equipmentwindow.h b/src/gui/windows/equipmentwindow.h
index 6ad9b2fd2..640aa2564 100644
--- a/src/gui/windows/equipmentwindow.h
+++ b/src/gui/windows/equipmentwindow.h
@@ -70,9 +70,9 @@ class EquipmentWindow final : public Window,
         /**
          * Draws the equipment window.
          */
-        void draw(Graphics *graphics) override final;
+        void draw(Graphics *graphics) override final A_NONNULL(2);
 
-        void safeDraw(Graphics *graphics) override final;
+        void safeDraw(Graphics *graphics) override final A_NONNULL(2);
 
         void action(const ActionEvent &event) override final;
 
diff --git a/src/gui/windows/minimap.h b/src/gui/windows/minimap.h
index 8c7150080..bd9126bba 100644
--- a/src/gui/windows/minimap.h
+++ b/src/gui/windows/minimap.h
@@ -59,11 +59,11 @@ class Minimap final : public Window, public ConfigListener
         /**
          * Draws the minimap.
          */
-        void draw(Graphics *graphics) override final;
+        void draw(Graphics *graphics) override final A_NONNULL(2);
 
-        void safeDraw(Graphics *graphics) override final;
+        void safeDraw(Graphics *graphics) override final A_NONNULL(2);
 
-        void draw2(Graphics *const graphics);
+        void draw2(Graphics *const graphics) A_NONNULL(2);
 
         void mouseMoved(MouseEvent &event) override final;
 
diff --git a/src/gui/windows/ministatuswindow.h b/src/gui/windows/ministatuswindow.h
index 0146b3f00..c1a93d6d9 100644
--- a/src/gui/windows/ministatuswindow.h
+++ b/src/gui/windows/ministatuswindow.h
@@ -69,9 +69,9 @@ class MiniStatusWindow final : public Window,
 
         void logic() override final;
 
-        void draw(Graphics *graphics) override final;
+        void draw(Graphics *graphics) override final A_NONNULL(2);
 
-        void safeDraw(Graphics *graphics) override final;
+        void safeDraw(Graphics *graphics) override final A_NONNULL(2);
 
         void mouseMoved(MouseEvent &event) override final;
 
diff --git a/src/gui/windows/outfitwindow.h b/src/gui/windows/outfitwindow.h
index b27bd7d4a..7033a3f13 100644
--- a/src/gui/windows/outfitwindow.h
+++ b/src/gui/windows/outfitwindow.h
@@ -52,9 +52,9 @@ class OutfitWindow final : public Window,
 
         void action(const ActionEvent &event) override final;
 
-        void draw(Graphics *graphics) override final;
+        void draw(Graphics *graphics) override final A_NONNULL(2);
 
-        void safeDraw(Graphics *graphics) override final;
+        void safeDraw(Graphics *graphics) override final A_NONNULL(2);
 
         void mousePressed(MouseEvent &event) override final;
 
diff --git a/src/imagesprite.h b/src/imagesprite.h
index b5623a12a..528b8c6ac 100644
--- a/src/imagesprite.h
+++ b/src/imagesprite.h
@@ -47,7 +47,8 @@ class ImageSprite final : public Sprite
         { return false; }
 
         void draw(Graphics *const graphics,
-                  const int posX, const int posY) const override final;
+                  const int posX, const int posY)
+                  const override final A_NONNULL(2);
 
         int getWidth() const override final A_WARN_UNUSED
         { return mImage ? mImage->getWidth() : 0; }
diff --git a/src/localconsts.h b/src/localconsts.h
index 1566292f5..dcd0613b2 100644
--- a/src/localconsts.h
+++ b/src/localconsts.h
@@ -70,6 +70,7 @@
 #define A_WARN_UNUSED __attribute__ ((warn_unused_result))
 #define DEPRECATED __attribute__ ((deprecated))
 #define restrict __restrict__
+#define A_NONNULL(...) __attribute__((nonnull (__VA_ARGS__)))
 #else
 #define A_UNUSED
 #define A_WARN_UNUSED
diff --git a/src/particle/imageparticle.h b/src/particle/imageparticle.h
index ecae08c37..b6b74362b 100644
--- a/src/particle/imageparticle.h
+++ b/src/particle/imageparticle.h
@@ -55,7 +55,7 @@ class ImageParticle notfinal : public Particle
          */
         virtual void draw(Graphics *const graphics,
                           const int offsetX,
-                          const int offsetY) const override final;
+                          const int offsetY) const override final A_NONNULL(2);
 
         void setAlpha(const float alpha) override final
         { mAlpha = alpha; }
diff --git a/src/particle/particle.h b/src/particle/particle.h
index ad141ffc7..7f3a743bf 100644
--- a/src/particle/particle.h
+++ b/src/particle/particle.h
@@ -95,7 +95,7 @@ class Particle notfinal : public Actor
          */
         virtual void draw(Graphics *const graphics,
                           const int offsetX,
-                          const int offsetY) const override;
+                          const int offsetY) const override A_NONNULL(2);
 
         /**
          * Necessary for sorting with the other sprites.
diff --git a/src/particle/textparticle.h b/src/particle/textparticle.h
index 1553c6ef3..6858ee6a1 100644
--- a/src/particle/textparticle.h
+++ b/src/particle/textparticle.h
@@ -41,7 +41,8 @@ class TextParticle final : public Particle
          * Draws the particle image.
          */
         void draw(Graphics *const graphics,
-                  const int offsetX, const int offsetY) const override final;
+                  const int offsetX,
+                  const int offsetY) const override final A_NONNULL(2);
 
         // hack to improve text visibility
         int getPixelY() const override final A_WARN_UNUSED
diff --git a/src/resources/ambientlayer.h b/src/resources/ambientlayer.h
index 906363a6f..06f60bdbe 100644
--- a/src/resources/ambientlayer.h
+++ b/src/resources/ambientlayer.h
@@ -57,9 +57,13 @@ class AmbientLayer final
 
         ~AmbientLayer();
 
-        void update(const int timePassed, const float dx, const float dy);
+        void update(const int timePassed,
+                    const float dx,
+                    const float dy);
 
-        void draw(Graphics *const graphics, const int x, const int y) const;
+        void draw(Graphics *const graphics,
+                  const int x,
+                  const int y) const A_NONNULL(2);
 
     private:
         Image *mImage;
diff --git a/src/resources/map/map.h b/src/resources/map/map.h
index 28bf9c4b2..4553f5aa8 100644
--- a/src/resources/map/map.h
+++ b/src/resources/map/map.h
@@ -109,14 +109,17 @@ class Map final : public Properties, public ConfigListener
          * the clipping rectangle set on the Graphics object. However,
          * currently the map is always drawn full-screen.
          */
-        void draw(Graphics *const graphics, int scrollX, int scrollY);
+        void draw(Graphics *const graphics,
+                  int scrollX,
+                  int scrollY) A_NONNULL(2);
 
         /**
          * Visualizes collision layer for debugging
          */
         void drawCollision(Graphics *const graphics,
-                           const int scrollX, const int scrollY,
-                           const MapTypeT drawFlags) const;
+                           const int scrollX,
+                           const int scrollY,
+                           const MapTypeT drawFlags) const A_NONNULL(2);
 
         /**
          * Adds a layer to this map. The map takes ownership of the layer.
@@ -357,8 +360,9 @@ class Map final : public Properties, public ConfigListener
         /**
          * Draws the foreground or background layers to the given graphics output.
          */
-        void drawAmbientLayers(Graphics *const graphics, const LayerType type,
-                               const int detail) const;
+        void drawAmbientLayers(Graphics *const graphics,
+                               const LayerType type,
+                               const int detail) const A_NONNULL(2);
 
         /**
          * Tells whether the given coordinates fall within the map boundaries.
diff --git a/src/resources/map/mapitem.h b/src/resources/map/mapitem.h
index e9203e564..4fd84320f 100644
--- a/src/resources/map/mapitem.h
+++ b/src/resources/map/mapitem.h
@@ -71,8 +71,9 @@ class MapItem final
         void setName(const std::string &name)
         { mName = name; }
 
-        void draw(Graphics *const graphics, const int x, const int y,
-                  const int dx, const int dy) const;
+        void draw(Graphics *const graphics,
+                  const int x, const int y,
+                  const int dx, const int dy) const A_NONNULL(2);
 
     private:
         Image *mImage;
diff --git a/src/resources/map/maplayer.h b/src/resources/map/maplayer.h
index 4cf30ade1..6588e0303 100644
--- a/src/resources/map/maplayer.h
+++ b/src/resources/map/maplayer.h
@@ -87,30 +87,43 @@ class MapLayer final: public ConfigListener
          * layer.
          */
         void draw(Graphics *const graphics,
-                  int startX, int startY, int endX, int endY,
-                  const int scrollX, const int scrollY) const;
+                  int startX,
+                  int startY,
+                  int endX,
+                  int endY,
+                  const int scrollX,
+                  const int scrollY) const A_NONNULL(2);
 
-        void drawSDL(Graphics *const graphics) const;
+        void drawSDL(Graphics *const graphics) const A_NONNULL(2);
 
 #ifdef USE_OPENGL
-        void drawOGL(Graphics *const graphics) const;
+        void drawOGL(Graphics *const graphics) const A_NONNULL(2);
 
         void updateOGL(Graphics *const graphics,
-                       int startX, int startY,
-                       int endX, int endY,
-                       const int scrollX, const int scrollY);
+                       int startX,
+                       int startY,
+                       int endX,
+                       int endY,
+                       const int scrollX,
+                       const int scrollY) A_NONNULL(2);
 #endif
 
         void updateSDL(const Graphics *const graphics,
-                       int startX, int startY,
-                       int endX, int endY,
-                       const int scrollX, const int scrollY);
+                       int startX,
+                       int startY,
+                       int endX,
+                       int endY,
+                       const int scrollX,
+                       const int scrollY) A_NONNULL(2);
 
         void drawFringe(Graphics *const graphics,
-                        int startX, int startY,
-                        int endX, int endY,
-                        const int scrollX, const int scrollY,
-                        const Actors *const actors) const;
+                        int startX,
+                        int startY,
+                        int endX,
+                        int endY,
+                        const int scrollX,
+                        const int scrollY,
+                        const Actors *const actors) const A_NONNULL(2);
 
         bool isFringeLayer() const A_WARN_UNUSED
         { return mIsFringeLayer; }
diff --git a/src/resources/map/speciallayer.h b/src/resources/map/speciallayer.h
index 518f23bcf..13a75a9d5 100644
--- a/src/resources/map/speciallayer.h
+++ b/src/resources/map/speciallayer.h
@@ -40,9 +40,10 @@ class SpecialLayer final
 
         ~SpecialLayer();
 
-        void draw(Graphics *const graphics, int startX, int startY,
+        void draw(Graphics *const graphics,
+                  int startX, int startY,
                   int endX, int endY,
-                  const int scrollX, const int scrollY) const;
+                  const int scrollX, const int scrollY) const A_NONNULL(2);
 
         MapItem* getTile(const int x, const int y) const A_WARN_UNUSED;
 
diff --git a/src/simpleanimation.h b/src/simpleanimation.h
index 2c290bb10..4e588e78b 100644
--- a/src/simpleanimation.h
+++ b/src/simpleanimation.h
@@ -64,7 +64,7 @@ class SimpleAnimation final
         bool update(const int timePassed);
 
         void draw(Graphics *const graphics,
-                  const int posX, const int posY) const;
+                  const int posX, const int posY) const A_NONNULL(2);
 
         /**
          * Resets the animation.
diff --git a/src/sprite.h b/src/sprite.h
index 568663590..1062615c9 100644
--- a/src/sprite.h
+++ b/src/sprite.h
@@ -62,7 +62,8 @@ class Sprite notfinal
          * pixels.
          */
         virtual void draw(Graphics *const graphics,
-                          const int posX, const int posY) const = 0;
+                          const int posX, const int posY)
+                          const A_NONNULL(2) = 0;
 
         /**
          * Gets the width in pixels of the image of the current frame
diff --git a/src/text.h b/src/text.h
index fc9b0f08c..ae53a5984 100644
--- a/src/text.h
+++ b/src/text.h
@@ -74,7 +74,7 @@ class Text notfinal
          * Draws the text.
          */
         virtual void draw(Graphics *const graphics,
-                          const int xOff, const int yOff);
+                          const int xOff, const int yOff) A_NONNULL(2);
 
     private:
         Font *mFont;           /**< The font of the text */
@@ -121,7 +121,7 @@ class FlashText final : public Text
          * Draws the text.
          */
         void draw(Graphics *const graphics,
-                  const int xOff, const int yOff) override final;
+                  const int xOff, const int yOff) override final A_NONNULL(2);
 
     private:
         int mTime;             /**< Time left for flashing */
diff --git a/src/textmanager.h b/src/textmanager.h
index 299c384c7..cebd4cec6 100644
--- a/src/textmanager.h
+++ b/src/textmanager.h
@@ -63,7 +63,8 @@ class TextManager final
          * Draw the text
          */
         void draw(Graphics *const graphics,
-                  const int xOff, const int yOff);
+                  const int xOff,
+                  const int yOff) A_NONNULL(2);
 
     private:
         /**