+ virtual void OnResize(int w, int h) { }
+
+ virtual void OnKeyDown(const SDL_KeyboardEvent &) { }
+ virtual void OnKeyUp(const SDL_KeyboardEvent &) { }
+ virtual void OnMouseDown(const SDL_MouseButtonEvent &) { }
+ virtual void OnMouseUp(const SDL_MouseButtonEvent &) { }
+ virtual void OnMouseMotion(const SDL_MouseMotionEvent &) { }
+ virtual void OnMouseWheel(const SDL_MouseWheelEvent &) { }
+ virtual void OnQuit();