Added SDL2 timers

src/window/sdl2/sdl2_display_window.cpp

@@ -365,16 +365,55 @@ void SDL2DisplayWindow::ExitLoop()
 	ExitRunLoop = true;
 }
 
+std::unordered_map<void *, std::function<void()>> SDL2DisplayWindow::Timers;
+std::unordered_map<void *, void *> SDL2DisplayWindow::TimerHandles;
+unsigned long SDL2DisplayWindow::TimerIDs = 0;
+Uint32 TimerEventID = SDL_RegisterEvents(1);
+
+Uint32 SDL2DisplayWindow::ExecTimer(Uint32 interval, void* execID)
+{
+	// cancel event and stop loop if function not found
+	if (Timers.find(execID) == Timers.end())
+		return 0;
+
+	SDL_Event timerEvent;
+	SDL_zero(timerEvent);
+
+	timerEvent.user.type = TimerEventID;
+	timerEvent.user.data1 = execID;
+
+	SDL_PushEvent(&timerEvent);
+
+	return interval;
+}
+
 void* SDL2DisplayWindow::StartTimer(int timeoutMilliseconds, std::function<void()> onTimer)
 {
-	// To do: implement timers
+	CheckInitSDL();
+
+	void* execID = (void*)(uintptr_t)++TimerIDs;
+	void* id = (void*)(uintptr_t)SDL_AddTimer(timeoutMilliseconds, SDL2DisplayWindow::ExecTimer, execID);
+
+	if (!id) return id;
+
+	Timers.insert({execID, onTimer});
+	TimerHandles.insert({id, execID});
 
-	return nullptr;
+	return id;
 }
 
 void SDL2DisplayWindow::StopTimer(void* timerID)
 {
-	// To do: implement timers
+	CheckInitSDL();
+
+	SDL_RemoveTimer((SDL_TimerID)(uintptr_t)timerID);
+
+	auto execID = TimerHandles.find(timerID);
+	if (execID == TimerHandles.end())
+		return;
+
+	Timers.erase(execID->second);
+	TimerHandles.erase(timerID);
 }
 
 SDL2DisplayWindow* SDL2DisplayWindow::FindEventWindow(const SDL_Event& event)
@@ -401,6 +440,10 @@ SDL2DisplayWindow* SDL2DisplayWindow::FindEventWindow(const SDL_Event& event)
 
 void SDL2DisplayWindow::DispatchEvent(const SDL_Event& event)
 {
+	// timers are created in a non-window context
+	if (event.type == TimerEventID)
+		return OnTimerEvent(event.user);
+
 	SDL2DisplayWindow* window = FindEventWindow(event);
 	if (!window) return;
 
@@ -509,6 +552,17 @@ void SDL2DisplayWindow::OnPaintEvent()
 	WindowHost->OnWindowPaint();
 }
 
+void SDL2DisplayWindow::OnTimerEvent(const SDL_UserEvent& event)
+{
+	auto func = Timers.find(event.data1);
+
+	// incase timer was cancelled before we get here
+	if (func == Timers.end())
+		return;
+
+	func->second();
+}
+
 InputKey SDL2DisplayWindow::ScancodeToInputKey(SDL_Scancode keycode)
 {
 	switch (keycode)

src/window/sdl2/sdl2_display_window.h

@@ -67,6 +67,7 @@ class SDL2DisplayWindow : public DisplayWindow
 	void OnMouseWheel(const SDL_MouseWheelEvent& event);
 	void OnMouseMotion(const SDL_MouseMotionEvent& event);
 	void OnPaintEvent();
+	static void OnTimerEvent(const SDL_UserEvent& event);
 
 	InputKey GetMouseButtonKey(const SDL_MouseButtonEvent& event);
 
@@ -86,6 +87,7 @@ class SDL2DisplayWindow : public DisplayWindow
 
 	static void* StartTimer(int timeoutMilliseconds, std::function<void()> onTimer);
 	static void StopTimer(void* timerID);
+	static Uint32 ExecTimer(Uint32 interval, void* id);
 
 	DisplayWindowHost* WindowHost = nullptr;
 	SDL2NativeHandle Handle;
@@ -102,4 +104,9 @@ class SDL2DisplayWindow : public DisplayWindow
 	static bool ExitRunLoop;
 	static Uint32 PaintEventNumber;
 	static std::unordered_map<int, SDL2DisplayWindow*> WindowList;
+
+	static std::unordered_map<void *, void *> TimerHandles;
+	static std::unordered_map<void *, std::function<void()>> Timers;
+	static unsigned long TimerIDs;
+	static Uint32 TimerEventNumber;
 };