SDL: Clean up graphics manager switching slighty.

Sadly this also requires us to extend GraphicsManager for this SDL specific
feature. However, since that's only used in the SDL backend and Tizen it
should be fine for now...

backends/graphics/graphics.h

@@ -37,6 +37,27 @@ class GraphicsManager : public PaletteManager {
 public:
 	virtual ~GraphicsManager() {}
 
+	/**
+	 * Makes this graphics manager active. That means it should be ready to
+	 * process inputs now. However, even without being active it should be
+	 * able to query the supported modes and other bits.
+	 *
+	 * HACK: Actually this is specific to SdlGraphicsManager subclasses.
+	 * But sadly we cannot cast from GraphicsManager to SdlGraphicsManager
+	 * because there is no relation between these two.
+	 */
+	virtual void activateManager() {}
+
+	/**
+	 * Makes this graphics manager inactive. This should allow another
+	 * graphics manager to become active again.
+	 *
+	 * HACK: Actually this is specific to SdlGraphicsManager subclasses.
+	 * But sadly we cannot cast from GraphicsManager to SdlGraphicsManager
+	 * because there is no relation between these two.
+	 */
+	virtual void deactivateManager() {}
+
 	virtual bool hasFeature(OSystem::Feature f) = 0;
 	virtual void setFeatureState(OSystem::Feature f, bool enable) = 0;
 	virtual bool getFeatureState(OSystem::Feature f) = 0;

backends/graphics/openglsdl/openglsdl-graphics.cpp

@@ -82,15 +82,24 @@ OpenGLSdlGraphicsManager::OpenGLSdlGraphicsManager(uint desktopWidth, uint deskt
 }
 
 OpenGLSdlGraphicsManager::~OpenGLSdlGraphicsManager() {
+}
+
+void OpenGLSdlGraphicsManager::activateManager() {
+	OpenGLGraphicsManager::activateManager();
+	initEventSource();
+
+	// Register the graphics manager as a event observer
+	g_system->getEventManager()->getEventDispatcher()->registerObserver(this, 10, false);
+}
+
+void OpenGLSdlGraphicsManager::deactivateManager() {
 	// Unregister the event observer
 	if (g_system->getEventManager()->getEventDispatcher()) {
 		g_system->getEventManager()->getEventDispatcher()->unregisterObserver(this);
 	}
-}
 
-void OpenGLSdlGraphicsManager::initEventObserver() {
-	// Register the graphics manager as a event observer
-	g_system->getEventManager()->getEventDispatcher()->registerObserver(this, 10, false);
+	deinitEventSource();
+	OpenGLGraphicsManager::deactivateManager();
 }
 
 bool OpenGLSdlGraphicsManager::hasFeature(OSystem::Feature f) {

backends/graphics/openglsdl/openglsdl-graphics.h

@@ -35,9 +35,10 @@ class OpenGLSdlGraphicsManager : public OpenGL::OpenGLGraphicsManager, public Sd
 	OpenGLSdlGraphicsManager(uint desktopWidth, uint desktopHeight, SdlEventSource *eventSource);
 	virtual ~OpenGLSdlGraphicsManager();
 
-	void initEventObserver();
-
 	// GraphicsManager API
+	virtual void activateManager();
+	virtual void deactivateManager();
+
 	virtual bool hasFeature(OSystem::Feature f);
 	virtual void setFeatureState(OSystem::Feature f, bool enable);
 	virtual bool getFeatureState(OSystem::Feature f);

backends/graphics/sdl/sdl-graphics.cpp

@@ -26,10 +26,15 @@
 
 SdlGraphicsManager::SdlGraphicsManager(SdlEventSource *source)
 	: _eventSource(source) {
-	_eventSource->setGraphicsManager(this);
 }
 
 SdlGraphicsManager::~SdlGraphicsManager() {
-	_eventSource->setGraphicsManager(0);
 }
 
+void SdlGraphicsManager::initEventSource() {
+	_eventSource->setGraphicsManager(this);
+}
+
+void SdlGraphicsManager::deinitEventSource() {
+	_eventSource->setGraphicsManager(0);
+}

backends/graphics/sdl/sdl-graphics.h

@@ -80,6 +80,9 @@ class SdlGraphicsManager {
 	virtual void notifyMousePos(Common::Point mouse) = 0;
 
 protected:
+	void initEventSource();
+	void deinitEventSource();
+
 	SdlEventSource *_eventSource;
 };
 

backends/graphics/surfacesdl/surfacesdl-graphics.cpp

@@ -193,10 +193,6 @@ SurfaceSdlGraphicsManager::SurfaceSdlGraphicsManager(SdlEventSource *sdlEventSou
 }
 
 SurfaceSdlGraphicsManager::~SurfaceSdlGraphicsManager() {
-	// Unregister the event observer
-	if (g_system->getEventManager()->getEventDispatcher() != NULL)
-		g_system->getEventManager()->getEventDispatcher()->unregisterObserver(this);
-
 	unloadGFXMode();
 	if (_mouseSurface)
 		SDL_FreeSurface(_mouseSurface);
@@ -211,11 +207,24 @@ SurfaceSdlGraphicsManager::~SurfaceSdlGraphicsManager() {
 	free(_mouseData);
 }
 
-void SurfaceSdlGraphicsManager::initEventObserver() {
+void SurfaceSdlGraphicsManager::activateManager() {
+	GraphicsManager::activateManager();
+	initEventSource();
+
 	// Register the graphics manager as a event observer
 	g_system->getEventManager()->getEventDispatcher()->registerObserver(this, 10, false);
 }
 
+void SurfaceSdlGraphicsManager::deactivateManager() {
+	// Unregister the event observer
+	if (g_system->getEventManager()->getEventDispatcher()) {
+		g_system->getEventManager()->getEventDispatcher()->unregisterObserver(this);
+	}
+
+	deinitEventSource();
+	GraphicsManager::deactivateManager();
+}
+
 bool SurfaceSdlGraphicsManager::hasFeature(OSystem::Feature f) {
 	return
 		(f == OSystem::kFeatureFullscreenMode) ||

backends/graphics/surfacesdl/surfacesdl-graphics.h

@@ -80,7 +80,8 @@ class SurfaceSdlGraphicsManager : public GraphicsManager, public SdlGraphicsMana
 	SurfaceSdlGraphicsManager(SdlEventSource *sdlEventSource);
 	virtual ~SurfaceSdlGraphicsManager();
 
-	virtual void initEventObserver();
+	virtual void activateManager();
+	virtual void deactivateManager();
 
 	virtual bool hasFeature(OSystem::Feature f);
 	virtual void setFeatureState(OSystem::Feature f, bool enable);

backends/platform/sdl/sdl.cpp

@@ -89,6 +89,9 @@ OSystem_SDL::~OSystem_SDL() {
 	// Hence, we perform the destruction on our own.
 	delete _savefileManager;
 	_savefileManager = 0;
+	if (_graphicsManager) {
+		_graphicsManager->deactivateManager();
+	}
 	delete _graphicsManager;
 	_graphicsManager = 0;
 	delete _eventManager;
@@ -161,8 +164,6 @@ void OSystem_SDL::initBackend() {
 	if (_eventSource == 0)
 		_eventSource = new SdlEventSource();
 
-	int graphicsManagerType = 0;
-
 #ifdef USE_OPENGL
 	// Query the desktop resolution. We simply hope nothing tried to change
 	// the resolution so far.
@@ -193,13 +194,11 @@ void OSystem_SDL::initBackend() {
 			// If the gfx_mode is from OpenGL, create the OpenGL graphics manager
 			if (use_opengl) {
 				_graphicsManager = new OpenGLSdlGraphicsManager(_desktopWidth, _desktopHeight, _eventSource);
-				graphicsManagerType = 1;
 			}
 		}
 #endif
 		if (_graphicsManager == 0) {
 			_graphicsManager = new SurfaceSdlGraphicsManager(_eventSource);
-			graphicsManagerType = 0;
 		}
 	}
 
@@ -242,13 +241,7 @@ void OSystem_SDL::initBackend() {
 	// so the virtual keyboard can be initialized, but we have to add the
 	// graphics manager as an event observer after initializing the event
 	// manager.
-	if (graphicsManagerType == 0)
-		((SurfaceSdlGraphicsManager *)_graphicsManager)->initEventObserver();
-#ifdef USE_OPENGL
-	else if (graphicsManagerType == 1)
-		((OpenGLSdlGraphicsManager *)_graphicsManager)->initEventObserver();
-#endif
-
+	_graphicsManager->activateManager();
 }
 
 #if defined(USE_TASKBAR)
@@ -595,25 +588,26 @@ bool OSystem_SDL::setGraphicsMode(int mode) {
 			// manager, delete and create the new mode graphics manager
 			if (_graphicsMode >= _sdlModesCount && mode < _sdlModesCount) {
 				debug(1, "switching to plain SDL graphics");
+				_graphicsManager->deactivateManager();
 				delete _graphicsManager;
 				_graphicsManager = new SurfaceSdlGraphicsManager(_eventSource);
-				((SurfaceSdlGraphicsManager *)_graphicsManager)->initEventObserver();
-				_graphicsManager->beginGFXTransaction();
 
 				switchedManager = true;
 			} else if (_graphicsMode < _sdlModesCount && mode >= _sdlModesCount) {
 				debug(1, "switching to OpenGL graphics");
+				_graphicsManager->deactivateManager();
 				delete _graphicsManager;
 				_graphicsManager = new OpenGLSdlGraphicsManager(_desktopWidth, _desktopHeight, _eventSource);
-				((OpenGLSdlGraphicsManager *)_graphicsManager)->initEventObserver();
-				_graphicsManager->beginGFXTransaction();
 
 				switchedManager = true;
 			}
 
 			_graphicsMode = mode;
 
 			if (switchedManager) {
+				_graphicsManager->activateManager();
+
+				_graphicsManager->beginGFXTransaction();
 #ifdef USE_RGB_COLOR
 				_graphicsManager->initSize(screenWidth, screenHeight, &pixelFormat);
 #else