SDL: Make activateManager/deactivateManager SdlGraphicsManager specific.

We can do this now that we can use virtual inheritance and dynamic_cast
because we enabled RTTI.

backends/graphics/graphics.h

@@ -37,27 +37,6 @@ 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

@@ -73,7 +73,7 @@ OpenGLSdlGraphicsManager::~OpenGLSdlGraphicsManager() {
 }
 
 void OpenGLSdlGraphicsManager::activateManager() {
-	OpenGLGraphicsManager::activateManager();
+	SdlGraphicsManager::activateManager();
 	initEventSource();
 
 	// Register the graphics manager as a event observer
@@ -87,7 +87,7 @@ void OpenGLSdlGraphicsManager::deactivateManager() {
 	}
 
 	deinitEventSource();
-	OpenGLGraphicsManager::deactivateManager();
+	SdlGraphicsManager::deactivateManager();
 }
 
 bool OpenGLSdlGraphicsManager::hasFeature(OSystem::Feature f) {

backends/graphics/sdl/sdl-graphics.h

@@ -39,6 +39,19 @@ public:
 	SdlGraphicsManager(SdlEventSource *source);
 	virtual ~SdlGraphicsManager();
 
+	/**
+	 * 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.
+	 */
+	virtual void activateManager() {}
+
+	/**
+	 * Makes this graphics manager inactive. This should allow another
+	 * graphics manager to become active again.
+	 */
+	virtual void deactivateManager() {}
+
 	/**
 	 * Notify the graphics manager that the graphics needs to be redrawn, since
 	 * the application window was modified.

backends/graphics/surfacesdl/surfacesdl-graphics.cpp

@@ -198,7 +198,7 @@ SurfaceSdlGraphicsManager::~SurfaceSdlGraphicsManager() {
 }
 
 void SurfaceSdlGraphicsManager::activateManager() {
-	GraphicsManager::activateManager();
+	SdlGraphicsManager::activateManager();
 	initEventSource();
 
 	// Register the graphics manager as a event observer
@@ -212,7 +212,7 @@ void SurfaceSdlGraphicsManager::deactivateManager() {
 	}
 
 	deinitEventSource();
-	GraphicsManager::deactivateManager();
+	SdlGraphicsManager::deactivateManager();
 }
 
 bool SurfaceSdlGraphicsManager::hasFeature(OSystem::Feature f) {

backends/platform/sdl/sdl.cpp

@@ -91,7 +91,7 @@ OSystem_SDL::~OSystem_SDL() {
 	delete _savefileManager;
 	_savefileManager = 0;
 	if (_graphicsManager) {
-		_graphicsManager->deactivateManager();
+		dynamic_cast<SdlGraphicsManager *>(_graphicsManager)->deactivateManager();
 	}
 	delete _graphicsManager;
 	_graphicsManager = 0;
@@ -240,7 +240,7 @@ 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.
-	_graphicsManager->activateManager();
+	dynamic_cast<SdlGraphicsManager *>(_graphicsManager)->activateManager();
 }
 
 #if defined(USE_TASKBAR)
@@ -585,14 +585,14 @@ bool OSystem_SDL::setGraphicsMode(int mode) {
 	// manager, delete and create the new mode graphics manager
 	if (_graphicsMode >= _firstGLMode && mode < _firstGLMode) {
 		debug(1, "switching to plain SDL graphics");
-		_graphicsManager->deactivateManager();
+		dynamic_cast<SdlGraphicsManager *>(_graphicsManager)->deactivateManager();
 		delete _graphicsManager;
 		_graphicsManager = new SurfaceSdlGraphicsManager(_eventSource);
 
 		switchedManager = true;
 	} else if (_graphicsMode < _firstGLMode && mode >= _firstGLMode) {
 		debug(1, "switching to OpenGL graphics");
-		_graphicsManager->deactivateManager();
+		dynamic_cast<SdlGraphicsManager *>(_graphicsManager)->deactivateManager();
 		delete _graphicsManager;
 		_graphicsManager = new OpenGLSdlGraphicsManager(_desktopWidth, _desktopHeight, _eventSource);
 
@@ -602,7 +602,7 @@ bool OSystem_SDL::setGraphicsMode(int mode) {
 	_graphicsMode = mode;
 
 	if (switchedManager) {
-		_graphicsManager->activateManager();
+		dynamic_cast<SdlGraphicsManager *>(_graphicsManager)->activateManager();
 
 		_graphicsManager->beginGFXTransaction();
 #ifdef USE_RGB_COLOR