7 files changed, 63 insertions, 14 deletions
diff --git a/backends/graphics/graphics.h b/backends/graphics/graphics.h
index 24397228e6..74258b8910 100644
--- a/backends/graphics/graphics.h
+++ b/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;
diff --git a/backends/graphics/openglsdl/openglsdl-graphics.cpp b/backends/graphics/openglsdl/openglsdl-graphics.cpp
index 925237b75e..088e97b1f7 100644
--- a/backends/graphics/openglsdl/openglsdl-graphics.cpp
+++ b/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) {
diff --git a/backends/graphics/openglsdl/openglsdl-graphics.h b/backends/graphics/openglsdl/openglsdl-graphics.h
index 0644f27602..9934ca79e2 100644
--- a/backends/graphics/openglsdl/openglsdl-graphics.h
+++ b/backends/graphics/openglsdl/openglsdl-graphics.h
@@ -35,9 +35,10 @@ public:
 	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);
diff --git a/backends/graphics/sdl/sdl-graphics.cpp b/backends/graphics/sdl/sdl-graphics.cpp
index 2eca4b8aab..417f4faf54 100644
--- a/backends/graphics/sdl/sdl-graphics.cpp
+++ b/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);
+}
diff --git a/backends/graphics/sdl/sdl-graphics.h b/backends/graphics/sdl/sdl-graphics.h
index ea9149fccb..4d4338af16 100644
--- a/backends/graphics/sdl/sdl-graphics.h
+++ b/backends/graphics/sdl/sdl-graphics.h
@@ -80,6 +80,9 @@ public:
 	virtual void notifyMousePos(Common::Point mouse) = 0;
 
 protected:
+	void initEventSource();
+	void deinitEventSource();
+
 	SdlEventSource *_eventSource;
 };
 
diff --git a/backends/graphics/surfacesdl/surfacesdl-graphics.cpp b/backends/graphics/surfacesdl/surfacesdl-graphics.cpp
index 871c6c49b2..ba8807aaf4 100644
--- a/backends/graphics/surfacesdl/surfacesdl-graphics.cpp
+++ b/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) ||
diff --git a/backends/graphics/surfacesdl/surfacesdl-graphics.h b/backends/graphics/surfacesdl/surfacesdl-graphics.h
index 97de0f9c97..0bee70bf0c 100644
--- a/backends/graphics/surfacesdl/surfacesdl-graphics.h
+++ b/backends/graphics/surfacesdl/surfacesdl-graphics.h
@@ -80,7 +80,8 @@ public:
 	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);