10 files changed, 80 insertions, 7 deletions

diff --git a/backends/events/default/default-events.cpp b/backends/events/default/default-events.cpp
index c7c39da069..667914b023 100644
--- a/backends/events/default/default-events.cpp
+++ b/backends/events/default/default-events.cpp
@@ -254,4 +254,30 @@ void DefaultEventManager::pushEvent(const Common::Event &event) {
 		_artificialEventSource.addEvent(event);
 }
 
+void DefaultEventManager::purgeMouseEvents() {
+	_dispatcher.dispatch();
+
+	Common::Queue<Common::Event> filteredQueue;
+	while (!_eventQueue.empty()) {
+		Common::Event event = _eventQueue.pop();
+		switch (event.type) {
+		case Common::EVENT_MOUSEMOVE:
+		case Common::EVENT_LBUTTONDOWN:
+		case Common::EVENT_LBUTTONUP:
+		case Common::EVENT_RBUTTONDOWN:
+		case Common::EVENT_RBUTTONUP:
+		case Common::EVENT_WHEELUP:
+		case Common::EVENT_WHEELDOWN:
+		case Common::EVENT_MBUTTONDOWN:
+		case Common::EVENT_MBUTTONUP:
+			// do nothing
+			break;
+		default:
+			filteredQueue.push(event);
+			break;
+		}
+	}
+	_eventQueue = filteredQueue;
+}
+
 #endif // !defined(DISABLE_DEFAULT_EVENTMANAGER)
diff --git a/backends/events/default/default-events.h b/backends/events/default/default-events.h
index f378fb9ff0..38406c25aa 100644
--- a/backends/events/default/default-events.h
+++ b/backends/events/default/default-events.h
@@ -80,6 +80,7 @@ public:
 	virtual void init();
 	virtual bool pollEvent(Common::Event &event);
 	virtual void pushEvent(const Common::Event &event);
+	virtual void purgeMouseEvents() override;
 
 	virtual Common::Point getMousePos() const { return _mousePos; }
 	virtual int getButtonState() const { return _buttonState; }
diff --git a/backends/events/sdl/sdl-events.cpp b/backends/events/sdl/sdl-events.cpp
index 6f34420674..91ca0f5df6 100644
--- a/backends/events/sdl/sdl-events.cpp
+++ b/backends/events/sdl/sdl-events.cpp
@@ -75,7 +75,7 @@ static uint32 convUTF8ToUTF32(const char *src) {
 #endif
 
 SdlEventSource::SdlEventSource()
-    : EventSource(), _scrollLock(false), _joystick(0), _lastScreenID(0), _graphicsManager(0)
+    : EventSource(), _scrollLock(false), _joystick(0), _lastScreenID(0), _graphicsManager(0), _queuedFakeMouseMove(false)
 #if SDL_VERSION_ATLEAST(2, 0, 0)
       , _queuedFakeKeyUp(false), _fakeKeyUp()
 #endif
@@ -508,6 +508,12 @@ bool SdlEventSource::pollEvent(Common::Event &event) {
 		return true;
 	}
 
+	if (_queuedFakeMouseMove) {
+		event = _fakeMouseMove;
+		_queuedFakeMouseMove = false;
+		return true;
+	}
+
 	SDL_Event ev;
 	while (SDL_PollEvent(&ev)) {
 		preprocessEvents(&ev);
@@ -1003,6 +1009,12 @@ void SdlEventSource::resetKeyboardEmulation(int16 x_max, int16 y_max) {
 	_km.joy_y = 0;
 }
 
+void SdlEventSource::fakeWarpMouse(const int x, const int y) {
+	_queuedFakeMouseMove = true;
+	_fakeMouseMove.type = Common::EVENT_MOUSEMOVE;
+	_fakeMouseMove.mouse = Common::Point(x, y);
+}
+
 bool SdlEventSource::handleResizeEvent(Common::Event &event, int w, int h) {
 	if (_graphicsManager) {
 		_graphicsManager->notifyResize(w, h);
diff --git a/backends/events/sdl/sdl-events.h b/backends/events/sdl/sdl-events.h
index 1d701f5ecf..5fd3cb7ea5 100644
--- a/backends/events/sdl/sdl-events.h
+++ b/backends/events/sdl/sdl-events.h
@@ -51,6 +51,12 @@ public:
 	 */
 	virtual void resetKeyboardEmulation(int16 x_max, int16 y_max);
 
+	/**
+	 * Emulates a mouse movement that would normally be caused by a mouse warp
+	 * of the system mouse.
+	 */
+	void fakeWarpMouse(const int x, const int y);
+
 protected:
 	/** @name Keyboard mouse emulation
 	 * Disabled by fingolfin 2004-12-18.
@@ -156,6 +162,18 @@ protected:
 	 */
 	SDLKey obtainKeycode(const SDL_keysym keySym);
 
+	/**
+	 * Whether _fakeMouseMove contains an event we need to send.
+	 */
+	bool _queuedFakeMouseMove;
+
+	/**
+	 * A fake mouse motion event sent when the graphics manager is told to warp
+	 * the mouse but the system mouse is unable to be warped (e.g. because the
+	 * window is not focused).
+	 */
+	Common::Event _fakeMouseMove;
+
 #if SDL_VERSION_ATLEAST(2, 0, 0)
 	/**
 	 * Whether _fakeKeyUp contains an event we need to send.
diff --git a/backends/graphics/sdl/sdl-graphics.cpp b/backends/graphics/sdl/sdl-graphics.cpp
index e6699df1cd..64ee9f7aa1 100644
--- a/backends/graphics/sdl/sdl-graphics.cpp
+++ b/backends/graphics/sdl/sdl-graphics.cpp
@@ -212,6 +212,13 @@ bool SdlGraphicsManager::notifyMousePosition(Common::Point &mouse) {
 	return valid;
 }
 
+void SdlGraphicsManager::setSystemMousePosition(const int x, const int y) {
+	assert(_window);
+	if (!_window->warpMouseInWindow(x, y)) {
+		_eventSource->fakeWarpMouse(x, y);
+	}
+}
+
 void SdlGraphicsManager::handleResizeImpl(const int width, const int height) {
 	_eventSource->resetKeyboardEmulation(width - 1, height - 1);
 	_forceRedraw = true;
diff --git a/backends/graphics/sdl/sdl-graphics.h b/backends/graphics/sdl/sdl-graphics.h
index 993a1c3db6..526306270b 100644
--- a/backends/graphics/sdl/sdl-graphics.h
+++ b/backends/graphics/sdl/sdl-graphics.h
@@ -150,10 +150,7 @@ protected:
 #endif
 	}
 
-	virtual void setSystemMousePosition(const int x, const int y) override {
-		assert(_window);
-		_window->warpMouseInWindow(x, y);
-	}
+	virtual void setSystemMousePosition(const int x, const int y) override;
 
 	virtual void handleResizeImpl(const int width, const int height) override;
 
diff --git a/backends/modular-backend.cpp b/backends/modular-backend.cpp
index c9adbd3100..944ddd5a47 100644
--- a/backends/modular-backend.cpp
+++ b/backends/modular-backend.cpp
@@ -217,6 +217,7 @@ bool ModularBackend::showMouse(bool visible) {
 }
 
 void ModularBackend::warpMouse(int x, int y) {
+	_eventManager->purgeMouseEvents();
 	_graphicsManager->warpMouse(x, y);
 }
 
diff --git a/backends/platform/sdl/sdl-window.cpp b/backends/platform/sdl/sdl-window.cpp
index a550fbbd40..fe27d84de2 100644
--- a/backends/platform/sdl/sdl-window.cpp
+++ b/backends/platform/sdl/sdl-window.cpp
@@ -155,16 +155,20 @@ bool SdlWindow::hasMouseFocus() const {
 #endif
 }
 
-void SdlWindow::warpMouseInWindow(int x, int y) {
+bool SdlWindow::warpMouseInWindow(int x, int y) {
 	if (hasMouseFocus()) {
 #if SDL_VERSION_ATLEAST(2, 0, 0)
 		if (_window) {
 			SDL_WarpMouseInWindow(_window, x, y);
+			return true;
 		}
 #else
 		SDL_WarpMouse(x, y);
+		return true;
 #endif
 	}
+
+	return false;
 }
 
 void SdlWindow::iconifyWindow() {
diff --git a/backends/platform/sdl/sdl-window.h b/backends/platform/sdl/sdl-window.h
index 4f6d924411..e1a3499d19 100644
--- a/backends/platform/sdl/sdl-window.h
+++ b/backends/platform/sdl/sdl-window.h
@@ -58,8 +58,10 @@ public:
 	/**
 	 * Warp the mouse to the specified position in window coordinates. The mouse
 	 * will only be warped if the window is focused in the window manager.
+	 *
+	 * @returns true if the system cursor was warped.
 	 */
-	void warpMouseInWindow(int x, int y);
+	bool warpMouseInWindow(int x, int y);
 
 	/**
 	 * Iconifies the window.
diff --git a/common/events.h b/common/events.h
index 21a65a642b..e5bb8cab50 100644
--- a/common/events.h
+++ b/common/events.h
@@ -395,6 +395,11 @@ public:
 	 */
 	virtual void pushEvent(const Event &event) = 0;
 
+	/**
+	 * Purges all unprocessed mouse events already in the event queue.
+	 */
+	virtual void purgeMouseEvents() = 0;
+
 	/** Return the current mouse position */
 	virtual Point getMousePos() const = 0;