Nicer behaviour for edgescroll in windowed mode

OpenRA.Game/Game.cs

@@ -42,6 +42,7 @@ namespace OpenRA
 
 		public static Renderer Renderer;
 		public static Session LobbyInfo = new Session();
+		public static bool HasInputFocus = false;
 		
 		static void LoadMap(string uid)
 		{

OpenRA.Game/Widgets/ViewportScrollControllerWidget.cs

@@ -125,7 +125,7 @@ namespace OpenRA.Widgets
 		public override void Tick(World world)
 		{
 			Edge = ScrollDirection.None;
-			if (Game.Settings.Game.ViewportEdgeScroll)
+			if (Game.Settings.Game.ViewportEdgeScroll && Game.HasInputFocus)
 			{
 				// Check for edge-scroll
 				if (Viewport.LastMousePos.X < EdgeScrollThreshold)
@@ -137,6 +137,7 @@ namespace OpenRA.Widgets
 				if (Viewport.LastMousePos.Y >= Game.viewport.Height - EdgeScrollThreshold)
 					Edge = Edge.Set(ScrollDirection.Down, true);
 			}
+			
 			if(Keyboard != ScrollDirection.None || Edge != ScrollDirection.None)
 			{
 				var scroll = new float2(0,0);

OpenRA.Gl/GraphicsDevice.cs

@@ -182,6 +182,7 @@ namespace OpenRA.GlRenderer
         public void Present()
         {
             Sdl.SDL_GL_SwapBuffers();
+			Game.HasInputFocus = 0 != (Sdl.SDL_GetAppState() & Sdl.SDL_APPINPUTFOCUS);
 			
             var mods = MakeModifiers(Sdl.SDL_GetModState());
             Game.HandleModifierKeys(mods);