Let the Renderer decide when to exit fullscreen.

This ensures the transition from/to exclusive mode happens while the RenderFrame is fullscreen.

This prevents fullscreen loops and relieves us of having to restore the window size after we exit fullscreen.

Source/Core/DolphinWX/Frame.cpp

@@ -640,6 +640,11 @@ void CFrame::OnHostMessage(wxCommandEvent& event)
 		}
 		break;
 
+	case IDM_FULLSCREENREQUEST:
+		if (m_RenderFrame != nullptr)
+			m_RenderFrame->ShowFullScreen(event.GetInt() == 0 ? false : true);
+		break;
+
 	case WM_USER_CREATE:
 		if (SConfig::GetInstance().m_LocalCoreStartupParameter.bHideCursor)
 			m_RenderParent->SetCursor(wxCURSOR_BLANK);
@@ -1185,7 +1190,18 @@ void CFrame::DoFullscreen(bool bF)
 		[window toggleFullScreen:nil];
 	}
 #else
-	m_RenderFrame->ShowFullScreen(bF, wxFULLSCREEN_ALL);
+	if (bF)
+	{
+		m_RenderFrame->ShowFullScreen(true, wxFULLSCREEN_ALL);
+	}
+	else if (!g_ActiveConfig.backend_info.bSupportsExclusiveFullscreen ||
+		SConfig::GetInstance().m_LocalCoreStartupParameter.bRenderToMain ||
+		g_ActiveConfig.bForceBorderlessFullscreen)
+	{
+		// Exiting exclusive fullscreen should be done from a Renderer callback.
+		// Therefore we don't exit fullscreen from here if we support exclusive mode.
+		m_RenderFrame->ShowFullScreen(false, wxFULLSCREEN_ALL);
+	}
 #endif
 
 	if (SConfig::GetInstance().m_LocalCoreStartupParameter.bRenderToMain)

Source/Core/DolphinWX/Globals.h

@@ -256,6 +256,7 @@ enum
 	IDM_WINDOWSIZEREQUEST,
 	IDM_STOPPED,
 	IDM_HOST_MESSAGE,
+	IDM_FULLSCREENREQUEST,
 
 	IDM_MPANEL, ID_STATUSBAR,
 

Source/Core/DolphinWX/Main.cpp

@@ -627,6 +627,13 @@ void Host_RequestRenderWindowSize(int width, int height)
 	main_frame->GetEventHandler()->AddPendingEvent(event);
 }
 
+void Host_RequestFullscreen(bool fullscreen)
+{
+	wxCommandEvent event(wxEVT_HOST_COMMAND, IDM_FULLSCREENREQUEST);
+	event.SetInt(fullscreen ? 1 : 0);
+	main_frame->GetEventHandler()->AddPendingEvent(event);
+}
+
 void Host_SetStartupDebuggingParameters()
 {
 	SCoreStartupParameter& StartUp = SConfig::GetInstance().m_LocalCoreStartupParameter;

Source/Core/DolphinWX/MainAndroid.cpp

@@ -94,6 +94,9 @@ void Host_GetRenderWindowSize(int& x, int& y, int& width, int& height)
 }
 
 void Host_RequestRenderWindowSize(int width, int height) {}
+
+void Host_RequestFullscreen(bool fullscreen) {}
+
 void Host_SetStartupDebuggingParameters()
 {
 }

Source/Core/DolphinWX/MainNoGUI.cpp

@@ -88,6 +88,9 @@ void Host_GetRenderWindowSize(int& x, int& y, int& width, int& height)
 }
 
 void Host_RequestRenderWindowSize(int width, int height) {}
+
+void Host_RequestFullscreen(bool fullscreen) {}
+
 void Host_SetStartupDebuggingParameters()
 {
 	SCoreStartupParameter& StartUp = SConfig::GetInstance().m_LocalCoreStartupParameter;