Host: Add a new "UIHasFocus" hook to determine if the UI has focus

We can't use RendererHasFocus for this purpose because of some issues
with exclusive fullscreen, and the new RendererHasFocus implementation
didn't work for non-Render to Main Window cases, since the renderer
window wasn't managed by wx.

Source/Core/Core/Host.h

@@ -23,6 +23,7 @@
 // The host can be just a command line app that opens a window, or a full blown debugger
 // interface.
 
+bool Host_UIHasFocus();
 bool Host_RendererHasFocus();
 void Host_ConnectWiimote(int wm_idx, bool connect);
 void Host_GetRenderWindowSize(int& x, int& y, int& width, int& height);

Source/Core/DolphinWX/Frame.cpp

@@ -773,6 +773,19 @@ bool CFrame::RendererHasFocus()
 	return false;
 }
 
+bool CFrame::UIHasFocus()
+{
+	// UIHasFocus should return true any time any one of our UI
+	// windows has the focus, including any dialogs or other windows.
+	//
+	// wxGetActiveWindow() returns the current wxWindow which has
+	// focus. If it's not one of our windows, then it will return
+	// null.
+
+	wxWindow *focusWindow = wxGetActiveWindow();
+	return (focusWindow != nullptr);
+}
+
 void CFrame::OnGameListCtrl_ItemActivated(wxListEvent& WXUNUSED (event))
 {
 	// Show all platforms and regions if...

Source/Core/DolphinWX/Frame.h

@@ -138,6 +138,7 @@ public:
 	void OnRenderParentClose(wxCloseEvent& event);
 	void OnRenderParentMove(wxMoveEvent& event);
 	bool RendererHasFocus();
+	bool UIHasFocus();
 	void DoFullscreen(bool bF);
 	void ToggleDisplayMode (bool bFullscreen);
 	void UpdateWiiMenuChoice(wxMenuItem *WiiMenuItem=nullptr);

Source/Core/DolphinWX/Main.cpp

@@ -678,6 +678,11 @@ void Host_SetWiiMoteConnectionState(int _State)
 	main_frame->GetEventHandler()->AddPendingEvent(event);
 }
 
+bool Host_UIHasFocus()
+{
+	return main_frame->UIHasFocus();
+}
+
 bool Host_RendererHasFocus()
 {
 	return main_frame->RendererHasFocus();

Source/Core/DolphinWX/MainAndroid.cpp

@@ -98,6 +98,11 @@ void Host_SetStartupDebuggingParameters()
 {
 }
 
+bool Host_UIHasFocus()
+{
+	return true;
+}
+
 bool Host_RendererHasFocus()
 {
 	return true;

Source/Core/DolphinWX/MainNoGUI.cpp

@@ -95,6 +95,11 @@ void Host_SetStartupDebuggingParameters()
 	StartUp.bBootToPause = false;
 }
 
+bool Host_UIHasFocus()
+{
+	return false;
+}
+
 bool Host_RendererHasFocus()
 {
 	return rendererHasFocus;

Source/Core/InputCommon/ControllerInterface/Device.cpp

@@ -84,7 +84,7 @@ bool Device::Control::InputGateOn()
 {
 	if (SConfig::GetInstance().m_BackgroundInput)
 		return true;
-	else if (Host_RendererHasFocus())
+	else if (Host_RendererHasFocus() || Host_UIHasFocus())
 		return true;
 	else
 		return false;