// Copyright 1998-2017 Epic Games, Inc. All Rights Reserved.


#include "Framework/Application/SlateApplication.h"
#include "Rendering/SlateDrawBuffer.h"
#include "Misc/CommandLine.h"
#include "Misc/ScopeLock.h"
#include "Misc/TimeGuard.h"
#include "Misc/ConfigCacheIni.h"
#include "Misc/CoreDelegates.h"
#include "Misc/App.h"
#include "Modules/ModuleManager.h"
#include "InputCoreModule.h"
#include "Layout/LayoutUtils.h"
#include "Sound/ISlateSoundDevice.h"
#include "Sound/NullSlateSoundDevice.h"
#include "Framework/Text/PlatformTextField.h"
#include "Framework/Application/NavigationConfig.h"
#include "Widgets/SWeakWidget.h"
#include "Widgets/Images/SImage.h"
#include "Widgets/Layout/SBox.h"
#include "Widgets/SToolTip.h"
#include "Widgets/SViewport.h"
#include "Framework/Application/SWindowTitleBar.h"
#include "Input/HittestGrid.h"
#include "Stats/SlateStats.h"
#include "HardwareCursor.h"

#include "Framework/Application/IWidgetReflector.h"
#include "Framework/Commands/GenericCommands.h"
#include "Framework/Notifications/NotificationManager.h"
#include "Framework/Application/IInputProcessor.h"
#include "GenericPlatform/ITextInputMethodSystem.h"
#include "ToolboxModule.h"
#include "Framework/Docking/TabCommands.h"

#define SLATE_HAS_WIDGET_REFLECTOR !UE_BUILD_SHIPPING || PLATFORM_DESKTOP

#if PLATFORM_WINDOWS
#include "WindowsHWrapper.h"
#endif

extern SLATECORE_API TOptional<FShortRect> GSlateScissorRect;

class FEventRouter
{

// @todo slate : making too many event copies when translating events( i.e. Translate<EventType>::PointerEvent ).



// @todo slate : Widget Reflector should log: (1) Every process reply (2) Every time the event is handled and by who.

// @todo slate : Remove remaining [&]-style mass captures.

// @todo slate : Eliminate all ad-hoc uses of SetEventPath()

// @todo slate : Remove CALL_WIDGET_FUNCTION

public:

	class FDirectPolicy
	{
	public:
		FDirectPolicy( const FWidgetAndPointer& InTarget, const FWidgetPath& InRoutingPath )
		: bEventSent(false)
		, RoutingPath(InRoutingPath)
		, Target(InTarget)
		{
		}

		bool ShouldKeepGoing() const
		{
			return !bEventSent;
		}

		void Next()
		{
			bEventSent = true;
		}

		FWidgetAndPointer GetWidget() const
		{
			return Target;
		}

		const FWidgetPath& GetRoutingPath() const
		{
			return RoutingPath;
		}

	private:
		bool bEventSent;
		const FWidgetPath& RoutingPath;
		const FWidgetAndPointer& Target;
	};

	class FToLeafmostPolicy
	{
	public:
		FToLeafmostPolicy( const FWidgetPath& InRoutingPath )
		: bEventSent(false)
		, RoutingPath(InRoutingPath)
		{
		}

		bool ShouldKeepGoing() const
		{
			return !bEventSent && RoutingPath.Widgets.Num() > 0;
		}

		void Next()
		{
			bEventSent = true;
		}

		FWidgetAndPointer GetWidget() const
		{
			const int32 WidgetIndex = RoutingPath.Widgets.Num()-1;
			return FWidgetAndPointer(RoutingPath.Widgets[WidgetIndex], RoutingPath.VirtualPointerPositions[WidgetIndex]);
		}

		const FWidgetPath& GetRoutingPath() const
		{
			return RoutingPath;
		}

	private:
		bool bEventSent;
		const FWidgetPath& RoutingPath;
	};

	class FTunnelPolicy
	{
	public:
		FTunnelPolicy( const FWidgetPath& InRoutingPath )
		: WidgetIndex(0)
		, RoutingPath(InRoutingPath)
		{
		}

		bool ShouldKeepGoing() const
		{
			return WidgetIndex < RoutingPath.Widgets.Num();
		}

		void Next()
		{
			++WidgetIndex;
		}

		FWidgetAndPointer GetWidget() const
		{
			return FWidgetAndPointer(RoutingPath.Widgets[WidgetIndex], RoutingPath.VirtualPointerPositions[WidgetIndex]);
		}
		
		const FWidgetPath& GetRoutingPath() const
		{
			return RoutingPath;
		}


	private:
		int32 WidgetIndex;
		const FWidgetPath& RoutingPath;
	};

	class FBubblePolicy
	{
	public:
		FBubblePolicy( const FWidgetPath& InRoutingPath )
		: WidgetIndex( InRoutingPath.Widgets.Num()-1 )
		, RoutingPath (InRoutingPath)
		{
		}

		bool ShouldKeepGoing() const
		{
			return WidgetIndex >= 0;
		}

		void Next()
		{
			--WidgetIndex;
		}

		FWidgetAndPointer GetWidget() const
		{
			return FWidgetAndPointer(RoutingPath.Widgets[WidgetIndex], RoutingPath.VirtualPointerPositions[WidgetIndex]);
		}

		const FWidgetPath& GetRoutingPath() const
		{
			return RoutingPath;
		}
	
	private:
		int32 WidgetIndex;
		const FWidgetPath& RoutingPath;
	};

	static void LogEvent( FSlateApplication* ThisApplication, const FInputEvent& Event, const FReplyBase& Reply )
	{
		TSharedPtr<IWidgetReflector> Reflector = ThisApplication->WidgetReflectorPtr.Pin();
		if (Reflector.IsValid() && Reply.IsEventHandled())
		{
			Reflector->OnEventProcessed( Event, Reply );
		}
	}

	/**
	 * Route an event along a focus path (as opposed to PointerPath)
	 *
	 * Focus paths are used focus devices.(e.g. Keyboard or Game Pads)
	 * Focus paths change when the user navigates focus (e.g. Tab or
	 * Shift Tab, clicks on a focusable widget, or navigation with keyboard/game pad.)
	 */
	template< typename RoutingPolicyType, typename FuncType, typename EventType >
	static FReply RouteAlongFocusPath( FSlateApplication* ThisApplication, RoutingPolicyType RoutingPolicy, EventType KeyEventCopy, const FuncType& Lambda )
	{
		return Route<FReply>(ThisApplication, RoutingPolicy, KeyEventCopy, Lambda);
	}

	/**
	 * Route an event based on the Routing Policy.
	 */
	template< typename ReplyType, typename RoutingPolicyType, typename EventType, typename FuncType >
	static ReplyType Route( FSlateApplication* ThisApplication, RoutingPolicyType RoutingPolicy, EventType EventCopy, const FuncType& Lambda )
	{
		ReplyType Reply = ReplyType::Unhandled();
		const FWidgetPath& RoutingPath = RoutingPolicy.GetRoutingPath();
		
		EventCopy.SetEventPath( RoutingPath );

		for ( ; !Reply.IsEventHandled() && RoutingPolicy.ShouldKeepGoing(); RoutingPolicy.Next() )
		{
			const FWidgetAndPointer& ArrangedWidget = RoutingPolicy.GetWidget();
			const EventType TranslatedEvent = Translate<EventType>::PointerEvent( ArrangedWidget.PointerPosition, EventCopy );
			Reply = Lambda( ArrangedWidget, TranslatedEvent ).SetHandler( ArrangedWidget.Widget );
			ProcessReply(ThisApplication, RoutingPath, Reply, &RoutingPath, &TranslatedEvent);
		}

		LogEvent(ThisApplication, EventCopy, Reply);

		return Reply;
	}

	static void ProcessReply( FSlateApplication* Application, const FWidgetPath& RoutingPath, const FNoReply& Reply, const FWidgetPath* WidgetsUnderCursor, const FInputEvent* )
	{
	}

	static void ProcessReply( FSlateApplication* Application, const FWidgetPath& RoutingPath, const FCursorReply& Reply, const FWidgetPath* WidgetsUnderCursor, const FInputEvent* )
	{
	}

	static void ProcessReply( FSlateApplication* Application, const FWidgetPath& RoutingPath, const FReply& Reply, const FWidgetPath* WidgetsUnderCursor, const FInputEvent* PointerEvent )
	{
		Application->ProcessReply(RoutingPath, Reply, WidgetsUnderCursor, nullptr, PointerEvent->GetUserIndex());
	}

	static void ProcessReply( FSlateApplication* Application, const FWidgetPath& RoutingPath, const FReply& Reply, const FWidgetPath* WidgetsUnderCursor, const FPointerEvent* PointerEvent )
	{
		Application->ProcessReply(RoutingPath, Reply, WidgetsUnderCursor, PointerEvent, PointerEvent->GetUserIndex());
	}

	template<typename EventType>
	struct Translate
	{
		static EventType PointerEvent( const TSharedPtr<FVirtualPointerPosition>& InPosition, const EventType& InEvent )
		{
			// Most events do not do any coordinate translation.
			return InEvent;
		}
	};

};


template<>
struct FEventRouter::Translate<FPointerEvent>
{
	static  FPointerEvent PointerEvent( const TSharedPtr<FVirtualPointerPosition>& InPosition, const FPointerEvent& InEvent )
	{
		// Pointer events are translated into the virtual window space. For 3D Widget Components this means
		if ( !InPosition.IsValid() )
		{
			return InEvent;
		}
		else
		{
			return FPointerEvent::MakeTranslatedEvent<FPointerEvent>( InEvent, *InPosition );
		}
	}
};


FSlateUser::FSlateUser(int32 InUserIndex, bool InVirtualUser)
	: UserIndex(InUserIndex)
	, bVirtualUser(InVirtualUser)
{
	Focus.WidgetPath = FWidgetPath();
	Focus.FocusCause = EFocusCause::Cleared;
	Focus.ShowFocus = false;
}

FSlateUser::~FSlateUser()
{
}

TSharedPtr<SWidget> FSlateUser::GetFocusedWidget() const
{
	if ( Focus.WidgetPath.IsValid() )
	{
		return Focus.WidgetPath.GetLastWidget().Pin();
	}

	return TSharedPtr<SWidget>();
}


FSlateVirtualUser::FSlateVirtualUser(int32 InUserIndex, int32 InVirtualUserIndex)
	: UserIndex(InUserIndex)
	, VirtualUserIndex(InVirtualUserIndex)
{
}

FSlateVirtualUser::~FSlateVirtualUser()
{
	if ( FSlateApplication::IsInitialized() )
	{
		FSlateApplication::Get().UnregisterUser(UserIndex);
	}
}


DECLARE_CYCLE_STAT( TEXT("Message Tick Time"), STAT_SlateMessageTick, STATGROUP_Slate );
DECLARE_CYCLE_STAT( TEXT("Update Tooltip Time"), STAT_SlateUpdateTooltip, STATGROUP_Slate );
DECLARE_CYCLE_STAT( TEXT("Total Slate Tick Time"), STAT_SlateTickTime, STATGROUP_Slate );
DECLARE_CYCLE_STAT( TEXT("SlatePrepass"), STAT_SlatePrepass, STATGROUP_Slate );
DECLARE_CYCLE_STAT( TEXT("Draw Window And Children Time"), STAT_SlateDrawWindowTime, STATGROUP_Slate );
DECLARE_CYCLE_STAT( TEXT("TickWidgets"), STAT_SlateTickWidgets, STATGROUP_Slate );
DECLARE_CYCLE_STAT( TEXT("TickRegisteredWidgets"), STAT_SlateTickRegisteredWidgets, STATGROUP_Slate );
DECLARE_CYCLE_STAT( TEXT("Slate::PreTickEvent"), STAT_SlatePreTickEvent, STATGROUP_Slate );

DECLARE_CYCLE_STAT(TEXT("ShowVirtualKeyboard"), STAT_ShowVirtualKeyboard, STATGROUP_Slate);

DECLARE_CYCLE_STAT(TEXT("ProcessKeyDown"), STAT_ProcessKeyDown, STATGROUP_Slate);
DECLARE_CYCLE_STAT(TEXT("ProcessKeyUp"), STAT_ProcessKeyUp, STATGROUP_Slate);
DECLARE_CYCLE_STAT(TEXT("ProcessKeyChar"), STAT_ProcessKeyChar, STATGROUP_Slate);
DECLARE_CYCLE_STAT(TEXT("ProcessKeyChar (route focus)"), STAT_ProcessKeyChar_RouteAlongFocusPath, STATGROUP_Slate);
DECLARE_CYCLE_STAT(TEXT("ProcessKeyChar (call OnKeyChar)"), STAT_ProcessKeyChar_Call_OnKeyChar, STATGROUP_Slate);

DECLARE_CYCLE_STAT(TEXT("ProcessAnalogInput"), STAT_ProcessAnalogInput, STATGROUP_Slate);
DECLARE_CYCLE_STAT(TEXT("ProcessMouseButtonDown"), STAT_ProcessMouseButtonDown, STATGROUP_Slate);
DECLARE_CYCLE_STAT(TEXT("ProcessMouseButtonDoubleClick"), STAT_ProcessMouseButtonDoubleClick, STATGROUP_Slate);
DECLARE_CYCLE_STAT(TEXT("ProcessMouseButtonUp"), STAT_ProcessMouseButtonUp, STATGROUP_Slate);
DECLARE_CYCLE_STAT(TEXT("ProcessMouseWheelGesture"), STAT_ProcessMouseWheelGesture, STATGROUP_Slate);
DECLARE_CYCLE_STAT(TEXT("ProcessMouseMove"), STAT_ProcessMouseMove, STATGROUP_Slate);


SLATE_DECLARE_CYCLE_COUNTER(GSlateTotalTickTime, "Total Slate Tick Time");
SLATE_DECLARE_CYCLE_COUNTER(GMessageTickTime, "Message Tick Time");
SLATE_DECLARE_CYCLE_COUNTER(GUpdateTooltipTime, "Update Tooltip Time");
SLATE_DECLARE_CYCLE_COUNTER(GSlateSynthesizeMouseMove, "Synthesize Mouse Move");
SLATE_DECLARE_CYCLE_COUNTER(GTickWidgets, "TickWidgets");
SLATE_DECLARE_CYCLE_COUNTER(GSlateTickNotificationManager, "NotificationManager Tick");
SLATE_DECLARE_CYCLE_COUNTER(GSlateDrawWindows, "DrawWindows");
SLATE_DECLARE_CYCLE_COUNTER(GSlateDrawWindowAndChildren, "Draw Window And Children");
SLATE_DECLARE_CYCLE_COUNTER(GSlateRendererDrawWindows, "Renderer DrawWindows");
SLATE_DECLARE_CYCLE_COUNTER(GSlateDrawPrepass, "DrawPrepass");
SLATE_DECLARE_CYCLE_COUNTER(GSlatePrepassWindowAndChildren, "Prepass Window And Children");

// Slate Event Logging is enabled to allow crash log dumping
#define LOG_SLATE_EVENTS 0


#if LOG_SLATE_EVENTS
	#define LOG_EVENT_CONTENT( EventType, AdditionalContent, WidgetOrReply ) LogSlateEvent(EventLogger, EventType, AdditionalContent, WidgetOrReply);
	
	#define LOG_EVENT( EventType, WidgetOrReply ) LOG_EVENT_CONTENT( EventType, FString(), WidgetOrReply )
	static void LogSlateEvent( const TSharedPtr<IEventLogger>& EventLogger, EEventLog::Type Event, const FString& AdditionalContent, const TSharedPtr<SWidget>& HandlerWidget )
	{
		if (EventLogger.IsValid())
		{
			EventLogger->Log( Event, AdditionalContent, HandlerWidget );
		}
	}

	static void LogSlateEvent( const TSharedPtr<IEventLogger>& EventLogger, EEventLog::Type Event, const FString& AdditionalContent, const FReply& InReply )
	{
		if ( EventLogger.IsValid() && InReply.IsEventHandled() )
		{
			EventLogger->Log( Event, AdditionalContent, InReply.GetHandler() );
		}
	}
#else
	#define LOG_EVENT_CONTENT( EventType, AdditionalContent, WidgetOrReply )
	
	#define LOG_EVENT( Event, WidgetOrReply ) CheckReplyCorrectness(WidgetOrReply);
	static void CheckReplyCorrectness(const TSharedPtr<SWidget>& HandlerWidget)
	{
	}
	static void CheckReplyCorrectness(const FReply& InReply)
	{
		check( !InReply.IsEventHandled() || InReply.GetHandler().IsValid() );
	}
#endif


namespace SlateDefs
{
	// How far tool tips should be offset from the mouse cursor position, in pixels
	static const FVector2D ToolTipOffsetFromMouse( 12.0f, 8.0f );

	// How far tool tips should be pushed out from a force field border, in pixels
	static const FVector2D ToolTipOffsetFromForceField( 4.0f, 3.0f );
}


/** True if we should allow throttling based on mouse movement activity.  int32 instead of bool only for console variable system. */
TAutoConsoleVariable<int32> ThrottleWhenMouseIsMoving( 
	TEXT( "Slate.ThrottleWhenMouseIsMoving" ),
	false,
	TEXT( "Whether to attempt to increase UI responsiveness based on mouse cursor movement." ) );

/** Minimum sustained average frame rate required before we consider the editor to be "responsive" for a smooth UI experience */
TAutoConsoleVariable<int32> TargetFrameRateForResponsiveness(
	TEXT( "Slate.TargetFrameRateForResponsiveness" ),
	35,	// Frames per second
	TEXT( "Minimum sustained average frame rate required before we consider the editor to be \"responsive\" for a smooth UI experience" ) );

/** Whether to skip the second Slate PrePass call (the one right before rendering). */
TAutoConsoleVariable<int32> SkipSecondPrepass(
	TEXT("Slate.SkipSecondPrepass"),
	0,
	TEXT("Whether to skip the second Slate PrePass call (the one right before rendering)."));

/** Whether Slate should go to sleep when there are no active timers and the user is idle */
TAutoConsoleVariable<int32> AllowSlateToSleep(
	TEXT("Slate.AllowSlateToSleep"),
	true,
	TEXT("Whether Slate should go to sleep when there are no active timers and the user is idle"));

/** The amount of time that must pass without any user action before Slate is put to sleep (provided that there are no active timers). */
TAutoConsoleVariable<float> SleepBufferPostInput(
	TEXT("Slate.SleepBufferPostInput"),
	0.0f,
	TEXT("The amount of time that must pass without any user action before Slate is put to sleep (provided that there are no active timers)."));

//////////////////////////////////////////////////////////////////////////
bool FSlateApplication::MouseCaptorHelper::HasCapture() const
{
	for (auto PointerPathPair : PointerIndexToMouseCaptorWeakPathMap)
	{
		if (PointerPathPair.Value.IsValid())
		{
			return true;
		}
	}
	return false;
}

bool FSlateApplication::MouseCaptorHelper::HasCaptureForUser(uint32 UserIndex) const
{
	for ( auto PointerPathPair : PointerIndexToMouseCaptorWeakPathMap )
	{
		const FUserAndPointer& UserAndPointer = PointerPathPair.Key;
		if ( UserAndPointer.UserIndex == UserIndex )
		{
			if ( PointerPathPair.Value.IsValid() )
			{
				return true;
			}
		}
	}

	return false;
}

bool FSlateApplication::MouseCaptorHelper::HasCaptureForPointerIndex(uint32 UserIndex, uint32 PointerIndex) const
{
	const FWeakWidgetPath* MouseCaptorWeakPath = PointerIndexToMouseCaptorWeakPathMap.Find( FUserAndPointer(UserIndex,PointerIndex) );
	return MouseCaptorWeakPath && MouseCaptorWeakPath->IsValid();
}

bool FSlateApplication::MouseCaptorHelper::DoesWidgetHaveMouseCaptureByUser(const TSharedPtr<const SWidget> Widget, int32 UserIndex, TOptional<int32> PointerIndex) const
{
	for ( const auto& PointerPathPair : PointerIndexToMouseCaptorWeakPathMap )
	{
		const FUserAndPointer& UserAndPointer = PointerPathPair.Key;
		if ( UserAndPointer.UserIndex == UserIndex )
		{
			// If the pointer index is set, filter on that as well.
			if ( PointerIndex.IsSet() && UserAndPointer.PointerIndex != PointerIndex.GetValue() )
			{
				continue;
			}

			if ( PointerPathPair.Value.IsValid() )
			{
				TSharedPtr<SWidget> LastWidget = PointerPathPair.Value.GetLastWidget().Pin();
				if ( LastWidget == Widget )
				{
					return true;
				}
			}
		}
	}

	return false;
}

bool FSlateApplication::MouseCaptorHelper::DoesWidgetHaveMouseCapture(const TSharedPtr<const SWidget> Widget) const
{
	for ( const auto& IndexPathPair : PointerIndexToMouseCaptorWeakPathMap )
	{
		TSharedPtr<SWidget> LastWidget = IndexPathPair.Value.GetLastWidget().Pin();
		if ( LastWidget == Widget )
		{
			return true;
		}
	}

	return false;
}

TSharedPtr< SWidget > FSlateApplication::MouseCaptorHelper::ToSharedWidget(uint32 UserIndex, uint32 PointerIndex) const
{
	// If the path is valid then get the last widget, this is the current mouse captor
	TSharedPtr< SWidget > SharedWidgetPtr;
	const FWeakWidgetPath* MouseCaptorWeakPath = PointerIndexToMouseCaptorWeakPathMap.Find( FUserAndPointer(UserIndex,PointerIndex) );
	if (MouseCaptorWeakPath && MouseCaptorWeakPath->IsValid() )
	{
		TWeakPtr< SWidget > WeakWidgetPtr = MouseCaptorWeakPath->GetLastWidget();
		SharedWidgetPtr = WeakWidgetPtr.Pin();
	}

	return SharedWidgetPtr;
}

TArray<TSharedRef<SWidget>> FSlateApplication::MouseCaptorHelper::ToSharedWidgets() const
{
	TArray<TSharedRef<SWidget>> Widgets;
	Widgets.Empty(PointerIndexToMouseCaptorWeakPathMap.Num());

	for (const auto& IndexPathPair : PointerIndexToMouseCaptorWeakPathMap)
	{
		TSharedPtr<SWidget> LastWidget = IndexPathPair.Value.GetLastWidget().Pin();
		if (LastWidget.IsValid())
		{
			Widgets.Add(LastWidget.ToSharedRef());
		}
	}
	return Widgets;
}

TSharedPtr< SWidget > FSlateApplication::MouseCaptorHelper::ToSharedWindow(uint32 UserIndex, uint32 PointerIndex)
{
	// if the path is valid then we can get the window the current mouse captor belongs to
	FWidgetPath MouseCaptorPath = ToWidgetPath( UserIndex, PointerIndex );
	if ( MouseCaptorPath.IsValid() )
	{
		return MouseCaptorPath.GetWindow();
	}

	return TSharedPtr< SWidget >();
}

void FSlateApplication::MouseCaptorHelper::SetMouseCaptor(uint32 UserIndex, uint32 PointerIndex, const FWidgetPath& EventPath, TSharedPtr< SWidget > Widget)
{
	// Caller is trying to set a new mouse captor, so invalidate the current one - when the function finishes
	// it still may not have a valid captor widget, this is ok
	InvalidateCaptureForPointer(UserIndex, PointerIndex);

	if ( Widget.IsValid() )
	{
		TSharedRef< SWidget > WidgetRef = Widget.ToSharedRef();
		FWidgetPath NewMouseCaptorPath = EventPath.GetPathDownTo( WidgetRef );

		const auto IsPathToCaptorFound = []( const FWidgetPath& PathToTest, const TSharedRef<SWidget>& WidgetToFind )
		{
			return PathToTest.Widgets.Num() > 0 && PathToTest.Widgets.Last().Widget == WidgetToFind;
		};

		FWeakWidgetPath MouseCaptorWeakPath;
		if ( IsPathToCaptorFound( NewMouseCaptorPath, WidgetRef ) )
		{
			MouseCaptorWeakPath = NewMouseCaptorPath;
		}
		else if (EventPath.Widgets.Num() > 0)
		{
			// If the target widget wasn't found on the event path then start the search from the root
			NewMouseCaptorPath = EventPath.GetPathDownTo( EventPath.Widgets[0].Widget );
			NewMouseCaptorPath.ExtendPathTo( FWidgetMatcher( WidgetRef ) );
			
			MouseCaptorWeakPath = IsPathToCaptorFound( NewMouseCaptorPath, WidgetRef )
				? NewMouseCaptorPath
				: FWeakWidgetPath();
		}
		else
		{
			ensureMsgf(EventPath.Widgets.Num() > 0, TEXT("An unknown widget is attempting to set capture to %s"), *Widget->ToString() );
		}

		if (MouseCaptorWeakPath.IsValid())
		{
			PointerIndexToMouseCaptorWeakPathMap.Add(FUserAndPointer(UserIndex,PointerIndex), MouseCaptorWeakPath);
		}
	}
}

void FSlateApplication::MouseCaptorHelper::InvalidateCaptureForAllPointers()
{
	TArray<FUserAndPointer> PointerIndices;
	PointerIndexToMouseCaptorWeakPathMap.GenerateKeyArray(PointerIndices);
	for (FUserAndPointer UserAndPointer : PointerIndices)
	{
		InvalidateCaptureForPointer(UserAndPointer.UserIndex, UserAndPointer.PointerIndex);
	}
}

void FSlateApplication::MouseCaptorHelper::InvalidateCaptureForUser(uint32 UserIndex)
{
	TArray<FUserAndPointer> PointerIndices;
	PointerIndexToMouseCaptorWeakPathMap.GenerateKeyArray(PointerIndices);
	for ( FUserAndPointer UserAndPointer : PointerIndices )
	{
		if ( UserAndPointer.UserIndex == UserIndex )
		{
			InvalidateCaptureForPointer(UserAndPointer.UserIndex, UserAndPointer.PointerIndex);
		}
	}
}

FWidgetPath FSlateApplication::MouseCaptorHelper::ToWidgetPath( FWeakWidgetPath::EInterruptedPathHandling::Type InterruptedPathHandling, const FPointerEvent* PointerEvent )
{
	FWidgetPath WidgetPath;
	const FWeakWidgetPath* MouseCaptorWeakPath = PointerIndexToMouseCaptorWeakPathMap.Find(FUserAndPointer(PointerEvent->GetUserIndex(),PointerEvent->GetPointerIndex()));
	if ( MouseCaptorWeakPath->IsValid() )
	{
		if ( MouseCaptorWeakPath->ToWidgetPath( WidgetPath, InterruptedPathHandling, PointerEvent ) == FWeakWidgetPath::EPathResolutionResult::Truncated )
		{
			// If the path was truncated then it means this widget is no longer part of the active set,
			// so we make sure to invalidate its capture
			InvalidateCaptureForPointer(PointerEvent->GetUserIndex(), PointerEvent->GetPointerIndex());
		}
	}

	return WidgetPath;
}

FWidgetPath FSlateApplication::MouseCaptorHelper::ToWidgetPath(uint32 UserIndex, uint32 PointerIndex, FWeakWidgetPath::EInterruptedPathHandling::Type InterruptedPathHandling)
{
	FWidgetPath WidgetPath;
	const FWeakWidgetPath* MouseCaptorWeakPath = PointerIndexToMouseCaptorWeakPathMap.Find(FUserAndPointer(UserIndex,PointerIndex));
	if (MouseCaptorWeakPath && MouseCaptorWeakPath->IsValid() )
	{
		if ( MouseCaptorWeakPath->ToWidgetPath( WidgetPath, InterruptedPathHandling ) == FWeakWidgetPath::EPathResolutionResult::Truncated )
		{
			// If the path was truncated then it means this widget is no longer part of the active set,
			// so we make sure to invalidate its capture
			InvalidateCaptureForPointer(UserIndex,PointerIndex);
		}
	}

	return WidgetPath;
}

void FSlateApplication::MouseCaptorHelper::InvalidateCaptureForPointer(uint32 UserIndex, uint32 PointerIndex)
{
	InformCurrentCaptorOfCaptureLoss(UserIndex, PointerIndex);
	PointerIndexToMouseCaptorWeakPathMap.Remove( FUserAndPointer(UserIndex, PointerIndex) );
}

TArray<FWidgetPath> FSlateApplication::MouseCaptorHelper::ToWidgetPaths()
{
	TArray<FWidgetPath> WidgetPaths;
	TArray<FUserAndPointer> PointerIndices;
	PointerIndexToMouseCaptorWeakPathMap.GenerateKeyArray(PointerIndices);
	for (auto Index : PointerIndices)
	{
		WidgetPaths.Add(ToWidgetPath(Index.UserIndex,Index.PointerIndex));
	}
	return WidgetPaths;
}

FWeakWidgetPath FSlateApplication::MouseCaptorHelper::ToWeakPath(uint32 UserIndex, uint32 PointerIndex) const
{
	const FWeakWidgetPath* MouseCaptorWeakPath = PointerIndexToMouseCaptorWeakPathMap.Find(FUserAndPointer(UserIndex,PointerIndex));
	if (MouseCaptorWeakPath)
	{
		return *MouseCaptorWeakPath;
	}
	return FWeakWidgetPath();
}

void FSlateApplication::MouseCaptorHelper::InformCurrentCaptorOfCaptureLoss(uint32 UserIndex,uint32 PointerIndex) const
{
	// if we have a path to a widget then it is the current mouse captor and needs to know it has lost capture
	const FWeakWidgetPath* MouseCaptorWeakPath = PointerIndexToMouseCaptorWeakPathMap.Find(FUserAndPointer(UserIndex,PointerIndex));
	if (MouseCaptorWeakPath && MouseCaptorWeakPath->IsValid() )
	{
		TWeakPtr< SWidget > WeakWidgetPtr = MouseCaptorWeakPath->GetLastWidget();
		TSharedPtr< SWidget > SharedWidgetPtr = WeakWidgetPtr.Pin();
		if ( SharedWidgetPtr.IsValid() )
		{
			SharedWidgetPtr->OnMouseCaptureLost();
		}
	}
}

//////////////////////////////////////////////////////////////////////////

void FSlateApplication::FDragDetector::StartDragDetection(const FWidgetPath& PathToWidget, int32 UserIndex, int32 PointerIndex, FKey DragButton, FVector2D StartLocation)
{
	PointerIndexToDragState.Add(FUserAndPointer(UserIndex, PointerIndex), FDragDetectionState(PathToWidget, UserIndex, PointerIndex, DragButton, StartLocation));
}

bool FSlateApplication::FDragDetector::IsDetectingDrag(const FPointerEvent& PointerEvent)
{
	FUserAndPointer UserAndPointer(PointerEvent.GetUserIndex(), PointerEvent.GetPointerIndex());
	FDragDetectionState* DetectionState = PointerIndexToDragState.Find(UserAndPointer);

	if ( DetectionState )
	{
		return true;
	}

	return false;
}

bool FSlateApplication::FDragDetector::DetectDrag(const FPointerEvent& PointerEvent, float InDragTriggerDistance, FWeakWidgetPath*& OutWeakWidgetPath)
{
	FUserAndPointer UserAndPointer(PointerEvent.GetUserIndex(), PointerEvent.GetPointerIndex());
	FDragDetectionState* DetectionState = PointerIndexToDragState.Find(UserAndPointer);

	if ( DetectionState )
	{
		if ( DetectionState->DetectDragUserIndex == PointerEvent.GetUserIndex() &&
			 DetectionState->DetectDragPointerIndex == PointerEvent.GetPointerIndex() )
		{
			const FVector2D DragDelta = DetectionState->DetectDragStartLocation - PointerEvent.GetScreenSpacePosition();
			const bool bDragDetected = ( DragDelta.SizeSquared() > FMath::Square(InDragTriggerDistance) );
			if ( bDragDetected )
			{
				OutWeakWidgetPath = &DetectionState->DetectDragForWidget;
				return true;
			}
		}
	}

	OutWeakWidgetPath = nullptr;
	return false;
}

void FSlateApplication::FDragDetector::OnPointerRelease(const FPointerEvent& PointerEvent)
{
	FUserAndPointer UserAndPointer(PointerEvent.GetUserIndex(), PointerEvent.GetPointerIndex());
	FDragDetectionState* DetectionState = PointerIndexToDragState.Find(UserAndPointer);

	if ( DetectionState )
	{
		if ( DetectionState->DetectDragButton == PointerEvent.GetEffectingButton() && 
			 DetectionState->DetectDragUserIndex == PointerEvent.GetUserIndex() && 
			 DetectionState->DetectDragPointerIndex == PointerEvent.GetPointerIndex() )
		{
			// The user has released the button (or finger) that was supposed to start the drag; stop detecting it.
			PointerIndexToDragState.Remove(UserAndPointer);
		}
	}
}

void FSlateApplication::FDragDetector::ResetDetection()
{
	PointerIndexToDragState.Reset();
}

//////////////////////////////////////////////////////////////////////////

FDelegateHandle FPopupSupport::RegisterClickNotification( const TSharedRef<SWidget>& NotifyWhenClickedOutsideMe, const FOnClickedOutside& InNotification )
{
	// If the subscriber or a zone object is destroyed, the subscription is
	// no longer active. Clean it up here so that consumers of this API have an
	// easy time with resource management.
	struct { void operator()( TArray<FClickSubscriber>& Notifications ) {
		for ( int32 SubscriberIndex=0; SubscriberIndex < Notifications.Num(); )
		{
			if ( !Notifications[SubscriberIndex].ShouldKeep() )
			{
				Notifications.RemoveAtSwap(SubscriberIndex);
			}
			else
			{
				SubscriberIndex++;
			}		
		}
	}} ClearOutStaleNotifications;
	
	ClearOutStaleNotifications( ClickZoneNotifications );

	// Add a new notification.
	ClickZoneNotifications.Add( FClickSubscriber( NotifyWhenClickedOutsideMe, InNotification ) );

	return ClickZoneNotifications.Last().Notification.GetHandle();
}

void FPopupSupport::UnregisterClickNotification( FDelegateHandle Handle )
{
	for (int32 SubscriptionIndex=0; SubscriptionIndex < ClickZoneNotifications.Num();)
	{
		if (ClickZoneNotifications[SubscriptionIndex].Notification.GetHandle() == Handle)
		{
			ClickZoneNotifications.RemoveAtSwap(SubscriptionIndex);
		}
		else
		{
			SubscriptionIndex++;
		}
	}	
}

void FPopupSupport::SendNotifications( const FWidgetPath& WidgetsUnderCursor )
{
	struct FArrangedWidgetMatcher
	{
		FArrangedWidgetMatcher( const TSharedRef<SWidget>& InWidgetToMatch )
		: WidgetToMatch( InWidgetToMatch )
		{}

		bool operator()(const FArrangedWidget& Candidate) const
		{
			return WidgetToMatch == Candidate.Widget;
		}

		const TSharedRef<SWidget>& WidgetToMatch;
	};

	// For each subscription, if the widget in question is not being clicked, send the notification.
	// i.e. Notifications are saying "some widget outside you was clicked".
	for (int32 SubscriberIndex=0; SubscriberIndex < ClickZoneNotifications.Num(); ++SubscriberIndex)
	{
		FClickSubscriber& Subscriber = ClickZoneNotifications[SubscriberIndex];
		if (Subscriber.DetectClicksOutsideMe.IsValid())
		{
			// Did we click outside the region in this subscription? If so send the notification.
			FArrangedWidgetMatcher Matcher(Subscriber.DetectClicksOutsideMe.Pin().ToSharedRef());
			const bool bClickedOutsideOfWidget = WidgetsUnderCursor.Widgets.GetInternalArray().IndexOfByPredicate(Matcher) == INDEX_NONE;
			if ( bClickedOutsideOfWidget )
			{
				Subscriber.Notification.ExecuteIfBound();
			}
		}
	}
}

void FSlateApplication::SetPlatformApplication(const TSharedRef<class GenericApplication>& InPlatformApplication)
{
	PlatformApplication->SetMessageHandler(MakeShareable(new FGenericApplicationMessageHandler()));

	PlatformApplication = InPlatformApplication;
	PlatformApplication->SetMessageHandler(CurrentApplication.ToSharedRef());
}

void FSlateApplication::Create()
{
	Create(MakeShareable(FPlatformMisc::CreateApplication()));
}

TSharedRef<FSlateApplication> FSlateApplication::Create(const TSharedRef<class GenericApplication>& InPlatformApplication)
{
	EKeys::Initialize();

	FCoreStyle::ResetToDefault();

	CurrentApplication = MakeShareable( new FSlateApplication() );
	CurrentBaseApplication = CurrentApplication;

	PlatformApplication = InPlatformApplication;
	PlatformApplication->SetMessageHandler( CurrentApplication.ToSharedRef() );

	// The grid needs to know the size and coordinate system of the desktop.
	// Some monitor setups have a primary monitor on the right and below the
	// left one, so the leftmost upper right monitor can be something like (-1280, -200)
	{
		// Get an initial value for the VirtualDesktop geometry
		CurrentApplication->VirtualDesktopRect = []()
		{
			FDisplayMetrics DisplayMetrics;
			FSlateApplicationBase::Get().GetDisplayMetrics(DisplayMetrics);
			const FPlatformRect& VirtualDisplayRect = DisplayMetrics.VirtualDisplayRect;
			return FSlateRect(VirtualDisplayRect.Left, VirtualDisplayRect.Top, VirtualDisplayRect.Right, VirtualDisplayRect.Bottom);
		}();

		// Sign up for updates from the OS. Polling this every frame is too expensive on at least some OSs.
		PlatformApplication->OnDisplayMetricsChanged().AddSP(CurrentApplication.ToSharedRef(), &FSlateApplication::OnVirtualDesktopSizeChanged);
	}

	return CurrentApplication.ToSharedRef();
}

void FSlateApplication::Shutdown(bool bShutdownPlatform)
{
	if (FSlateApplication::IsInitialized())
	{
		CurrentApplication->OnShutdown();
		CurrentApplication->DestroyRenderer();
		CurrentApplication->Renderer.Reset();

		if (bShutdownPlatform)
		{
			PlatformApplication->DestroyApplication();
		}

		PlatformApplication.Reset();
		CurrentApplication.Reset();
		CurrentBaseApplication.Reset();
	}
}

TSharedPtr<FSlateApplication> FSlateApplication::CurrentApplication = nullptr;

FSlateApplication::FSlateApplication()
	: SynthesizeMouseMovePending(0)
	, bAppIsActive(true)
	, bSlateWindowActive(true)
	, Scale( 1.0f )
	, DragTriggerDistance( 5.0f )
	, CursorRadius( 0.0f )
	, LastUserInteractionTime( 0.0 )
	, LastUserInteractionTimeForThrottling( 0.0 )
	, LastMouseMoveTime( 0.0 )
	, SlateSoundDevice( MakeShareable(new FNullSlateSoundDevice()) )
	, CurrentTime( FPlatformTime::Seconds() )
	, LastTickTime( 0.0 )
	, AverageDeltaTime( 1.0f / 30.0f )	// Prime the running average with a typical frame rate so it doesn't have to spin up from zero
	, AverageDeltaTimeForResponsiveness( 1.0f / 30.0f )
	, OnExitRequested()
	, EventLogger( TSharedPtr<IEventLogger>() )
	, NumExternalModalWindowsActive( 0 )
	, bAllowToolTips( true )
	, ToolTipDelay( 0.15f )
	, ToolTipFadeInDuration( 0.1f )
	, ToolTipSummonTime( 0.0 )
	, DesiredToolTipLocation( FVector2D::ZeroVector )
	, ToolTipOffsetDirection( EToolTipOffsetDirection::Undetermined )
	, bRequestLeaveDebugMode( false )
	, bLeaveDebugForSingleStep( false )
	, CVarAllowToolTips(
		TEXT( "Slate.AllowToolTips" ),
		bAllowToolTips,
		TEXT( "Whether to allow tool-tips to spawn at all." ) )
	, CVarToolTipDelay(
		TEXT( "Slate.ToolTipDelay" ),
		ToolTipDelay,
		TEXT( "Delay in seconds before a tool-tip is displayed near the mouse cursor when hovering over widgets that supply tool-tip data." ) )
	, CVarToolTipFadeInDuration(
		TEXT( "Slate.ToolTipFadeInDuration" ),
		ToolTipFadeInDuration,
		TEXT( "How long it takes for a tool-tip to fade in, in seconds." ) )
	, bIsExternalUIOpened( false )
	, SlateTextField( nullptr )
	, bIsFakingTouch(FParse::Param(FCommandLine::Get(), TEXT("simmobile")) || FParse::Param(FCommandLine::Get(), TEXT("faketouches")))
	, bIsGameFakingTouch( false )
	, bIsFakingTouched( false )
	, bTouchFallbackToMouse( true )
	, bSoftwareCursorAvailable( false )	
	, bQueryCursorRequested( false )
	, bMenuAnimationsEnabled( true )
	, AppIcon( FCoreStyle::Get().GetBrush("DefaultAppIcon") )
	, VirtualDesktopRect( 0,0,0,0 )
	, NavigationConfig(MakeShareable(new FNavigationConfig()))
	, ProcessingInput(0)
{
#if WITH_UNREAL_DEVELOPER_TOOLS
	FModuleManager::Get().LoadModule(TEXT("Settings"));
#endif

	if (GConfig)
	{
		GConfig->GetBool(TEXT("MobileSlateUI"),TEXT("bTouchFallbackToMouse"),bTouchFallbackToMouse,GEngineIni);
		GConfig->GetBool(TEXT("CursorControl"), TEXT("bAllowSoftwareCursor"), bSoftwareCursorAvailable, GEngineIni);
	}


	// causes InputCore to initialize, even if statically linked
	FInputCoreModule& InputCore = FModuleManager::LoadModuleChecked<FInputCoreModule>(TEXT("InputCore"));

	FGenericCommands::Register();
	FTabCommands::Register();

	NormalExecutionGetter.BindRaw( this, &FSlateApplication::IsNormalExecution );
	PointerIndexLastPositionMap.Add(CursorPointerIndex, FVector2D::ZeroVector);

	// Add the standard 'default' user because there's always 1 user.
	RegisterUser(MakeShareable(new FSlateUser(0, false)));
}

FSlateApplication::~FSlateApplication()
{
	FTabCommands::Unregister();
	FGenericCommands::Unregister();
	
	if (SlateTextField != nullptr)
	{
		delete SlateTextField;
		SlateTextField = nullptr;
	}
}

const FStyleNode* FSlateApplication::GetRootStyle() const
{
	return RootStyleNode;
}

bool FSlateApplication::InitializeRenderer( TSharedRef<FSlateRenderer> InRenderer, bool bQuietMode )
{
	Renderer = InRenderer;
	bool bResult = Renderer->Initialize();
	if (!bResult && !bQuietMode)
	{
		FPlatformMisc::MessageBoxExt(EAppMsgType::Ok, *NSLOCTEXT("SlateD3DRenderer", "ProblemWithGraphicsCard", "There is a problem with your graphics card. Please ensure your card meets the minimum system requirements and that you have the latest drivers installed.").ToString(), *NSLOCTEXT("SlateD3DRenderer", "UnsupportedVideoCardErrorTitle", "Unsupported Graphics Card").ToString());
	}
	return bResult;
}

void FSlateApplication::InitializeSound( const TSharedRef<ISlateSoundDevice>& InSlateSoundDevice )
{
	SlateSoundDevice = InSlateSoundDevice;
}

void FSlateApplication::DestroyRenderer()
{
	if( Renderer.IsValid() )
	{
		Renderer->Destroy();
	}
}

/**
 * Called when the user closes the outermost frame (ie quitting the app). Uses standard UE4 global variable
 * so normal UE4 applications work as expected
 */
static void OnRequestExit()
{
	GIsRequestingExit = true;
}

void FSlateApplication::PlaySound( const FSlateSound& SoundToPlay, int32 UserIndex ) const
{
	SlateSoundDevice->PlaySound(SoundToPlay, UserIndex);
}

float FSlateApplication::GetSoundDuration(const FSlateSound& Sound) const
{
	return SlateSoundDevice->GetSoundDuration(Sound);
}

FVector2D FSlateApplication::GetCursorPos() const
{
	if ( ICursor* Cursor = PlatformApplication->Cursor.Get() )
	{
		return Cursor->GetPosition();
	}

	return FVector2D( 0, 0 );
}

FVector2D FSlateApplication::GetLastCursorPos() const
{
	return PointerIndexLastPositionMap[CursorPointerIndex];
}

void FSlateApplication::SetCursorPos( const FVector2D& MouseCoordinate )
{
	if (ICursor* Cursor = PlatformApplication->Cursor.Get())
	{
		return Cursor->SetPosition( MouseCoordinate.X, MouseCoordinate.Y );
	}
}

FWidgetPath FSlateApplication::LocateWindowUnderMouse( FVector2D ScreenspaceMouseCoordinate, const TArray< TSharedRef< SWindow > >& Windows, bool bIgnoreEnabledStatus )
{
	// First, give the OS a chance to tell us which window to use, in case a child window is not guaranteed to stay on top of its parent window
	TSharedPtr<FGenericWindow> NativeWindowUnderMouse = PlatformApplication->GetWindowUnderCursor();
	if (NativeWindowUnderMouse.IsValid())
	{
		TSharedPtr<SWindow> Window = FSlateWindowHelper::FindWindowByPlatformWindow(Windows, NativeWindowUnderMouse.ToSharedRef());
		if (Window.IsValid())
		{
			FWidgetPath PathToLocatedWidget = LocateWidgetInWindow(ScreenspaceMouseCoordinate, Window.ToSharedRef(), bIgnoreEnabledStatus);
			if (PathToLocatedWidget.IsValid())
			{
				return PathToLocatedWidget;
			}
		}
	}

	bool bPrevWindowWasModal = false;

	for (int32 WindowIndex = Windows.Num() - 1; WindowIndex >= 0; --WindowIndex)
	{ 
		const TSharedRef<SWindow>& Window = Windows[WindowIndex];

		if ( !Window->IsVisible() || Window->IsWindowMinimized())
		{
			continue;
		}
		
		// Hittest the window's children first.
		FWidgetPath ResultingPath = LocateWindowUnderMouse(ScreenspaceMouseCoordinate, Window->GetChildWindows(), bIgnoreEnabledStatus);
		if (ResultingPath.IsValid())
		{
			return ResultingPath;
		}

		// If none of the children were hit, hittest the parent.

		// Only accept input if the current window accepts input and the current window is not under a modal window or an interactive tooltip

		if (!bPrevWindowWasModal)
		{
			FWidgetPath PathToLocatedWidget = LocateWidgetInWindow(ScreenspaceMouseCoordinate, Window, bIgnoreEnabledStatus);
			if (PathToLocatedWidget.IsValid())
			{
				return PathToLocatedWidget;
			}
		}
	}
	
	return FWidgetPath();
}

bool FSlateApplication::IsWindowHousingInteractiveTooltip(const TSharedRef<const SWindow>& WindowToTest) const
{
	const TSharedPtr<IToolTip> ActiveToolTipPtr = ActiveToolTip.Pin();
	const TSharedPtr<SWindow> ToolTipWindowPtr = ToolTipWindow.Pin();
	const bool bIsHousingInteractiveTooltip =
		WindowToTest == ToolTipWindowPtr &&
		ActiveToolTipPtr.IsValid() &&
		ActiveToolTipPtr->IsInteractive();

	return bIsHousingInteractiveTooltip;
}

void FSlateApplication::DrawWindows()
{
	SLATE_CYCLE_COUNTER_SCOPE(GSlateDrawWindows);
	FPlatformMisc::BeginNamedEvent(FColor::Magenta, "Slate::DrawWindows");
	PrivateDrawWindows();
	FPlatformMisc::EndNamedEvent();
}

struct FDrawWindowArgs
{
	FDrawWindowArgs( FSlateDrawBuffer& InDrawBuffer, const FWidgetPath& InWidgetsUnderCursor )
		: OutDrawBuffer( InDrawBuffer )
		, WidgetsUnderCursor( InWidgetsUnderCursor )
	{}

	FSlateDrawBuffer& OutDrawBuffer;
	const FWidgetPath& WidgetsUnderCursor;
};


void FSlateApplication::DrawWindowAndChildren( const TSharedRef<SWindow>& WindowToDraw, FDrawWindowArgs& DrawWindowArgs )
{
	// On Mac, where child windows can be on screen even if their parent is hidden or minimized, we want to always draw child windows.
	// On other platforms we set bDrawChildWindows to true only if we draw the current window.
	bool bDrawChildWindows = PLATFORM_MAC;

	// Only draw visible windows
	if( WindowToDraw->IsVisible() && (!WindowToDraw->IsWindowMinimized() || FApp::UseVRFocus()) )
	{
		SLATE_CYCLE_COUNTER_SCOPE_CUSTOM(GSlateDrawWindowAndChildren, WindowToDraw->GetCreatedInLocation());
	
		// Switch to the appropriate world for drawing
		FScopedSwitchWorldHack SwitchWorld( WindowToDraw );

		//FPlatformMisc::BeginNamedEvent(FColor::Magenta, "Slate::DrawPrep");
		FSlateWindowElementList& WindowElementList = DrawWindowArgs.OutDrawBuffer.AddWindowElementList( WindowToDraw );
		//FPlatformMisc::EndNamedEvent();

		// Drawing is done in window space, so null out the positions and keep the size.
		FGeometry WindowGeometry = WindowToDraw->GetWindowGeometryInWindow();
		int32 MaxLayerId = 0;
		{
			//FPlatformMisc::BeginNamedEvent(FColor::Magenta, "Slate::ClearHitTestGrid");
			WindowToDraw->GetHittestGrid()->ClearGridForNewFrame( VirtualDesktopRect );
			//FPlatformMisc::EndNamedEvent();

			FPlatformMisc::BeginNamedEvent(FColor::Magenta, "Slate::DrawWindow");
			MaxLayerId = WindowToDraw->PaintWindow(
				FPaintArgs(WindowToDraw.Get(), *WindowToDraw->GetHittestGrid(), WindowToDraw->GetPositionInScreen(), GetCurrentTime(), GetDeltaTime()),
				WindowGeometry, WindowToDraw->GetClippingRectangleInWindow(),
				WindowElementList,
				0,
				FWidgetStyle(),
				WindowToDraw->IsEnabled() );
			FPlatformMisc::EndNamedEvent();

			// Draw drag drop operation if it's windowless.
			if ( IsDragDropping() && DragDropContent->IsWindowlessOperation() )
			{
				TSharedPtr<SWindow> DragDropWindow = DragDropWindowPtr.Pin();
				if ( DragDropWindow.IsValid() && DragDropWindow == WindowToDraw )
				{
					TSharedPtr<SWidget> DecoratorWidget = DragDropContent->GetDefaultDecorator();
					if ( DecoratorWidget.IsValid() && DecoratorWidget->GetVisibility().IsVisible() )
					{
						DecoratorWidget->SetVisibility(EVisibility::HitTestInvisible);
						DecoratorWidget->SlatePrepass(GetApplicationScale()*DragDropWindow->GetNativeWindow()->GetDPIScaleFactor());

						FVector2D DragDropContentInWindowSpace = WindowToDraw->GetWindowGeometryInScreen().AbsoluteToLocal(DragDropContent->GetDecoratorPosition());
						const FGeometry DragDropContentGeometry = FGeometry::MakeRoot(DecoratorWidget->GetDesiredSize(), FSlateLayoutTransform(DragDropContentInWindowSpace));

						DecoratorWidget->Paint(
							FPaintArgs(WindowToDraw.Get(), *WindowToDraw->GetHittestGrid(), WindowToDraw->GetPositionInScreen(), GetCurrentTime(), GetDeltaTime()),
							DragDropContentGeometry, WindowToDraw->GetClippingRectangleInWindow(),
							WindowElementList,
							++MaxLayerId,
							FWidgetStyle(),
							WindowToDraw->IsEnabled());
					}
				}
			}

			// Draw Software Cursor
			TSharedPtr<SWindow> CursorWindow = CursorWindowPtr.Pin();
			if (CursorWindow.IsValid() && WindowToDraw == CursorWindow)
			{
				TSharedPtr<SWidget> CursorWidget = CursorWidgetPtr.Pin();
				
				if (CursorWidget.IsValid())
				{
					CursorWidget->SlatePrepass(GetApplicationScale()*CursorWindow->GetNativeWindow()->GetDPIScaleFactor());

					FVector2D CursorPosInWindowSpace = WindowToDraw->GetWindowGeometryInScreen().AbsoluteToLocal(GetCursorPos());
					CursorPosInWindowSpace += (CursorWidget->GetDesiredSize() * -0.5);
					const FGeometry CursorGeometry = FGeometry::MakeRoot(CursorWidget->GetDesiredSize(), FSlateLayoutTransform(CursorPosInWindowSpace));

					CursorWidget->Paint(
						FPaintArgs(WindowToDraw.Get(), *WindowToDraw->GetHittestGrid(), WindowToDraw->GetPositionInScreen(), GetCurrentTime(), GetDeltaTime()),
						CursorGeometry, WindowToDraw->GetClippingRectangleInWindow(),
						WindowElementList,
						++MaxLayerId,
						FWidgetStyle(),
						WindowToDraw->IsEnabled());
				}
			}
		}

#if SLATE_HAS_WIDGET_REFLECTOR

		// The widget reflector may want to paint some additional stuff as part of the Widget introspection that it performs.
		// For example: it may draw layout rectangles for hovered widgets.
		const bool bVisualizeLayoutUnderCursor = DrawWindowArgs.WidgetsUnderCursor.IsValid();
		const bool bCapturingFromThisWindow = bVisualizeLayoutUnderCursor && DrawWindowArgs.WidgetsUnderCursor.TopLevelWindow == WindowToDraw;
		TSharedPtr<IWidgetReflector> WidgetReflector = WidgetReflectorPtr.Pin();
		if ( bCapturingFromThisWindow || (WidgetReflector.IsValid() && WidgetReflector->ReflectorNeedsToDrawIn(WindowToDraw)) )
		{
			MaxLayerId = WidgetReflector->Visualize( DrawWindowArgs.WidgetsUnderCursor, WindowElementList, MaxLayerId );
		}

		// Visualize pointer presses and pressed keys for demo-recording purposes.
		const bool bVisualiseMouseClicks = WidgetReflector.IsValid() && PlatformApplication->Cursor.IsValid() && PlatformApplication->Cursor->GetType() != EMouseCursor::None;
		if (bVisualiseMouseClicks )
		{
			MaxLayerId = WidgetReflector->VisualizeCursorAndKeys( WindowElementList, MaxLayerId );
		}

#endif

		// This window is visible, so draw its child windows as well
		bDrawChildWindows = true;
	}

	if (bDrawChildWindows)
	{
		// Draw the child windows
		const TArray< TSharedRef<SWindow> >& WindowChildren = WindowToDraw->GetChildWindows();
		for (int32 ChildIndex=0; ChildIndex < WindowChildren.Num(); ++ChildIndex)
		{
			DrawWindowAndChildren( WindowChildren[ChildIndex], DrawWindowArgs );
		}
	}
}

static void PrepassWindowAndChildren( TSharedRef<SWindow> WindowToPrepass )
{
	if (UNLIKELY(!FApp::CanEverRender()))
	{
		return;
	}

	if ( WindowToPrepass->IsVisible() && !WindowToPrepass->IsWindowMinimized() )
	{
		SLATE_CYCLE_COUNTER_SCOPE_CUSTOM(GSlatePrepassWindowAndChildren, WindowToPrepass->GetCreatedInLocation());
		FScopedSwitchWorldHack SwitchWorld(WindowToPrepass);
		
		{
			SCOPE_CYCLE_COUNTER(STAT_SlatePrepass);
			WindowToPrepass->SlatePrepass(FSlateApplication::Get().GetApplicationScale() * WindowToPrepass->GetNativeWindow()->GetDPIScaleFactor());
		}

		if ( WindowToPrepass->IsAutosized() )
		{
			WindowToPrepass->Resize(WindowToPrepass->GetDesiredSizeDesktopPixels());
		}

		for ( const TSharedRef<SWindow>& ChildWindow : WindowToPrepass->GetChildWindows() )
		{
			PrepassWindowAndChildren(ChildWindow);
		}
	}
}

void FSlateApplication::DrawPrepass( TSharedPtr<SWindow> DrawOnlyThisWindow )
{
	SLATE_CYCLE_COUNTER_SCOPE(GSlateDrawPrepass);
	TSharedPtr<SWindow> ActiveModalWindow = GetActiveModalWindow();

	if (ActiveModalWindow.IsValid())
	{
		PrepassWindowAndChildren( ActiveModalWindow.ToSharedRef() );

		for (TArray< TSharedRef<SWindow> >::TConstIterator CurrentWindowIt(SlateWindows); CurrentWindowIt; ++CurrentWindowIt)
		{
			const TSharedRef<SWindow>& CurrentWindow = *CurrentWindowIt;
			if (CurrentWindow->IsTopmostWindow())
			{
				PrepassWindowAndChildren( CurrentWindow );
			}
		}

		TArray< TSharedRef<SWindow> > NotificationWindows;
		FSlateNotificationManager::Get().GetWindows(NotificationWindows);
		for (auto CurrentWindowIt(NotificationWindows.CreateIterator()); CurrentWindowIt; ++CurrentWindowIt)
		{
			PrepassWindowAndChildren(*CurrentWindowIt );
		}
	}
	else if (DrawOnlyThisWindow.IsValid())
	{
		PrepassWindowAndChildren(DrawOnlyThisWindow.ToSharedRef());
	}
	else
	{
		// Draw all windows
		for (const TSharedRef<SWindow>& CurrentWindow : SlateWindows)
		{
			PrepassWindowAndChildren(CurrentWindow);
		}
	}
}


TArray<TSharedRef<SWindow>> GatherAllDescendants(const TArray< TSharedRef<SWindow> >& InWindowList)
{
	TArray<TSharedRef<SWindow>> GatheredDescendants(InWindowList);

	for (const TSharedRef<SWindow>& SomeWindow : InWindowList)
	{
		GatheredDescendants.Append( GatherAllDescendants( SomeWindow->GetChildWindows() ) );
	}
	
	return GatheredDescendants;
}

void FSlateApplication::PrivateDrawWindows( TSharedPtr<SWindow> DrawOnlyThisWindow )
{
	check(Renderer.IsValid());

#if SLATE_HAS_WIDGET_REFLECTOR
	// Is user expecting visual feedback from the Widget Reflector?
	const bool bVisualizeLayoutUnderCursor = WidgetReflectorPtr.IsValid() && WidgetReflectorPtr.Pin()->IsVisualizingLayoutUnderCursor();
#else
	const bool bVisualizeLayoutUnderCursor = false;
#endif

	FWidgetPath WidgetsUnderCursor = bVisualizeLayoutUnderCursor
		? WidgetsUnderCursorLastEvent.FindRef(FUserAndPointer(CursorUserIndex,CursorPointerIndex)).ToWidgetPath()
		: FWidgetPath();

	if ( !SkipSecondPrepass.GetValueOnGameThread() )
	{
		FPlatformMisc::BeginNamedEvent(FColor::Magenta, "Slate::Prepass");
		DrawPrepass( DrawOnlyThisWindow );
		FPlatformMisc::EndNamedEvent();
	}

	//FPlatformMisc::BeginNamedEvent(FColor::Magenta, "Slate::GetDrawBuffer");
	FDrawWindowArgs DrawWindowArgs( Renderer->GetDrawBuffer(), WidgetsUnderCursor );
	//FPlatformMisc::EndNamedEvent();

	{
		SCOPE_CYCLE_COUNTER( STAT_SlateDrawWindowTime );

		TSharedPtr<SWindow> ActiveModalWindow = GetActiveModalWindow(); 

		if (ActiveModalWindow.IsValid())
		{
			DrawWindowAndChildren( ActiveModalWindow.ToSharedRef(), DrawWindowArgs );

			for( TArray< TSharedRef<SWindow> >::TConstIterator CurrentWindowIt( SlateWindows ); CurrentWindowIt; ++CurrentWindowIt )
			{
				const TSharedRef<SWindow>& CurrentWindow = *CurrentWindowIt;
				if ( CurrentWindow->IsTopmostWindow() )
				{
					DrawWindowAndChildren(CurrentWindow, DrawWindowArgs);
				}
			}

			TArray< TSharedRef<SWindow> > NotificationWindows;
			FSlateNotificationManager::Get().GetWindows(NotificationWindows);
			for( auto CurrentWindowIt( NotificationWindows.CreateIterator() ); CurrentWindowIt; ++CurrentWindowIt )
			{
				DrawWindowAndChildren(*CurrentWindowIt, DrawWindowArgs);
			}	
		}
		else if( DrawOnlyThisWindow.IsValid() )
		{
			DrawWindowAndChildren( DrawOnlyThisWindow.ToSharedRef(), DrawWindowArgs );
		}
		else
		{
			// Draw all windows
			for( TArray< TSharedRef<SWindow> >::TConstIterator CurrentWindowIt( SlateWindows ); CurrentWindowIt; ++CurrentWindowIt )
			{
				TSharedRef<SWindow> CurrentWindow = *CurrentWindowIt;
				if ( CurrentWindow->IsVisible() )
				{
					DrawWindowAndChildren( CurrentWindow, DrawWindowArgs );
				}
			}
		}
	}

	// This is potentially dangerous on the movie playback thread that slate sometimes runs on
	if(!IsInSlateThread())
	{
		// Some windows may have been destroyed/removed.
		// Do not attempt to draw any windows that have been removed.
		TArray<TSharedRef<SWindow>> AllWindows = GatherAllDescendants(SlateWindows);
		DrawWindowArgs.OutDrawBuffer.GetWindowElementLists().RemoveAll([&](TSharedPtr<FSlateWindowElementList>& Candidate)
		{
			TSharedPtr<SWindow> CandidateWindow = Candidate->GetWindow();
			return !CandidateWindow.IsValid() || !AllWindows.Contains(CandidateWindow.ToSharedRef());
		});
	}

	{	
		SLATE_CYCLE_COUNTER_SCOPE(GSlateRendererDrawWindows);
		Renderer->DrawWindows( DrawWindowArgs.OutDrawBuffer );
	}
}

void FSlateApplication::PollGameDeviceState()
{
	if( ActiveModalWindows.Num() == 0 && !GIntraFrameDebuggingGameThread )
	{
		// Don't poll when a modal window open or intra frame debugging is happening
		PlatformApplication->PollGameDeviceState( GetDeltaTime() );
	}
}

void FSlateApplication::FinishedInputThisFrame()
{
	const float DeltaTime = GetDeltaTime();

	if (InputPreProcessor.IsValid() && PlatformApplication->Cursor.IsValid())
	{
		InputPreProcessor->Tick(DeltaTime, *this, PlatformApplication->Cursor.ToSharedRef());
	}

	// All the input events have been processed.

	// Any widgets that may have received pointer input events
	// are given a chance to process accumulated values.
	if (MouseCaptor.HasCapture())
	{
		TArray<TSharedRef<SWidget>> Captors = MouseCaptor.ToSharedWidgets();
		for (const auto & Captor : Captors )
		{
			Captor->OnFinishedPointerInput();
		}
	}
	else
	{
		for( auto LastWidgetIterator = WidgetsUnderCursorLastEvent.CreateConstIterator(); LastWidgetIterator; ++LastWidgetIterator )
		{
			FWeakWidgetPath Path = LastWidgetIterator.Value();

			for ( const TWeakPtr<SWidget>& WidgetPtr : Path.Widgets )
			{
				const TSharedPtr<SWidget>& Widget = WidgetPtr.Pin();
				if (Widget.IsValid())
				{
					Widget->OnFinishedPointerInput();
				}
				else
				{
					break;
				}
			}
		}
	}

	// Any widgets that may have recieved key events
	// are given a chance to process accumulated values.
	ForEachUser([&] (FSlateUser* User) {
		const FSlateUser::FUserFocusEntry& UserFocusEntry = User->Focus;
		for ( const TWeakPtr<SWidget>& WidgetPtr : UserFocusEntry.WidgetPath.Widgets )
		{
			const TSharedPtr<SWidget>& Widget = WidgetPtr.Pin();
			if ( Widget.IsValid() )
			{
				Widget->OnFinishedKeyInput();
			}
			else
			{
				break;
			}
		}
	});
}

void FSlateApplication::Tick(ESlateTickType TickType)
{
	SCOPE_TIME_GUARD(TEXT("FSlateApplication::Tick"));

	// It is not valid to tick Slate on any other thread but the game thread unless we are only updating time
	check(IsInGameThread() || TickType == ESlateTickType::TimeOnly);

	FScopeLock SlateTickAccess(&SlateTickCriticalSection);

	FPlatformMisc::BeginNamedEvent(FColor::Magenta, "Slate::Tick");

	{
		SCOPE_CYCLE_COUNTER(STAT_SlateTickTime);
		SLATE_CYCLE_COUNTER_SCOPE(GSlateTotalTickTime);

		const float DeltaTime = GetDeltaTime();

		if (TickType == ESlateTickType::All)
		{
			TickPlatform(DeltaTime);
		}
		TickApplication(TickType, DeltaTime);
	}

	// Update Slate Stats
	SLATE_STATS_END_FRAME(GetCurrentTime());

	FPlatformMisc::EndNamedEvent();
}

void FSlateApplication::TickPlatform(float DeltaTime)
{
	FPlatformMisc::BeginNamedEvent(FColor::Magenta, "Slate::TickPlatform");

	{
		SCOPE_CYCLE_COUNTER(STAT_SlateMessageTick);

		// We need to pump messages here so that slate can receive input.  
		if ( ( ActiveModalWindows.Num() > 0 ) || GIntraFrameDebuggingGameThread )
		{
			// We only need to pump messages for slate when a modal window or blocking mode is active is up because normally message pumping is handled in FEngineLoop::Tick
			PlatformApplication->PumpMessages(DeltaTime);

			if ( FCoreDelegates::StarvedGameLoop.IsBound() )
			{
				FCoreDelegates::StarvedGameLoop.Execute();
			}
		}

		PlatformApplication->Tick(DeltaTime);

		PlatformApplication->ProcessDeferredEvents(DeltaTime);
	}

	FPlatformMisc::EndNamedEvent();
}

void FSlateApplication::TickApplication(ESlateTickType TickType, float DeltaTime)
{
	if (Renderer.IsValid())
	{
		// Release any temporary material or texture resources we may have cached and are reporting to prevent
		// GC on those resources.  We don't need to force it, we just need to let the ones used last frame to
		// be queued up to be released.
		Renderer->ReleaseAccessedResources(/* Flush State */ false);
	}

	if(TickType == ESlateTickType::All)
	{
		FPlatformMisc::BeginNamedEvent(FColor::Magenta, "Slate::PreTick");
		{
			SCOPE_CYCLE_COUNTER(STAT_SlatePreTickEvent);
			PreTickEvent.Broadcast(DeltaTime);
		}
		FPlatformMisc::EndNamedEvent();

		//FPlatformMisc::BeginNamedEvent(FColor::Magenta, "Slate::UpdateCursorLockRegion");
		// The widget locking the cursor to its bounds may have been reshaped.
		// Check if the widget was reshaped and update the cursor lock
		// bounds if needed.
		UpdateCursorLockRegion();
		//FPlatformMisc::EndNamedEvent();

		//FPlatformMisc::BeginNamedEvent(FColor::Magenta, "Slate::CaptureAndToolTipUpdate");
		// When Slate captures the mouse, it is up to us to set the cursor 
		// because the OS assumes that we own the mouse.
		if (MouseCaptor.HasCapture() || bQueryCursorRequested)
		{
			QueryCursor();
		}

		{
			SCOPE_CYCLE_COUNTER(STAT_SlateUpdateTooltip);
			SLATE_CYCLE_COUNTER_SCOPE(GUpdateTooltipTime);

			// Update tool tip, if we have one
			const bool AllowSpawningOfToolTips = false;
			UpdateToolTip(AllowSpawningOfToolTips);
		}
	}
	//FPlatformMisc::EndNamedEvent();


	// Advance time
	LastTickTime = CurrentTime;
	CurrentTime = FPlatformTime::Seconds();

	// Update average time between ticks.  This is used to monitor how responsive the application "feels".
	// Note that we calculate this before we apply the max quantum clamping below, because we want to store
	// the actual frame rate, even if it is very low.
	if (TickType == ESlateTickType::All)
	{
		// Scalar percent of new delta time that contributes to running average.  Use a lower value to add more smoothing
		// to the average frame rate.  A value of 1.0 will disable smoothing.
		const float RunningAverageScale = 0.1f;

		AverageDeltaTime = AverageDeltaTime * ( 1.0f - RunningAverageScale ) + GetDeltaTime() * RunningAverageScale;

		// Don't update average delta time if we're in an exceptional situation, such as when throttling mode
		// is active, because the measured tick time will not be representative of the application's performance.
		// In these cases, the cached average delta time from before the throttle activated will be used until
		// throttling has finished.
		if( FSlateThrottleManager::Get().IsAllowingExpensiveTasks() )
		{
			// Clamp to avoid including huge hitchy frames in our average
			const float ClampedDeltaTime = FMath::Clamp( GetDeltaTime(), 0.0f, 1.0f );
			AverageDeltaTimeForResponsiveness = AverageDeltaTimeForResponsiveness * ( 1.0f - RunningAverageScale ) + ClampedDeltaTime * RunningAverageScale;
		}
	}

	// Handle large quantums
	const double MaxQuantumBeforeClamp = 1.0 / 8.0;		// 8 FPS
	if( GetDeltaTime() > MaxQuantumBeforeClamp )
	{
		LastTickTime = CurrentTime - MaxQuantumBeforeClamp;
	}

	if (TickType == ESlateTickType::All)
	{
		const bool bNeedsSyntheticMouseMouse = SynthesizeMouseMovePending > 0;
		if (bNeedsSyntheticMouseMouse && (!GIsGameThreadIdInitialized || IsInGameThread())) 
		{
			// Force a mouse move event to make sure all widgets know whether there is a mouse cursor hovering over them
			SynthesizeMouseMove();
			--SynthesizeMouseMovePending;
		}

		// Update auto-throttling based on elapsed time since user interaction
		ThrottleApplicationBasedOnMouseMovement();

		TSharedPtr<SWindow> ActiveModalWindow = GetActiveModalWindow();

		const float SleepThreshold = SleepBufferPostInput.GetValueOnGameThread();
		const double TimeSinceInput = LastTickTime - LastUserInteractionTime;
		const double TimeSinceMouseMove = LastTickTime - LastMouseMoveTime;

		const bool bIsUserIdle = (TimeSinceInput > SleepThreshold) && (TimeSinceMouseMove > SleepThreshold);
		const bool bAnyActiveTimersPending = AnyActiveTimersArePending();
		if (bAnyActiveTimersPending)
		{
			// Some UI might slide under the cursor. To a widget, this is
			// as if the cursor moved over it.
			QueueSynthesizedMouseMove();
		}

		// Check if any element lists used for caching need to be released
		{
			for (int32 CacheIndex = 0; CacheIndex < ReleasedCachedElementLists.Num(); CacheIndex++)
			{
				if (ReleasedCachedElementLists[CacheIndex]->IsInUse() == false)
				{
					ensure(ReleasedCachedElementLists[CacheIndex].IsUnique());
					ReleasedCachedElementLists[CacheIndex].Reset();
					ReleasedCachedElementLists.RemoveAtSwap(CacheIndex, 1, false);
					CacheIndex--;
				}
			}
		}

		// skip tick/draw if we are idle and there are no active timers registered that we need to drive slate for.
		// This effectively means the slate application is totally idle and we don't need to update the UI.
		// This relies on Widgets properly registering for Active timer when they need something to happen even
		// when the user is not providing any input (ie, animations, viewport rendering, async polling, etc).
		bIsSlateAsleep = true;
		if (!AllowSlateToSleep.GetValueOnGameThread() || bAnyActiveTimersPending || !bIsUserIdle || bNeedsSyntheticMouseMouse || FApp::UseVRFocus())
		{
			bIsSlateAsleep = false; // if we get here, then Slate is not sleeping

			// Update any notifications - this needs to be done after windows have updated themselves 
			// (so they know their size)
			{
				SLATE_CYCLE_COUNTER_SCOPE(GSlateTickNotificationManager);
				FSlateNotificationManager::Get().Tick();
			}

			// Draw all windows
			DrawWindows();
		}

		PostTickEvent.Broadcast(DeltaTime);
	}
}


void FSlateApplication::PumpMessages()
{
	PlatformApplication->PumpMessages( GetDeltaTime() );
}


void FSlateApplication::ThrottleApplicationBasedOnMouseMovement()
{
	bool bShouldThrottle = false;
	if( ThrottleWhenMouseIsMoving.GetValueOnGameThread() )	// Interpreted as bool here
	{
		// We only want to engage the throttle for a short amount of time after the mouse stops moving
		const float TimeToThrottleAfterMouseStops = 0.1f;

		// After a key or mouse button is pressed, we'll leave the throttle disengaged for awhile so the
		// user can use the keys to navigate in a viewport, for example.
		const float MinTimeSinceButtonPressToThrottle = 1.0f;

		// Use a small movement threshold to avoid engaging the throttle when the user bumps the mouse
		const float MinMouseMovePixelsBeforeThrottle = 2.0f;

		const FVector2D& CursorPos = GetCursorPos();
		static FVector2D LastCursorPos = GetCursorPos();
		//static double LastMouseMoveTime = FPlatformTime::Seconds();
		static bool bIsMouseMoving = false;
		if( CursorPos != LastCursorPos )
		{
			// Did the cursor move far enough that we care?
			if( bIsMouseMoving || ( CursorPos - LastCursorPos ).SizeSquared() >= MinMouseMovePixelsBeforeThrottle * MinMouseMovePixelsBeforeThrottle )
			{
				bIsMouseMoving = true;
				LastMouseMoveTime = this->GetCurrentTime();
				LastCursorPos = CursorPos;
			}
		}

		const float TimeSinceLastUserInteraction = CurrentTime - LastUserInteractionTimeForThrottling;
		const float TimeSinceLastMouseMove = CurrentTime - LastMouseMoveTime;
		if( TimeSinceLastMouseMove < TimeToThrottleAfterMouseStops )
		{
			// Only throttle if a Slate window is currently active.  If a Wx window (such as Matinee) is
			// being used, we don't want to throttle
			if( this->GetActiveTopLevelWindow().IsValid() )
			{
				// Only throttle if the user hasn't pressed a button in awhile
				if( TimeSinceLastUserInteraction > MinTimeSinceButtonPressToThrottle )
				{
					// If a widget has the mouse captured, then we won't bother throttling
					if( !MouseCaptor.HasCapture() )
					{
						// If there is no Slate window under the mouse, then we won't engage throttling
						if( LocateWindowUnderMouse( GetCursorPos(), GetInteractiveTopLevelWindows() ).IsValid() )
						{
							bShouldThrottle = true;
						}
					}
				}
			}
		}
		else
		{
			// Mouse hasn't moved in a bit, so reset our movement state
			bIsMouseMoving = false;
			LastCursorPos = CursorPos;
		}
	}

	if( bShouldThrottle )
	{
		if( !UserInteractionResponsivnessThrottle.IsValid() )
		{
			// Engage throttling
			UserInteractionResponsivnessThrottle = FSlateThrottleManager::Get().EnterResponsiveMode();
		}
	}
	else
	{
		if( UserInteractionResponsivnessThrottle.IsValid() )
		{
			// Disengage throttling
			FSlateThrottleManager::Get().LeaveResponsiveMode( UserInteractionResponsivnessThrottle );
		}
	}
}

FWidgetPath FSlateApplication::LocateWidgetInWindow(FVector2D ScreenspaceMouseCoordinate, const TSharedRef<SWindow>& Window, bool bIgnoreEnabledStatus) const
{
	const bool bAcceptsInput = Window->IsVisible() && (Window->AcceptsInput() || IsWindowHousingInteractiveTooltip(Window));
	if (bAcceptsInput && Window->IsScreenspaceMouseWithin(ScreenspaceMouseCoordinate))
	{
		const TArray<FWidgetAndPointer> WidgetsAndCursors = Window->GetHittestGrid()->GetBubblePath(ScreenspaceMouseCoordinate, GetCursorRadius(), bIgnoreEnabledStatus);
		return FWidgetPath(WidgetsAndCursors);
	}
	else
	{
		return FWidgetPath();
	}
}


TSharedRef<SWindow> FSlateApplication::AddWindow( TSharedRef<SWindow> InSlateWindow, const bool bShowImmediately )
{
	// Add the Slate window to the Slate application's top-level window array.  Note that neither the Slate window
	// or the native window are ready to be used yet, however we need to make sure they're in the Slate window
	// array so that we can properly respond to OS window messages as soon as they're sent.  For example, a window
	// activation message may be sent by the OS as soon as the window is shown (in the Init function), and if we
	// don't add the Slate window to our window list, we wouldn't be able to route that message to the window.

	FSlateWindowHelper::ArrangeWindowToFront(SlateWindows, InSlateWindow);
	TSharedRef<FGenericWindow> NewWindow = MakeWindow( InSlateWindow, bShowImmediately );

	if( bShowImmediately )
	{
		InSlateWindow->ShowWindow();

		//@todo Slate: Potentially dangerous and annoying if all slate windows that are created steal focus.
		if( InSlateWindow->SupportsKeyboardFocus() && InSlateWindow->IsFocusedInitially() )
		{
			InSlateWindow->GetNativeWindow()->SetWindowFocus();
		}
	}

	return InSlateWindow;
}

TSharedRef< FGenericWindow > FSlateApplication::MakeWindow( TSharedRef<SWindow> InSlateWindow, const bool bShowImmediately )
{
	TSharedPtr<FGenericWindow> NativeParent = nullptr;
	TSharedPtr<SWindow> ParentWindow = InSlateWindow->GetParentWindow();
	if ( ParentWindow.IsValid() )
	{
		NativeParent = ParentWindow->GetNativeWindow();
	}

	TSharedRef< FGenericWindowDefinition > Definition = MakeShareable( new FGenericWindowDefinition() );

	Definition->Type = InSlateWindow->GetType();

	const FVector2D Size = InSlateWindow->GetInitialDesiredSizeInScreen();
	Definition->WidthDesiredOnScreen = Size.X;
	Definition->HeightDesiredOnScreen = Size.Y;

	const FVector2D Position = InSlateWindow->GetInitialDesiredPositionInScreen();
	Definition->XDesiredPositionOnScreen = Position.X;
	Definition->YDesiredPositionOnScreen = Position.Y;

	Definition->HasOSWindowBorder = InSlateWindow->HasOSWindowBorder();
	Definition->TransparencySupport = InSlateWindow->GetTransparencySupport();
	Definition->AppearsInTaskbar = InSlateWindow->AppearsInTaskbar();
	Definition->IsTopmostWindow = InSlateWindow->IsTopmostWindow();
	Definition->AcceptsInput = InSlateWindow->AcceptsInput();
	Definition->ActivationPolicy = InSlateWindow->ActivationPolicy();
	Definition->FocusWhenFirstShown = InSlateWindow->IsFocusedInitially();

	Definition->HasCloseButton = InSlateWindow->HasCloseBox();
	Definition->SupportsMinimize = InSlateWindow->HasMinimizeBox();
	Definition->SupportsMaximize = InSlateWindow->HasMaximizeBox();

	Definition->IsModalWindow = InSlateWindow->IsModalWindow();
	Definition->IsRegularWindow = InSlateWindow->IsRegularWindow();
	Definition->HasSizingFrame = InSlateWindow->HasSizingFrame();
	Definition->SizeWillChangeOften = InSlateWindow->SizeWillChangeOften();
	Definition->ShouldPreserveAspectRatio = InSlateWindow->ShouldPreserveAspectRatio();
	Definition->ExpectedMaxWidth = InSlateWindow->GetExpectedMaxWidth();
	Definition->ExpectedMaxHeight = InSlateWindow->GetExpectedMaxHeight();

	Definition->Title = InSlateWindow->GetTitle().ToString();
	Definition->Opacity = InSlateWindow->GetOpacity();
	Definition->CornerRadius = InSlateWindow->GetCornerRadius();

	Definition->SizeLimits = InSlateWindow->GetSizeLimits();

	TSharedRef< FGenericWindow > NewWindow = PlatformApplication->MakeWindow();

	if (LIKELY(FApp::CanEverRender()))
	{
		InSlateWindow->SetNativeWindow(NewWindow);

		InSlateWindow->SetCachedScreenPosition( Position );
		InSlateWindow->SetCachedSize( Size );

		PlatformApplication->InitializeWindow( NewWindow, Definition, NativeParent, bShowImmediately );

		ITextInputMethodSystem* const TextInputMethodSystem = PlatformApplication->GetTextInputMethodSystem();
		if ( TextInputMethodSystem )
		{
			TextInputMethodSystem->ApplyDefaults( NewWindow );
		}
	}
	else
	{
		InSlateWindow->SetNativeWindow(MakeShareable(new FGenericWindow()));
	}

	return NewWindow;
}

bool FSlateApplication::CanAddModalWindow() const
{
	// A modal window cannot be opened until the renderer has been created.
	return CanDisplayWindows();
}

bool FSlateApplication::CanDisplayWindows() const
{
	// The renderer must be created and global shaders be available
	return Renderer.IsValid() && Renderer->AreShadersInitialized();
}


EUINavigation FSlateApplication::GetNavigationDirectionFromKey(const FKeyEvent& InKeyEvent) const
{
	return NavigationConfig->GetNavigationDirectionFromKey(InKeyEvent);
}

void FSlateApplication::AddModalWindow( TSharedRef<SWindow> InSlateWindow, const TSharedPtr<const SWidget> InParentWidget, bool bSlowTaskWindow )
{
	if( !CanAddModalWindow() )
	{
		// Bail out.  The incoming window will never be added, and no native window will be created.
		return;
	}



	// Push the active modal window onto the stack.  
	ActiveModalWindows.AddUnique( InSlateWindow );

	// Close the open tooltip when a new window is open.  Tooltips from non-modal windows can be dangerous and cause rentrancy into code that shouldnt execute in a modal state.
	CloseToolTip();

	// Set the modal flag on the window
	InSlateWindow->SetAsModalWindow();
	
	// Make sure we aren't in the middle of using a slate draw buffer
	Renderer->FlushCommands();

	// In slow task windows, depending on the frequency with which the window is updated, it could be quite some time 
	// before the window is ticked (and drawn) so we hide the window by default and the slow task window will show it when needed
	const bool bShowWindow = !bSlowTaskWindow;

	// Create the new window
	// Note: generally a modal window should not be added without a parent but 
	// due to this being called from wxWidget editors, this is not always possible
	if( InParentWidget.IsValid() )
	{
		// Find the window of the parent widget
		FWidgetPath WidgetPath;
		GeneratePathToWidgetChecked( InParentWidget.ToSharedRef(), WidgetPath );
		AddWindowAsNativeChild( InSlateWindow, WidgetPath.GetWindow(), bShowWindow );
	}
	else
	{
		AddWindow( InSlateWindow, bShowWindow );
	}

	if ( ActiveModalWindows.Num() == 1 )
	{
		// Signal that a slate modal window has opened so external windows may be disabled as well
		ModalWindowStackStartedDelegate.ExecuteIfBound();
	}

	// Release mouse capture here in case the new modal window has been added in one of the mouse button
	// event callbacks. Otherwise it will be unresponsive until the next mouse up event.
	ReleaseMouseCapture();

	// Clear the cached pressed mouse buttons, in case a new modal window has been added between the mouse down and mouse up of another window.
	PressedMouseButtons.Empty();

	// Also force the platform capture off as the call to ReleaseMouseCapture() above still relies on mouse up messages to clear the capture
	PlatformApplication->SetCapture( nullptr );

	// Disable high precision mouse mode when a modal window is added.  On some OS'es even when a window is diabled, raw input is sent to it.
	PlatformApplication->SetHighPrecisionMouseMode( false, nullptr );

	// Block on all modal windows unless its a slow task.  In that case the game thread is allowed to run.
	if( !bSlowTaskWindow )
	{
		// Show the cursor if it was previously hidden so users can interact with the window
		if ( PlatformApplication->Cursor.IsValid() )
		{
			PlatformApplication->Cursor->Show( true );
		}

		//Throttle loop data
		float LastLoopTime = (float)FPlatformTime::Seconds();
		const float MinThrottlePeriod = (1.0f / 60.0f); //Throttle the loop to a maximum of 60Hz

		// Tick slate from here in the event that we should not return until the modal window is closed.
		while( InSlateWindow == GetActiveModalWindow() )
		{
			//Throttle the loop
			const float CurrentLoopTime = FPlatformTime::Seconds();
			const float SleepTime = MinThrottlePeriod - (CurrentLoopTime-LastLoopTime);
			LastLoopTime = CurrentLoopTime;
			if (SleepTime > 0.0f)
			{
				// Sleep a bit to not eat up all CPU time
				FPlatformProcess::Sleep(SleepTime);
			}

			const float DeltaTime = GetDeltaTime();

			// Tick any other systems that need to update during modal dialogs
			ModalLoopTickEvent.Broadcast(DeltaTime);

			FPlatformMisc::BeginNamedEvent(FColor::Magenta, "Slate::Tick");

			{
				SCOPE_CYCLE_COUNTER(STAT_SlateTickTime);
				SLATE_CYCLE_COUNTER_SCOPE(GSlateTotalTickTime);

				// Tick and pump messages for the platform.
				TickPlatform(DeltaTime);

				// It's possible that during ticking the platform we'll find out the modal dialog was closed.
				// in which case we need to abort the current flow.
				if ( InSlateWindow != GetActiveModalWindow() )
				{
					break;
				}

				// Tick and render Slate
				TickApplication(ESlateTickType::All, DeltaTime);
			}

			// Update Slate Stats
			SLATE_STATS_END_FRAME(GetCurrentTime());

			FPlatformMisc::EndNamedEvent();

			// Synchronize the game thread and the render thread so that the render thread doesn't get too far behind.
			Renderer->Sync();
		}
	}
}

void FSlateApplication::SetModalWindowStackStartedDelegate(FModalWindowStackStarted StackStartedDelegate)
{
	ModalWindowStackStartedDelegate = StackStartedDelegate;
}

void FSlateApplication::SetModalWindowStackEndedDelegate(FModalWindowStackEnded StackEndedDelegate)
{
	ModalWindowStackEndedDelegate = StackEndedDelegate;
}

TSharedRef<SWindow> FSlateApplication::AddWindowAsNativeChild( TSharedRef<SWindow> InSlateWindow, TSharedRef<SWindow> InParentWindow, const bool bShowImmediately )
{
	// @VREDITOR HACK
	// Parent window must already have been added
	//checkSlow(FSlateWindowHelper::ContainsWindow(SlateWindows, InParentWindow));

	// Add the Slate window to the Slate application's top-level window array.  Note that neither the Slate window
	// or the native window are ready to be used yet, however we need to make sure they're in the Slate window
	// array so that we can properly respond to OS window messages as soon as they're sent.  For example, a window
	// activation message may be sent by the OS as soon as the window is shown (in the Init function), and if we
	// don't add the Slate window to our window list, we wouldn't be able to route that message to the window.
	InParentWindow->AddChildWindow( InSlateWindow );

	// Only make native generic windows if the parent has one. Nullrhi makes only generic windows, whose handles are always null
	if ( InParentWindow->GetNativeWindow()->GetOSWindowHandle() || !FApp::CanEverRender() )
	{
		TSharedRef<FGenericWindow> NewWindow = MakeWindow(InSlateWindow, bShowImmediately);

		if ( bShowImmediately )
		{
			InSlateWindow->ShowWindow();

			//@todo Slate: Potentially dangerous and annoying if all slate windows that are created steal focus.
			if ( InSlateWindow->SupportsKeyboardFocus() && InSlateWindow->IsFocusedInitially() )
			{
				InSlateWindow->GetNativeWindow()->SetWindowFocus();
			}
		}
	}

	return InSlateWindow;
}

TSharedPtr<IMenu> FSlateApplication::PushMenu(const TSharedRef<SWidget>& InParentWidget, const FWidgetPath& InOwnerPath, const TSharedRef<SWidget>& InContent, const FVector2D& SummonLocation, const FPopupTransitionEffect& TransitionEffect, const bool bFocusImmediately, const FVector2D& SummonLocationSize, TOptional<EPopupMethod> Method, const bool bIsCollapsedByParent)
{
	// Caller supplied a valid path? Pass it to the menu stack.
	if (InOwnerPath.IsValid())
	{
		return MenuStack.Push(InOwnerPath, InContent, SummonLocation, TransitionEffect, bFocusImmediately, SummonLocationSize, Method, bIsCollapsedByParent);
	}

	// If the caller doesn't specify a valid event path we'll generate one from InParentWidget
	FWidgetPath WidgetPath;
	if (GeneratePathToWidgetUnchecked(InParentWidget, WidgetPath))
	{
		return MenuStack.Push(WidgetPath, InContent, SummonLocation, TransitionEffect, bFocusImmediately, SummonLocationSize, Method, bIsCollapsedByParent);
	}

	UE_LOG(LogSlate, Warning, TEXT("Menu could not be pushed.  A path to the parent widget(%s) could not be found"), *InParentWidget->ToString());
	return TSharedPtr<IMenu>();
}

TSharedPtr<IMenu> FSlateApplication::PushMenu(const TSharedPtr<IMenu>& InParentMenu, const TSharedRef<SWidget>& InContent, const FVector2D& SummonLocation, const FPopupTransitionEffect& TransitionEffect, const bool bFocusImmediately, const FVector2D& SummonLocationSize, const bool bIsCollapsedByParent)
{
	return MenuStack.Push(InParentMenu, InContent, SummonLocation, TransitionEffect, bFocusImmediately, SummonLocationSize, bIsCollapsedByParent);
}

TSharedPtr<IMenu> FSlateApplication::PushHostedMenu(const TSharedRef<SWidget>& InParentWidget, const FWidgetPath& InOwnerPath, const TSharedRef<IMenuHost>& InMenuHost, const TSharedRef<SWidget>& InContent, TSharedPtr<SWidget>& OutWrappedContent, const FPopupTransitionEffect& TransitionEffect, EShouldThrottle ShouldThrottle, const bool bIsCollapsedByParent)
{
	// Caller supplied a valid path? Pass it to the menu stack.
	if (InOwnerPath.IsValid())
	{
		return MenuStack.PushHosted(InOwnerPath, InMenuHost, InContent, OutWrappedContent, TransitionEffect, ShouldThrottle, bIsCollapsedByParent);
	}

	// If the caller doesn't specify a valid event path we'll generate one from InParentWidget
	FWidgetPath WidgetPath;
	if (GeneratePathToWidgetUnchecked(InParentWidget, WidgetPath))
	{
		return MenuStack.PushHosted(WidgetPath, InMenuHost, InContent, OutWrappedContent, TransitionEffect, ShouldThrottle, bIsCollapsedByParent);
	}

	return TSharedPtr<IMenu>();
}

TSharedPtr<IMenu> FSlateApplication::PushHostedMenu(const TSharedPtr<IMenu>& InParentMenu, const TSharedRef<IMenuHost>& InMenuHost, const TSharedRef<SWidget>& InContent, TSharedPtr<SWidget>& OutWrappedContent, const FPopupTransitionEffect& TransitionEffect, EShouldThrottle ShouldThrottle, const bool bIsCollapsedByParent)
{
	return MenuStack.PushHosted(InParentMenu, InMenuHost, InContent, OutWrappedContent, TransitionEffect, ShouldThrottle, bIsCollapsedByParent);
}

bool FSlateApplication::HasOpenSubMenus(TSharedPtr<IMenu> InMenu) const
{
	return MenuStack.HasOpenSubMenus(InMenu);
}

bool FSlateApplication::AnyMenusVisible() const
{
	return MenuStack.HasMenus();
}

TSharedPtr<IMenu> FSlateApplication::FindMenuInWidgetPath(const FWidgetPath& InWidgetPath) const
{
	return MenuStack.FindMenuInWidgetPath(InWidgetPath);
}

TSharedPtr<SWindow> FSlateApplication::GetVisibleMenuWindow() const
{
	return MenuStack.GetHostWindow();
}

void FSlateApplication::DismissAllMenus()
{
	MenuStack.DismissAll();
}

void FSlateApplication::DismissMenu(const TSharedPtr<IMenu>& InFromMenu)
{
	MenuStack.DismissFrom(InFromMenu);
}

void FSlateApplication::DismissMenuByWidget(const TSharedRef<SWidget>& InWidgetInMenu)
{
	FWidgetPath WidgetPath;
	if (GeneratePathToWidgetUnchecked(InWidgetInMenu, WidgetPath))
	{
		TSharedPtr<IMenu> Menu = MenuStack.FindMenuInWidgetPath(WidgetPath);
		if (Menu.IsValid())
		{
			MenuStack.DismissFrom(Menu);
		}
	}
}

void FSlateApplication::RequestDestroyWindow( TSharedRef<SWindow> InWindowToDestroy )
{
	// Logging to track down window shutdown issues with movie loading threads. Too spammy in editor builds with all the windows
#if !WITH_EDITOR
	UE_LOG(LogSlate, Log, TEXT("Request Window '%s' being destroyed"), *InWindowToDestroy->GetTitle().ToString() );
#endif
	struct local
	{
		static void Helper( const TSharedRef<SWindow> WindowToDestroy, TArray< TSharedRef<SWindow> >& OutWindowDestroyQueue)
		{
			/** @return the list of this window's child windows */
			TArray< TSharedRef<SWindow> >& ChildWindows = WindowToDestroy->GetChildWindows();

			// Children need to be destroyed first. 
			if( ChildWindows.Num() > 0 )
			{
				for( int32 ChildIndex = 0; ChildIndex < ChildWindows.Num(); ++ChildIndex )
				{	
					// Recursively request that the window is destroyed which will also queue any children of children etc...
					Helper( ChildWindows[ ChildIndex ], OutWindowDestroyQueue );
				}
			}

			OutWindowDestroyQueue.AddUnique( WindowToDestroy );
		}
	};

	local::Helper( InWindowToDestroy, WindowDestroyQueue );

	DestroyWindowsImmediately();
}

void FSlateApplication::DestroyWindowImmediately( TSharedRef<SWindow> WindowToDestroy ) 
{
	// Request that the window and its children are destroyed
	RequestDestroyWindow( WindowToDestroy );

	DestroyWindowsImmediately();
}


void FSlateApplication::ExternalModalStart()
{
	if( NumExternalModalWindowsActive++ == 0 )
	{
		// Close all open menus.
		DismissAllMenus();

		// Close tool-tips
		CloseToolTip();

		// Tick and render Slate so that it can destroy any menu windows if necessary before we disable.
		Tick();
		Renderer->Sync();

		if( ActiveModalWindows.Num() > 0 )
		{
			// There are still modal windows so only enable the new active modal window.
			GetActiveModalWindow()->EnableWindow( false );
		}
		else
		{
			// We are creating a modal window so all other windows need to be disabled.
			for( TArray< TSharedRef<SWindow> >::TIterator CurrentWindowIt( SlateWindows ); CurrentWindowIt; ++CurrentWindowIt )
			{
				TSharedRef<SWindow> CurrentWindow = ( *CurrentWindowIt );
				CurrentWindow->EnableWindow( false );
			}
		}
	}
}


void FSlateApplication::ExternalModalStop()
{
	check(NumExternalModalWindowsActive > 0);
	if( --NumExternalModalWindowsActive == 0 )
	{
		if( ActiveModalWindows.Num() > 0 )
		{
			// There are still modal windows so only enable the new active modal window.
			GetActiveModalWindow()->EnableWindow( true );
		}
		else
		{
			// We are creating a modal window so all other windows need to be disabled.
			for( TArray< TSharedRef<SWindow> >::TIterator CurrentWindowIt( SlateWindows ); CurrentWindowIt; ++CurrentWindowIt )
			{
				TSharedRef<SWindow> CurrentWindow = ( *CurrentWindowIt );
				CurrentWindow->EnableWindow( true );
			}
		}
	}
}

void FSlateApplication::InvalidateAllViewports()
{
	Renderer->InvalidateAllViewports();
}

void FSlateApplication::RegisterGameViewport( TSharedRef<SViewport> InViewport )
{
	RegisterViewport(InViewport);
	
	if (GameViewportWidget != InViewport)
	{
		InViewport->SetActive(true);
		GameViewportWidget = InViewport;
	}
	
	ActivateGameViewport();
}

void FSlateApplication::RegisterViewport(TSharedRef<SViewport> InViewport)
{
	TSharedPtr<SWindow> ParentWindow = FindWidgetWindow(InViewport);
	if (ParentWindow.IsValid())
	{
		TWeakPtr<ISlateViewport> SlateViewport = InViewport->GetViewportInterface();
		if (ensure(SlateViewport.IsValid()))
		{
			ParentWindow->SetViewport(SlateViewport.Pin().ToSharedRef());
		}
	}
}

void FSlateApplication::UnregisterGameViewport()
{
	ResetToDefaultPointerInputSettings();

	if (GameViewportWidget.IsValid())
	{
		GameViewportWidget.Pin()->SetActive(false);
	}
	GameViewportWidget.Reset();
}

void FSlateApplication::RegisterVirtualWindow(TSharedRef<SWindow> InWindow)
{
	SlateVirtualWindows.AddUnique(InWindow);
}

void FSlateApplication::UnregisterVirtualWindow(TSharedRef<SWindow> InWindow)
{
	SlateVirtualWindows.Remove(InWindow);
}

void FSlateApplication::FlushRenderState()
{
	if ( Renderer.IsValid() )
	{
		// Release any temporary material or texture resources we may have cached and are reporting to prevent
		// GC on those resources.  If the game viewport is being unregistered, we need to flush these resources
		// to allow for them to be GC'ed.
		Renderer->ReleaseAccessedResources(/* Flush State */ true);
	}
}

TSharedPtr<SViewport> FSlateApplication::GetGameViewport() const
{
	return GameViewportWidget.Pin();
}

int32 FSlateApplication::GetUserIndexForKeyboard() const
{
	//@Todo Slate: Fix this to actual be a map and add API for the user to edit the mapping.
	// HACK! Just directly mapping the keyboard to User Index 0.
	return 0;
}
 
int32 FSlateApplication::GetUserIndexForController(int32 ControllerId) const
{
	//@Todo Slate: Fix this to actual be a map and add API for the user to edit the mapping.
	// HACK! Just directly mapping a controller to a User Index.
	return ControllerId;
}

void FSlateApplication::SetUserFocusToGameViewport(uint32 UserIndex, EFocusCause ReasonFocusIsChanging /* = EFocusCause::SetDirectly*/)
{
	TSharedPtr<SViewport> CurrentGameViewportWidget = GameViewportWidget.Pin();
	if (CurrentGameViewportWidget.IsValid())
	{
		SetUserFocus(UserIndex, CurrentGameViewportWidget, ReasonFocusIsChanging);
	}
}

void FSlateApplication::SetAllUserFocusToGameViewport(EFocusCause ReasonFocusIsChanging /* = EFocusCause::SetDirectly*/)
{
	TSharedPtr< SViewport > CurrentGameViewportWidget = GameViewportWidget.Pin();

	if (CurrentGameViewportWidget.IsValid())
	{
		FWidgetPath PathToWidget;
		FSlateWindowHelper::FindPathToWidget(SlateWindows, CurrentGameViewportWidget.ToSharedRef(), /*OUT*/ PathToWidget);

		ForEachUser([&] (FSlateUser* User) {
			SetUserFocus(User, PathToWidget, ReasonFocusIsChanging);
		});
	}
}

void FSlateApplication::ActivateGameViewport()
{
	// Only focus the window if the application is active, if not the application activation sequence will take care of it.
	if (bAppIsActive && GameViewportWidget.IsValid())
	{
		TSharedRef<SViewport> GameViewportWidgetRef = GameViewportWidget.Pin().ToSharedRef();
		
		FWidgetPath PathToViewport;
		// If we cannot find the window it could have been destroyed.
		if (FSlateWindowHelper::FindPathToWidget(SlateWindows, GameViewportWidgetRef, PathToViewport, EVisibility::All))
		{
			TSharedRef<SWindow> Window = PathToViewport.GetWindow();

			// Set keyboard focus on the actual OS window for the top level Slate window in the viewport path
			// This is needed because some OS messages are only sent to the window with keyboard focus
			// Slate will translate the message and send it to the actual widget with focus.
			// Without this we don't get WM_KEYDOWN or WM_CHAR messages in play in viewport sessions.
			Window->GetNativeWindow()->SetWindowFocus();

			// Activate the viewport and process the reply 
			FWindowActivateEvent ActivateEvent(FWindowActivateEvent::EA_Activate, Window);
			FReply ViewportActivatedReply = GameViewportWidgetRef->OnViewportActivated(ActivateEvent);
			if (ViewportActivatedReply.IsEventHandled())
			{
				ProcessReply(PathToViewport, ViewportActivatedReply, nullptr, nullptr);
			}
		}
	}
}

bool FSlateApplication::SetUserFocus(uint32 UserIndex, const TSharedPtr<SWidget>& WidgetToFocus, EFocusCause ReasonFocusIsChanging /* = EFocusCause::SetDirectly*/)
{
	const bool bValidWidget = WidgetToFocus.IsValid();
	ensureMsgf(bValidWidget, TEXT("Attempting to focus an invalid widget. If your intent is to clear focus use ClearUserFocus()"));
	if (bValidWidget)
	{
		if (FSlateUser* User = GetOrCreateUser(UserIndex))
		{
			FWidgetPath PathToWidget;
			const bool bFound = FSlateWindowHelper::FindPathToWidget(SlateWindows, WidgetToFocus.ToSharedRef(), /*OUT*/ PathToWidget);
			if (bFound)
			{
				return SetUserFocus(User, PathToWidget, ReasonFocusIsChanging);
			}
			else
			{
				const bool bFoundVirtual = FSlateWindowHelper::FindPathToWidget(SlateVirtualWindows, WidgetToFocus.ToSharedRef(), /*OUT*/ PathToWidget);
				if (bFoundVirtual)
				{
					return SetUserFocus(User, PathToWidget, ReasonFocusIsChanging);
				}
				else
				{
					//ensureMsgf(bFound, TEXT("Attempting to focus a widget that isn't in the tree and visible: %s. If your intent is to clear focus use ClearUserFocus()"), WidgetToFocus->ToString());
				}
			}
		}
	}

	return false;
}

void FSlateApplication::SetAllUserFocus(const TSharedPtr<SWidget>& WidgetToFocus, EFocusCause ReasonFocusIsChanging /*= EFocusCause::SetDirectly*/)
{
	const bool bValidWidget = WidgetToFocus.IsValid();
	ensureMsgf(bValidWidget, TEXT("Attempting to focus an invalid widget. If your intent is to clear focus use ClearAllUserFocus()"));
	if (bValidWidget)
	{
		FWidgetPath PathToWidget;
		const bool bFound = FSlateWindowHelper::FindPathToWidget(SlateWindows, WidgetToFocus.ToSharedRef(), /*OUT*/ PathToWidget);
		if (bFound)
		{
			SetAllUserFocus(PathToWidget, ReasonFocusIsChanging);
		}
		else
		{
			//ensureMsgf(bFound, TEXT("Attempting to focus a widget that isn't in the tree and visible: %s. If your intent is to clear focus use ClearAllUserFocus()"), WidgetToFocus->ToString());
		}
	}
}

TSharedPtr<SWidget> FSlateApplication::GetUserFocusedWidget(uint32 UserIndex) const
{
	if ( const FSlateUser* User = GetUser(UserIndex) )
	{
		return User->GetFocusedWidget();
	}

	return TSharedPtr<SWidget>();
}

void FSlateApplication::ClearUserFocus(uint32 UserIndex, EFocusCause ReasonFocusIsChanging /* = EFocusCause::SetDirectly*/)
{
	SetUserFocus(UserIndex, FWidgetPath(), ReasonFocusIsChanging);
}

void FSlateApplication::ClearAllUserFocus(EFocusCause ReasonFocusIsChanging /*= EFocusCause::SetDirectly*/)
{
	SetAllUserFocus(FWidgetPath(), ReasonFocusIsChanging);
}

bool FSlateApplication::SetKeyboardFocus(const TSharedPtr< SWidget >& OptionalWidgetToFocus, EFocusCause ReasonFocusIsChanging /* = EFocusCause::SetDirectly*/)
{
	return SetUserFocus(GetUserIndexForKeyboard(), OptionalWidgetToFocus, ReasonFocusIsChanging);
}

void FSlateApplication::ClearKeyboardFocus(const EFocusCause ReasonFocusIsChanging)
{
	SetUserFocus(GetUserIndexForKeyboard(), FWidgetPath(), ReasonFocusIsChanging);
}

void FSlateApplication::ResetToDefaultInputSettings()
{
	ProcessReply(FWidgetPath(), FReply::Handled().ClearUserFocus(true), nullptr, nullptr);
	ResetToDefaultPointerInputSettings();
}

void FSlateApplication::ResetToDefaultPointerInputSettings()
{
	for (auto MouseCaptorPath : MouseCaptor.ToWidgetPaths())
	{
		ProcessReply(MouseCaptorPath, FReply::Handled().ReleaseMouseCapture(), nullptr, nullptr);
	}

	ProcessReply(FWidgetPath(), FReply::Handled().ReleaseMouseLock(), nullptr, nullptr);

	if ( PlatformApplication->Cursor.IsValid() )
	{
		PlatformApplication->Cursor->SetType(EMouseCursor::Default);
	}
}

void* FSlateApplication::GetMouseCaptureWindow() const
{
	return PlatformApplication->GetCapture();
}

void FSlateApplication::ReleaseMouseCapture()
{
	MouseCaptor.InvalidateCaptureForAllPointers();
}

void FSlateApplication::ReleaseMouseCaptureForUser(int32 UserIndex)
{
	MouseCaptor.InvalidateCaptureForUser(UserIndex);
}


FDelegateHandle FSlateApplication::RegisterOnWindowActionNotification(const FOnWindowAction& Notification)
{
	OnWindowActionNotifications.Add(Notification);
	return OnWindowActionNotifications.Last().GetHandle();
}

void FSlateApplication::UnregisterOnWindowActionNotification(FDelegateHandle Handle)
{
	for (int32 Index = 0; Index < OnWindowActionNotifications.Num();)
	{
		if (OnWindowActionNotifications[Index].GetHandle() == Handle)
		{
			OnWindowActionNotifications.RemoveAtSwap(Index);
		}
		else
		{
			Index++;
		}
	}
}

TSharedPtr<SWindow> FSlateApplication::FindBestParentWindowForDialogs(const TSharedPtr<SWidget>& InWidget)
{
	TSharedPtr<SWindow> ParentWindow = ( InWidget.IsValid() ) ? FindWidgetWindow(InWidget.ToSharedRef()) : TSharedPtr<SWindow>();

	if ( !ParentWindow.IsValid() )
	{
		// First check the active top level window.
		TSharedPtr<SWindow> ActiveTopWindow = GetActiveTopLevelWindow();
		if ( ActiveTopWindow.IsValid() && ActiveTopWindow->IsRegularWindow() )
		{
			ParentWindow = ActiveTopWindow;
		}
		else
		{
			// If the active top level window isn't a good host, lets just try and find the first
			// reasonable window we can host new dialogs off of.
			for ( TSharedPtr<SWindow> SlateWindow : SlateWindows )
			{
				if ( SlateWindow->IsVisible() && SlateWindow->IsRegularWindow() )
				{
					ParentWindow = SlateWindow;
					break;
				}
			}
		}
	}

	return ParentWindow;
}

const void* FSlateApplication::FindBestParentWindowHandleForDialogs(const TSharedPtr<SWidget>& InWidget)
{
	TSharedPtr<SWindow> ParentWindow = FindBestParentWindowForDialogs(InWidget);

	const void* ParentWindowWindowHandle = nullptr;
	if ( ParentWindow.IsValid() && ParentWindow->GetNativeWindow().IsValid() )
	{
		ParentWindowWindowHandle = ParentWindow->GetNativeWindow()->GetOSWindowHandle();
	}

	return ParentWindowWindowHandle;
}

TSharedPtr<SWindow> FSlateApplication::GetActiveTopLevelWindow() const
{
	return ActiveTopLevelWindow.Pin();
}

TSharedPtr<SWindow> FSlateApplication::GetActiveModalWindow() const
{
	return (ActiveModalWindows.Num() > 0) ? ActiveModalWindows.Last() : nullptr;
}

bool FSlateApplication::SetKeyboardFocus(const FWidgetPath& InFocusPath, const EFocusCause InCause /*= EFocusCause::SetDirectly*/)
{
	return SetUserFocus(GetUserIndexForKeyboard(), InFocusPath, InCause);
}

bool FSlateApplication::SetUserFocus(const uint32 InUserIndex, const FWidgetPath& InFocusPath, const EFocusCause InCause)
{
	return SetUserFocus(GetOrCreateUser(InUserIndex), InFocusPath, InCause);
}

bool FSlateApplication::SetUserFocus(FSlateUser* User, const FWidgetPath& InFocusPath, const EFocusCause InCause)
{
	if ( !User )
	{
		return false;
	}

	FUserFocusEntry& UserFocusEntry = User->Focus;

	TSharedPtr<IWidgetReflector> WidgetReflector = WidgetReflectorPtr.Pin();
	const bool bReflectorShowingFocus = WidgetReflector.IsValid() && WidgetReflector->IsShowingFocus();

	// Get the old Widget information
	const FWeakWidgetPath OldFocusedWidgetPath = UserFocusEntry.WidgetPath;
	TSharedPtr<SWidget> OldFocusedWidget = OldFocusedWidgetPath.IsValid() ? OldFocusedWidgetPath.GetLastWidget().Pin() : TSharedPtr< SWidget >();

	// Get the new widget information by finding the first widget in the path that supports focus
	FWidgetPath NewFocusedWidgetPath;
	TSharedPtr<SWidget> NewFocusedWidget;

	if (InFocusPath.IsValid())
	{
		//UE_LOG(LogSlate, Warning, TEXT("Focus for user %i seeking focus path:\n%s"), InUserIndex, *InFocusPath.ToString());

		for (int32 WidgetIndex = InFocusPath.Widgets.Num() - 1; WidgetIndex >= 0; --WidgetIndex)
		{
			const FArrangedWidget& WidgetToFocus = InFocusPath.Widgets[WidgetIndex];

			// Does this widget support keyboard focus?  If so, then we'll go ahead and set it!
			if (WidgetToFocus.Widget->SupportsKeyboardFocus())
			{
				// Is we aren't changing focus then simply return
				if (WidgetToFocus.Widget == OldFocusedWidget)
				{
					//UE_LOG(LogSlate, Warning, TEXT("--Focus Has Not Changed--"));
					return false;
				}
				NewFocusedWidget = WidgetToFocus.Widget;
				NewFocusedWidgetPath = InFocusPath.GetPathDownTo(NewFocusedWidget.ToSharedRef());
				break;
			}
		}
	}

	// Notify widgets in the old focus path that focus is changing
	if (OldFocusedWidgetPath.IsValid())
	{
		FScopedSwitchWorldHack SwitchWorld(OldFocusedWidgetPath.Window.Pin());

		for (int32 ChildIndex = 0; ChildIndex < OldFocusedWidgetPath.Widgets.Num(); ++ChildIndex)
		{
			TSharedPtr<SWidget> SomeWidget = OldFocusedWidgetPath.Widgets[ChildIndex].Pin();
			if (SomeWidget.IsValid())
			{
				SomeWidget->OnFocusChanging(OldFocusedWidgetPath, NewFocusedWidgetPath, FFocusEvent(InCause, User->GetUserIndex()));
			}
		}
	}

	// Notify widgets in the new focus path that focus is changing
	if (NewFocusedWidgetPath.IsValid())
	{
		FScopedSwitchWorldHack SwitchWorld(NewFocusedWidgetPath.GetWindow());

		for (int32 ChildIndex = 0; ChildIndex < NewFocusedWidgetPath.Widgets.Num(); ++ChildIndex)
		{
			TSharedPtr<SWidget> SomeWidget = NewFocusedWidgetPath.Widgets[ChildIndex].Widget;
			if (SomeWidget.IsValid())
			{
				SomeWidget->OnFocusChanging(OldFocusedWidgetPath, NewFocusedWidgetPath, FFocusEvent(InCause, User->GetUserIndex()));
			}
		}
	}

	//UE_LOG(LogSlate, Warning, TEXT("Focus for user %i set to %s."), User->GetUserIndex(), NewFocusedWidget.IsValid() ? *NewFocusedWidget->ToString() : TEXT("Invalid"));

	// Store a weak widget path to the widget that's taking focus
	UserFocusEntry.WidgetPath = FWeakWidgetPath(NewFocusedWidgetPath);

	// Store the cause of the focus
	UserFocusEntry.FocusCause = InCause;

	// Figure out if we should show focus for this focus entry
	UserFocusEntry.ShowFocus = false;
	if (NewFocusedWidgetPath.IsValid())
	{
		UserFocusEntry.ShowFocus = InCause == EFocusCause::Navigation;
		for (int32 WidgetIndex = NewFocusedWidgetPath.Widgets.Num() - 1; WidgetIndex >= 0; --WidgetIndex)
		{
			TOptional<bool> ShowFocus = NewFocusedWidgetPath.Widgets[WidgetIndex].Widget->OnQueryShowFocus(InCause);
			if (ShowFocus.IsSet())
			{
				UserFocusEntry.ShowFocus = ShowFocus.GetValue();
				break;
			}
		}
	}

	// Let the old widget know that it lost keyboard focus
	if(OldFocusedWidget.IsValid())
	{
		// Switch worlds for widgets in the old path
		FScopedSwitchWorldHack SwitchWorld(OldFocusedWidgetPath.Window.Pin());

		// Let previously-focused widget know that it's losing focus
		OldFocusedWidget->OnFocusLost(FFocusEvent(InCause, User->GetUserIndex()));
	}

	if (bReflectorShowingFocus)
	{
		WidgetReflector->SetWidgetsToVisualize(NewFocusedWidgetPath);
	}

	// Let the new widget know that it's received keyboard focus
	if (NewFocusedWidget.IsValid())
	{
		TSharedPtr<SWindow> FocusedWindow = NewFocusedWidgetPath.GetWindow();

		// Switch worlds for widgets in the new path
		FScopedSwitchWorldHack SwitchWorld(FocusedWindow);

		// Set ActiveTopLevelWindow to the newly focused window
		ActiveTopLevelWindow = FocusedWindow;
		
		const FArrangedWidget& WidgetToFocus = NewFocusedWidgetPath.Widgets.Last();

		FReply Reply = NewFocusedWidget->OnFocusReceived(WidgetToFocus.Geometry, FFocusEvent(InCause, User->GetUserIndex()));
		if (Reply.IsEventHandled())
		{
			ProcessReply(InFocusPath, Reply, nullptr, nullptr, User->GetUserIndex());
		}
	}

	return true;
}


void FSlateApplication::SetAllUserFocus(const FWidgetPath& InFocusPath, const EFocusCause InCause)
{
	ForEachUser([&] (FSlateUser* User) {
		SetUserFocus(User, InFocusPath, InCause);
	});
}

void FSlateApplication::SetAllUserFocusAllowingDescendantFocus(const FWidgetPath& InFocusPath, const EFocusCause InCause)
{
	TSharedRef<SWidget> FocusWidget = InFocusPath.Widgets.Last().Widget;

	ForEachUser([&] (FSlateUser* User) {
		const FUserFocusEntry& UserFocusEntry = User->Focus;
		if (!UserFocusEntry.WidgetPath.ContainsWidget(FocusWidget))
		{
			SetUserFocus(User, InFocusPath, InCause);
		}
	});
}

FModifierKeysState FSlateApplication::GetModifierKeys() const
{
	return PlatformApplication->GetModifierKeys();
}


void FSlateApplication::OnShutdown()
{
	CloseAllWindowsImmediately();
}

void FSlateApplication::CloseAllWindowsImmediately()
{
	// Clean up our tooltip window
	TSharedPtr< SWindow > PinnedToolTipWindow(ToolTipWindow.Pin());
	if (PinnedToolTipWindow.IsValid())
	{
		PinnedToolTipWindow->RequestDestroyWindow();
		ToolTipWindow.Reset();
	}

	for (int32 WindowIndex = 0; WindowIndex < SlateWindows.Num(); ++WindowIndex)
	{
		// Destroy all top level windows.  This will also request that all children of each window be destroyed
		RequestDestroyWindow(SlateWindows[WindowIndex]);
	}

	DestroyWindowsImmediately();
}

void FSlateApplication::DestroyWindowsImmediately()
{
	// Destroy any windows that were queued for deletion.

	// Thomas.Sarkanen: I've changed this from a for() to a while() loop so that it is now valid to call RequestDestroyWindow()
	// in the callstack of another call to RequestDestroyWindow(). Previously this would cause a stack overflow, as the
	// WindowDestroyQueue would be continually added to each time the for() loop ran.
	while ( WindowDestroyQueue.Num() > 0 )
	{
		TSharedRef<SWindow> CurrentWindow = WindowDestroyQueue[0];
		WindowDestroyQueue.Remove(CurrentWindow);
		if( ActiveModalWindows.Num() > 0 && ActiveModalWindows.Contains( CurrentWindow ) )
		{
			ActiveModalWindows.Remove( CurrentWindow );

			if( ActiveModalWindows.Num() > 0 )
			{
				// There are still modal windows so only enable the new active modal window.
				GetActiveModalWindow()->EnableWindow( true );
			}
			else
			{
				//  There are no modal windows so renable all slate windows
				for ( TArray< TSharedRef<SWindow> >::TConstIterator SlateWindowIter( SlateWindows ); SlateWindowIter; ++SlateWindowIter )
				{
					// All other windows need to be re-enabled BEFORE a modal window is destroyed or focus will not be set correctly
					(*SlateWindowIter)->EnableWindow( true );
				}

				// Signal that all slate modal windows are closed
				ModalWindowStackEndedDelegate.ExecuteIfBound();
			}
		}

		// Any window being destroyed should be removed from the menu stack if its in it
		MenuStack.OnWindowDestroyed(CurrentWindow);

		// Perform actual cleanup of the window
		PrivateDestroyWindow( CurrentWindow );
	}

	WindowDestroyQueue.Empty();
}


void FSlateApplication::SetExitRequestedHandler( const FSimpleDelegate& OnExitRequestedHandler )
{
	OnExitRequested = OnExitRequestedHandler;
}


bool FSlateApplication::GeneratePathToWidgetUnchecked( TSharedRef< const SWidget > InWidget, FWidgetPath& OutWidgetPath, EVisibility VisibilityFilter ) const
{
	if ( !FSlateWindowHelper::FindPathToWidget(SlateWindows, InWidget, OutWidgetPath, VisibilityFilter) )
	{
		return FSlateWindowHelper::FindPathToWidget(SlateVirtualWindows, InWidget, OutWidgetPath, VisibilityFilter);
	}

	return true;
}


void FSlateApplication::GeneratePathToWidgetChecked( TSharedRef< const SWidget > InWidget, FWidgetPath& OutWidgetPath, EVisibility VisibilityFilter ) const
{
	if ( !FSlateWindowHelper::FindPathToWidget(SlateWindows, InWidget, OutWidgetPath, VisibilityFilter) )
	{
		const bool bWasFound = FSlateWindowHelper::FindPathToWidget(SlateVirtualWindows, InWidget, OutWidgetPath, VisibilityFilter);
		check(bWasFound);
	}
}


TSharedPtr<SWindow> FSlateApplication::FindWidgetWindow( TSharedRef< const SWidget > InWidget ) const
{
	FWidgetPath WidgetPath;
	return FindWidgetWindow( InWidget, WidgetPath );
}


TSharedPtr<SWindow> FSlateApplication::FindWidgetWindow( TSharedRef< const SWidget > InWidget, FWidgetPath& OutWidgetPath ) const
{
	// If the user wants a widget path back populate it instead
	if ( !FSlateWindowHelper::FindPathToWidget(SlateWindows, InWidget, OutWidgetPath, EVisibility::All) )
	{
		if ( !FSlateWindowHelper::FindPathToWidget(SlateVirtualWindows, InWidget, OutWidgetPath, EVisibility::All) )
		{
			return nullptr;
		}
	}

	return OutWidgetPath.TopLevelWindow;
}


void FSlateApplication::ProcessReply( const FWidgetPath& CurrentEventPath, const FReply TheReply, const FWidgetPath* WidgetsUnderMouse, const FPointerEvent* InMouseEvent, const uint32 UserIndex )
{
	const TSharedPtr<FDragDropOperation> ReplyDragDropContent = TheReply.GetDragDropContent();
	const bool bStartingDragDrop = ReplyDragDropContent.IsValid();
	const bool bIsVirtualInteraction = CurrentEventPath.IsValid() ? CurrentEventPath.GetWindow()->IsVirtualWindow() : false;

	// Release mouse capture if requested or if we are starting a drag and drop.
	// Make sure to only clobber WidgetsUnderCursor if we actually had a mouse capture.
	uint32 PointerIndex = InMouseEvent != nullptr ? InMouseEvent->GetPointerIndex() : CursorPointerIndex;

	if (MouseCaptor.HasCaptureForPointerIndex(UserIndex,PointerIndex) && (TheReply.ShouldReleaseMouse() || bStartingDragDrop) )
	{
		WidgetsUnderCursorLastEvent.Add( FUserAndPointer(UserIndex,PointerIndex), MouseCaptor.ToWeakPath(UserIndex,PointerIndex) );
		MouseCaptor.InvalidateCaptureForPointer(UserIndex,PointerIndex);

		// If mouse capture changes, we should refresh the cursor state.
		bQueryCursorRequested = true;
	}

	// Clear focus is requested.
	if (TheReply.ShouldReleaseUserFocus())
	{
		if (TheReply.AffectsAllUsers())
		{
			ForEachUser([&] (FSlateUser* User) {
				SetUserFocus(User, FWidgetPath(), TheReply.GetFocusCause());
			});
		}
		else
		{
			SetUserFocus(UserIndex, FWidgetPath(), TheReply.GetFocusCause());
		}
	}

	if (TheReply.ShouldEndDragDrop())
	{
		CancelDragDrop();
	}

	if ( bStartingDragDrop )
	{
		checkf( !this->DragDropContent.IsValid(), TEXT("Drag and Drop already in progress!") );
		check( true == TheReply.IsEventHandled() );
		check( WidgetsUnderMouse != nullptr );
		check( InMouseEvent != nullptr );
		DragDropContent = ReplyDragDropContent;

		// We have entered drag and drop mode.
		// Pretend that the mouse left all the previously hovered widgets, and a drag entered them.
		FEventRouter::Route<FNoReply>(this, FEventRouter::FBubblePolicy(*WidgetsUnderMouse), *InMouseEvent, [](const FArrangedWidget& SomeWidget, const FPointerEvent& PointerEvent)
		{
			SomeWidget.Widget->OnMouseLeave( PointerEvent );
			return FNoReply();
		});

		FEventRouter::Route<FNoReply>(this, FEventRouter::FBubblePolicy(*WidgetsUnderMouse), FDragDropEvent( *InMouseEvent, ReplyDragDropContent ), [](const FArrangedWidget& SomeWidget, const FDragDropEvent& DragDropEvent )
		{
			SomeWidget.Widget->OnDragEnter( SomeWidget.Geometry, DragDropEvent );
			return FNoReply();
		});
	}
	
	// Setting mouse capture, mouse position, and locking the mouse
	// are all operations that we shouldn't do if our application isn't Active (The OS ignores half of it, and we'd be in a half state)
	// We do allow the release of capture and lock when deactivated, this is innocuous of some platforms but required on others when 
	// the Application deactivated before the window. (Mac is an example of this)
	if (bAppIsActive || bIsVirtualInteraction)
	{
		TSharedPtr<SWidget> RequestedMouseCaptor = TheReply.GetMouseCaptor();

		// Do not capture the mouse if we are also starting a drag and drop.
		if (RequestedMouseCaptor.IsValid() && !bStartingDragDrop)
		{
			MouseCaptor.SetMouseCaptor(UserIndex, PointerIndex, CurrentEventPath, RequestedMouseCaptor);

			// When the cursor capture state changes we need to refresh cursor state.
			bQueryCursorRequested = true;
		}

		if ( !bIsVirtualInteraction && CurrentEventPath.IsValid() && RequestedMouseCaptor.IsValid())
		{
			// If the mouse is being captured or released, toggle high precision raw input if requested by the reply.
			// Raw input is only used with mouse capture
			if (TheReply.ShouldUseHighPrecisionMouse())
			{
				const TSharedRef< SWindow> Window = CurrentEventPath.GetWindow();
				PlatformApplication->SetCapture(Window->GetNativeWindow());
				PlatformApplication->SetHighPrecisionMouseMode(true, Window->GetNativeWindow());

				// When the cursor capture state changes we need to refresh cursor state.
				bQueryCursorRequested = true;
			}
		}

		TOptional<FIntPoint> RequestedMousePos = TheReply.GetRequestedMousePos();
		if (RequestedMousePos.IsSet())
		{
			const FVector2D Position = RequestedMousePos.GetValue();
			PointerIndexLastPositionMap.Add(CursorPointerIndex, Position);
			SetCursorPos(Position);
		}

		if (TheReply.GetMouseLockWidget().IsValid())
		{
			// The reply requested mouse lock so tell the native application to lock the mouse to the widget receiving the event
			LockCursor(TheReply.GetMouseLockWidget());
		}
	}

	// Releasing high precision mode.  @HACKISH We can only support high precision mode on true mouse hardware cursors
	// but if the user index isn't 0, there's no way it's the real mouse so we should ignore this if it's not user 0,
	// because that means it's a virtual controller.
	if ( UserIndex == 0 && !bIsVirtualInteraction )
	{
		if ( CurrentEventPath.IsValid() && TheReply.ShouldReleaseMouse() && !TheReply.ShouldUseHighPrecisionMouse() )
		{
			if ( PlatformApplication->IsUsingHighPrecisionMouseMode() )
			{
				PlatformApplication->SetHighPrecisionMouseMode(false, nullptr);
				PlatformApplication->SetCapture(nullptr);

				// When the cursor capture state changes we need to refresh cursor state.
				bQueryCursorRequested = true;
			}
		}
	}

	// Releasing Mouse Lock
	if (TheReply.ShouldReleaseMouseLock())
	{
		LockCursor(nullptr);
	}
	
	// If we have a valid Navigation request attempt the navigation.
	if (TheReply.GetNavigationDestination().IsValid() || TheReply.GetNavigationType() != EUINavigation::Invalid)
	{
		FWidgetPath NavigationSource;
		if (TheReply.GetNavigationSource() == ENavigationSource::WidgetUnderCursor)
		{
			NavigationSource = *WidgetsUnderMouse;
		}
		else if(const FSlateUser* User = GetOrCreateUser(UserIndex))
		{
			const FUserFocusEntry& UserFocusEntry = User->Focus;
			NavigationSource = UserFocusEntry.WidgetPath.ToWidgetPath();
		}

		if (NavigationSource.IsValid())
		{
			if (TheReply.GetNavigationDestination().IsValid())
			{
				ExecuteNavigation(NavigationSource, TheReply.GetNavigationDestination(), UserIndex);
			}
			else
			{
				FNavigationEvent NavigationEvent(PlatformApplication->GetModifierKeys(), UserIndex, TheReply.GetNavigationType(), TheReply.GetNavigationGenesis());

				FNavigationReply NavigationReply = FNavigationReply::Escape();
				for (int32 WidgetIndex = NavigationSource.Widgets.Num() - 1; WidgetIndex >= 0; --WidgetIndex)
				{
					FArrangedWidget& SomeWidgetGettingEvent = NavigationSource.Widgets[WidgetIndex];
					if (SomeWidgetGettingEvent.Widget->IsEnabled())
					{
						NavigationReply = SomeWidgetGettingEvent.Widget->OnNavigation(SomeWidgetGettingEvent.Geometry, NavigationEvent).SetHandler(SomeWidgetGettingEvent.Widget);
						if (NavigationReply.GetBoundaryRule() != EUINavigationRule::Escape || WidgetIndex == 0)
						{
							AttemptNavigation(NavigationSource, NavigationEvent, NavigationReply, SomeWidgetGettingEvent);
							break;
						}
					}
				}
			}
		}
	}

	if ( TheReply.GetDetectDragRequest().IsValid() )
	{
		checkSlow(InMouseEvent);

		DragDetector.StartDragDetection(
			WidgetsUnderMouse->GetPathDownTo(TheReply.GetDetectDragRequest().ToSharedRef()),
			InMouseEvent->GetUserIndex(),
			InMouseEvent->GetPointerIndex(),
			TheReply.GetDetectDragRequestButton(),
			InMouseEvent->GetScreenSpacePosition());
	}

	// Set focus if requested.
	TSharedPtr<SWidget> RequestedFocusRecepient = TheReply.GetUserFocusRecepient();
	if (TheReply.ShouldSetUserFocus() || RequestedFocusRecepient.IsValid())
	{
		if (TheReply.AffectsAllUsers())
		{
			ForEachUser([&] (FSlateUser* User) {
				SetUserFocus(User->GetUserIndex(), RequestedFocusRecepient, TheReply.GetFocusCause());
			});
		}
		else
		{
			SetUserFocus(UserIndex, RequestedFocusRecepient, TheReply.GetFocusCause());
		}
	}
}

void FSlateApplication::LockCursor(const TSharedPtr<SWidget>& Widget)
{
	if (PlatformApplication->Cursor.IsValid())
	{
		if (Widget.IsValid())
		{
			// Get a path to this widget so we know the position and size of its geometry
			FWidgetPath WidgetPath;
			const bool bFoundWidget = GeneratePathToWidgetUnchecked(Widget.ToSharedRef(), WidgetPath);
			if ( ensureMsgf(bFoundWidget, TEXT("Attempting to LockCursor() to widget but could not find widget %s"), *Widget->ToString()) )
			{
				LockCursorToPath(WidgetPath);
			}
		}
		else
		{
			UnlockCursor();
		}
	}
}

void FSlateApplication::LockCursorToPath(const FWidgetPath& WidgetPath)
{
	// The last widget in the path should be the widget we are locking the cursor to
	const FArrangedWidget& WidgetGeom = WidgetPath.Widgets[WidgetPath.Widgets.Num() - 1];

	TSharedRef<SWindow> Window = WidgetPath.GetWindow();
	// Do not attempt to lock the cursor to the window if its not in the foreground.  It would cause annoying side effects
	if (Window->GetNativeWindow()->IsForegroundWindow())
	{
		const FSlateRect SlateClipRect = WidgetGeom.Geometry.GetClippingRect();
		CursorLock.LastComputedBounds = SlateClipRect;
		CursorLock.PathToLockingWidget = WidgetPath;
			
		// Generate a screen space clip rect based on the widgets geometry

		// Note: We round the upper left coordinate of the clip rect so we guarantee the rect is inside the geometry of the widget.  If we truncated when there is a half pixel we would cause the clip
		// rect to be half a pixel larger than the geometry and cause the mouse to go outside of the geometry.
		RECT ClipRect;
		ClipRect.left = FMath::RoundToInt(SlateClipRect.Left);
		ClipRect.top = FMath::RoundToInt(SlateClipRect.Top);
		ClipRect.right = FMath::TruncToInt(SlateClipRect.Right);
		ClipRect.bottom = FMath::TruncToInt(SlateClipRect.Bottom);

		// Lock the mouse to the widget
		PlatformApplication->Cursor->Lock(&ClipRect);
	}
}

void FSlateApplication::UnlockCursor()
{
	// Unlock the mouse
	PlatformApplication->Cursor->Lock(nullptr);
	CursorLock.PathToLockingWidget = FWeakWidgetPath();
}

void FSlateApplication::UpdateCursorLockRegion()
{
	const FWidgetPath PathToWidget = CursorLock.PathToLockingWidget.ToWidgetPath(FWeakWidgetPath::EInterruptedPathHandling::ReturnInvalid);
	if (PathToWidget.IsValid())
	{
		const FSlateRect ComputedClipRect = PathToWidget.Widgets.Last().Geometry.GetClippingRect();
		if (ComputedClipRect != CursorLock.LastComputedBounds)
		{
			LockCursorToPath(PathToWidget);
		}
	}
}

void FSlateApplication::SetLastUserInteractionTime(double InCurrentTime)
{
	if (LastUserInteractionTime != InCurrentTime)
	{
		LastUserInteractionTime = InCurrentTime;
		LastUserInteractionTimeUpdateEvent.Broadcast(LastUserInteractionTime);
	}
}

void FSlateApplication::QueryCursor()
{
	bQueryCursorRequested = false;

	// The slate loading widget thread is not allowed to execute this code 
	// as it is unsafe to read the hittest grid in another thread
	if ( PlatformApplication->Cursor.IsValid() && IsInGameThread() )
	{
		// drag-drop overrides cursor
		FCursorReply CursorReply = FCursorReply::Unhandled();
		if ( IsDragDropping() )
		{
			CursorReply = DragDropContent->OnCursorQuery();
		}
		
		if (!CursorReply.IsEventHandled())
		{
			FWidgetPath WidgetsToQueryForCursor;
			const TSharedPtr<SWindow> ActiveModalWindow = GetActiveModalWindow();

			const FVector2D CurrentCursorPosition = GetCursorPos();
			const FVector2D LastCursorPosition = GetLastCursorPos();
			const FPointerEvent CursorEvent(
				CursorPointerIndex,
				CurrentCursorPosition,
				LastCursorPosition,
				CurrentCursorPosition - LastCursorPosition,
				PressedMouseButtons,
				PlatformApplication->GetModifierKeys()
				);

			// Query widgets with mouse capture for the cursor
			if (MouseCaptor.HasCaptureForPointerIndex(CursorUserIndex, CursorPointerIndex))
			{
				FWidgetPath MouseCaptorPath = MouseCaptor.ToWidgetPath( FWeakWidgetPath::EInterruptedPathHandling::Truncate, &CursorEvent);
				if ( MouseCaptorPath.IsValid() )
				{
					TSharedRef< SWindow > CaptureWindow = MouseCaptorPath.GetWindow();

					// Never query the mouse captor path if it is outside an active modal window
					if ( !ActiveModalWindow.IsValid() || ( CaptureWindow == ActiveModalWindow || CaptureWindow->IsDescendantOf(ActiveModalWindow) ) )
					{
						WidgetsToQueryForCursor = MouseCaptorPath;
					}
				}
			}
			else
			{
				WidgetsToQueryForCursor = LocateWindowUnderMouse( GetCursorPos(), GetInteractiveTopLevelWindows() );
			}

			if (WidgetsToQueryForCursor.IsValid())
			{
				// Switch worlds for widgets in the current path
				FScopedSwitchWorldHack SwitchWorld( WidgetsToQueryForCursor );

				for (int32 WidgetIndex = WidgetsToQueryForCursor.Widgets.Num() - 1; WidgetIndex >= 0; --WidgetIndex)
				{
					const FArrangedWidget& ArrangedWidget = WidgetsToQueryForCursor.Widgets[WidgetIndex];

					CursorReply = ArrangedWidget.Widget->OnCursorQuery(ArrangedWidget.Geometry, CursorEvent);
					if (CursorReply.IsEventHandled())
					{
						if (!CursorReply.GetCursorWidget().IsValid())
						{
							for (; WidgetIndex >= 0; --WidgetIndex)
							{
								TOptional<TSharedRef<SWidget>> CursorWidget = WidgetsToQueryForCursor.Widgets[WidgetIndex].Widget->OnMapCursor(CursorReply);
								if (CursorWidget.IsSet())
								{
									CursorReply.SetCursorWidget(WidgetsToQueryForCursor.GetWindow(), CursorWidget.GetValue());
									break;
								}
							}
						}
						break;
					}
				}

				if (!CursorReply.IsEventHandled() && WidgetsToQueryForCursor.IsValid())
				{
					// Query was NOT handled, and we are still over a slate window.
					CursorReply = FCursorReply::Cursor(EMouseCursor::Default);
				}
			}
			else
			{
				// Set the default cursor when there isn't an active window under the cursor and the mouse isn't captured
				CursorReply = FCursorReply::Cursor(EMouseCursor::Default);
			}
		}
		ProcessCursorReply(CursorReply);
	}
}

void FSlateApplication::ProcessCursorReply(const FCursorReply& CursorReply)
{
	if (CursorReply.IsEventHandled())
	{
		CursorWidgetPtr = CursorReply.GetCursorWidget();
		if (CursorReply.GetCursorWidget().IsValid())
		{
			CursorReply.GetCursorWidget()->SetVisibility(EVisibility::HitTestInvisible);
			CursorWindowPtr = CursorReply.GetCursorWindow();
			PlatformApplication->Cursor->SetType(EMouseCursor::Custom);
		}
		else
		{
			CursorWindowPtr.Reset();
			PlatformApplication->Cursor->SetType(CursorReply.GetCursorType());
		}
	}
	else
	{
		CursorWindowPtr.Reset();
		CursorWidgetPtr.Reset();
	}
}

void FSlateApplication::SpawnToolTip( const TSharedRef<IToolTip>& InToolTip, const FVector2D& InSpawnLocation )
{
	// Close existing tool tip, if we have one
	CloseToolTip();

	// Spawn the new tool tip
	{
		TSharedPtr< SWindow > NewToolTipWindow( ToolTipWindow.Pin() );
		if( !NewToolTipWindow.IsValid() )
		{
			// Create the tool tip window
			NewToolTipWindow = SWindow::MakeToolTipWindow();

			// Don't show the window yet.  We'll set it up with some content first!
			const bool bShowImmediately = false;
			AddWindow( NewToolTipWindow.ToSharedRef(), bShowImmediately );
		}

		NewToolTipWindow->SetContent
		(
			SNew(SWeakWidget)
			.PossiblyNullContent(InToolTip->AsWidget())
		);

		// Move the window again to recalculate popup window position if necessary (tool tip may spawn outside of the monitors work area)
		// and in that case we need to adjust it
		DesiredToolTipLocation = InSpawnLocation;
		{
			// Make sure the desired size is valid
			NewToolTipWindow->SlatePrepass(FSlateApplication::Get().GetApplicationScale()*NewToolTipWindow->GetNativeWindow()->GetDPIScaleFactor());

			FSlateRect Anchor(DesiredToolTipLocation.X, DesiredToolTipLocation.Y, DesiredToolTipLocation.X, DesiredToolTipLocation.Y);
			DesiredToolTipLocation = CalculatePopupWindowPosition( Anchor, NewToolTipWindow->GetDesiredSizeDesktopPixels() );

			// MoveWindowTo will adjust the window's position, if needed
			NewToolTipWindow->MoveWindowTo( DesiredToolTipLocation );
		}

		NewToolTipWindow->SetOpacity(0.0f);

		// Show the window
		NewToolTipWindow->ShowWindow();

		// Keep a weak reference to the tool tip window
		ToolTipWindow = NewToolTipWindow;

		// Keep track of when this tool tip was spawned
		ToolTipSummonTime = FPlatformTime::Seconds();
	}
}

void FSlateApplication::CloseToolTip()
{
	// Notify the source widget that its tooltip is closing
	{
		TSharedPtr<SWidget> SourceWidget = ActiveToolTipWidgetSource.Pin();
		if (SourceWidget.IsValid())
		{
			SourceWidget->OnToolTipClosing();
		}
	}

	// Notify the active tooltip that it's being closed.
	TSharedPtr<IToolTip> StableActiveToolTip = ActiveToolTip.Pin();
	if ( StableActiveToolTip.IsValid() )
	{
		StableActiveToolTip->OnClosed();
	}

	// If the tooltip had a new window holding it, hide the window.
	TSharedPtr< SWindow > PinnedToolTipWindow( ToolTipWindow.Pin() );
	if( PinnedToolTipWindow.IsValid() && PinnedToolTipWindow->IsVisible() )
	{
		// Hide the tool tip window.  We don't destroy the window, because we want to reuse it for future tool tips.
		PinnedToolTipWindow->HideWindow();
	}

	ActiveToolTip.Reset();
	ActiveToolTipWidgetSource.Reset();

	ToolTipOffsetDirection = EToolTipOffsetDirection::Undetermined;
}

void FSlateApplication::UpdateToolTip( bool AllowSpawningOfNewToolTips )
{
	const bool bCheckForToolTipChanges =
		IsInGameThread() &&					// We should never allow the slate loading thread to create new windows or interact with the hittest grid
		bAllowToolTips &&					// Tool-tips must be enabled
		!IsUsingHighPrecisionMouseMovment() && // If we are using HighPrecision movement then we can't rely on the OS cursor to be accurate
		!IsDragDropping();					// We must not currwently be in the middle of a drag-drop action
	
	// We still want to show tooltips for widgets that are disabled
	const bool bIgnoreEnabledStatus = true;

	float DPIScaleFactor = 1.0f;
	
	FWidgetPath WidgetsToQueryForToolTip;
	// We don't show any tooltips when drag and dropping or when another app is active
	if (bCheckForToolTipChanges)
	{
		// Ask each widget under the Mouse if they have a tool tip to show.
		FWidgetPath WidgetsUnderMouse = LocateWindowUnderMouse( GetCursorPos(), GetInteractiveTopLevelWindows(), bIgnoreEnabledStatus );
		// Don't attempt to show tooltips inside an existing tooltip
		if (!WidgetsUnderMouse.IsValid() || WidgetsUnderMouse.GetWindow() != ToolTipWindow.Pin())
		{
			WidgetsToQueryForToolTip = WidgetsUnderMouse;
			if (false)// @na (WidgetsUnderMouse.IsValid())
			{
				DPIScaleFactor = WidgetsUnderMouse.GetWindow()->GetNativeWindow()->GetDPIScaleFactor();
			}
		}
	}

	bool bHaveForceFieldRect = false;
	FSlateRect ForceFieldRect;

	TSharedPtr<IToolTip> NewToolTip;
	TSharedPtr<SWidget> WidgetProvidingNewToolTip;
	for ( int32 WidgetIndex=WidgetsToQueryForToolTip.Widgets.Num()-1; WidgetIndex >= 0; --WidgetIndex )
	{
		FArrangedWidget* CurWidgetGeometry = &WidgetsToQueryForToolTip.Widgets[WidgetIndex];
		const TSharedRef<SWidget>& CurWidget = CurWidgetGeometry->Widget;

		if( !NewToolTip.IsValid() )
		{
			TSharedPtr< IToolTip > WidgetToolTip = CurWidget->GetToolTip();

			// Make sure the tool-tip currently is displaying something before spawning it.
			if( WidgetToolTip.IsValid() && !WidgetToolTip->IsEmpty() )
			{
				WidgetProvidingNewToolTip = CurWidget;
				NewToolTip = WidgetToolTip;
			}
		}

		// Keep track of the root most widget with a tool-tip force field enabled
		if( CurWidget->HasToolTipForceField() )
		{
			if( !bHaveForceFieldRect )
			{
				bHaveForceFieldRect = true;
				ForceFieldRect = CurWidgetGeometry->Geometry.GetClippingRect();				
			}
			else
			{
				// Grow the rect to encompass this geometry.  Usually, the parent's rect should always be inclusive
				// of it's child though.  Just is kind of just being paranoid.
				ForceFieldRect = ForceFieldRect.Expand( CurWidgetGeometry->Geometry.GetClippingRect() );
			}
			ForceFieldRect = (1.0f / DPIScaleFactor) * ForceFieldRect;
		}
	}

	// Did the tool tip change from last time?
	const bool bToolTipChanged = (NewToolTip != ActiveToolTip.Pin());
	
	// Any widgets that wish to handle visualizing the tooltip get a chance here.
	TSharedPtr<SWidget> NewTooltipVisualizer;
	if (bToolTipChanged)
	{
		// Remove existing tooltip if there is one.
		if (TooltipVisualizerPtr.IsValid())
		{
			TooltipVisualizerPtr.Pin()->OnVisualizeTooltip( nullptr );
		}

		// Notify the new tooltip that it's about to be opened.
		if ( NewToolTip.IsValid() )
		{
			NewToolTip->OnOpening();
		}

		TSharedPtr<SWidget> NewToolTipWidget = NewToolTip.IsValid() ? NewToolTip->AsWidget() : TSharedPtr<SWidget>();

		bool bOnVisualizeTooltipHandled = false;
		// Some widgets might want to provide an alternative Tooltip Handler.
		for ( int32 WidgetIndex=WidgetsToQueryForToolTip.Widgets.Num()-1; !bOnVisualizeTooltipHandled && WidgetIndex >= 0; --WidgetIndex )
		{
			const FArrangedWidget& CurWidgetGeometry = WidgetsToQueryForToolTip.Widgets[WidgetIndex];
			bOnVisualizeTooltipHandled = CurWidgetGeometry.Widget->OnVisualizeTooltip( NewToolTipWidget );
			if (bOnVisualizeTooltipHandled)
			{
				// Someone is taking care of visualizing this tooltip
				NewTooltipVisualizer = CurWidgetGeometry.Widget;
			}
		}
	}


	// If a widget under the cursor has a tool-tip forcefield active, then go through any menus
	// in the menu stack that are above that widget's window, and make sure those windows also
	// prevent the tool-tip from encroaching.  This prevents tool-tips from drawing over sub-menus
	// spawned from menu items in a different window, for example.
	if( bHaveForceFieldRect && WidgetsToQueryForToolTip.IsValid() )
	{
		TSharedPtr<IMenu> MenuInPath = MenuStack.FindMenuInWidgetPath(WidgetsToQueryForToolTip);

		if (MenuInPath.IsValid())
		{
			ForceFieldRect = ForceFieldRect.Expand(MenuStack.GetToolTipForceFieldRect(MenuInPath.ToSharedRef(), WidgetsToQueryForToolTip));
		}
	}

	{
		TSharedPtr<IToolTip> ActiveToolTipPtr = ActiveToolTip.Pin();
		if ( ( ActiveToolTipPtr.IsValid() && !ActiveToolTipPtr->IsInteractive() ) || ( NewToolTip.IsValid() && NewToolTip != ActiveToolTip.Pin() ) )
		{
			// Keep track of where we want tool tips to be positioned
			DesiredToolTipLocation = GetLastCursorPos() + SlateDefs::ToolTipOffsetFromMouse;
		}
	}

	TSharedPtr< SWindow > ToolTipWindowPtr = ToolTipWindow.Pin();
	if ( ToolTipWindowPtr.IsValid() )
	{
		FSlateRect Anchor(DesiredToolTipLocation.X, DesiredToolTipLocation.Y, DesiredToolTipLocation.X, DesiredToolTipLocation.Y);
		DesiredToolTipLocation = CalculatePopupWindowPosition( Anchor, ToolTipWindowPtr->GetDesiredSizeDesktopPixels());
	}

	// Repel tool-tip from a force field, if necessary
	if( bHaveForceFieldRect )
	{
		FVector2D ToolTipShift;
		ToolTipShift.X = ( ForceFieldRect.Right + SlateDefs::ToolTipOffsetFromForceField.X ) - DesiredToolTipLocation.X;
		ToolTipShift.Y = ( ForceFieldRect.Bottom + SlateDefs::ToolTipOffsetFromForceField.Y ) - DesiredToolTipLocation.Y;

		// Make sure the tool-tip needs to be offset
		if( ToolTipShift.X > 0.0f && ToolTipShift.Y > 0.0f )
		{
			// Find the best edge to move the tool-tip towards
			if( ToolTipOffsetDirection == EToolTipOffsetDirection::Right ||
				( ToolTipOffsetDirection == EToolTipOffsetDirection::Undetermined && ToolTipShift.X < ToolTipShift.Y ) )
			{
				// Move right
				DesiredToolTipLocation.X += ToolTipShift.X;
				ToolTipOffsetDirection = EToolTipOffsetDirection::Right;
			}
			else
			{
				// Move down
				DesiredToolTipLocation.Y += ToolTipShift.Y;
				ToolTipOffsetDirection = EToolTipOffsetDirection::Down;
			}
		}
	}

	// The tool tip changed...
	if ( bToolTipChanged )
	{
		// Close any existing tooltips; Unless the current tooltip is interactive and we don't have a valid tooltip to replace it
		TSharedPtr<IToolTip> ActiveToolTipPtr = ActiveToolTip.Pin();
		if ( NewToolTip.IsValid() || ( ActiveToolTipPtr.IsValid() && !ActiveToolTipPtr->IsInteractive() ) )
		{
			CloseToolTip();
			
			if (NewTooltipVisualizer.IsValid())
			{
				TooltipVisualizerPtr = NewTooltipVisualizer;
			}
			else if( bAllowToolTips && AllowSpawningOfNewToolTips )
			{
				// Spawn a new one if we have it
				if( NewToolTip.IsValid() )
				{
					SpawnToolTip( NewToolTip.ToSharedRef(), DesiredToolTipLocation );
				}
			}
			else
			{
				NewToolTip = nullptr;
			}

			ActiveToolTip = NewToolTip;
			ActiveToolTipWidgetSource = WidgetProvidingNewToolTip;
		}
	}

	// Do we have a tool tip window?
	if( ToolTipWindow.IsValid() )
	{
		// Only enable tool-tip transitions if we're running at a decent frame rate
		const bool bAllowInstantToolTips = false;
		const bool bAllowAnimations = !bAllowInstantToolTips && FSlateApplication::Get().IsRunningAtTargetFrameRate();

		// How long since the tool tip was summoned?
		const float TimeSinceSummon = FPlatformTime::Seconds() - ToolTipDelay - ToolTipSummonTime;
		const float ToolTipOpacity = bAllowInstantToolTips ? 1.0f : FMath::Clamp< float >( TimeSinceSummon / ToolTipFadeInDuration, 0.0f, 1.0f );

		// Update window opacity
		TSharedRef< SWindow > PinnedToolTipWindow( ToolTipWindow.Pin().ToSharedRef() );
		PinnedToolTipWindow->SetOpacity( ToolTipOpacity );

		// How far tool tips should slide
		const FVector2D SlideDistance( 30.0f, 5.0f );

		// Apply steep inbound curve to the movement, so it looks like it quickly decelerating
		const float SlideProgress = bAllowAnimations ? FMath::Pow( 1.0f - ToolTipOpacity, 3.0f ) : 0.0f;

		FVector2D WindowLocation = DesiredToolTipLocation + SlideProgress * SlideDistance;
		if( WindowLocation != PinnedToolTipWindow->GetPositionInScreen() )
		{
			// Avoid the edges of the desktop
			FSlateRect Anchor(WindowLocation.X, WindowLocation.Y, WindowLocation.X, WindowLocation.Y);
			WindowLocation = CalculatePopupWindowPosition( Anchor, PinnedToolTipWindow->GetDesiredSizeDesktopPixels());

			// Update the tool tip window positioning
			// SetCachedScreenPosition is a hack (issue tracked as TTP #347070) which is needed because code in TickWindowAndChildren()/DrawPrepass()
			// assumes GetPositionInScreen() to correspond to the new window location in the same tick. This is true on Windows, but other
			// OSes (Linux in particular) may not update cached screen position until next time events are polled.
			PinnedToolTipWindow->SetCachedScreenPosition( WindowLocation );
			PinnedToolTipWindow->MoveWindowTo( WindowLocation );
		}
	}
}

TArray< TSharedRef<SWindow> > FSlateApplication::GetInteractiveTopLevelWindows()
{
	if (ActiveModalWindows.Num() > 0)
	{
		// If we have modal windows, only the topmost modal window and its children are interactive.
		TArray< TSharedRef<SWindow>, TInlineAllocator<1> > OutWindows;
		OutWindows.Add( ActiveModalWindows.Last().ToSharedRef() );
		return TArray< TSharedRef<SWindow> >(OutWindows);
	}
	else
	{
		// No modal windows? All windows are interactive.
		return SlateWindows;
	}
}

void FSlateApplication::GetAllVisibleWindowsOrdered(TArray< TSharedRef<SWindow> >& OutWindows)
{
	for( TArray< TSharedRef<SWindow> >::TConstIterator CurrentWindowIt( SlateWindows ); CurrentWindowIt; ++CurrentWindowIt )
	{
		TSharedRef<SWindow> CurrentWindow = *CurrentWindowIt;
		if ( CurrentWindow->IsVisible() && !CurrentWindow->IsWindowMinimized() )
		{
			GetAllVisibleChildWindows(OutWindows, CurrentWindow);
		}
	}
}

void FSlateApplication::GetAllVisibleChildWindows(TArray< TSharedRef<SWindow> >& OutWindows, TSharedRef<SWindow> CurrentWindow)
{
	if ( CurrentWindow->IsVisible() && !CurrentWindow->IsWindowMinimized() )
	{
		OutWindows.Add(CurrentWindow);

		const TArray< TSharedRef<SWindow> >& WindowChildren = CurrentWindow->GetChildWindows();
		for (int32 ChildIndex=0; ChildIndex < WindowChildren.Num(); ++ChildIndex)
		{
			GetAllVisibleChildWindows( OutWindows, WindowChildren[ChildIndex] );
		}
	}
}

bool FSlateApplication::IsDragDropping() const
{
	return DragDropContent.IsValid();
}

TSharedPtr<FDragDropOperation> FSlateApplication::GetDragDroppingContent() const
{
	return DragDropContent;
}

void FSlateApplication::CancelDragDrop()
{
	for( auto LastWidgetIterator = WidgetsUnderCursorLastEvent.CreateConstIterator(); LastWidgetIterator; ++LastWidgetIterator)
	{
		
		FWidgetPath WidgetsToDragLeave = LastWidgetIterator.Value().ToWidgetPath(FWeakWidgetPath::EInterruptedPathHandling::Truncate);
		if(WidgetsToDragLeave.IsValid())
		{
			const FDragDropEvent DragDropEvent(FPointerEvent(), DragDropContent);
			for(int32 WidgetIndex = WidgetsToDragLeave.Widgets.Num() - 1; WidgetIndex >= 0; --WidgetIndex)
			{
				WidgetsToDragLeave.Widgets[WidgetIndex].Widget->OnDragLeave(DragDropEvent);
			}
		}
	}

	WidgetsUnderCursorLastEvent.Empty();
	DragDropContent.Reset();
}

void FSlateApplication::EnterDebuggingMode()
{
	bRequestLeaveDebugMode = false;

	// Note it is ok to hold a reference here as the game viewport should not be destroyed while in debugging mode
	TSharedPtr<SViewport> PreviousGameViewport;

	// Disable any game viewports while we are in debug mode so that mouse capture is released and the cursor is visible
	// We need to retain the keyboard input for debugging purposes, so this is called directly rather than calling UnregisterGameViewport which resets input.
	if (GameViewportWidget.IsValid())
	{
		PreviousGameViewport = GameViewportWidget.Pin();
		PreviousGameViewport->SetActive(false);
		GameViewportWidget.Reset();
	}

	Renderer->FlushCommands();
	
	// We are about to start an in stack tick. Make sure the rendering thread isn't already behind
	Renderer->Sync();

#if WITH_EDITORONLY_DATA
	// Flag that we're about to enter the first frame of intra-frame debugging.
	GFirstFrameIntraFrameDebugging = true;
#endif	//WITH_EDITORONLY_DATA


	// The scissor rect stack must be reset when re-entering the tick loop to avoid graphical artifacts with existing clip rects applied new widgets
	TOptional<FShortRect> PreviousScissorRect = GSlateScissorRect;
	GSlateScissorRect.Reset();
	
	// Tick slate from here in the event that we should not return until the modal window is closed.
	while (!bRequestLeaveDebugMode)
	{
		// Tick and render Slate
		Tick();

		// Synchronize the game thread and the render thread so that the render thread doesn't get too far behind.
		Renderer->Sync();

#if WITH_EDITORONLY_DATA
		// We are done with the first frame
		GFirstFrameIntraFrameDebugging = false;

		// If we are requesting leaving debugging mode, leave it now.
		GIntraFrameDebuggingGameThread = !bRequestLeaveDebugMode;
#endif	//WITH_EDITORONLY_DATA
	}

	bRequestLeaveDebugMode = false;
	
	if ( PreviousGameViewport.IsValid() )
	{
		check(!GameViewportWidget.IsValid());

		// When in single step mode, register the game viewport so we can unregister it later
		// but do not do any of the other stuff like locking or capturing the mouse.
		if( bLeaveDebugForSingleStep )
		{
			GameViewportWidget = PreviousGameViewport;
		}
		else
		{
			// If we had a game viewport before debugging, re-register it now to capture the mouse and lock the cursor
			RegisterGameViewport( PreviousGameViewport.ToSharedRef() );
		}
	}

	// Reset the scissor rect back to what it was before we started debugging
	GSlateScissorRect = PreviousScissorRect;

	bLeaveDebugForSingleStep = false;
}

void FSlateApplication::LeaveDebuggingMode(  bool bLeavingForSingleStep )
{
	bRequestLeaveDebugMode = true;
	bLeaveDebugForSingleStep = bLeavingForSingleStep;
}

bool FSlateApplication::IsWindowInDestroyQueue(TSharedRef<SWindow> Window) const
{
	return WindowDestroyQueue.Contains(Window);
}

void FSlateApplication::SynthesizeMouseMove()
{
	SLATE_CYCLE_COUNTER_SCOPE(GSlateSynthesizeMouseMove);
	// The slate loading widget thread is not allowed to execute this code 
	// as it is unsafe to read the hittest grid in another thread
	if (PlatformApplication->Cursor.IsValid() && IsInGameThread())
	{
		// Synthetic mouse events accomplish two goals:
		// 1) The UI can change even if the mosue doesn't move.
		//    Synthesizing a mouse move sends out events.
		//    In this case, the current and previous position will be the same.
		//
		// 2) The mouse moves, but the OS decided not to send us an event.
		//    e.g. Mouse moved outside of our window.
		//    In this case, the previous and current positions differ.

		FPointerEvent MouseEvent
		(
			CursorPointerIndex,
			GetCursorPos(),
			GetLastCursorPos(),
			PressedMouseButtons,
			EKeys::Invalid,
			0,
			PlatformApplication->GetModifierKeys()
		);

		ProcessMouseMoveEvent(MouseEvent, true);
	}
}

void FSlateApplication::QueueSynthesizedMouseMove()
{
	SynthesizeMouseMovePending = 2;
}

void FSlateApplication::OnLogSlateEvent(EEventLog::Type Event, const FString& AdditionalContent)
{
#if LOG_SLATE_EVENTS
	if (EventLogger.IsValid())
	{
		LOG_EVENT_CONTENT(Event, AdditionalContent, TSharedPtr<SWidget>());
	}
#endif
}

void FSlateApplication::OnLogSlateEvent(EEventLog::Type Event, const FText& AdditionalContent )
{
#if LOG_SLATE_EVENTS
	if (EventLogger.IsValid())
	{
		LOG_EVENT_CONTENT(Event, AdditionalContent.ToString(), TSharedPtr<SWidget>());
	}
#endif
};

void FSlateApplication::SetSlateUILogger(TSharedPtr<IEventLogger> InEventLogger)
{
#if LOG_SLATE_EVENTS
	EventLogger = InEventLogger;
#endif
}

void FSlateApplication::SetUnhandledKeyDownEventHandler( const FOnKeyEvent& NewHandler )
{
	UnhandledKeyDownEventHandler = NewHandler;
}

float FSlateApplication::GetDragTriggerDistance() const
{
	return DragTriggerDistance;
}

void FSlateApplication::SetDragTriggerDistance( float ScreenPixels )
{
	DragTriggerDistance = ScreenPixels;
}

void FSlateApplication::SetInputPreProcessor(bool bEnable, TSharedPtr<class IInputProcessor> NewInputProcessor)
{
	if (bEnable && NewInputProcessor.IsValid())
	{
		InputPreProcessor = NewInputProcessor;
	}
	else
	{
		InputPreProcessor.Reset();
	}
}

void FSlateApplication::SetCursorRadius(float NewRadius)
{
	CursorRadius = FMath::Max<float>(0.0f, NewRadius);
}

float FSlateApplication::GetCursorRadius() const
{
	return CursorRadius;
}

FVector2D FSlateApplication::CalculatePopupWindowPosition( const FSlateRect& InAnchor, const FVector2D& InSize, const EOrientation Orientation ) const
{
	FVector2D CalculatedPopUpWindowPosition( 0, 0 );

	FPlatformRect AnchorRect;
	AnchorRect.Left = InAnchor.Left;
	AnchorRect.Top = InAnchor.Top;
	AnchorRect.Right = InAnchor.Right;
	AnchorRect.Bottom = InAnchor.Bottom;

	EPopUpOrientation::Type PopUpOrientation = EPopUpOrientation::Horizontal;

	if ( Orientation == EOrientation::Orient_Vertical )
	{
		PopUpOrientation =  EPopUpOrientation::Vertical;
	}

	if ( PlatformApplication->TryCalculatePopupWindowPosition( AnchorRect, InSize, PopUpOrientation, /*OUT*/&CalculatedPopUpWindowPosition ) )
	{
		return CalculatedPopUpWindowPosition;
	}
	else
	{
		// Calculate the rectangle around our work area
		// Use our own rect.  This window as probably doesn't have a size or position yet.
		// Use a size of 1 to get the closest monitor to the start point
		FPlatformRect WorkAreaFinderRect(AnchorRect);
		WorkAreaFinderRect.Left = AnchorRect.Left + 1;
		WorkAreaFinderRect.Top = AnchorRect.Top + 1;
		const FPlatformRect PlatformWorkArea = PlatformApplication->GetWorkArea(WorkAreaFinderRect);

		const FSlateRect WorkAreaRect( 
			PlatformWorkArea.Left, 
			PlatformWorkArea.Top, 
			PlatformWorkArea.Left+(PlatformWorkArea.Right - PlatformWorkArea.Left), 
			PlatformWorkArea.Top+(PlatformWorkArea.Bottom - PlatformWorkArea.Top) );

		// Assume natural left-to-right, top-to-bottom flow; position popup below and to the right.
		const FVector2D ProposedPlacement(
			Orientation == Orient_Horizontal ? AnchorRect.Right : AnchorRect.Left,
			Orientation == Orient_Horizontal ? AnchorRect.Top : AnchorRect.Bottom);

		return ComputePopupFitInRect(InAnchor, FSlateRect(ProposedPlacement, ProposedPlacement+InSize), Orientation, WorkAreaRect);
	}
}

bool FSlateApplication::IsRunningAtTargetFrameRate() const
{
	const float MinimumDeltaTime = 1.0f / TargetFrameRateForResponsiveness.GetValueOnGameThread();
	return ( AverageDeltaTimeForResponsiveness <= MinimumDeltaTime ) || !IsNormalExecution();
}


bool FSlateApplication::AreMenuAnimationsEnabled() const
{
	return bMenuAnimationsEnabled;
}


void FSlateApplication::EnableMenuAnimations( const bool bEnableAnimations )
{
	bMenuAnimationsEnabled = bEnableAnimations;
}


void FSlateApplication::SetAppIcon(const FSlateBrush* const InAppIcon)
{
	check(InAppIcon);
	AppIcon = InAppIcon;
}


const FSlateBrush* FSlateApplication::GetAppIcon() const
{
	return AppIcon;
}


void FSlateApplication::ShowVirtualKeyboard( bool bShow, int32 UserIndex, TSharedPtr<IVirtualKeyboardEntry> TextEntryWidget )
{
	SCOPE_CYCLE_COUNTER(STAT_ShowVirtualKeyboard);

	if(SlateTextField == nullptr)
	{
		SlateTextField = new FPlatformTextField();
	}

	SlateTextField->ShowVirtualKeyboard(bShow, UserIndex, TextEntryWidget);
}

FSlateRect FSlateApplication::GetPreferredWorkArea() const
{
	if ( const FSlateUser* User = GetUser(GetUserIndexForKeyboard()) )
	{
		const FWeakWidgetPath & FocusedWidgetPath = User->Focus.WidgetPath;

		// First see if we have a focused widget
		if ( FocusedWidgetPath.IsValid() && FocusedWidgetPath.Window.IsValid() )
		{
			const FVector2D WindowPos = FocusedWidgetPath.Window.Pin()->GetPositionInScreen();
			const FVector2D WindowSize = FocusedWidgetPath.Window.Pin()->GetSizeInScreen();
			return GetWorkArea(FSlateRect(WindowPos.X, WindowPos.Y, WindowPos.X + WindowSize.X, WindowPos.Y + WindowSize.Y));
		}
	}

	// no focus widget, so use mouse position if there are windows present in the work area
	const FVector2D CursorPos = GetCursorPos();
	const FSlateRect WorkArea = GetWorkArea(FSlateRect(CursorPos.X, CursorPos.Y, CursorPos.X + 1.0f, CursorPos.Y + 1.0f));

	if ( FSlateWindowHelper::CheckWorkAreaForWindows(SlateWindows, WorkArea) )
	{
		return WorkArea;
	}

	// If we can't find a window where the cursor is at, try finding a main window.
	TSharedPtr<SWindow> ActiveTop = GetActiveTopLevelWindow();
	if ( ActiveTop.IsValid() )
	{
		// Use the current top level windows rect
		return GetWorkArea(ActiveTop->GetRectInScreen());
	}

	// If we can't find a top level window check for an active modal window
	TSharedPtr<SWindow> ActiveModal = GetActiveModalWindow();
	if ( ActiveModal.IsValid() )
	{
		// Use the current active modal windows rect
		return GetWorkArea(ActiveModal->GetRectInScreen());
	}

	// no windows on work area - default to primary display
	FDisplayMetrics DisplayMetrics;
	GetDisplayMetrics(DisplayMetrics);

	const FPlatformRect& DisplayRect = DisplayMetrics.PrimaryDisplayWorkAreaRect;
	return FSlateRect((float)DisplayRect.Left, (float)DisplayRect.Top, (float)DisplayRect.Right, (float)DisplayRect.Bottom);
}

FSlateRect FSlateApplication::GetWorkArea( const FSlateRect& InRect ) const
{
	FPlatformRect InPlatformRect;
	InPlatformRect.Left = FMath::TruncToInt(InRect.Left);
	InPlatformRect.Top = FMath::TruncToInt(InRect.Top);
	InPlatformRect.Right = FMath::TruncToInt(InRect.Right);
	InPlatformRect.Bottom = FMath::TruncToInt(InRect.Bottom);

	const FPlatformRect OutPlatformRect = PlatformApplication->GetWorkArea( InPlatformRect );
	return FSlateRect( OutPlatformRect.Left, OutPlatformRect.Top, OutPlatformRect.Right, OutPlatformRect.Bottom );
}

bool FSlateApplication::SupportsSourceAccess() const
{
	if(QuerySourceCodeAccessDelegate.IsBound())
	{
		return QuerySourceCodeAccessDelegate.Execute();
	}
	return false;
}

void FSlateApplication::GotoLineInSource(const FString& FileName, int32 LineNumber) const
{
	if ( SupportsSourceAccess() )
	{
		if(SourceCodeAccessDelegate.IsBound())
		{
			SourceCodeAccessDelegate.Execute(FileName, LineNumber, 0);
		}
	}
}

void FSlateApplication::ForceRedrawWindow(const TSharedRef<SWindow>& InWindowToDraw)
{
	PrivateDrawWindows( InWindowToDraw );
}

bool FSlateApplication::TakeScreenshot(const TSharedRef<SWidget>& Widget, TArray<FColor>&OutColorData, FIntVector& OutSize)
{
	return TakeScreenshot(Widget, FIntRect(), OutColorData, OutSize);
}

bool FSlateApplication::TakeScreenshot(const TSharedRef<SWidget>& Widget, const FIntRect& InnerWidgetArea, TArray<FColor>& OutColorData, FIntVector& OutSize)
{
	// We can't screenshot the widget unless there's a valid window handle to draw it in.
	TSharedPtr<SWindow> WidgetWindow = FSlateApplication::Get().FindWidgetWindow(Widget);
	if ( !WidgetWindow.IsValid() )
	{
		return false;
	}

	TSharedRef<SWindow> CurrentWindowRef = WidgetWindow.ToSharedRef();

	FWidgetPath WidgetPath;
	FSlateApplication::Get().GeneratePathToWidgetChecked(Widget, WidgetPath);

	FArrangedWidget ArrangedWidget = WidgetPath.FindArrangedWidget(Widget).Get(FArrangedWidget::NullWidget);
	FVector2D Position = ArrangedWidget.Geometry.AbsolutePosition;
	FVector2D Size = ArrangedWidget.Geometry.GetDrawSize();
	FVector2D WindowPosition = WidgetWindow->GetPositionInScreen();

	FIntRect ScreenshotRect = InnerWidgetArea.IsEmpty() ? FIntRect(0, 0, (int32)Size.X, (int32)Size.Y) : InnerWidgetArea;

	ScreenshotRect.Min.X += ( Position.X - WindowPosition.X );
	ScreenshotRect.Min.Y += ( Position.Y - WindowPosition.Y );
	ScreenshotRect.Max.X += ( Position.X - WindowPosition.X );
	ScreenshotRect.Max.Y += ( Position.Y - WindowPosition.Y );

	Renderer->PrepareToTakeScreenshot(ScreenshotRect, &OutColorData);
	PrivateDrawWindows(WidgetWindow);

	OutSize.X = ScreenshotRect.Size().X;
	OutSize.Y = ScreenshotRect.Size().Y;

	return (OutSize.X != 0 && OutSize.Y != 0);
}

TSharedPtr< FSlateWindowElementList > FSlateApplication::GetCachableElementList(const TSharedPtr<SWindow>& CurrentWindow, const ILayoutCache* LayoutCache)
{
	TSharedPtr<FCacheElementPools> Pools = CachedElementLists.FindRef(LayoutCache);
	if ( !Pools.IsValid() )
	{
		Pools = MakeShareable( new FCacheElementPools() );
		CachedElementLists.Add(LayoutCache, Pools);
	}

	TSharedPtr< FSlateWindowElementList > NextElementList = Pools->GetNextCachableElementList(CurrentWindow);

	return NextElementList;
}

TSharedPtr< FSlateWindowElementList > FSlateApplication::FCacheElementPools::GetNextCachableElementList(const TSharedPtr<SWindow>& CurrentWindow)
{
	TSharedPtr< FSlateWindowElementList > NextElementList;

	// Move any inactive element lists in the active pool to the inactive pool.
	for ( int32 i = ActiveCachedElementListPool.Num() - 1; i >= 0; i-- )
	{
		if ( ActiveCachedElementListPool[i]->IsCachedRenderDataInUse() == false )
		{
			InactiveCachedElementListPool.Add(ActiveCachedElementListPool[i]);
			ActiveCachedElementListPool.RemoveAtSwap(i, 1, false);
		}
	}

	// Remove inactive lists that don't belong to this window.
	for ( int32 i = InactiveCachedElementListPool.Num() - 1; i >= 0; i-- )
	{
		if ( InactiveCachedElementListPool[i]->GetWindow() != CurrentWindow )
		{
			InactiveCachedElementListPool.RemoveAtSwap(i, 1, false);
		}
	}

	// Create a new element list if none are available, or use an existing one.
	if ( InactiveCachedElementListPool.Num() == 0 )
	{
		NextElementList = MakeShareable(new FSlateWindowElementList(CurrentWindow));
	}
	else
	{
		NextElementList = InactiveCachedElementListPool[0];
		NextElementList->ResetBuffers();

		InactiveCachedElementListPool.RemoveAtSwap(0, 1, false);
	}

	ActiveCachedElementListPool.Add(NextElementList);

	return NextElementList;
}

bool FSlateApplication::FCacheElementPools::IsInUse() const
{
	bool bInUse = false;
	for ( TSharedPtr< FSlateWindowElementList > ElementList : InactiveCachedElementListPool )
	{
		bInUse |= ElementList->IsCachedRenderDataInUse();
	}

	for ( TSharedPtr< FSlateWindowElementList > ElementList : ActiveCachedElementListPool )
	{
		bInUse |= ElementList->IsCachedRenderDataInUse();
	}

	return bInUse;
}

void FSlateApplication::ReleaseResourcesForLayoutCache(const ILayoutCache* LayoutCache)
{
	TSharedPtr<FCacheElementPools> Pools = CachedElementLists.FindRef(LayoutCache);
	if ( Pools.IsValid() )
	{
		ReleasedCachedElementLists.Add(Pools);
	}

	CachedElementLists.Remove(LayoutCache);

	// Release the rendering related resources.
	Renderer->ReleaseCachingResourcesFor(LayoutCache);
}

TSharedRef<FSlateVirtualUser> FSlateApplication::FindOrCreateVirtualUser(int32 VirtualUserIndex)
{
	// Ensure we have a large enough array to add the new virtual user.
	if ( VirtualUserIndex >= VirtualUsers.Num() )
	{
		VirtualUsers.SetNum(VirtualUserIndex + 1);
	}

	TSharedPtr<FSlateVirtualUser> VirtualUser = VirtualUsers[VirtualUserIndex].Pin();
	if ( VirtualUser.IsValid() )
	{
		return VirtualUser.ToSharedRef();
	}

	// Register new virtual user with slates standard set of users.
	int32 NextVirtualUserIndex = SlateApplicationDefs::MaxHardwareUsers;
	while ( GetUser(NextVirtualUserIndex) )
	{
		NextVirtualUserIndex++;
	}

	TSharedRef<FSlateUser> NewUser = MakeShareable(new FSlateUser(NextVirtualUserIndex, true));
	RegisterUser(NewUser);

	// Make a virtual user handle that can be released automatically when all virtual users
	// of this same user index are collected.
	VirtualUser = MakeShareable(new FSlateVirtualUser(NewUser->GetUserIndex(), VirtualUserIndex));

	// Update the virtual user array, so we can get this user back later.
	VirtualUsers[VirtualUserIndex] = VirtualUser;

	return VirtualUser.ToSharedRef();
}

void FSlateApplication::RegisterUser(TSharedRef<FSlateUser> NewUser)
{
	if ( NewUser->UserIndex == -1 )
	{
		int32 Index = Users.Add(NewUser);
		NewUser->UserIndex = Index;
	}
	else
	{
		// Ensure we have a large enough array to add the new user.
		if ( NewUser->GetUserIndex() >= Users.Num() )
		{
			Users.SetNum(NewUser->GetUserIndex() + 1);
		}

		if ( FSlateUser* ExistingUser = Users[NewUser->GetUserIndex()].Get() )
		{
			// Migrate any state we know about that needs to be maintained if the
			// user is replaced.
			NewUser->Focus = ExistingUser->Focus;
		}

		// Replace the user that's at this index with the new user.
		Users[NewUser->GetUserIndex()] = NewUser;
	}
}

void FSlateApplication::UnregisterUser(int32 UserIndex)
{
	if ( UserIndex < Users.Num() )
	{
		ClearUserFocus(UserIndex, EFocusCause::SetDirectly);
		Users[UserIndex].Reset();
	}
}

void FSlateApplication::ForEachUser(TFunctionRef<void(FSlateUser*)> InPredicate, bool bIncludeVirtualUsers)
{
	for ( int32 UserIndex = 0; UserIndex < Users.Num(); UserIndex++ )
	{
		if ( FSlateUser* User = Users[UserIndex].Get() )
		{
			// Ignore virutal users unless told not to.
			if ( !bIncludeVirtualUsers && User->IsVirtualUser() )
			{
				continue;
			}

			InPredicate(User);
		}
	}
}


/* FSlateApplicationBase interface
 *****************************************************************************/

FVector2D FSlateApplication::GetCursorSize( ) const
{
	if ( PlatformApplication->Cursor.IsValid() )
	{
		int32 X;
		int32 Y;
		PlatformApplication->Cursor->GetSize( X, Y );
		return FVector2D( X, Y );
	}

	return FVector2D( 1.0f, 1.0f );
}

EVisibility FSlateApplication::GetSoftwareCursorVis( ) const
{
	const TSharedPtr<ICursor>& Cursor = PlatformApplication->Cursor;
	if (bSoftwareCursorAvailable && Cursor.IsValid() && Cursor->GetType() != EMouseCursor::None)
	{
		return EVisibility::HitTestInvisible;
	}
	return EVisibility::Hidden;
}

TSharedPtr< SWidget > FSlateApplication::GetKeyboardFocusedWidget() const
{
	if ( const FSlateUser* User = GetUser(GetUserIndexForKeyboard()) )
	{
		const FUserFocusEntry& UserFocusEntry = User->Focus;
		if ( UserFocusEntry.WidgetPath.IsValid() )
		{
			return UserFocusEntry.WidgetPath.GetLastWidget().Pin();
		}
	}

	return TSharedPtr< SWidget >();
}

TSharedPtr<SWidget> FSlateApplication::GetMouseCaptorImpl() const
{
	return MouseCaptor.ToSharedWidget(CursorUserIndex,CursorPointerIndex);
}

bool FSlateApplication::HasAnyMouseCaptor() const
{
	return MouseCaptor.HasCapture();
}

bool FSlateApplication::HasUserMouseCapture(int32 UserIndex) const
{
	return MouseCaptor.HasCaptureForUser(UserIndex);
}

bool FSlateApplication::DoesWidgetHaveMouseCaptureByUser(const TSharedPtr<const SWidget> Widget, int32 UserIndex, TOptional<int32> PointerIndex) const
{
	return MouseCaptor.DoesWidgetHaveMouseCaptureByUser(Widget, UserIndex, PointerIndex);
}

bool FSlateApplication::DoesWidgetHaveMouseCapture(const TSharedPtr<const SWidget> Widget) const
{
	return MouseCaptor.DoesWidgetHaveMouseCapture(Widget);
}

TOptional<EFocusCause> FSlateApplication::HasUserFocus(const TSharedPtr<const SWidget> Widget, int32 UserIndex) const
{
	if ( const FSlateUser* User = GetUser(UserIndex) )
	{
		if ( User->GetFocusedWidget() == Widget )
		{
			TOptional<EFocusCause> FocusReason(User->Focus.FocusCause);
			return FocusReason;
		}
	}

	return TOptional<EFocusCause>();
}

TOptional<EFocusCause> FSlateApplication::HasAnyUserFocus(const TSharedPtr<const SWidget> Widget) const
{
	for ( int32 UserIndex = 0; UserIndex < Users.Num(); UserIndex++ )
	{
		if ( const FSlateUser* User = Users[UserIndex].Get() )
		{
			if ( User->GetFocusedWidget() == Widget )
			{
				TOptional<EFocusCause> FocusReason(User->Focus.FocusCause);
				return FocusReason;
			}
		}
	}

	return TOptional<EFocusCause>();
}

bool FSlateApplication::IsWidgetDirectlyHovered(const TSharedPtr<const SWidget> Widget) const
{
	for( auto LastWidgetIterator = WidgetsUnderCursorLastEvent.CreateConstIterator(); LastWidgetIterator; ++LastWidgetIterator )
	{
		const FWeakWidgetPath& WeakPath = LastWidgetIterator.Value();
		if( WeakPath.IsValid() && Widget == WeakPath.GetLastWidget().Pin() )
		{
			return true;
		}
	}
	return false;
}

bool FSlateApplication::ShowUserFocus(const TSharedPtr<const SWidget> Widget) const
{
	for ( int32 UserIndex = 0; UserIndex < Users.Num(); UserIndex++ )
	{
		if ( const FSlateUser* User = Users[UserIndex].Get() )
		{
			const FUserFocusEntry& UserFocusEntry = User->Focus;
			const FWeakWidgetPath & FocusedWidgetPath = UserFocusEntry.WidgetPath;
			if ( FocusedWidgetPath.IsValid() && FocusedWidgetPath.GetLastWidget().Pin() == Widget )
			{
				return UserFocusEntry.ShowFocus;
			}
		}
	}

	return false;
}

bool FSlateApplication::HasUserFocusedDescendants(const TSharedRef< const SWidget >& Widget, int32 UserIndex) const
{
	if ( const FSlateUser* User = GetUser(UserIndex) )
	{
		const FUserFocusEntry& UserFocusEntry = User->Focus;
		const FWeakWidgetPath & FocusedWidgetPath = UserFocusEntry.WidgetPath;
		if ( FocusedWidgetPath.IsValid() && FocusedWidgetPath.GetLastWidget().Pin() != Widget && FocusedWidgetPath.ContainsWidget(Widget) )
		{
			return true;
		}
	}

	return false;
}

bool FSlateApplication::HasFocusedDescendants( const TSharedRef< const SWidget >& Widget ) const
{
	for ( int32 UserIndex = 0; UserIndex < Users.Num(); UserIndex++ )
	{
		if ( const FSlateUser* User = Users[UserIndex].Get() )
		{
			const FUserFocusEntry& UserFocusEntry = User->Focus;
			const FWeakWidgetPath & FocusedWidgetPath = UserFocusEntry.WidgetPath;
			if ( FocusedWidgetPath.IsValid() && FocusedWidgetPath.GetLastWidget().Pin() != Widget && FocusedWidgetPath.ContainsWidget(Widget) )
			{
				return true;
			}
		}
	}
	return false;
}

bool FSlateApplication::IsExternalUIOpened()
{
	return bIsExternalUIOpened;
}


TSharedRef<SWidget> FSlateApplication::MakeImage( const TAttribute<const FSlateBrush*>& Image, const TAttribute<FSlateColor>& Color, const TAttribute<EVisibility>& Visibility ) const
{
	return SNew(SImage)
		.ColorAndOpacity(Color)
		.Image(Image)
		.Visibility(Visibility);
}


TSharedRef<SWidget> FSlateApplication::MakeWindowTitleBar( const TSharedRef<SWindow>& Window, const TSharedPtr<SWidget>& CenterContent, EHorizontalAlignment CenterContentAlignment, TSharedPtr<IWindowTitleBar>& OutTitleBar ) const
{
	TSharedRef<SWindowTitleBar> TitleBar = SNew(SWindowTitleBar, Window, CenterContent, CenterContentAlignment)
		.Visibility(EVisibility::SelfHitTestInvisible);

	OutTitleBar = TitleBar;

	return TitleBar;
}


TSharedRef<IToolTip> FSlateApplication::MakeToolTip(const TAttribute<FText>& ToolTipText)
{
	return SNew(SToolTip)
		.Text(ToolTipText);
}


TSharedRef<IToolTip> FSlateApplication::MakeToolTip( const FText& ToolTipText )
{
	return SNew(SToolTip)
		.Text(ToolTipText);
}


/* FGenericApplicationMessageHandler interface
 *****************************************************************************/

bool FSlateApplication::ShouldProcessUserInputMessages( const TSharedPtr< FGenericWindow >& PlatformWindow ) const
{
	TSharedPtr< SWindow > Window;
	if ( PlatformWindow.IsValid() )
	{
		Window = FSlateWindowHelper::FindWindowByPlatformWindow( SlateWindows, PlatformWindow.ToSharedRef() );
	}

	if ( ActiveModalWindows.Num() == 0 || 
		( Window.IsValid() &&
			( Window->IsDescendantOf( GetActiveModalWindow() ) || ActiveModalWindows.Contains( Window ) ) ) )
	{
		return true;
	}
	return false;
}

bool FSlateApplication::OnKeyChar( const TCHAR Character, const bool IsRepeat )
{
	FCharacterEvent CharacterEvent( Character, PlatformApplication->GetModifierKeys(), 0, IsRepeat );
	return ProcessKeyCharEvent( CharacterEvent );
}

bool FSlateApplication::ProcessKeyCharEvent( FCharacterEvent& InCharacterEvent )
{
	SCOPE_CYCLE_COUNTER(STAT_ProcessKeyChar);

	TScopeCounter<int32> BeginInput(ProcessingInput);

	FReply Reply = FReply::Unhandled();

	// NOTE: We intentionally don't reset LastUserInteractionTimeForThrottling here so that the UI can be responsive while typing

	// Bubble the key event
	if ( FSlateUser* User = GetOrCreateUser(InCharacterEvent.GetUserIndex()) )
	{
		FWidgetPath EventPath = User->Focus.WidgetPath.ToWidgetPath();

		// Switch worlds for widgets in the current path
		FScopedSwitchWorldHack SwitchWorld(EventPath);

		{
			SCOPE_CYCLE_COUNTER(STAT_ProcessKeyChar_RouteAlongFocusPath);
			Reply = FEventRouter::RouteAlongFocusPath(this, FEventRouter::FBubblePolicy(EventPath), InCharacterEvent, [] (const FArrangedWidget& SomeWidgetGettingEvent, const FCharacterEvent& Event)
			{
				SCOPE_CYCLE_COUNTER(STAT_ProcessKeyChar_Call_OnKeyChar);
				return SomeWidgetGettingEvent.Widget->IsEnabled()
					? SomeWidgetGettingEvent.Widget->OnKeyChar(SomeWidgetGettingEvent.Geometry, Event)
					: FReply::Unhandled();
			});
		}

		LOG_EVENT_CONTENT(EEventLog::KeyChar, FString::Printf(TEXT("%c"), InCharacterEvent.GetCharacter()), Reply);
	}

	return Reply.IsEventHandled();
}

bool FSlateApplication::OnKeyDown( const int32 KeyCode, const uint32 CharacterCode, const bool IsRepeat ) 
{
	FKey const Key = FInputKeyManager::Get().GetKeyFromCodes( KeyCode, CharacterCode );
	FKeyEvent KeyEvent(Key, PlatformApplication->GetModifierKeys(), GetUserIndexForKeyboard(), IsRepeat, CharacterCode, KeyCode);

	return ProcessKeyDownEvent( KeyEvent );
}

bool FSlateApplication::ProcessKeyDownEvent( FKeyEvent& InKeyEvent )
{
	TScopeCounter<int32> BeginInput(ProcessingInput);

	SCOPE_CYCLE_COUNTER(STAT_ProcessKeyDown);

#if WITH_EDITOR
	//Send the key input to all pre input key down listener function
	if (OnApplicationPreInputKeyDownListenerEvent.IsBound())
	{
		OnApplicationPreInputKeyDownListenerEvent.Broadcast(InKeyEvent);
	}
#endif //WITH_EDITOR

	QueueSynthesizedMouseMove();

	// Analog cursor gets first chance at the input
	if (InputPreProcessor.IsValid() && InputPreProcessor->HandleKeyDownEvent(*this, InKeyEvent))
	{
		return true;
	}

	FReply Reply = FReply::Unhandled();

	SetLastUserInteractionTime(this->GetCurrentTime());
	
	if (IsDragDropping() && InKeyEvent.GetKey() == EKeys::Escape)
	{
		// Pressing ESC while drag and dropping terminates the drag drop.
		CancelDragDrop();
		Reply = FReply::Handled();
	}
	else
	{
		LastUserInteractionTimeForThrottling = LastUserInteractionTime;

#if SLATE_HAS_WIDGET_REFLECTOR
		// If we are inspecting, pressing ESC exits inspection mode.
		if ( InKeyEvent.GetKey() == EKeys::Escape )
		{
			TSharedPtr<IWidgetReflector> WidgetReflector = WidgetReflectorPtr.Pin();
			const bool bIsWidgetReflectorPicking = WidgetReflector.IsValid() && WidgetReflector->IsInPickingMode();
			if ( bIsWidgetReflectorPicking )
			{
					WidgetReflector->OnWidgetPicked();
					Reply = FReply::Handled();

					return Reply.IsEventHandled();
			}
		}
#endif

#if !(UE_BUILD_SHIPPING || UE_BUILD_TEST)
		// Ctrl+Shift+~ summons the Toolbox.
		if (InKeyEvent.GetKey() == EKeys::Tilde && InKeyEvent.IsControlDown() && InKeyEvent.IsShiftDown())
		{
			IToolboxModule* ToolboxModule = FModuleManager::LoadModulePtr<IToolboxModule>("Toolbox");
			if (ToolboxModule)
			{
				ToolboxModule->SummonToolbox();
			}
		}

#endif //!(UE_BUILD_SHIPPING || UE_BUILD_TEST)

		// Bubble the keyboard event
		if ( FSlateUser* User = GetOrCreateUser(InKeyEvent.GetUserIndex()) )
		{
			FWidgetPath EventPath = User->Focus.WidgetPath.ToWidgetPath();

			// Switch worlds for widgets inOnPreviewMouseButtonDown the current path
			FScopedSwitchWorldHack SwitchWorld(EventPath);

			// Tunnel the keyboard event
			Reply = FEventRouter::RouteAlongFocusPath(this, FEventRouter::FTunnelPolicy(EventPath), InKeyEvent, [] (const FArrangedWidget& CurrentWidget, const FKeyEvent& Event)
			{
				return ( CurrentWidget.Widget->IsEnabled() )
					? CurrentWidget.Widget->OnPreviewKeyDown(CurrentWidget.Geometry, Event)
					: FReply::Unhandled();
			});

			// Send out key down events.
			if ( !Reply.IsEventHandled() )
			{
				Reply = FEventRouter::RouteAlongFocusPath(this, FEventRouter::FBubblePolicy(EventPath), InKeyEvent, [] (const FArrangedWidget& SomeWidgetGettingEvent, const FKeyEvent& Event)
				{
					return ( SomeWidgetGettingEvent.Widget->IsEnabled() )
						? SomeWidgetGettingEvent.Widget->OnKeyDown(SomeWidgetGettingEvent.Geometry, Event)
						: FReply::Unhandled();
				});
			}

			LOG_EVENT_CONTENT(EEventLog::KeyDown, InKeyEvent.GetKey().ToString(), Reply);

			// If the key event was not processed by any widget...
			if ( !Reply.IsEventHandled() && UnhandledKeyDownEventHandler.IsBound() )
			{
				Reply = UnhandledKeyDownEventHandler.Execute(InKeyEvent);
			}
		}
	}

	return Reply.IsEventHandled();
}

bool FSlateApplication::OnKeyUp( const int32 KeyCode, const uint32 CharacterCode, const bool IsRepeat )
{
	FKey const Key = FInputKeyManager::Get().GetKeyFromCodes( KeyCode, CharacterCode );
	FKeyEvent KeyEvent(Key, PlatformApplication->GetModifierKeys(), GetUserIndexForKeyboard(), IsRepeat, CharacterCode, KeyCode);

	return ProcessKeyUpEvent( KeyEvent );
}

bool FSlateApplication::ProcessKeyUpEvent( FKeyEvent& InKeyEvent )
{
	SCOPE_CYCLE_COUNTER(STAT_ProcessKeyUp);

	TScopeCounter<int32> BeginInput(ProcessingInput);

	QueueSynthesizedMouseMove();

	// Analog cursor gets first chance at the input
	if (InputPreProcessor.IsValid() && InputPreProcessor->HandleKeyUpEvent(*this, InKeyEvent))
	{
		return true;
	}

	FReply Reply = FReply::Unhandled();

	SetLastUserInteractionTime(this->GetCurrentTime());
	
	LastUserInteractionTimeForThrottling = LastUserInteractionTime;

	// Bubble the key event
	if ( FSlateUser* User = GetOrCreateUser(InKeyEvent.GetUserIndex()) )
	{
		FWidgetPath EventPath = User->Focus.WidgetPath.ToWidgetPath();

		// Switch worlds for widgets in the current path
		FScopedSwitchWorldHack SwitchWorld(EventPath);

		Reply = FEventRouter::RouteAlongFocusPath(this, FEventRouter::FBubblePolicy(EventPath), InKeyEvent, [] (const FArrangedWidget& SomeWidgetGettingEvent, const FKeyEvent& Event)
		{
			return ( SomeWidgetGettingEvent.Widget->IsEnabled() )
				? SomeWidgetGettingEvent.Widget->OnKeyUp(SomeWidgetGettingEvent.Geometry, Event)
				: FReply::Unhandled();
		});

		LOG_EVENT_CONTENT(EEventLog::KeyUp, InKeyEvent.GetKey().ToString(), Reply);
	}

	return Reply.IsEventHandled();
}

bool FSlateApplication::ProcessAnalogInputEvent(FAnalogInputEvent& InAnalogInputEvent)
{
	SCOPE_CYCLE_COUNTER(STAT_ProcessAnalogInput);

	TScopeCounter<int32> BeginInput(ProcessingInput);

	QueueSynthesizedMouseMove();

	FReply Reply = FReply::Unhandled();

	// Analog cursor gets first chance at the input
	if (InputPreProcessor.IsValid() && InputPreProcessor->HandleAnalogInputEvent(*this, InAnalogInputEvent))
	{
		Reply = FReply::Handled();
	}
	else
	{
		// Bubble the key event
		if ( FSlateUser* User = GetOrCreateUser(InAnalogInputEvent.GetUserIndex()) )
		{
			FWidgetPath EventPath = User->Focus.WidgetPath.ToWidgetPath();
			InAnalogInputEvent.SetEventPath(EventPath);

			// Switch worlds for widgets in the current path
			FScopedSwitchWorldHack SwitchWorld(EventPath);

			Reply = FEventRouter::RouteAlongFocusPath(this, FEventRouter::FBubblePolicy(EventPath), InAnalogInputEvent, [] (const FArrangedWidget& SomeWidgetGettingEvent, const FAnalogInputEvent& Event)
			{
				return ( SomeWidgetGettingEvent.Widget->IsEnabled() )
					? SomeWidgetGettingEvent.Widget->OnAnalogValueChanged(SomeWidgetGettingEvent.Geometry, Event)
					: FReply::Unhandled();
			});

		LOG_EVENT_CONTENT(EEventLog::AnalogInput, InAnalogInputEvent.GetKey().ToString(), Reply);

			QueueSynthesizedMouseMove();
		}
	}

	// If no one handled this, it was probably motion in the deadzone.  Don't treat it as activity.
	if (Reply.IsEventHandled())
	{
		SetLastUserInteractionTime(this->GetCurrentTime());
		LastUserInteractionTimeForThrottling = LastUserInteractionTime;
		return true;
	}
	else
	{
		return false;
	}
}

FKey TranslateMouseButtonToKey( const EMouseButtons::Type Button )
{
	FKey Key = EKeys::Invalid;

	switch( Button )
	{
	case EMouseButtons::Left:
		Key = EKeys::LeftMouseButton;
		break;
	case EMouseButtons::Middle:
		Key = EKeys::MiddleMouseButton;
		break;
	case EMouseButtons::Right:
		Key = EKeys::RightMouseButton;
		break;
	case EMouseButtons::Thumb01:
		Key = EKeys::ThumbMouseButton;
		break;
	case EMouseButtons::Thumb02:
		Key = EKeys::ThumbMouseButton2;
		break;
	}

	return Key;
}

void FSlateApplication::SetGameIsFakingTouchEvents(const bool bIsFaking, FVector2D* CursorLocation)
{
	if (bIsFakingTouched && !bIsFaking && bIsGameFakingTouch && !bIsFakingTouch)
	{
		OnTouchEnded((CursorLocation ? *CursorLocation : PlatformApplication->Cursor->GetPosition()), 0, 0);
	}
	bIsGameFakingTouch = bIsFaking;
}

bool FSlateApplication::IsFakingTouchEvents() const
{
	return bIsFakingTouch || bIsGameFakingTouch;
}

bool FSlateApplication::OnMouseDown(const TSharedPtr< FGenericWindow >& PlatformWindow, const EMouseButtons::Type Button)
{
	return OnMouseDown(PlatformWindow, Button, GetCursorPos());
}

bool FSlateApplication::OnMouseDown( const TSharedPtr< FGenericWindow >& PlatformWindow, const EMouseButtons::Type Button, const FVector2D CursorPos )
{
	// convert to touch event if we are faking it	
	if (bIsFakingTouch || bIsGameFakingTouch)
	{
		bIsFakingTouched = true;
		return OnTouchStarted( PlatformWindow, PlatformApplication->Cursor->GetPosition(), 0, 0 );
	}

	FKey Key = TranslateMouseButtonToKey( Button );

	FPointerEvent MouseEvent(
		CursorPointerIndex,
		CursorPos,
		GetLastCursorPos(),
		PressedMouseButtons,
		Key,
		0,
		PlatformApplication->GetModifierKeys()
		);

	return ProcessMouseButtonDownEvent( PlatformWindow, MouseEvent );
}

bool FSlateApplication::ProcessMouseButtonDownEvent( const TSharedPtr< FGenericWindow >& PlatformWindow, FPointerEvent& MouseEvent )
{
	SCOPE_CYCLE_COUNTER(STAT_ProcessMouseButtonDown);
	
	TScopeCounter<int32> BeginInput(ProcessingInput);

#if WITH_EDITOR
	//Send the key input to all pre input key down listener function
	if (OnApplicationMousePreInputButtonDownListenerEvent.IsBound())
	{
		OnApplicationMousePreInputButtonDownListenerEvent.Broadcast(MouseEvent);
	}
#endif //WITH_EDITOR

	QueueSynthesizedMouseMove();
	SetLastUserInteractionTime(this->GetCurrentTime());
	LastUserInteractionTimeForThrottling = LastUserInteractionTime;
	
	if (PlatformWindow.IsValid())
	{
		PlatformApplication->SetCapture(PlatformWindow);
	}
	PressedMouseButtons.Add( MouseEvent.GetEffectingButton() );

	// Input preprocessor gets first chance at the input
	if( InputPreProcessor.IsValid() && InputPreProcessor->HandleMouseButtonDownEvent( *this, MouseEvent ) )
	{
		return true;
	}

	bool bInGame = false;

	// Only process mouse down messages if we are not drag/dropping
	if ( !IsDragDropping() )
	{
		FReply Reply = FReply::Unhandled();
		if (MouseCaptor.HasCaptureForPointerIndex(MouseEvent.GetUserIndex(), MouseEvent.GetPointerIndex()))
		{
			FWidgetPath MouseCaptorPath = MouseCaptor.ToWidgetPath( FWeakWidgetPath::EInterruptedPathHandling::Truncate, &MouseEvent );
			FArrangedWidget& MouseCaptorWidget = MouseCaptorPath.Widgets.Last();

			// Switch worlds widgets in the current path
			FScopedSwitchWorldHack SwitchWorld(MouseCaptorPath);
			bInGame = FApp::IsGame();

			Reply = FEventRouter::Route<FReply>(this, FEventRouter::FToLeafmostPolicy(MouseCaptorPath), MouseEvent, [] (const FArrangedWidget& InMouseCaptorWidget, const FPointerEvent& Event)
			{
				return InMouseCaptorWidget.Widget->OnPreviewMouseButtonDown(InMouseCaptorWidget.Geometry, Event);
			});

			if ( !Reply.IsEventHandled() )
			{
				Reply = FEventRouter::Route<FReply>(this, FEventRouter::FToLeafmostPolicy(MouseCaptorPath), MouseEvent,
					[this] (const FArrangedWidget& InMouseCaptorWidget, const FPointerEvent& Event)
				{
					FReply TempReply = FReply::Unhandled();
					if ( Event.IsTouchEvent() )
					{
						TempReply = InMouseCaptorWidget.Widget->OnTouchStarted(InMouseCaptorWidget.Geometry, Event);
					}
					if ( !Event.IsTouchEvent() || ( !TempReply.IsEventHandled() && this->bTouchFallbackToMouse ) )
					{
						TempReply = InMouseCaptorWidget.Widget->OnMouseButtonDown(InMouseCaptorWidget.Geometry, Event);
					}
					return TempReply;
				});
			}
			LOG_EVENT(EEventLog::MouseButtonDown, Reply);
		}
		else
		{
			FWidgetPath WidgetsUnderCursor = LocateWindowUnderMouse( MouseEvent.GetScreenSpacePosition(), GetInteractiveTopLevelWindows() );

			PopupSupport.SendNotifications( WidgetsUnderCursor );

			// Switch worlds widgets in the current path
			FScopedSwitchWorldHack SwitchWorld(WidgetsUnderCursor);
			bInGame = FApp::IsGame();

			Reply = RoutePointerDownEvent(WidgetsUnderCursor, MouseEvent);
		}

		// See if expensive tasks should be throttled.  By default on mouse down expensive tasks are throttled
		// to ensure Slate responsiveness in low FPS situations
		if (Reply.IsEventHandled() && !bInGame && !MouseEvent.IsTouchEvent())
		{
			// Enter responsive mode if throttling should occur and its not already happening
			if( Reply.ShouldThrottle() && !MouseButtonDownResponsivnessThrottle.IsValid() )
			{
				MouseButtonDownResponsivnessThrottle = FSlateThrottleManager::Get().EnterResponsiveMode();
			}
			else if( !Reply.ShouldThrottle() && MouseButtonDownResponsivnessThrottle.IsValid() )
			{
				// Leave responsive mode if a widget chose not to throttle
				FSlateThrottleManager::Get().LeaveResponsiveMode( MouseButtonDownResponsivnessThrottle );
			}
		}
	}

	PointerIndexLastPositionMap.Add(MouseEvent.GetPointerIndex(), MouseEvent.GetScreenSpacePosition());
	return true;
}

FReply FSlateApplication::RoutePointerDownEvent(FWidgetPath& WidgetsUnderPointer, FPointerEvent& PointerEvent)
{
	TScopeCounter<int32> BeginInput(ProcessingInput);

#if PLATFORM_MAC
	NSWindow* ActiveWindow = [ NSApp keyWindow ];
	const bool bNeedToActivateWindow = ( ActiveWindow == nullptr );
#else
	const bool bNeedToActivateWindow = false;
#endif

	const TSharedPtr<SWidget> PreviouslyFocusedWidget = GetKeyboardFocusedWidget();

	FReply Reply = FEventRouter::Route<FReply>( this, FEventRouter::FTunnelPolicy( WidgetsUnderPointer ), PointerEvent, []( const FArrangedWidget TargetWidget, const FPointerEvent& Event )
	{
		return TargetWidget.Widget->OnPreviewMouseButtonDown( TargetWidget.Geometry, Event );
	} );

	if( !Reply.IsEventHandled() )
	{
		Reply = FEventRouter::Route<FReply>( this, FEventRouter::FBubblePolicy( WidgetsUnderPointer ), PointerEvent, [this]( const FArrangedWidget TargetWidget, const FPointerEvent& Event )
		{
			FReply ThisReply = FReply::Unhandled();
			if( !ThisReply.IsEventHandled() )
			{
				if( Event.IsTouchEvent() )
				{
					ThisReply = TargetWidget.Widget->OnTouchStarted( TargetWidget.Geometry, Event );
				}
				if( !Event.IsTouchEvent() || ( !ThisReply.IsEventHandled() && this->bTouchFallbackToMouse ) )
				{
					ThisReply = TargetWidget.Widget->OnMouseButtonDown( TargetWidget.Geometry, Event );
				}
			}
			return ThisReply;
		} );
	}
	LOG_EVENT( EEventLog::MouseButtonDown, Reply );

	// If none of the widgets requested keyboard focus to be set (or set the keyboard focus explicitly), set it to the leaf-most widget under the mouse.
	// On Mac we prevent the OS from activating the window on mouse down, so we have full control and can activate only if there's nothing draggable under the mouse cursor.
	const bool bFocusChangedByEventHandler = PreviouslyFocusedWidget != GetKeyboardFocusedWidget();
	if( ( !bFocusChangedByEventHandler || bNeedToActivateWindow ) &&
		( !Reply.GetUserFocusRecepient().IsValid()
#if PLATFORM_MAC
			|| (
				PointerEvent.GetEffectingButton() == EKeys::LeftMouseButton &&
				!DragDetector.IsDetectingDrag(PointerEvent)
			)
#endif
		)
	)
	{
		for ( int32 WidgetIndex = WidgetsUnderPointer.Widgets.Num() - 1; WidgetIndex >= 0; --WidgetIndex )
		{
			FArrangedWidget& CurWidget = WidgetsUnderPointer.Widgets[WidgetIndex];
			if ( CurWidget.Widget->SupportsKeyboardFocus() )
			{
				FWidgetPath NewFocusedWidgetPath = WidgetsUnderPointer.GetPathDownTo(CurWidget.Widget);
				SetUserFocus(PointerEvent.GetUserIndex(), NewFocusedWidgetPath, EFocusCause::Mouse);
				break;
			}
		}

#if PLATFORM_MAC
		const bool bIsVirtualInteraction = WidgetsUnderPointer.TopLevelWindow.IsValid() ? WidgetsUnderPointer.TopLevelWindow->IsVirtualWindow() : false;
		if ( !bIsVirtualInteraction )
		{
			TSharedPtr<SWindow> TopLevelWindow = WidgetsUnderPointer.TopLevelWindow;
			if ( bNeedToActivateWindow || ( TopLevelWindow.IsValid() && TopLevelWindow->GetNativeWindow()->GetOSWindowHandle() != ActiveWindow ) )
			{
				// Clicking on a context menu should not activate anything
				// @todo: This needs to be updated when we have window type in SWindow and we no longer have to guess if WidgetsUnderCursor.TopLevelWindow is a menu
				const bool bIsContextMenu = TopLevelWindow.IsValid() && !TopLevelWindow->IsRegularWindow() && TopLevelWindow->HasMinimizeBox() && TopLevelWindow->HasMaximizeBox();
				if ( !bIsContextMenu && PointerEvent.GetEffectingButton() == EKeys::LeftMouseButton && !DragDetector.IsDetectingDrag(PointerEvent) && ActiveWindow == [NSApp keyWindow] )
				{
					MouseCaptorHelper Captor = MouseCaptor;
					FPlatformMisc::ActivateApplication();
					if ( TopLevelWindow.IsValid() )
					{
						TopLevelWindow->BringToFront(true);
					}
					MouseCaptor = Captor;
				}
			}
		}
#endif
	}

	return Reply;
}


FReply FSlateApplication::RoutePointerUpEvent(FWidgetPath& WidgetsUnderPointer, FPointerEvent& PointerEvent)
{
	TScopeCounter<int32> BeginInput(ProcessingInput);

	FReply Reply = FReply::Unhandled();

#if PLATFORM_MAC
	NSWindow* ActiveNativeWindow = [NSApp keyWindow];
	TSharedPtr<SWindow> TopLevelWindow;
#endif

	// Update the drag detector, this release may stop a drag detection.
	DragDetector.OnPointerRelease(PointerEvent);

	if (MouseCaptor.HasCaptureForPointerIndex(PointerEvent.GetUserIndex(), PointerEvent.GetPointerIndex()))
	{
		//FWidgetPath MouseCaptorPath = MouseCaptor.ToWidgetPath(PointerEvent.GetPointerIndex());
		FWidgetPath MouseCaptorPath = MouseCaptor.ToWidgetPath( FWeakWidgetPath::EInterruptedPathHandling::Truncate, &PointerEvent );
		if ( ensureMsgf(MouseCaptorPath.Widgets.Num() > 0, TEXT("A window had a widget with mouse capture. That entire window has been dismissed before the mouse up could be processed.")) )
		{
			// Switch worlds widgets in the current path
			FScopedSwitchWorldHack SwitchWorld( MouseCaptorPath );

			Reply =
				FEventRouter::Route<FReply>( this, FEventRouter::FToLeafmostPolicy(MouseCaptorPath), PointerEvent, [this]( const FArrangedWidget& TargetWidget, const FPointerEvent& Event )
				{
					FReply TempReply = FReply::Unhandled();
					if (Event.IsTouchEvent())
					{
						TempReply = TargetWidget.Widget->OnTouchEnded( TargetWidget.Geometry, Event );
					}

					if (!Event.IsTouchEvent() || (!TempReply.IsEventHandled() && this->bTouchFallbackToMouse))
					{
						TempReply = TargetWidget.Widget->OnMouseButtonUp( TargetWidget.Geometry, Event );
					}
					return TempReply;
				});

#if PLATFORM_MAC
			TopLevelWindow = MouseCaptorPath.TopLevelWindow;
#endif
			LOG_EVENT( EEventLog::MouseButtonUp, Reply );
		}
	}
	else
	{
		FWidgetPath LocalWidgetsUnderCursor = WidgetsUnderPointer.IsValid() ? WidgetsUnderPointer : LocateWindowUnderMouse( PointerEvent.GetScreenSpacePosition(), GetInteractiveTopLevelWindows() );

		// Switch worlds widgets in the current path
		FScopedSwitchWorldHack SwitchWorld( LocalWidgetsUnderCursor );
		
		// Cache the drag drop content and reset the pointer in case OnMouseButtonUpMessage re-enters as a result of OnDrop
		const bool bIsDragDropping = IsDragDropping();
		TSharedPtr< FDragDropOperation > LocalDragDropContent = DragDropContent;
		DragDropContent.Reset();

		Reply = FEventRouter::Route<FReply>( this, FEventRouter::FBubblePolicy(LocalWidgetsUnderCursor), PointerEvent, [&](const FArrangedWidget& CurWidget, const FPointerEvent& Event)
		{
			if (bIsDragDropping)
			{
				return CurWidget.Widget->OnDrop(CurWidget.Geometry, FDragDropEvent(Event, LocalDragDropContent));
			}
			FReply TempReply = FReply::Unhandled();
			if (Event.IsTouchEvent())
			{
				TempReply = CurWidget.Widget->OnTouchEnded( CurWidget.Geometry, Event );
			}
			if (!Event.IsTouchEvent() || (!TempReply.IsEventHandled() && bTouchFallbackToMouse))
			{
				TempReply =  CurWidget.Widget->OnMouseButtonUp( CurWidget.Geometry, Event );
			}
			return TempReply;		
		});

		LOG_EVENT( bIsDragDropping ? EEventLog::DragDrop : EEventLog::MouseButtonUp, Reply );

		// If we were dragging, notify the content
		if ( bIsDragDropping )
		{
			// @todo slate : depending on SetEventPath() is not ideal.
			PointerEvent.SetEventPath( LocalWidgetsUnderCursor );
			LocalDragDropContent->OnDrop( Reply.IsEventHandled(), PointerEvent );

			WidgetsUnderCursorLastEvent.Remove( FUserAndPointer( PointerEvent.GetUserIndex(), PointerEvent.GetPointerIndex() ) );
		}
#if PLATFORM_MAC
		else if (ActiveNativeWindow == nullptr) // activate only if the app is in the background
		{
			TopLevelWindow = LocalWidgetsUnderCursor.TopLevelWindow;
		}
#endif
	}

#if PLATFORM_MAC
	// Activate a window under the mouse if it's inactive and mouse up didn't bring any window to front
	TSharedPtr<SWindow> ActiveWindow = GetActiveTopLevelWindow();
	if ( PointerEvent.GetEffectingButton() == EKeys::LeftMouseButton && TopLevelWindow.IsValid() && ActiveWindow != TopLevelWindow
		&& ActiveNativeWindow == [NSApp keyWindow] && ![(NSWindow*)TopLevelWindow->GetNativeWindow()->GetOSWindowHandle() isMiniaturized] )
	{
		FPlatformMisc::ActivateApplication();

		if ( !TopLevelWindow->IsVirtualWindow() )
		{
			TopLevelWindow->BringToFront(true);
		}
	}
#endif

	return Reply;
}

bool FSlateApplication::RoutePointerMoveEvent(const FWidgetPath& WidgetsUnderPointer, FPointerEvent& PointerEvent, bool bIsSynthetic)
{
	TScopeCounter<int32> BeginInput(ProcessingInput);

	bool bHandled = false;

	FWeakWidgetPath LastWidgetsUnderCursor;

	// User asked us to detect a drag.
	bool bDragDetected = false;
	bool bShouldStartDetectingDrag = true;

	//@TODO VREDITOR - Remove and move to interaction component
	if (OnDragDropCheckOverride.IsBound())
	{
		bShouldStartDetectingDrag = OnDragDropCheckOverride.Execute();
	}

	if ( !bIsSynthetic && bShouldStartDetectingDrag )
	{
		FWeakWidgetPath* DetectDragForWidget;
		bDragDetected = DragDetector.DetectDrag(PointerEvent, GetDragTriggerDistance(), DetectDragForWidget);
		if ( bDragDetected )
		{
			FWidgetPath DragDetectPath = DetectDragForWidget->ToWidgetPath(FWeakWidgetPath::EInterruptedPathHandling::ReturnInvalid);
			const TSharedPtr<SWidget> DragDetectRequestor = DetectDragForWidget->GetLastWidget().Pin();
			if ( DragDetectPath.IsValid() && DragDetectRequestor.IsValid() )
			{
				FWidgetAndPointer DetectDragForMe = DragDetectPath.FindArrangedWidgetAndCursor(DragDetectRequestor.ToSharedRef()).Get(FWidgetAndPointer());

				// A drag has been triggered. The cursor exited some widgets as a result.
				// This assignment ensures that we will send OnLeave notifications to those widgets.
				LastWidgetsUnderCursor = *DetectDragForWidget;

				DragDetector.ResetDetection();

				// Switch worlds widgets in the current path
				FScopedSwitchWorldHack SwitchWorld(DragDetectPath);

				// Send an OnDragDetected to the widget that requested drag-detection.
				FReply Reply = FEventRouter::Route<FReply>(this, FEventRouter::FDirectPolicy(DetectDragForMe, DragDetectPath), PointerEvent, [] (const FArrangedWidget& InDetectDragForMe, const FPointerEvent& TranslatedMouseEvent)
				{
					return InDetectDragForMe.Widget->OnDragDetected(InDetectDragForMe.Geometry, TranslatedMouseEvent);
				});

				LOG_EVENT(EEventLog::DragDetected, Reply);
			}
			else
			{
				bDragDetected = false;
			}
		}
	}


	if (bDragDetected)
	{
		// When a drag was detected, we pretend that the widgets under the mouse last time around.
		// We have set LastWidgetsUnderCursor accordingly when the drag was detected above.
	}
	else
	{
		// No Drag Detection
		LastWidgetsUnderCursor = WidgetsUnderCursorLastEvent.FindRef( FUserAndPointer( PointerEvent.GetUserIndex(), PointerEvent.GetPointerIndex() ) );
	}

	FWidgetPath MouseCaptorPath;
	if ( MouseCaptor.HasCaptureForPointerIndex(PointerEvent.GetUserIndex(), PointerEvent.GetPointerIndex()) )
	{
		//MouseCaptorPath = MouseCaptor.ToWidgetPath(MouseEvent.GetPointerIndex(), FWeakWidgetPath::EInterruptedPathHandling::ReturnInvalid);
		MouseCaptorPath = MouseCaptor.ToWidgetPath(FWeakWidgetPath::EInterruptedPathHandling::ReturnInvalid, &PointerEvent);
	}

	// Send out mouse leave events
	// If we are doing a drag and drop, we will send this event instead.
	{
		FDragDropEvent DragDropEvent( PointerEvent, DragDropContent );
		// Switch worlds widgets in the current path
		FScopedSwitchWorldHack SwitchWorld( LastWidgetsUnderCursor.Window.Pin() );

		for ( int32 WidgetIndex = LastWidgetsUnderCursor.Widgets.Num()-1; WidgetIndex >=0; --WidgetIndex )
		{
			// Guards for cases where WidgetIndex can become invalid due to MouseMove being re-entrant.
			while ( WidgetIndex >= LastWidgetsUnderCursor.Widgets.Num() )
			{
				WidgetIndex--;
			}

			if ( WidgetIndex >= 0 )
			{
				const TSharedPtr<SWidget>& SomeWidgetPreviouslyUnderCursor = LastWidgetsUnderCursor.Widgets[WidgetIndex].Pin();
				if( SomeWidgetPreviouslyUnderCursor.IsValid() )
				{
					TOptional<FArrangedWidget> FoundWidget = WidgetsUnderPointer.FindArrangedWidget( SomeWidgetPreviouslyUnderCursor.ToSharedRef() );
					const bool bWidgetNoLongerUnderMouse = !FoundWidget.IsSet();
					if ( bWidgetNoLongerUnderMouse )
					{
						// Widget is no longer under cursor, so send a MouseLeave.
						// The widget might not even be in the hierarchy any more!
						// Thus, we cannot translate the PointerPosition into the appropriate space for this event.
						if ( IsDragDropping() )
						{
							// Note that the event's pointer position is not translated.
							SomeWidgetPreviouslyUnderCursor->OnDragLeave( DragDropEvent );
							LOG_EVENT( EEventLog::DragLeave, SomeWidgetPreviouslyUnderCursor );

							// Reset the cursor override
							DragDropEvent.GetOperation()->SetCursorOverride( TOptional<EMouseCursor::Type>() );
						}
						else
						{
							// Only fire mouse leave events for widgets inside the captor path, or whoever if there is no captor path.
							if ( MouseCaptorPath.IsValid() == false || MouseCaptorPath.ContainsWidget(SomeWidgetPreviouslyUnderCursor.ToSharedRef()) )
							{
								// Note that the event's pointer position is not translated.
								SomeWidgetPreviouslyUnderCursor->OnMouseLeave(PointerEvent);
								LOG_EVENT(EEventLog::MouseLeave, SomeWidgetPreviouslyUnderCursor);
							}
						}			
					}
				}
			}
		}
	}


	

	if (MouseCaptorPath.IsValid())
	{
		if ( !bIsSynthetic )
		{
			// Switch worlds widgets in the current path
			FScopedSwitchWorldHack SwitchWorld( MouseCaptorPath );

			FEventRouter::Route<FNoReply>(this, FEventRouter::FBubblePolicy(WidgetsUnderPointer), PointerEvent, [&MouseCaptorPath, &LastWidgetsUnderCursor] (const FArrangedWidget& WidgetUnderCursor, const FPointerEvent& Event)
			{
				if ( !LastWidgetsUnderCursor.ContainsWidget(WidgetUnderCursor.Widget) )
				{
					if ( MouseCaptorPath.ContainsWidget(WidgetUnderCursor.Widget) )
					{
						WidgetUnderCursor.Widget->OnMouseEnter(WidgetUnderCursor.Geometry, Event);
					}
				}
				return FNoReply();
			});

			FReply Reply = FEventRouter::Route<FReply>( this, FEventRouter::FToLeafmostPolicy(MouseCaptorPath), PointerEvent, [this]( const FArrangedWidget& MouseCaptorWidget, const FPointerEvent& Event )
			{
				FReply TempReply = FReply::Unhandled();
				if (Event.IsTouchEvent())
				{
					TempReply = MouseCaptorWidget.Widget->OnTouchMoved( MouseCaptorWidget.Geometry, Event );
				}
				if (!Event.IsTouchEvent() || (!TempReply.IsEventHandled() && this->bTouchFallbackToMouse))
				{
					TempReply = MouseCaptorWidget.Widget->OnMouseMove( MouseCaptorWidget.Geometry, Event );
				}
				return TempReply;
			} );
			bHandled = Reply.IsEventHandled();
		}
	}
	else
	{	
		// Switch worlds widgets in the current path
		FScopedSwitchWorldHack SwitchWorld( WidgetsUnderPointer );

		// Send out mouse enter events.
		if (IsDragDropping())
		{
			FDragDropEvent DragDropEvent( PointerEvent, DragDropContent );
			FEventRouter::Route<FNoReply>( this, FEventRouter::FBubblePolicy(WidgetsUnderPointer), DragDropEvent, [&LastWidgetsUnderCursor](const FArrangedWidget& WidgetUnderCursor, const FDragDropEvent& InDragDropEvent)
			{
				if ( !LastWidgetsUnderCursor.ContainsWidget(WidgetUnderCursor.Widget) )
				{
					WidgetUnderCursor.Widget->OnDragEnter( WidgetUnderCursor.Geometry, InDragDropEvent );
				}
				return FNoReply();
			} );
		}
		else
		{
			FEventRouter::Route<FNoReply>(this, FEventRouter::FBubblePolicy(WidgetsUnderPointer), PointerEvent, [&LastWidgetsUnderCursor] (const FArrangedWidget& WidgetUnderCursor, const FPointerEvent& Event)
			{
				if ( !LastWidgetsUnderCursor.ContainsWidget(WidgetUnderCursor.Widget) )
				{
					WidgetUnderCursor.Widget->OnMouseEnter( WidgetUnderCursor.Geometry, Event );
				}
				return FNoReply();
			} );
		}
		
		// Bubble the MouseMove event.
		FReply Reply = FEventRouter::Route<FReply>(this, FEventRouter::FBubblePolicy(WidgetsUnderPointer), PointerEvent, [&](const FArrangedWidget& CurWidget, const FPointerEvent& Event)
		{
			FReply TempReply = FReply::Unhandled();

			if (Event.IsTouchEvent())
			{
				TempReply = CurWidget.Widget->OnTouchMoved( CurWidget.Geometry, Event );
			}
			if (!TempReply.IsEventHandled())
			{
				TempReply = (IsDragDropping())
					? CurWidget.Widget->OnDragOver( CurWidget.Geometry, FDragDropEvent( Event, DragDropContent ) )
					: CurWidget.Widget->OnMouseMove( CurWidget.Geometry, Event );
			}

			return TempReply;
		});

		LOG_EVENT( IsDragDropping() ? EEventLog::DragOver : EEventLog::MouseMove, Reply )

			bHandled = Reply.IsEventHandled();
	}

	// Give the current drag drop operation a chance to do something
	// custom (e.g. update the Drag/Drop preview based on content)
	if (IsDragDropping())
	{
		FDragDropEvent DragDropEvent( PointerEvent, DragDropContent );
		//@TODO VREDITOR - Remove and move to interaction component
		if (OnDragDropCheckOverride.IsBound() && DragDropEvent.GetOperation().IsValid())
		{
			DragDropEvent.GetOperation()->SetDecoratorVisibility(false);
			DragDropEvent.GetOperation()->SetCursorOverride(EMouseCursor::None);
			DragDropContent->SetCursorOverride(EMouseCursor::None);
		}
		FScopedSwitchWorldHack SwitchWorld( WidgetsUnderPointer );
		DragDropContent->OnDragged( DragDropEvent );

		// Update the window we're under for rendering the drag drop operation if
		// it's a windowless drag drop operation.
		if ( WidgetsUnderPointer.IsValid() )
		{
			DragDropWindowPtr = WidgetsUnderPointer.GetWindow();
		}
		else
		{
			DragDropWindowPtr = nullptr;
		}

		// Don't update the cursor for the platform if we don't have a valid cursor on this platform
		if ( PlatformApplication->Cursor.IsValid() )
		{
			FCursorReply CursorReply = DragDropContent->OnCursorQuery();
			if ( !CursorReply.IsEventHandled() )
			{
				// Set the default cursor when there isn't an active window under the cursor and the mouse isn't captured
				CursorReply = FCursorReply::Cursor(EMouseCursor::Default);
			}

			ProcessCursorReply(CursorReply);
		}
	}
	else
	{
		DragDropWindowPtr = nullptr;
	}

	WidgetsUnderCursorLastEvent.Add( FUserAndPointer( PointerEvent.GetUserIndex(), PointerEvent.GetPointerIndex() ), FWeakWidgetPath( WidgetsUnderPointer ) );

	PointerIndexLastPositionMap.Add(PointerEvent.GetPointerIndex(), PointerEvent.GetScreenSpacePosition());
	return bHandled;
}

bool FSlateApplication::OnMouseDoubleClick( const TSharedPtr< FGenericWindow >& PlatformWindow, const EMouseButtons::Type Button )
{
	return OnMouseDoubleClick(PlatformWindow, Button, GetCursorPos());
}

bool FSlateApplication::OnMouseDoubleClick( const TSharedPtr< FGenericWindow >& PlatformWindow, const EMouseButtons::Type Button, const FVector2D CursorPos )
{
	if (bIsFakingTouch || bIsGameFakingTouch)
	{
		bIsFakingTouched = true;
		return OnTouchStarted(PlatformWindow, PlatformApplication->Cursor->GetPosition(), 0, 0);
	}

	FKey Key = TranslateMouseButtonToKey( Button );

	FPointerEvent MouseEvent(
		CursorPointerIndex,
		CursorPos,
		GetLastCursorPos(),
		PressedMouseButtons,
		Key,
		0,
		PlatformApplication->GetModifierKeys()
		);

	return ProcessMouseButtonDoubleClickEvent( PlatformWindow, MouseEvent );
}

bool FSlateApplication::ProcessMouseButtonDoubleClickEvent( const TSharedPtr< FGenericWindow >& PlatformWindow, FPointerEvent& InMouseEvent )
{
	SCOPE_CYCLE_COUNTER(STAT_ProcessMouseButtonDoubleClick);

	QueueSynthesizedMouseMove();
	SetLastUserInteractionTime(this->GetCurrentTime());
	LastUserInteractionTimeForThrottling = LastUserInteractionTime;
	
	PlatformApplication->SetCapture( PlatformWindow );
	PressedMouseButtons.Add( InMouseEvent.GetEffectingButton() );

	if (MouseCaptor.HasCaptureForPointerIndex(InMouseEvent.GetUserIndex(), InMouseEvent.GetPointerIndex()))
	{
		// If a widget has mouse capture, we've opted to simply treat this event as a mouse down
		return ProcessMouseButtonDownEvent(PlatformWindow, InMouseEvent);
	}
	
	FWidgetPath WidgetsUnderCursor = LocateWindowUnderMouse(InMouseEvent.GetScreenSpacePosition(), GetInteractiveTopLevelWindows());

	FReply Reply = RoutePointerDoubleClickEvent( WidgetsUnderCursor, InMouseEvent );

	PointerIndexLastPositionMap.Add(InMouseEvent.GetPointerIndex(), InMouseEvent.GetScreenSpacePosition());
	
	return Reply.IsEventHandled();
}


FReply FSlateApplication::RoutePointerDoubleClickEvent(FWidgetPath& WidgetsUnderPointer, FPointerEvent& PointerEvent)
{
	TScopeCounter<int32> BeginInput(ProcessingInput);

	FReply Reply = FReply::Unhandled();

	// Switch worlds widgets in the current path
	FScopedSwitchWorldHack SwitchWorld( WidgetsUnderPointer );

	Reply = FEventRouter::Route<FReply>( this, FEventRouter::FBubblePolicy( WidgetsUnderPointer ), PointerEvent, []( const FArrangedWidget& TargetWidget, const FPointerEvent& Event )
	{
		return TargetWidget.Widget->OnMouseButtonDoubleClick( TargetWidget.Geometry, Event );
	} );

	LOG_EVENT( EEventLog::MouseButtonDoubleClick, Reply );

	return Reply;
}


bool FSlateApplication::OnMouseUp( const EMouseButtons::Type Button )
{
	return OnMouseUp(Button, GetCursorPos());
}

bool FSlateApplication::OnMouseUp( const EMouseButtons::Type Button, const FVector2D CursorPos )
{
	// convert to touch event if we are faking it	
	if (bIsFakingTouch || bIsGameFakingTouch)
	{
		bIsFakingTouched = false;
		return OnTouchEnded(PlatformApplication->Cursor->GetPosition(), 0, 0);
	}

	FKey Key = TranslateMouseButtonToKey( Button );

	FPointerEvent MouseEvent(
		CursorPointerIndex,
		CursorPos,
		GetLastCursorPos(),
		PressedMouseButtons,
		Key,
		0,
		PlatformApplication->GetModifierKeys()
		);

	return ProcessMouseButtonUpEvent( MouseEvent );
}

bool FSlateApplication::ProcessMouseButtonUpEvent( FPointerEvent& MouseEvent )
{
	SCOPE_CYCLE_COUNTER(STAT_ProcessMouseButtonUp);

	QueueSynthesizedMouseMove();
	SetLastUserInteractionTime(this->GetCurrentTime());
	LastUserInteractionTimeForThrottling = LastUserInteractionTime;
	PressedMouseButtons.Remove( MouseEvent.GetEffectingButton() );

	// Input preprocessor gets first chance at the input
	if( InputPreProcessor.IsValid() && InputPreProcessor->HandleMouseButtonUpEvent( *this, MouseEvent ) )
	{
		return true;
	}

	// An empty widget path is passed in.  As an optimization, one will be generated only if a captured mouse event isn't routed
	FWidgetPath EmptyPath;
	const bool bHandled = RoutePointerUpEvent( EmptyPath, MouseEvent ).IsEventHandled();

	// If in responsive mode throttle, leave it on mouse up.
	if( MouseButtonDownResponsivnessThrottle.IsValid() )
	{
		FSlateThrottleManager::Get().LeaveResponsiveMode( MouseButtonDownResponsivnessThrottle );
	}

	if ( PressedMouseButtons.Num() == 0 )
	{
		// Release Capture
		PlatformApplication->SetCapture( nullptr );
	}

	return bHandled;
}

bool FSlateApplication::OnMouseWheel( const float Delta )
{
	return OnMouseWheel(Delta, GetCursorPos());
}

bool FSlateApplication::OnMouseWheel( const float Delta, const FVector2D CursorPos )
{
	FPointerEvent MouseWheelEvent(
		CursorPointerIndex,
		CursorPos,
		CursorPos,
		PressedMouseButtons,
		EKeys::Invalid,
		Delta,
		PlatformApplication->GetModifierKeys()
		);

	return ProcessMouseWheelOrGestureEvent( MouseWheelEvent, nullptr );
}

bool FSlateApplication::ProcessMouseWheelOrGestureEvent( FPointerEvent& InWheelEvent, const FPointerEvent* InGestureEvent )
{
	SCOPE_CYCLE_COUNTER(STAT_ProcessMouseWheelGesture);

	QueueSynthesizedMouseMove();

	const bool bShouldProcessEvent = InWheelEvent.GetWheelDelta() != 0 ||
		(InGestureEvent != nullptr && InGestureEvent->GetGestureDelta() != FVector2D::ZeroVector);
	
	if ( !bShouldProcessEvent )
	{
		return false;
	}

	SetLastUserInteractionTime(this->GetCurrentTime());
	
	// NOTE: We intentionally don't reset LastUserInteractionTimeForThrottling here so that the UI can be responsive while scrolling

	FWidgetPath EventPath = LocateWindowUnderMouse(InWheelEvent.GetScreenSpacePosition(), GetInteractiveTopLevelWindows());

	return RouteMouseWheelOrGestureEvent(EventPath, InWheelEvent, InGestureEvent).IsEventHandled();
}

FReply FSlateApplication::RouteMouseWheelOrGestureEvent(const FWidgetPath& WidgetsUnderPointer, const FPointerEvent& InWheelEvent, const FPointerEvent* InGestureEvent)
{
	TScopeCounter<int32> BeginInput(ProcessingInput);

	FWidgetPath MouseCaptorPath;
	if ( MouseCaptor.HasCaptureForPointerIndex(InWheelEvent.GetUserIndex(), InWheelEvent.GetPointerIndex()) )
	{
		MouseCaptorPath = MouseCaptor.ToWidgetPath(FWeakWidgetPath::EInterruptedPathHandling::ReturnInvalid, &InWheelEvent);
	}

	const FWidgetPath& EventPath = MouseCaptorPath.IsValid() ? MouseCaptorPath : WidgetsUnderPointer;

	// Switch worlds widgets in the current path
	FScopedSwitchWorldHack SwitchWorld(EventPath);

	FReply Reply = FEventRouter::Route<FReply>(this, FEventRouter::FBubblePolicy(EventPath), InWheelEvent, [&InGestureEvent] (const FArrangedWidget& CurWidget, const FPointerEvent& Event)
	{
		FReply TempReply = FReply::Unhandled();
		// Gesture event gets first shot, if slate doesn't respond to it, we'll try the wheel event.
		if ( InGestureEvent != nullptr && InGestureEvent->GetGestureDelta() != FVector2D::ZeroVector )
		{
			TempReply = CurWidget.Widget->OnTouchGesture(CurWidget.Geometry, *InGestureEvent);
		}

		// Send the mouse wheel event if we haven't already handled the gesture version of this event.
		if ( !TempReply.IsEventHandled() && Event.GetWheelDelta() != 0 )
		{
			TempReply = CurWidget.Widget->OnMouseWheel(CurWidget.Geometry, Event);
		}

		return TempReply;
	});

	LOG_EVENT(InGestureEvent ? EEventLog::TouchGesture : EEventLog::MouseWheel, Reply);

	return Reply;
}

bool FSlateApplication::OnMouseMove()
{
	// convert to touch event if we are faking it	
	if (bIsFakingTouched)
	{
		return OnTouchMoved(PlatformApplication->Cursor->GetPosition(), 0, 0);
	}
	else if (!bIsGameFakingTouch && bIsFakingTouch)
	{
		return false;
	}

	bool Result = true;
	const FVector2D CurrentCursorPosition = GetCursorPos();
	const FVector2D LastCursorPosition = GetLastCursorPos();
	if ( LastCursorPosition != CurrentCursorPosition )
	{
		LastMouseMoveTime = GetCurrentTime();

		FPointerEvent MouseEvent(
			CursorPointerIndex,
			CurrentCursorPosition,
			LastCursorPosition,
			PressedMouseButtons,
			EKeys::Invalid,
			0,
			PlatformApplication->GetModifierKeys()
			);

		if (InputPreProcessor.IsValid() && InputPreProcessor->HandleMouseMoveEvent(*this, MouseEvent))
		{
			return true;
		}

		Result = ProcessMouseMoveEvent( MouseEvent );
	}

	return Result;
}

bool FSlateApplication::OnRawMouseMove( const int32 X, const int32 Y )
{
	if (bIsFakingTouched)
	{
		return OnTouchMoved(GetCursorPos(), 0, 0);
	}
	
	if ( X != 0 || Y != 0 )
	{
		FPointerEvent MouseEvent(
			CursorPointerIndex,
			GetCursorPos(),
			GetLastCursorPos(),
			FVector2D( X, Y ), 
			PressedMouseButtons,
			PlatformApplication->GetModifierKeys()
		);

		if (InputPreProcessor.IsValid() && InputPreProcessor->HandleMouseMoveEvent(*this, MouseEvent))
		{
			return true;
		}

		ProcessMouseMoveEvent(MouseEvent);
	}
	
	return true;
}

bool FSlateApplication::ProcessMouseMoveEvent( FPointerEvent& MouseEvent, bool bIsSynthetic )
{
	SCOPE_CYCLE_COUNTER(STAT_ProcessMouseMove);

	if ( !bIsSynthetic )
	{
		QUICK_SCOPE_CYCLE_COUNTER(STAT_ProcessMouseMove_Tooltip);

		QueueSynthesizedMouseMove();

		// Detecting a mouse move of zero delta is our way of filtering out synthesized move events
		const bool AllowSpawningOfToolTips = true;
		UpdateToolTip( AllowSpawningOfToolTips );
		
		// Guard against synthesized mouse moves and only track user interaction if the cursor pos changed
		SetLastUserInteractionTime(this->GetCurrentTime());
	}

	// When the event came from the OS, we are guaranteed to be over a slate window.
	// Otherwise, we are synthesizing a MouseMove ourselves, and must verify that the
	// cursor is indeed over a Slate window.
	const bool bOverSlateWindow = !bIsSynthetic || PlatformApplication->IsCursorDirectlyOverSlateWindow();
	
	FWidgetPath WidgetsUnderCursor = bOverSlateWindow
		? LocateWindowUnderMouse(MouseEvent.GetScreenSpacePosition(), GetInteractiveTopLevelWindows())
		: FWidgetPath();

	bool bResult;

	{
		QUICK_SCOPE_CYCLE_COUNTER(STAT_ProcessMouseMove_RoutePointerMoveEvent);
		bResult = RoutePointerMoveEvent(WidgetsUnderCursor, MouseEvent, bIsSynthetic);
	}

	return bResult;
}

bool FSlateApplication::OnCursorSet()
{
	bQueryCursorRequested = true;
	return true;
}

void FSlateApplication::NavigateToWidget(const uint32 UserIndex, const TSharedPtr<SWidget>& NavigationDestination, ENavigationSource NavigationSource)
{
	if (NavigationDestination.IsValid())
	{
		FWidgetPath NavigationSourceWP;
		if (NavigationSource == ENavigationSource::WidgetUnderCursor)
		{
			NavigationSourceWP = LocateWindowUnderMouse(GetCursorPos(), GetInteractiveTopLevelWindows());
		}
		else if (const FSlateUser* User = GetOrCreateUser(UserIndex))
		{
			const FUserFocusEntry& UserFocusEntry = User->Focus;
			NavigationSourceWP = UserFocusEntry.WidgetPath.ToWidgetPath();
		}

		if (NavigationSourceWP.IsValid())
		{
			ExecuteNavigation(NavigationSourceWP, NavigationDestination, UserIndex);
		}
	}
}

bool FSlateApplication::AttemptNavigation(const FWidgetPath& NavigationSource, const FNavigationEvent& NavigationEvent, const FNavigationReply& NavigationReply, const FArrangedWidget& BoundaryWidget)
{
	if ( !NavigationSource.IsValid() )
	{
		return false;
	}

	TSharedPtr<SWidget> DestinationWidget = TSharedPtr<SWidget>();

	EUINavigation NavigationType = NavigationEvent.GetNavigationType();
	if ( NavigationReply.GetBoundaryRule() == EUINavigationRule::Explicit )
	{
		DestinationWidget = NavigationReply.GetFocusRecipient();
	}
	else if ( NavigationReply.GetBoundaryRule() == EUINavigationRule::Custom )
	{
		const FNavigationDelegate& FocusDelegate = NavigationReply.GetFocusDelegate();
		if ( FocusDelegate.IsBound() )
		{
			DestinationWidget = FocusDelegate.Execute(NavigationType);
		}
	}
	else
	{
		// Find the next widget
		if (NavigationType == EUINavigation::Next || NavigationType == EUINavigation::Previous)
		{
			// Fond the next widget
			FWeakWidgetPath WeakNavigationSource(NavigationSource);
			FWidgetPath NewFocusedWidgetPath = WeakNavigationSource.ToNextFocusedPath(NavigationType, NavigationReply, BoundaryWidget);

			// Resolve the Widget Path
			FArrangedWidget& NewFocusedArrangedWidget = NewFocusedWidgetPath.Widgets.Last();
			DestinationWidget = NewFocusedArrangedWidget.Widget;
		}
		else
		{
			// Resolve the Widget Path
			const FArrangedWidget& FocusedArrangedWidget = NavigationSource.Widgets.Last();

			// Switch worlds for widgets in the current path 
			FScopedSwitchWorldHack SwitchWorld(NavigationSource);

			DestinationWidget = NavigationSource.GetWindow()->GetHittestGrid()->FindNextFocusableWidget(FocusedArrangedWidget, NavigationType, NavigationReply, BoundaryWidget);
		}
	}

	return ExecuteNavigation(NavigationSource, DestinationWidget, NavigationEvent.GetUserIndex());
}

bool FSlateApplication::ExecuteNavigation(const FWidgetPath& NavigationSource, TSharedPtr<SWidget> DestinationWidget, const uint32 UserIndex)
{
	bool bHandled = false;

	// Give the custom viewport navigation event handler a chance to handle the navigation if the NavigationSource is contained within it.
	TSharedPtr<ISlateViewport> Viewport = NavigationSource.GetWindow()->GetViewport();
	if (Viewport.IsValid())
	{
		TSharedPtr<SWidget> ViewportWidget = Viewport->GetWidget().Pin();
		if (ViewportWidget.IsValid())
		{
			if (NavigationSource.ContainsWidget(ViewportWidget.ToSharedRef()))
			{
				bHandled = Viewport->HandleNavigation(UserIndex, DestinationWidget);
			}
		}
	}

	// Set controller focus if the navigation hasn't been handled have a valid widget
	if (!bHandled && DestinationWidget.IsValid())
	{
		SetUserFocus(UserIndex, DestinationWidget, EFocusCause::Navigation);
		bHandled = true;
	}

	return bHandled;
}

bool FSlateApplication::OnControllerAnalog( FGamepadKeyNames::Type KeyName, int32 ControllerId, float AnalogValue )
{
	FKey Key(KeyName);
	check(Key.IsValid());

	int32 UserIndex = GetUserIndexForController(ControllerId);
	
	FAnalogInputEvent AnalogInputEvent(Key, PlatformApplication->GetModifierKeys(), UserIndex, false, 0, 0, AnalogValue);

	return ProcessAnalogInputEvent(AnalogInputEvent);
}

bool FSlateApplication::OnControllerButtonPressed( FGamepadKeyNames::Type KeyName, int32 ControllerId, bool IsRepeat )
{
	FKey Key(KeyName);
	check(Key.IsValid());

	int32 UserIndex = GetUserIndexForController(ControllerId);

	FKeyEvent KeyEvent(Key, PlatformApplication->GetModifierKeys(), UserIndex, IsRepeat, 0, 0);

	return ProcessKeyDownEvent(KeyEvent);
}

bool FSlateApplication::OnControllerButtonReleased( FGamepadKeyNames::Type KeyName, int32 ControllerId, bool IsRepeat )
{
	FKey Key(KeyName);
	check(Key.IsValid());

	int32 UserIndex = GetUserIndexForController(ControllerId);
	
	FKeyEvent KeyEvent(Key, PlatformApplication->GetModifierKeys(),UserIndex, IsRepeat,  0, 0);

	return ProcessKeyUpEvent(KeyEvent);
}

bool FSlateApplication::OnTouchGesture( EGestureEvent::Type GestureType, const FVector2D &Delta, const float MouseWheelDelta, bool bIsDirectionInvertedFromDevice )
{
	const FVector2D CurrentCursorPosition = GetCursorPos();
	
	FPointerEvent GestureEvent(
		CurrentCursorPosition,
		CurrentCursorPosition,
		PressedMouseButtons,
		PlatformApplication->GetModifierKeys(),
		GestureType,
		Delta,
		bIsDirectionInvertedFromDevice
	);
	
	FPointerEvent MouseWheelEvent(
		CursorPointerIndex,
		CurrentCursorPosition,
		CurrentCursorPosition,
		PressedMouseButtons,
		EKeys::Invalid,
		MouseWheelDelta,
		PlatformApplication->GetModifierKeys()
	);
	
	return ProcessMouseWheelOrGestureEvent( MouseWheelEvent, &GestureEvent );
}

bool FSlateApplication::OnTouchStarted( const TSharedPtr< FGenericWindow >& PlatformWindow, const FVector2D& Location, int32 TouchIndex, int32 ControllerId )
{
	FPointerEvent PointerEvent(
		ControllerId,
		TouchIndex,
		Location,
		Location,
		true);
	ProcessTouchStartedEvent( PlatformWindow, PointerEvent );

	return true;
}

void FSlateApplication::ProcessTouchStartedEvent( const TSharedPtr< FGenericWindow >& PlatformWindow, FPointerEvent& PointerEvent )
{
	ProcessMouseButtonDownEvent( PlatformWindow, PointerEvent );
}

bool FSlateApplication::OnTouchMoved( const FVector2D& Location, int32 TouchIndex, int32 ControllerId )
{
	FVector2D LastLocation = PointerIndexLastPositionMap.Contains(TouchIndex) ? 
		PointerIndexLastPositionMap[TouchIndex] : Location;
	FPointerEvent PointerEvent(
		ControllerId,
		TouchIndex,
		Location,
		LastLocation,
		true);
	ProcessTouchMovedEvent(PointerEvent);

	return true;
}

void FSlateApplication::ProcessTouchMovedEvent( FPointerEvent& PointerEvent )
{
	ProcessMouseMoveEvent(PointerEvent);
}

bool FSlateApplication::OnTouchEnded( const FVector2D& Location, int32 TouchIndex, int32 ControllerId )
{
	FPointerEvent PointerEvent(
		ControllerId,
		TouchIndex,
		Location,
		Location,
		true);
	ProcessTouchEndedEvent(PointerEvent);

	return true;
}

void FSlateApplication::ProcessTouchEndedEvent( FPointerEvent& PointerEvent )
{
	ProcessMouseButtonUpEvent(PointerEvent);
}

bool FSlateApplication::OnMotionDetected(const FVector& Tilt, const FVector& RotationRate, const FVector& Gravity, const FVector& Acceleration, int32 ControllerId)
{
	FMotionEvent MotionEvent( 
		ControllerId,
		Tilt,
		RotationRate,
		Gravity,
		Acceleration
		);
	ProcessMotionDetectedEvent(MotionEvent);

	return true;
}

void FSlateApplication::ProcessMotionDetectedEvent( FMotionEvent& MotionEvent )
{
	QueueSynthesizedMouseMove();
	SetLastUserInteractionTime(this->GetCurrentTime());
	
	if ( FSlateUser* User = GetOrCreateUser(MotionEvent.GetUserIndex()) )
	{
		if (InputPreProcessor.IsValid() && InputPreProcessor->HandleMotionDetectedEvent(*this, MotionEvent))
		{
			return;
		}

		if ( User->Focus.WidgetPath.IsValid() )
		{
			/* Get the controller focus target for this user */
			const FWidgetPath PathToWidget = User->Focus.WidgetPath.ToWidgetPath();

			FScopedSwitchWorldHack SwitchWorld(PathToWidget);

			FReply Reply = FEventRouter::Route<FReply>(this, FEventRouter::FBubblePolicy(PathToWidget), MotionEvent, [] (const FArrangedWidget& SomeWidget, const FMotionEvent& InMotionEvent)
			{
				return SomeWidget.Widget->OnMotionDetected(SomeWidget.Geometry, InMotionEvent);
			});
		}
	}
}

bool FSlateApplication::OnSizeChanged( const TSharedRef< FGenericWindow >& PlatformWindow, const int32 Width, const int32 Height, bool bWasMinimized )
{
	TSharedPtr< SWindow > Window = FSlateWindowHelper::FindWindowByPlatformWindow( SlateWindows, PlatformWindow );

	if ( Window.IsValid() )
	{
		Window->SetCachedSize( FVector2D( Width, Height ) );

		Renderer->RequestResize( Window, Width, Height );

		if ( !bWasMinimized && Window->IsRegularWindow() && !Window->HasOSWindowBorder() && Window->IsVisible() && Window->IsDrawingEnabled() )
		{
			PrivateDrawWindows( Window );
		}

		if( !bWasMinimized && Window->IsVisible() && Window->IsRegularWindow() && Window->IsAutosized() )
		{
			// Reduces flickering due to one frame lag when windows are resized automatically
			Renderer->FlushCommands();
		}

		// Inform the notification manager we have activated a window - it may want to force notifications 
		// back to the front of the z-order
		FSlateNotificationManager::Get().ForceNotificationsInFront( Window.ToSharedRef() );
	}

	return true;
}

void FSlateApplication::OnOSPaint( const TSharedRef< FGenericWindow >& PlatformWindow )
{
	TSharedPtr< SWindow > Window = FSlateWindowHelper::FindWindowByPlatformWindow( SlateWindows, PlatformWindow );
	PrivateDrawWindows( Window );
	Renderer->FlushCommands();
}

FWindowSizeLimits FSlateApplication::GetSizeLimitsForWindow(const TSharedRef<FGenericWindow>& Window) const
{
	TSharedPtr<SWindow> SlateWindow = FSlateWindowHelper::FindWindowByPlatformWindow(SlateWindows, Window);
	if (SlateWindow.IsValid())
	{
		return SlateWindow->GetSizeLimits();
	}
	else
	{
		return FWindowSizeLimits();
	}

}

void FSlateApplication::OnResizingWindow( const TSharedRef< FGenericWindow >& PlatformWindow )
{
	// Flush the rendering command queue to ensure that there aren't pending viewport draw commands for the old viewport size.
	Renderer->FlushCommands();
}

bool FSlateApplication::BeginReshapingWindow( const TSharedRef< FGenericWindow >& PlatformWindow )
{
	if(!IsExternalUIOpened())
	{
		if (!ThrottleHandle.IsValid())
		{
			ThrottleHandle = FSlateThrottleManager::Get().EnterResponsiveMode();
		}

		return true;
	}

	return false;
}

void FSlateApplication::FinishedReshapingWindow( const TSharedRef< FGenericWindow >& PlatformWindow )
{
	if (ThrottleHandle.IsValid())
	{
		FSlateThrottleManager::Get().LeaveResponsiveMode(ThrottleHandle);
	}
}

void FSlateApplication::OnMovedWindow( const TSharedRef< FGenericWindow >& PlatformWindow, const int32 X, const int32 Y )
{
	TSharedPtr< SWindow > Window = FSlateWindowHelper::FindWindowByPlatformWindow( SlateWindows, PlatformWindow );

	if ( Window.IsValid() )
	{
		Window->SetCachedScreenPosition( FVector2D( X, Y ) );
	}
}

FWindowActivateEvent::EActivationType TranslationWindowActivationMessage( const EWindowActivation::Type ActivationType )
{
	FWindowActivateEvent::EActivationType Result = FWindowActivateEvent::EA_Activate;

	switch( ActivationType )
	{
	case EWindowActivation::Activate:
		Result = FWindowActivateEvent::EA_Activate;
		break;
	case EWindowActivation::ActivateByMouse:
		Result = FWindowActivateEvent::EA_ActivateByMouse;
		break;
	case EWindowActivation::Deactivate:
		Result = FWindowActivateEvent::EA_Deactivate;
		break;
	default:
		check( false );
	}

	return Result;
}

bool FSlateApplication::OnWindowActivationChanged( const TSharedRef< FGenericWindow >& PlatformWindow, const EWindowActivation::Type ActivationType )
{
	TSharedPtr< SWindow > Window = FSlateWindowHelper::FindWindowByPlatformWindow( SlateWindows, PlatformWindow );

	if ( !Window.IsValid() )
	{
		return false;
	}

	FWindowActivateEvent::EActivationType TranslatedActivationType = TranslationWindowActivationMessage( ActivationType );
	FWindowActivateEvent WindowActivateEvent( TranslatedActivationType, Window.ToSharedRef() );

	return ProcessWindowActivatedEvent( WindowActivateEvent );
}

bool FSlateApplication::ProcessWindowActivatedEvent( const FWindowActivateEvent& ActivateEvent )
{
	//UE_LOG(LogSlate, Warning, TEXT("Window being %s: %p"), ActivateEvent.GetActivationType() == FWindowActivateEvent::EA_Deactivate ? TEXT("Deactivated") : TEXT("Activated"), &(ActivateEvent.GetAffectedWindow().Get()));

	TSharedPtr<SWindow> ActiveModalWindow = GetActiveModalWindow();

	if ( ActivateEvent.GetActivationType() != FWindowActivateEvent::EA_Deactivate )
	{
		const bool bActivatedByMouse = ActivateEvent.GetActivationType() == FWindowActivateEvent::EA_ActivateByMouse;
		
		// Only window activate by mouse is considered a user interaction
		if (bActivatedByMouse)
		{
			SetLastUserInteractionTime(this->GetCurrentTime());
		}
		
		// Widgets that happen to be under the mouse need to update if activation changes
		// This also serves as a force redraw which is needed when restoring a window that was previously inactive.
		QueueSynthesizedMouseMove();

		// NOTE: The window is brought to front even when a modal window is active and this is not the modal window one of its children 
		// The reason for this is so that the Slate window order is in sync with the OS window order when a modal window is open.  This is important so that when the modal window closes the proper window receives input from Slate.
		// If you change this be sure to test windows are activated properly and receive input when they are opened when a modal dialog is open.
		FSlateWindowHelper::BringWindowToFront(SlateWindows, ActivateEvent.GetAffectedWindow());

		// Do not process activation messages unless we have no modal windows or the current window is modal
		if( !ActiveModalWindow.IsValid() || ActivateEvent.GetAffectedWindow() == ActiveModalWindow || ActivateEvent.GetAffectedWindow()->IsDescendantOf(ActiveModalWindow) )
		{
			// Window being ACTIVATED
			{
				// Switch worlds widgets in the current path
				FScopedSwitchWorldHack SwitchWorld( ActivateEvent.GetAffectedWindow() );
				ActivateEvent.GetAffectedWindow()->OnIsActiveChanged( ActivateEvent );
			}

			if ( ActivateEvent.GetAffectedWindow()->IsRegularWindow() )
			{
				ActiveTopLevelWindow = ActivateEvent.GetAffectedWindow();
			}

			// A Slate window was activated
			bSlateWindowActive = true;


			{
				FScopedSwitchWorldHack SwitchWorld( ActivateEvent.GetAffectedWindow() );
				// let the menu stack know of new window being activated.  We may need to close menus as a result
				MenuStack.OnWindowActivated( ActivateEvent.GetAffectedWindow() );
			}

			// Inform the notification manager we have activated a window - it may want to force notifications 
			// back to the front of the z-order
			FSlateNotificationManager::Get().ForceNotificationsInFront( ActivateEvent.GetAffectedWindow() );

			// As we've just been activated, attempt to restore the resolution that the engine previously cached.
			// This allows us to force ourselves back to the correct resolution after alt-tabbing out of a fullscreen
			// window and then going back in again.
			Renderer->RestoreSystemResolution(ActivateEvent.GetAffectedWindow());

			// Synthesize mouse move to resume rendering in the next tick if Slate is sleeping
			QueueSynthesizedMouseMove();
		}
		else
		{
			// An attempt is being made to activate another window when a modal window is running
			ActiveModalWindow->BringToFront();
			ActiveModalWindow->FlashWindow();
		}

		
		TSharedRef<SWindow> Window = ActivateEvent.GetAffectedWindow();
		TSharedPtr<ISlateViewport> Viewport = Window->GetViewport();
		if (Viewport.IsValid())
		{
			TSharedPtr<SWidget> ViewportWidgetPtr = Viewport->GetWidget().Pin();
			if (ViewportWidgetPtr.IsValid())
			{
				TArray< TSharedRef<SWindow> > JustThisWindow;
				JustThisWindow.Add(Window);

				FWidgetPath PathToViewport;
				if (FSlateWindowHelper::FindPathToWidget(JustThisWindow, ViewportWidgetPtr.ToSharedRef(), PathToViewport, EVisibility::All))
				{
					// Activate the viewport and process the reply 
					FReply ViewportActivatedReply = Viewport->OnViewportActivated(ActivateEvent);
					if (ViewportActivatedReply.IsEventHandled())
					{
						ProcessReply(PathToViewport, ViewportActivatedReply, nullptr, nullptr);
					}
				}
			}
		}
	}
	else
	{
		// Window being DEACTIVATED

		// If our currently-active top level window was deactivated, take note of that
		if ( ActivateEvent.GetAffectedWindow()->IsRegularWindow() &&
			ActivateEvent.GetAffectedWindow() == ActiveTopLevelWindow.Pin() )
		{
			ActiveTopLevelWindow.Reset();
		}

		// A Slate window was deactivated.  Currently there is no active Slate window
		bSlateWindowActive = false;

		// Switch worlds for the activated window
		FScopedSwitchWorldHack SwitchWorld( ActivateEvent.GetAffectedWindow() );
		ActivateEvent.GetAffectedWindow()->OnIsActiveChanged( ActivateEvent );

		TSharedRef<SWindow> Window = ActivateEvent.GetAffectedWindow();
		TSharedPtr<ISlateViewport> Viewport = Window->GetViewport();
		if (Viewport.IsValid())
		{
			Viewport->OnViewportDeactivated(ActivateEvent);
		}

		// A window was deactivated; mouse capture should be cleared
		ResetToDefaultPointerInputSettings();
	}

	return true;
}

bool FSlateApplication::OnApplicationActivationChanged( const bool IsActive )
{
	ProcessApplicationActivationEvent( IsActive );
	return true;
}

void FSlateApplication::ProcessApplicationActivationEvent(bool InAppActivated)
{
	const bool UserSwitchedAway = bAppIsActive && !InAppActivated;

	bAppIsActive = InAppActivated;

	// If the user switched to a different application then we should dismiss our pop-ups.  In the case
	// where a user clicked on a different Slate window, OnWindowActivatedMessage() will be call MenuStack.OnWindowActivated()
	// to destroy any windows in our stack that are no longer appropriate to be displayed.
	if (UserSwitchedAway)
	{
		// Close pop-up menus
		DismissAllMenus();

		// Close tool-tips
		CloseToolTip();

		// No slate window is active when our entire app becomes inactive
		bSlateWindowActive = false;

		// If we have a slate-only drag-drop occurring, stop the drag drop.
		if (IsDragDropping() && !DragDropContent->IsExternalOperation())
		{
			DragDropContent.Reset();
		}
	}
	else
	{
		//Ensure that slate ticks/renders next frame
		QueueSynthesizedMouseMove();
	}

	OnApplicationActivationStateChanged().Broadcast(InAppActivated);
}


void FSlateApplication::SetNavigationConfig(TSharedRef<FNavigationConfig> Config)
{
	NavigationConfig = Config;
}

bool FSlateApplication::OnConvertibleLaptopModeChanged()
{
	EConvertibleLaptopMode NewMode = FPlatformMisc::GetConvertibleLaptopMode();

	// Notify that we want the mobile experience when in tablet mode, otherwise use mouse and keyboard
	if (!(FParse::Param(FCommandLine::Get(), TEXT("simmobile")) || FParse::Param(FCommandLine::Get(), TEXT("faketouches"))))
	{
		// Not sure what the correct long-term strategy is. Use bIsFakingTouch for now to get things going.
		if (NewMode == EConvertibleLaptopMode::Tablet)
		{
			bIsFakingTouch = true;
		}
		else
		{
			bIsFakingTouch = false;
		}
	}

	FCoreDelegates::PlatformChangedLaptopMode.Broadcast(NewMode);

	return true;
}


EWindowZone::Type FSlateApplication::GetWindowZoneForPoint( const TSharedRef< FGenericWindow >& PlatformWindow, const int32 X, const int32 Y )
{
	TSharedPtr< SWindow > Window = FSlateWindowHelper::FindWindowByPlatformWindow( SlateWindows, PlatformWindow );

	if ( Window.IsValid() )
	{
		return Window->GetCurrentWindowZone( FVector2D( X, Y ) );
	}

	return EWindowZone::NotInWindow;
}


void FSlateApplication::PrivateDestroyWindow( const TSharedRef<SWindow>& DestroyedWindow )
{
	// Notify the window that it is going to be destroyed.  The window must be completely intact when this is called 
	// because delegates are allowed to leave Slate here
	DestroyedWindow->NotifyWindowBeingDestroyed();

	// Release rendering resources.  
	// This MUST be done before destroying the native window as the native window is required to be valid before releasing rendering resources with some API's
	Renderer->OnWindowDestroyed( DestroyedWindow );

	// Destroy the native window
	DestroyedWindow->DestroyWindowImmediately();

	// Remove the window and all its children from the Slate window list
	FSlateWindowHelper::RemoveWindowFromList(SlateWindows, DestroyedWindow);

	// Shutdown the application if there are no more windows
	{
		bool bAnyRegularWindows = false;
		for( auto WindowIter( SlateWindows.CreateConstIterator() ); WindowIter; ++WindowIter )
		{
			auto Window = *WindowIter;
			if( Window->IsRegularWindow() )
			{
				bAnyRegularWindows = true;
				break;
			}
		}

		if (!bAnyRegularWindows)
		{
			OnExitRequested.ExecuteIfBound();
		}
	}
}

void FSlateApplication::OnWindowClose( const TSharedRef< FGenericWindow >& PlatformWindow )
{
	TSharedPtr< SWindow > Window = FSlateWindowHelper::FindWindowByPlatformWindow( SlateWindows, PlatformWindow );

	if ( Window.IsValid() )
	{
		bool bCanCloseWindow = true;
		TSharedPtr< SViewport > CurrentGameViewportWidget = GameViewportWidget.Pin();
		if (CurrentGameViewportWidget.IsValid())
		{
			TSharedPtr< ISlateViewport > SlateViewport = CurrentGameViewportWidget->GetViewportInterface().Pin();
			if (SlateViewport.IsValid())
			{
				bCanCloseWindow = !SlateViewport->OnRequestWindowClose().bIsHandled;
			}
		}
		
		if (bCanCloseWindow)
		{
		    Window->RequestDestroyWindow();
		}	 
	}
}

EDropEffect::Type FSlateApplication::OnDragEnterText( const TSharedRef< FGenericWindow >& Window, const FString& Text )
{
	const TSharedPtr< FExternalDragOperation > DragDropOperation = FExternalDragOperation::NewText( Text );
	const TSharedPtr< SWindow > EffectingWindow = FSlateWindowHelper::FindWindowByPlatformWindow( SlateWindows, Window );

	EDropEffect::Type Result = EDropEffect::None;
	if ( DragDropOperation.IsValid() && EffectingWindow.IsValid() )
	{
		Result = OnDragEnter( EffectingWindow.ToSharedRef(), DragDropOperation.ToSharedRef() );
	}

	return Result;
}

EDropEffect::Type FSlateApplication::OnDragEnterFiles( const TSharedRef< FGenericWindow >& Window, const TArray< FString >& Files )
{
	const TSharedPtr< FExternalDragOperation > DragDropOperation = FExternalDragOperation::NewFiles( Files );
	const TSharedPtr< SWindow > EffectingWindow = FSlateWindowHelper::FindWindowByPlatformWindow( SlateWindows, Window );

	EDropEffect::Type Result = EDropEffect::None;
	if ( DragDropOperation.IsValid() && EffectingWindow.IsValid() )
	{
		Result = OnDragEnter( EffectingWindow.ToSharedRef(), DragDropOperation.ToSharedRef() );
	}

	return Result;
}

EDropEffect::Type FSlateApplication::OnDragEnterExternal( const TSharedRef< FGenericWindow >& Window, const FString& Text, const TArray< FString >& Files )
{
	const TSharedPtr< FExternalDragOperation > DragDropOperation = FExternalDragOperation::NewOperation( Text, Files );
	const TSharedPtr< SWindow > EffectingWindow = FSlateWindowHelper::FindWindowByPlatformWindow( SlateWindows, Window );

	EDropEffect::Type Result = EDropEffect::None;
	if ( DragDropOperation.IsValid() && EffectingWindow.IsValid() )
	{
		Result = OnDragEnter( EffectingWindow.ToSharedRef(), DragDropOperation.ToSharedRef() );
	}

	return Result;
}

EDropEffect::Type FSlateApplication::OnDragEnter( const TSharedRef< SWindow >& Window, const TSharedRef<FExternalDragOperation>& DragDropOperation )
{
	// We are encountering a new drag and drop operation.
	// Assume we cannot handle it.
	DragIsHandled = false;

	const FVector2D CurrentCursorPosition = GetCursorPos();
	const FVector2D LastCursorPosition = GetLastCursorPos();

	// Tell slate to enter drag and drop mode.
	// Make a faux mouse event for slate, so we can initiate a drag and drop.
	FDragDropEvent DragDropEvent(
		FPointerEvent(
		CursorPointerIndex,
		CurrentCursorPosition,
		LastCursorPosition,
		PressedMouseButtons,
		EKeys::Invalid,
		0,
		PlatformApplication->GetModifierKeys() ),
		DragDropOperation
	);

	ProcessDragEnterEvent( Window, DragDropEvent );
	return EDropEffect::None;
}

bool FSlateApplication::ProcessDragEnterEvent( TSharedRef<SWindow> WindowEntered, FDragDropEvent& DragDropEvent )
{
	SetLastUserInteractionTime(this->GetCurrentTime());
	
	FWidgetPath WidgetsUnderCursor = LocateWindowUnderMouse( DragDropEvent.GetScreenSpacePosition(), GetInteractiveTopLevelWindows() );

	// Switch worlds for widgets in the current path
	FScopedSwitchWorldHack SwitchWorld( WidgetsUnderCursor );

	FReply TriggerDragDropReply = FReply::Handled().BeginDragDrop( DragDropEvent.GetOperation().ToSharedRef() );
	ProcessReply( WidgetsUnderCursor, TriggerDragDropReply, &WidgetsUnderCursor, &DragDropEvent );

	PointerIndexLastPositionMap.Add(DragDropEvent.GetPointerIndex(), DragDropEvent.GetScreenSpacePosition());
	return true;
}

EDropEffect::Type FSlateApplication::OnDragOver( const TSharedPtr< FGenericWindow >& Window )
{
	EDropEffect::Type Result = EDropEffect::None;

	if ( IsDragDropping() )
	{
		bool MouseMoveHandled = true;
		FVector2D CursorMovementDelta( 0, 0 );
		const FVector2D CurrentCursorPosition = GetCursorPos();
		const FVector2D LastCursorPosition = GetLastCursorPos();

		if ( LastCursorPosition != CurrentCursorPosition )
		{
			FPointerEvent MouseEvent(
				CursorPointerIndex,
				CurrentCursorPosition,
				LastCursorPosition,
				PressedMouseButtons,
				EKeys::Invalid,
				0,
				PlatformApplication->GetModifierKeys()
			);

			MouseMoveHandled = ProcessMouseMoveEvent( MouseEvent );
			CursorMovementDelta = MouseEvent.GetCursorDelta();
		}

		// Slate is now in DragAndDrop mode. It is tracking the payload.
		// We just need to convey mouse movement.
		if ( CursorMovementDelta.SizeSquared() > 0 )
		{
			DragIsHandled = MouseMoveHandled;
		}

		if ( DragIsHandled )
		{
			Result = EDropEffect::Copy;
		}
	}

	return Result;
}

void FSlateApplication::OnDragLeave( const TSharedPtr< FGenericWindow >& Window )
{
	DragDropContent.Reset();
}

EDropEffect::Type FSlateApplication::OnDragDrop( const TSharedPtr< FGenericWindow >& Window )
{
	EDropEffect::Type Result = EDropEffect::None;

	if ( IsDragDropping() )
	{
		FPointerEvent MouseEvent(
			CursorPointerIndex,
			GetCursorPos(),
			GetLastCursorPos(),
			PressedMouseButtons,
			EKeys::LeftMouseButton,
			0,
			PlatformApplication->GetModifierKeys()
			);

		// User dropped into a Slate window. Slate is already in drag and drop mode.
		// It knows what to do based on a mouse up.
		if ( ProcessMouseButtonUpEvent( MouseEvent ) )
{
			Result = EDropEffect::Copy;
		}
	}

	return Result;
}

bool FSlateApplication::OnWindowAction( const TSharedRef< FGenericWindow >& PlatformWindow, const EWindowAction::Type InActionType)
{
	// Return false to tell the OS layer that it should ignore the action

	if (IsExternalUIOpened())
	{
		return false;
	}

	bool bResult = true;

	for (int32 Index = 0; Index < OnWindowActionNotifications.Num(); Index++)
	{
		if (OnWindowActionNotifications[Index].IsBound())
		{
			if (OnWindowActionNotifications[Index].Execute(PlatformWindow, InActionType))
			{
				// If the delegate returned true, it means that it wants the OS layer to stop processing the action
				bResult = false;
			}
		}
	}

	return bResult;
}

void FSlateApplication::OnVirtualDesktopSizeChanged(const FDisplayMetrics& NewDisplayMetric)
{
	const FPlatformRect& VirtualDisplayRect = NewDisplayMetric.VirtualDisplayRect;
	VirtualDesktopRect = FSlateRect(
		VirtualDisplayRect.Left,
		VirtualDisplayRect.Top,
		VirtualDisplayRect.Right,
		VirtualDisplayRect.Bottom);
}


/* 
 *****************************************************************************/

TSharedRef<FSlateApplication> FSlateApplication::InitializeAsStandaloneApplication(const TSharedRef<FSlateRenderer>& PlatformRenderer)
{
	return InitializeAsStandaloneApplication(PlatformRenderer, MakeShareable(FPlatformMisc::CreateApplication()));
}


TSharedRef<FSlateApplication> FSlateApplication::InitializeAsStandaloneApplication(const TSharedRef< class FSlateRenderer >& PlatformRenderer, const TSharedRef<class GenericApplication>& InPlatformApplication)
{
	// create the platform slate application (what FSlateApplication::Get() returns)
	TSharedRef<FSlateApplication> Slate = FSlateApplication::Create(InPlatformApplication);

	// initialize renderer
	FSlateApplication::Get().InitializeRenderer(PlatformRenderer);

	// set the normal UE4 GIsRequestingExit when outer frame is closed
	FSlateApplication::Get().SetExitRequestedHandler(FSimpleDelegate::CreateStatic(&OnRequestExit));

	return Slate;
}

void FSlateApplication::SetWidgetReflector(const TSharedRef<IWidgetReflector>& WidgetReflector)
{
	if ( SourceCodeAccessDelegate.IsBound() )
	{
		WidgetReflector->SetSourceAccessDelegate(SourceCodeAccessDelegate);
	}

	if ( AssetAccessDelegate.IsBound() )
	{
		WidgetReflector->SetAssetAccessDelegate(AssetAccessDelegate);
	}

	WidgetReflectorPtr = WidgetReflector;
}

void FSlateApplication::NavigateFromWidgetUnderCursor(const uint32 InUserIndex, EUINavigation InNavigationType, TSharedRef<SWindow> InWindow)
{
	if (InNavigationType != EUINavigation::Invalid)
	{
		FWidgetPath PathToLocatedWidget = LocateWidgetInWindow(GetCursorPos(), InWindow, false);
		if (PathToLocatedWidget.IsValid())
		{
			TSharedPtr<SWidget> WidgetToNavFrom = PathToLocatedWidget.Widgets.Last().Widget;

			if (WidgetToNavFrom.IsValid())
			{
				FSlateApplication::Get().ProcessReply(PathToLocatedWidget, FReply::Handled().SetNavigation(InNavigationType, ENavigationGenesis::User, ENavigationSource::WidgetUnderCursor), &PathToLocatedWidget, nullptr, InUserIndex);
			}
		}
	}
}

#undef SLATE_HAS_WIDGET_REFLECTOR