FReply FSceneViewport::OnMouseButtonDoubleClick( const FGeometry& InGeometry, const FPointerEvent& InMouseEvent )
{
	// Start a new reply state
	CurrentReplyState = FReply::Handled(); 

	// Note: When double-clicking, the following message sequence is sent:
	//	WM_*BUTTONDOWN
	//	WM_*BUTTONUP
	//	WM_*BUTTONDBLCLK	(Needs to set the KeyStates[*] to true)
	//	WM_*BUTTONUP
	KeyStateMap.Add( InMouseEvent.GetEffectingButton(), true );
	UpdateCachedMousePos( InGeometry, InMouseEvent );
	UpdateCachedGeometry(InGeometry);

	if( ViewportClient && GetSizeXY() != FIntPoint::ZeroValue  )
	{
		// Switch to the viewport clients world before processing input
		FScopedConditionalWorldSwitcher WorldSwitcher( ViewportClient );

		if (!ViewportClient->InputKey(this, InMouseEvent.GetUserIndex(), InMouseEvent.GetEffectingButton(), IE_DoubleClick))
		{
			CurrentReplyState = FReply::Unhandled(); 
		}
	}
	return CurrentReplyState;
}
FReply FSceneViewport::OnMouseWheel( const FGeometry& InGeometry, const FPointerEvent& InMouseEvent )
{
	// Start a new reply state
	CurrentReplyState = FReply::Handled();

	UpdateCachedMousePos( InGeometry, InMouseEvent );
	UpdateCachedGeometry(InGeometry);

	if( ViewportClient  && GetSizeXY() != FIntPoint::ZeroValue  )
	{
		// Switch to the viewport clients world before processing input
		FScopedConditionalWorldSwitcher WorldSwitcher( ViewportClient );

		// The viewport client accepts two different keys depending on the direction of scroll.  
		FKey const ViewportClientKey = InMouseEvent.GetWheelDelta() < 0 ? EKeys::MouseScrollDown : EKeys::MouseScrollUp;

		// Pressed and released should be sent
		ViewportClient->InputKey(this, InMouseEvent.GetUserIndex(), ViewportClientKey, IE_Pressed);
		ViewportClient->InputKey(this, InMouseEvent.GetUserIndex(), ViewportClientKey, IE_Released);
		ViewportClient->InputAxis(this, InMouseEvent.GetUserIndex(), EKeys::MouseWheelAxis, InMouseEvent.GetWheelDelta(), FApp::GetDeltaTime());
	}
	return CurrentReplyState;
}
FReply FSceneViewport::OnMouseButtonUp( const FGeometry& InGeometry, const FPointerEvent& InMouseEvent )
{
	// Start a new reply state
	CurrentReplyState = FReply::Handled();

	KeyStateMap.Add( InMouseEvent.GetEffectingButton(), false );
	UpdateModifierKeys( InMouseEvent );
	UpdateCachedMousePos( InGeometry, InMouseEvent );
	UpdateCachedGeometry(InGeometry);

	// Switch to the viewport clients world before processing input
	FScopedConditionalWorldSwitcher WorldSwitcher( ViewportClient );
	bool bCursorVisible = true;
	bool bReleaseMouse = true;
	if( ViewportClient && GetSizeXY() != FIntPoint::ZeroValue  )
	{
		if (!ViewportClient->InputKey(this, InMouseEvent.GetUserIndex(), InMouseEvent.GetEffectingButton(), IE_Released))
		{
			CurrentReplyState = FReply::Unhandled(); 
		}
		bCursorVisible = ViewportClient->GetCursor(this, GetMouseX(), GetMouseY()) != EMouseCursor::None;
		bReleaseMouse = 
			bCursorVisible || 
			ViewportClient->CaptureMouseOnClick() == EMouseCaptureMode::CaptureDuringMouseDown ||
			( ViewportClient->CaptureMouseOnClick() == EMouseCaptureMode::CaptureDuringRightMouseDown && InMouseEvent.GetEffectingButton() == EKeys::RightMouseButton );
	}
	if (!((FApp::IsGame() && !GIsEditor) || bIsPlayInEditorViewport) || bReleaseMouse)
	{
		// On mouse up outside of the game (editor viewport) or if the cursor is visible in game, we should make sure the mouse is no longer captured
		// as long as the left or right mouse buttons are not still down
		if( !InMouseEvent.IsMouseButtonDown( EKeys::RightMouseButton ) && !InMouseEvent.IsMouseButtonDown( EKeys::LeftMouseButton ))
		{
			if( bCursorHiddenDueToCapture )
			{
				bCursorHiddenDueToCapture = false;
				CurrentReplyState.SetMousePos( MousePosBeforeHiddenDueToCapture );
				MousePosBeforeHiddenDueToCapture = FIntPoint( -1, -1 );
			}

			CurrentReplyState.ReleaseMouseCapture();
			if (bCursorVisible)
			{
				CurrentReplyState.ReleaseMouseLock();
			}
		}
	}
	return CurrentReplyState;
}
FReply FSceneViewport::OnTouchEnded( const FGeometry& MyGeometry, const FPointerEvent& TouchEvent )
{
	// Start a new reply state
	CurrentReplyState = FReply::Handled(); 

	UpdateCachedMousePos(MyGeometry, TouchEvent);
	UpdateCachedGeometry(MyGeometry);

	if( ViewportClient )
	{
		// Switch to the viewport clients world before processing input
		FScopedConditionalWorldSwitcher WorldSwitcher( ViewportClient );

		const FVector2D TouchPosition = MyGeometry.AbsoluteToLocal(TouchEvent.GetLastScreenSpacePosition());

		if( !ViewportClient->InputTouch( this, TouchEvent.GetUserIndex(), TouchEvent.GetPointerIndex(), ETouchType::Ended, TouchPosition, FDateTime::Now(), TouchEvent.GetTouchpadIndex()) )
		{
			CurrentReplyState = FReply::Unhandled(); 
		}
	}

	return CurrentReplyState;
}
FReply FSceneViewport::OnMouseButtonDown( const FGeometry& InGeometry, const FPointerEvent& InMouseEvent )
{
	// Start a new reply state
	// Prevent throttling when interacting with the viewport so we can move around in it
	CurrentReplyState = FReply::Handled().PreventThrottling();

	KeyStateMap.Add(InMouseEvent.GetEffectingButton(), true);
	UpdateModifierKeys( InMouseEvent );
	UpdateCachedMousePos( InGeometry, InMouseEvent );
	UpdateCachedGeometry(InGeometry);

	// Switch to the viewport clients world before processing input
	FScopedConditionalWorldSwitcher WorldSwitcher( ViewportClient );
	if( ViewportClient && GetSizeXY() != FIntPoint::ZeroValue )
	{
		// If we're obtaining focus, we have to copy the modifier key states prior to processing this mouse button event, as this is the only point at which the mouse down
		// event is processed when focus initially changes and the modifier keys need to be in-place to detect any unique drag-like events.
		if ( !HasFocus() )
		{
			FModifierKeysState KeysState = FSlateApplication::Get().GetModifierKeys();
			ApplyModifierKeys( KeysState );
		}

		const bool bAnyMenuWasVisible = FSlateApplication::Get().AnyMenusVisible();

		// Process the mouse event
		if (!ViewportClient->InputKey(this, InMouseEvent.GetUserIndex(), InMouseEvent.GetEffectingButton(), IE_Pressed))
		{
			CurrentReplyState = FReply::Unhandled(); 
		}

		// a new menu was opened if there was previously not a menu visible but now there is
		const bool bNewMenuWasOpened = !bAnyMenuWasVisible && FSlateApplication::Get().AnyMenusVisible();

		if (!ViewportClient->IgnoreInput() &&
			!bNewMenuWasOpened && // We should not focus the viewport if a menu was opened as it would close the menu
			( ViewportClient->CaptureMouseOnClick() == EMouseCaptureMode::CapturePermanently ||
			  ViewportClient->CaptureMouseOnClick() == EMouseCaptureMode::CaptureDuringMouseDown ||
			  ( ViewportClient->CaptureMouseOnClick() == EMouseCaptureMode::CaptureDuringRightMouseDown && InMouseEvent.GetEffectingButton() == EKeys::RightMouseButton ) ) )
		{
			TSharedRef<SViewport> ViewportWidgetRef = ViewportWidget.Pin().ToSharedRef();

			// Mouse down should focus viewport for user input
			CurrentReplyState.SetUserFocus(ViewportWidgetRef, EFocusCause::SetDirectly, true);
			
			UWorld* World = ViewportClient->GetWorld();
			if (World && World->IsGameWorld() && World->GetFirstPlayerController())
			{
				CurrentReplyState.CaptureMouse(ViewportWidgetRef);
				CurrentReplyState.LockMouseToWidget(ViewportWidgetRef);

				bool bShouldShowMouseCursor = World->GetFirstPlayerController()->ShouldShowMouseCursor();
				if (ViewportClient->HideCursorDuringCapture() && bShouldShowMouseCursor)
				{
					bCursorHiddenDueToCapture = true;
					MousePosBeforeHiddenDueToCapture = FIntPoint( InMouseEvent.GetScreenSpacePosition().X, InMouseEvent.GetScreenSpacePosition().Y );
				}
				if (bCursorHiddenDueToCapture || !bShouldShowMouseCursor)
				{
					CurrentReplyState.UseHighPrecisionMouseMovement(ViewportWidgetRef);
				}
			}
			else
			{
				CurrentReplyState.UseHighPrecisionMouseMovement(ViewportWidgetRef);
			}
		}
	}
	
	// Re-set prevent throttling here as it can get reset when inside of InputKey()
	CurrentReplyState.PreventThrottling();

	return CurrentReplyState;
}
int32 UKismetInputLibrary::PointerEvent_GetUserIndex(const FPointerEvent& Input)
{
	return Input.GetUserIndex();
}