private void Focus(DependencyObject focus, bool askOld, bool askNew, bool forceToNullIfFailed)
{
// Make sure that the element is valid for receiving focus.
bool isValid = true;
if (focus != null)
{
isValid = Keyboard.IsFocusable(focus);
if (!isValid && forceToNullIfFailed)
{
focus = null;
isValid = true;
}
}
if (isValid)
{
// Get the keyboard input provider that provides input for the active source.
IKeyboardInputProvider keyboardInputProvider = null;
DependencyObject containingVisual = InputElement.GetContainingVisual(focus);
if (containingVisual != null)
{
PresentationSource source = PresentationSource.CriticalFromVisual(containingVisual);
if (source != null)
{
keyboardInputProvider = (IKeyboardInputProvider)source.GetInputProvider(typeof(KeyboardDevice));
}
}
// Start the focus-change operation.
TryChangeFocus(focus, keyboardInputProvider, askOld, askNew, forceToNullIfFailed);
}
}
private void OnReevaluateCapturedWithinAsync()
{
if (_captured == null)
{
return;
}
bool killCapture = false;
//
// First, check things like IsEnabled, IsVisible, etc. on a
// UIElement vs. ContentElement basis.
//
UIElement uiElement;
ContentElement contentElement;
UIElement3D uiElement3D;
CastInputElement(_captured, out uiElement, out contentElement, out uiElement3D);
if (uiElement != null)
{
killCapture = !uiElement.IsEnabled || !uiElement.IsVisible || !uiElement.IsHitTestVisible;
}
else if (contentElement != null)
{
killCapture = !contentElement.IsEnabled;
}
else if (uiElement3D != null)
{
killCapture = !uiElement3D.IsEnabled || !uiElement3D.IsVisible || !uiElement3D.IsHitTestVisible;
}
else
{
killCapture = true;
}
//
// Second, if we still haven't thought of a reason to kill capture, validate
// it on a Visual basis for things like still being in the right tree.
//
if (killCapture == false)
{
DependencyObject containingVisual = InputElement.GetContainingVisual(_captured as DependencyObject);
killCapture = !ValidateVisualForCapture(containingVisual);
}
//
// Lastly, if we found any reason above, kill capture.
//
if (killCapture)
{
Capture(null);
}
// Refresh AreAnyTouchCapturesWithinProperty so that ReverseInherited flags are updated.
if ((_capturedWithinTreeState != null) && !_capturedWithinTreeState.IsEmpty)
{
UpdateReverseInheritedProperty(/* capture = */ true, _captured, _captured);
}
}
private void GetRootTransforms(IInputElement relativeTo, out GeneralTransform elementToRoot, out GeneralTransform rootToElement)
{
elementToRoot = rootToElement = null;
DependencyObject containingVisual = InputElement.GetContainingVisual(relativeTo as DependencyObject);
if (containingVisual != null)
{
PresentationSource relativePresentationSource = PresentationSource.CriticalFromVisual(containingVisual);
Visual rootVisual = (relativePresentationSource != null) ? relativePresentationSource.RootVisual : null;
Visual containingVisual2D = VisualTreeHelper.GetContainingVisual2D(containingVisual);
if ((rootVisual != null) && (containingVisual2D != null))
{
elementToRoot = containingVisual2D.TransformToAncestor(rootVisual);
rootToElement = rootVisual.TransformToDescendant(containingVisual2D);
}
}
}
/// <summary>
/// Gets the transform relative to a particular element in the visual tree.
/// </summary>
internal static GeneralTransform GetElementTransform(IInputElement relativeTo)
{
GeneralTransform elementTransform = Transform.Identity;
DependencyObject doRelativeTo = relativeTo as DependencyObject;
if (doRelativeTo != null)
{
Visual visualFirstAncestor = VisualTreeHelper.GetContainingVisual2D(InputElement.GetContainingVisual(doRelativeTo));
Visual visualRoot = VisualTreeHelper.GetContainingVisual2D(InputElement.GetRootVisual(doRelativeTo));
GeneralTransform g = visualRoot.TransformToDescendant(visualFirstAncestor);
if (g != null)
{
elementTransform = g;
}
}
return(elementTransform);
}
private PresentationSource GetSourceForElement(IInputElement element)
{
PresentationSource source = null;
DependencyObject elementDO = element as DependencyObject;
// Use internal helpers to try to find the source of the element.
// Because IInputElements can move around without notification we need to
// look up the source every time.
if (elementDO != null)
{
DependencyObject containingVisual = InputElement.GetContainingVisual(elementDO);
if (containingVisual != null)
{
source = PresentationSource.CriticalFromVisual(containingVisual);
}
}
// NOTE: source can be null but IsTargetable(element) == true if the
// element is in an orphaned tree but the tree has not yet been garbage collected.
return(source);
}
public static int GetIntermediatePoints(IInputElement relativeTo, Point[] points)
{
// Security Mitigation: do not give out input state if the device is not active.
if (Mouse.PrimaryDevice.IsActive)
{
if (relativeTo != null)
{
PresentationSource inputSource = PresentationSource.FromDependencyObject(InputElement.GetContainingVisual(relativeTo as DependencyObject));
if (inputSource != null)
{
IMouseInputProvider mouseInputProvider = inputSource.GetInputProvider(typeof(MouseDevice)) as IMouseInputProvider;
if (null != mouseInputProvider)
{
return(mouseInputProvider.GetIntermediatePoints(relativeTo, points));
}
}
}
}
return(-1);
}
/// <summary>
/// Determines if we can remain focused on the element we think has focus
/// </summary>
/// <remarks>
/// Invoked asynchronously by ReevaluateFocusAsync.
/// Confirms that the element we think has focus is:
/// - still enabled
/// - still visible
/// - still in the tree
/// </remarks>
private object ReevaluateFocusCallback(object arg)
{
_reevaluateFocusOperation = null;
if (_focus == null)
{
return(null);
}
//
// Reevaluate the eligability of the focused element to actually
// have focus. If that element is no longer focusable, then search
// for an ancestor that is.
//
DependencyObject element = _focus;
while (element != null)
{
if (Keyboard.IsFocusable(element))
{
break;
}
// Walk the current tree structure.
element = DeferredElementTreeState.GetCoreParent(element, null);
}
// Get the PresentationSource that contains the element to be focused.
PresentationSource presentationSource = null;
DependencyObject visualContainer = InputElement.GetContainingVisual(element);
if (visualContainer != null)
{
presentationSource = PresentationSource.CriticalFromVisual(visualContainer);
}
// The default action is to reset focus to the root element
// of the active presentation source.
bool moveFocus = true;
DependencyObject moveFocusTo = null;
if (presentationSource != null)
{
IKeyboardInputProvider keyboardProvider = presentationSource.GetInputProvider(typeof(KeyboardDevice)) as IKeyboardInputProvider;
if (keyboardProvider != null)
{
// Confirm with the keyboard provider for this
// presentation source that it has acquired focus.
if (keyboardProvider.AcquireFocus(true))
{
if (element == _focus)
{
// The focus element is still good.
moveFocus = false;
}
else
{
// The focus element is no longer focusable, but we found
// an ancestor that is, so move focus there.
moveFocus = true;
moveFocusTo = element;
}
}
}
}
if (moveFocus)
{
if (moveFocusTo == null && _activeSource != null)
{
moveFocusTo = _activeSource.Value.RootVisual as DependencyObject;
}
Focus(moveFocusTo, /*askOld=*/ false, /*askNew=*/ true, /*forceToNullIfFailed=*/ true);
}
else
{
// Refresh FocusWithinProperty so that ReverseInherited Flags are updated.
//
// We only need to do this if there is any information about the old
// tree structure.
if (_focusTreeState != null && !_focusTreeState.IsEmpty)
{
UIElement.FocusWithinProperty.OnOriginValueChanged(_focus, _focus, ref _focusTreeState);
}
}
return(null);
}
internal static Point TranslatePoint(Point pt, DependencyObject from, DependencyObject to, out bool translated)
{
translated = false;
Point ptTranslated = pt;
// Get the containing and root visuals we are coming from.
DependencyObject vFromAsDO = InputElement.GetContainingVisual(from);
Visual rootFrom = InputElement.GetRootVisual(from) as Visual;
Visual vFrom = vFromAsDO as Visual;
if (vFromAsDO != null && vFrom == null)
{
// must be a Visual3D - get it's 2D visual parent
vFrom = VisualTreeHelper.GetContainingVisual2D(vFromAsDO);
}
if (vFrom != null && rootFrom != null)
{
GeneralTransform gUp;
Matrix mUp;
bool isUpSimple = false;
isUpSimple = vFrom.TrySimpleTransformToAncestor(rootFrom,
false, /* do not apply inverse */
out gUp,
out mUp);
if (isUpSimple)
{
ptTranslated = mUp.Transform(ptTranslated);
}
else if (gUp.TryTransform(ptTranslated, out ptTranslated) == false)
{
// Error. Out parameter has been set false.
return(new Point());
}
// If no element was specified to translate to, we leave the coordinates
// translated to the root.
if (to != null)
{
// Get the containing and root visuals we are going to.
DependencyObject vTo = InputElement.GetContainingVisual(to);
Visual rootTo = InputElement.GetRootVisual(to) as Visual;
if (vTo != null && rootTo != null)
{
// If both are under the same root visual, we can easily translate the point
// between them by translating up to the root, and then back down.
//
// However, if both are under different roots, we can only translate
// between them if we know how to relate the two root visuals. Currently
// we only know how to do that if both roots are sourced in HwndSources.
if (rootFrom != rootTo)
{
HwndSource sourceFrom = PresentationSource.CriticalFromVisual(rootFrom) as HwndSource;
HwndSource sourceTo = PresentationSource.CriticalFromVisual(rootTo) as HwndSource;
if (sourceFrom != null && sourceFrom.CriticalHandle != IntPtr.Zero && sourceFrom.CompositionTarget != null &&
sourceTo != null && sourceTo.CriticalHandle != IntPtr.Zero && sourceTo.CompositionTarget != null)
{
// Translate the point into client coordinates.
ptTranslated = PointUtil.RootToClient(ptTranslated, sourceFrom);
// Translate the point into screen coordinates.
Point ptScreen = PointUtil.ClientToScreen(ptTranslated, sourceFrom);
// Translate the point back the the client coordinates of the To window.
ptTranslated = PointUtil.ScreenToClient(ptScreen, sourceTo);
// Translate the point back to the root element.
ptTranslated = PointUtil.ClientToRoot(ptTranslated, sourceTo);
}
else
{
// Error. Out parameter has been set false.
return(new Point());
}
}
// Translate the point from the root to the visual.
GeneralTransform gDown;
Matrix mDown;
Visual vToAsVisual = vTo as Visual;
if (vToAsVisual == null)
{
// must be a Visual3D
vToAsVisual = VisualTreeHelper.GetContainingVisual2D(vTo);
}
bool isDownSimple = vToAsVisual.TrySimpleTransformToAncestor(rootTo,
true, /* apply inverse */
out gDown,
out mDown);
if (isDownSimple)
{
ptTranslated = mDown.Transform(ptTranslated);
}
else if (gDown != null)
{
if (gDown.TryTransform(ptTranslated, out ptTranslated) == false)
{
// Error. Out parameter has been set false.
return(new Point());
}
}
else
{
// Error. Out parameter has been set false.
return(new Point());
}
}
else
{
// Error. Out parameter has been set false.
return(new Point());
}
}
}
else
{
// Error. Out parameter has been set false.
return(new Point());
}
translated = true;
return(ptTranslated);
}