internal static Visual GetElementFromPoint(IntPtr hwnd, Visual root, Point pointScreen)
{
HwndSource hwndSource = HwndSource.CriticalFromHwnd(hwnd);
if (hwndSource == null)
{
return(null);
}
Point pointClient = PointUtil.ScreenToClient(pointScreen, hwndSource);
Point pointRoot = PointUtil.ClientToRoot(pointClient, hwndSource);
PointHitTestResult result = VisualTreeUtils.AsNearestPointHitTestResult(VisualTreeHelper.HitTest(root, pointRoot));
Visual visual = (result != null) ? result.VisualHit : null;
return(visual);
}
internal override Point GetPosition(IInputElement relativeTo)
{
VerifyAccess();
// Validate that relativeTo is either a UIElement or a ContentElement
if (relativeTo != null && !InputElement.IsValid(relativeTo))
{
throw new InvalidOperationException();
}
PresentationSource relativePresentationSource = null;
if (relativeTo != null)
{
DependencyObject dependencyObject = relativeTo as DependencyObject;
DependencyObject containingVisual = InputElement.GetContainingVisual(dependencyObject);
if (containingVisual != null)
{
relativePresentationSource = PresentationSource.CriticalFromVisual(containingVisual);
}
}
else
{
if (_inputSource != null)
{
relativePresentationSource = _inputSource.Value;
}
}
// Verify that we have a valid PresentationSource with a valid RootVisual
// - if we don't we won't be able to invoke ClientToRoot or TranslatePoint and
// we will just return 0,0
if (relativePresentationSource == null || relativePresentationSource.RootVisual == null)
{
return(new Point(0, 0));
}
Point curPoint = new Point(_pointerData.Info.ptPixelLocationRaw.X, _pointerData.Info.ptPixelLocationRaw.Y);
Point ptClient = PointUtil.ScreenToClient(curPoint, relativePresentationSource);
Point ptRoot = PointUtil.ClientToRoot(ptClient, relativePresentationSource);
Point ptRelative = InputElement.TranslatePoint(ptRoot, relativePresentationSource.RootVisual, (DependencyObject)relativeTo);
return(ptRelative);
}
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);
}