private void InputHitTest(Point pt, out IInputElement enabledHit, out IInputElement rawHit, out PointHitTestResult rawHitResult)
{
var hitTestParameters = new PointHitTestParameters(pt);
var inputHitTestResult = new InputHitTestResult();
VisualTreeHelper.HitTest(this, hitTestParameters, InputHitTestFilterCallback, inputHitTestResult.InputHitTestResultCallback);
var visualHit = inputHitTestResult.Result;
rawHit = (visualHit as IInputElement);
rawHitResult = inputHitTestResult.HitTestResult;
enabledHit = null;
while (visualHit != null)
{
var uIElement = visualHit as UIElement;
if (uIElement != null)
{
if (rawHit == null)
{
rawHit = uIElement;
rawHitResult = null;
}
if (uIElement.IsEnabled)
{
enabledHit = uIElement;
return;
}
}
if (visualHit == this)
{
break;
}
visualHit = visualHit.Parent;
}
}
/// <summary>
/// Returns the input element within this element that is
/// at the specified coordinates relative to this element.
/// </summary>
/// <param name="pt">
/// This is the coordinate, relative to this element, at which
/// to look for elements within this one.
/// </param>
/// <param name="enabledHit">
/// This element is the deepest enabled input element that is at the
/// specified coordinates.
/// </param>
/// <param name="rawHit">
/// This element is the deepest input element (not necessarily enabled)
/// that is at the specified coordinates.
/// </param>
/// <param name="rawHitResult">
/// Visual hit test result for the rawHit element
/// </param>
internal void InputHitTest(Point pt, out IInputElement enabledHit, out IInputElement rawHit, out HitTestResult rawHitResult)
{
PointHitTestParameters hitTestParameters = new PointHitTestParameters(pt);
// We store the result of the hit testing here. Note that the
// HitTestResultCallback is an instance method on this class
// so that it can store the element we hit.
InputHitTestResult result = new InputHitTestResult();
VisualTreeHelper.HitTest(this,
new HitTestFilterCallback(InputHitTestFilterCallback),
new HitTestResultCallback(result.InputHitTestResultCallback),
hitTestParameters);
DependencyObject candidate = result.Result;
rawHit = candidate as IInputElement;
rawHitResult = result.HitTestResult;
enabledHit = null;
while (candidate != null)
{
IContentHost contentHost = candidate as IContentHost;
if (contentHost != null)
{
// Do not call IContentHost.InputHitTest if the containing UIElement
// is not enabled.
DependencyObject containingElement = InputElement.GetContainingUIElement(candidate);
if ((bool)containingElement.GetValue(IsEnabledProperty))
{
pt = InputElement.TranslatePoint(pt, this, candidate);
enabledHit = rawHit = contentHost.InputHitTest(pt);
rawHitResult = null;
if (enabledHit != null)
{
break;
}
}
}
UIElement element = candidate as UIElement;
if (element != null)
{
if (rawHit == null)
{
// Earlier we hit a non-IInputElement. This is the first one
// we've found, so use that as rawHit.
rawHit = element;
rawHitResult = null;
}
if (element.IsEnabled)
{
enabledHit = element;
break;
}
}
UIElement3D element3D = candidate as UIElement3D;
if (element3D != null)
{
if (rawHit == null)
{
// Earlier we hit a non-IInputElement. This is the first one
// we've found, so use that as rawHit.
rawHit = element3D;
rawHitResult = null;
}
if (element3D.IsEnabled)
{
enabledHit = element3D;
break;
}
}
if (candidate == this)
{
// We are at the element where the hit-test was initiated.
// If we haven't found the hit element by now, we missed
// everything.
break;
}
candidate = VisualTreeHelper.GetParentInternal(candidate);
}
}
