private void UpdatePointersInViews(UIElement reactView, PointerPoint rootPoint, PointerRoutedEventArgs e)
{
// Create list of react views that should be tracked based on the
// view hierarchy starting from reactView, keeping in just the views that intersect the rootPoint
var newViews = reactView != null ? new HashSet <DependencyObject>(
RootViewHelper.GetReactViewHierarchy(reactView).Where((v) =>
{
if (v is FrameworkElement element)
{
var viewPoint = e.GetCurrentPoint(element);
return(viewPoint.Position.X >= 0 && viewPoint.Position.X < element.ActualWidth &&
viewPoint.Position.Y >= 0 && viewPoint.Position.Y < element.ActualHeight);
}
else
{
return(false);
}
})) :
new HashSet <DependencyObject>();
// Get existing list of react views for the pointer id
HashSet <DependencyObject> existingViews;
if (!_pointersInViews.TryGetValue(e.Pointer.PointerId, out existingViews))
{
existingViews = new HashSet <DependencyObject>();
}
// Return quick if list didn't change
if (newViews.SetEquals(existingViews))
{
return;
}
// Notify the tags that disappeared from the list if:
// - there's still a tag associated with the view (it hasn't been removed from tree)
// - there's a need (driven by handlers hooked on the JS side) to send events
foreach (var existingView in existingViews)
{
if (!newViews.Contains(existingView) &&
existingView.HasTag() &&
ShouldSendPointerEnterLeaveOverOutEvent(existingView, out var enterOrLeave, out var overOrOut))
{
OnPointerEnteredExited(TouchEventType.Exited, (UIElement)existingView, rootPoint, e, enterOrLeave, overOrOut);
}
}
// Notify the new views that showed up if:
// - there's a need (driven by handlers hooked on the JS side) to send events
foreach (var newView in newViews)
{
if (!existingViews.Contains(newView) &&
ShouldSendPointerEnterLeaveOverOutEvent(newView, out var enterOrLeave, out var overOrOut))
{
OnPointerEnteredExited(TouchEventType.Entered, (UIElement)newView, rootPoint, e, enterOrLeave, overOrOut);
}
}
_pointersInViews[e.Pointer.PointerId] = newViews;
}
private UIElement GetReactViewTarget(DependencyObject originalSource, Point point)
{
// If the target is not a child of the root view, then this pointer
// event does not belong to React.
if (!RootViewHelper.IsReactSubview(originalSource))
{
return null;
}
// population of sources provided by:
// http://stackoverflow.com/questions/2059475/what-is-the-silverlights-findelementsinhostcoordinates-equivalent-in-wpf
var sources = new List<DependencyObject>();
//changed from external edits, because VisualHit is
//only a DependencyObject and may not be a UIElement
//this could cause exceptions or may not be compiling at all
//simply filter the result for class UIElement and
//cast it to IEnumerable<UIElement> if you need
//the very exact same result including type
VisualTreeHelper.HitTest(
_view,
null,
new HitTestResultCallback(
hit =>
{
var source = hit.VisualHit;
if (!source.HasTag())
{
return HitTestResultBehavior.Continue;
}
var pointerEvents = source.GetPointerEvents();
if (pointerEvents == PointerEvents.None || pointerEvents == PointerEvents.BoxNone)
{
return HitTestResultBehavior.Continue;
}
sources.Add(hit.VisualHit);
return HitTestResultBehavior.Continue;
}),
new PointHitTestParameters(point));
// Get the first React view that does not have pointer events set
// to 'none' or 'box-none', and is not a child of a view with
// 'box-only' or 'none' settings for pointer events.
// TODO: use pooled data structure
var isBoxOnlyCache = new Dictionary<DependencyObject, bool>();
foreach (var source in sources)
{
var viewHierarchy = RootViewHelper.GetReactViewHierarchy(source);
var isBoxOnly = IsBoxOnlyWithCache(viewHierarchy, isBoxOnlyCache);
if (!isBoxOnly)
{
return (UIElement)source;
}
}
return null;
}
private static bool ShouldSendPointerMoveEvent(DependencyObject view)
{
// This is a bubbling event, so we have to check if mouse move handler is hooked to any ancestor
return(RootViewHelper.GetReactViewHierarchy(view).Any(
v => v.GetMouseHandlerPresent(
ViewExtensions.MouseHandlerMask.MouseMove |
ViewExtensions.MouseHandlerMask.MouseMoveCapture)));
}
public int GetReactTagAtPoint(UIElement reactView, Point point)
{
var richTextBlock = reactView.As <TextBlock>();
var textPointer = richTextBlock.GetPositionFromPoint(point, true);
var parentView = RootViewHelper.GetReactViewHierarchy(textPointer.Parent).First();
return(parentView.GetTag());
}
private UIElement GetReactViewTarget(DependencyObject originalSource, Point point)
{
// If the target is not a child of the root view, then this pointer
// event does not belong to React.
if (!RootViewHelper.IsReactSubview(originalSource))
{
return(null);
}
var adjustedPoint = AdjustPointForStatusBar(point);
var sources = VisualTreeHelper.FindElementsInHostCoordinates(adjustedPoint, _view);
// Get the first React view that does not have pointer events set
// to 'none' or 'box-none', and is not a child of a view with
// 'box-only' or 'none' settings for pointer events.
// TODO: use pooled data structure
var isBoxOnlyCache = new Dictionary <DependencyObject, bool>();
foreach (var source in sources)
{
if (!source.HasTag())
{
continue;
}
var pointerEvents = source.GetPointerEvents();
if (pointerEvents == PointerEvents.None || pointerEvents == PointerEvents.BoxNone)
{
continue;
}
var viewHierarchy = RootViewHelper.GetReactViewHierarchy(source);
var isBoxOnly = IsBoxOnlyWithCache(viewHierarchy, isBoxOnlyCache);
if (!isBoxOnly)
{
return(source);
}
}
return(null);
}
private static bool ShouldSendEnterLeaveEvent(DependencyObject view)
{
// If the target is not a child of the root view, then this pointer
// event does not belong to React.
if (!RootViewHelper.IsReactSubview(view))
{
return false;
}
var viewHierarchy = RootViewHelper.GetReactViewHierarchy(view);
foreach (var ancestor in viewHierarchy)
{
var pointerEvents = ancestor.GetPointerEvents();
if (pointerEvents == PointerEvents.None || pointerEvents == PointerEvents.BoxNone)
{
return false;
}
}
return true;
}
public void RootViewHelper_Null()
{
Assert.IsNull(RootViewHelper.GetRootView(null));
}
private DependencyObject GetReactViewTarget(PointerRoutedEventArgs e)
{
// Ensure the original source is a DependencyObject
var originalSource = e.OriginalSource as DependencyObject;
if (originalSource == null)
{
return(null);
}
// Get the React view hierarchy from the original source.
var enumerator = RootViewHelper.GetReactViewHierarchy(originalSource).GetEnumerator();
// Try to get the first React view.
if (!enumerator.MoveNext())
{
return(null);
}
// If the first React view has `pointerEvents: box-none`, revert
// to using the `VisualTreeHelper` to find potentially occluded views.
// This condition should be rare.
if (enumerator.Current.GetPointerEvents() == PointerEvents.BoxNone)
{
var rootPoint = e.GetCurrentPoint(_view);
var transform = _view.TransformToVisual(Window.Current.Content);
var point = transform.TransformPoint(rootPoint.Position);
var adjustedPoint = AdjustPointForStatusBar(point);
// Get the first view in at the pointer point that is not `box-none`.
// Note: Rounding related errors can keep the position outside all react views, hence using FirstOrDefault.
var nonBoxOnlyView = VisualTreeHelper.FindElementsInHostCoordinates(adjustedPoint, _view)
.FirstOrDefault(v => v.HasTag() && v.GetPointerEvents() != PointerEvents.BoxNone);
// Update the enumerator for the non-`box-only` view.
enumerator = RootViewHelper.GetReactViewHierarchy(nonBoxOnlyView).GetEnumerator();
if (!enumerator.MoveNext())
{
return(null);
}
}
// Views with `pointerEvents: none` are not hit test enabled, so we
// will not encounter any view subtrees with this value. Given the
// prior conditional for `pointerEvents: box-none`, we only need to
// loop through the parents of the current React view target to
// check for uses of `pointerEvents: box-only`. If found, the
// parent becomes the new target.
var source = enumerator.Current;
while (enumerator.MoveNext())
{
var current = enumerator.Current;
if (source == null || current.GetPointerEvents() == PointerEvents.BoxOnly)
{
source = current;
}
}
return(source);
}
private UIElement GetReactViewTarget(DependencyObject originalSource, Point point)
{
// If the target is not a child of the root view, then this pointer
// event does not belong to React.
if (!RootViewHelper.IsReactSubview(originalSource))
{
return(null);
}
// population of sources provided by:
// http://stackoverflow.com/questions/2059475/what-is-the-silverlights-findelementsinhostcoordinates-equivalent-in-wpf
var sources = new List <DependencyObject>();
//changed from external edits, because VisualHit is
//only a DependencyObject and may not be a UIElement
//this could cause exceptions or may not be compiling at all
//simply filter the result for class UIElement and
//cast it to IEnumerable<UIElement> if you need
//the very exact same result including type
VisualTreeHelper.HitTest(
_view,
null,
new HitTestResultCallback(
hit =>
{
var source = hit.VisualHit;
if (!source.HasTag())
{
return(HitTestResultBehavior.Continue);
}
var pointerEvents = source.GetPointerEvents();
if (pointerEvents == PointerEvents.None || pointerEvents == PointerEvents.BoxNone)
{
return(HitTestResultBehavior.Continue);
}
sources.Add(hit.VisualHit);
return(HitTestResultBehavior.Continue);
}),
new PointHitTestParameters(point));
var viewHierarchy = RootViewHelper.GetReactViewHierarchy(originalSource);
var dependencyObjects = viewHierarchy as DependencyObject[] ?? viewHierarchy.ToArray();
var enumerator = dependencyObjects.GetEnumerator();
if (!enumerator.MoveNext())
{
return(null);
}
if (enumerator.Current.GetPointerEvents() == PointerEvents.BoxNone)
{
var nonBoxOnlyView =
sources.FirstOrDefault(x => x.HasTag() && x.GetPointerEvents() != PointerEvents.BoxNone);
enumerator = RootViewHelper.GetReactViewHierarchy(nonBoxOnlyView).GetEnumerator();
if (!enumerator.MoveNext())
{
return(null);
}
}
var element = enumerator.Current;
while (enumerator.MoveNext())
{
var current = enumerator.Current;
if (element == null || current.GetPointerEvents() == PointerEvents.BoxOnly || !(element is UIElement))
{
element = current;
}
}
return((UIElement)element);
}
