void GestureRecognizersOnCollectionChanged(object?sender, NotifyCollectionChangedEventArgs notifyCollectionChangedEventArgs)
{
if (_platformView != null)
{
_platformView.AccessibilityTraits &= ~_addedFlags;
if (_defaultAccessibilityRespondsToUserInteraction != null)
{
_platformView.AccessibilityRespondsToUserInteraction = _defaultAccessibilityRespondsToUserInteraction.Value;
}
}
_addedFlags = UIAccessibilityTrait.None;
_defaultAccessibilityRespondsToUserInteraction = null;
LoadRecognizers();
}
void LoadRecognizers()
{
if (ElementGestureRecognizers == null)
{
return;
}
if (_shouldReceiveTouch == null)
{
// Cache this so we don't create a new UITouchEventArgs instance for every recognizer
_shouldReceiveTouch = ShouldReceiveTouch;
}
CalculateUserInteractionEnabled();
UIDragInteraction?uIDragInteraction = null;
UIDropInteraction?uIDropInteraction = null;
if (_dragAndDropDelegate != null && _platformView != null)
{
if (PlatformVersion.IsAtLeast(11))
{
foreach (var interaction in _platformView.Interactions)
{
if (interaction is UIDragInteraction uIDrag && uIDrag.Delegate == _dragAndDropDelegate)
{
uIDragInteraction = uIDrag;
}
if (interaction is UIDropInteraction uiDrop && uiDrop.Delegate == _dragAndDropDelegate)
{
uIDropInteraction = uiDrop;
}
}
}
}
bool dragFound = false;
bool dropFound = false;
if (_platformView != null &&
_handler.VirtualView is View v &&
v.TapGestureRecognizerNeedsDelegate() &&
(_platformView.AccessibilityTraits & UIAccessibilityTrait.Button) != UIAccessibilityTrait.Button)
{
_platformView.AccessibilityTraits |= UIAccessibilityTrait.Button;
_addedFlags |= UIAccessibilityTrait.Button;
if (PlatformVersion.IsAtLeast(13))
{
_defaultAccessibilityRespondsToUserInteraction = _platformView.AccessibilityRespondsToUserInteraction;
_platformView.AccessibilityRespondsToUserInteraction = true;
}
}
for (int i = 0; i < ElementGestureRecognizers.Count; i++)
{
IGestureRecognizer recognizer = ElementGestureRecognizers[i];
if (_gestureRecognizers.ContainsKey(recognizer))
{
continue;
}
var nativeRecognizer = GetPlatformRecognizer(recognizer);
if (nativeRecognizer != null && _platformView != null)
{
nativeRecognizer.ShouldReceiveTouch = _shouldReceiveTouch;
_platformView.AddGestureRecognizer(nativeRecognizer);
_gestureRecognizers[recognizer] = nativeRecognizer;
}
if (PlatformVersion.IsAtLeast(11) && recognizer is DragGestureRecognizer)
{
dragFound = true;
_dragAndDropDelegate = _dragAndDropDelegate ?? new DragAndDropDelegate(_handler);
if (uIDragInteraction == null && _handler.PlatformView != null)
{
var interaction = new UIDragInteraction(_dragAndDropDelegate);
interaction.Enabled = true;
_handler.PlatformView.AddInteraction(interaction);
}
}
if (PlatformVersion.IsAtLeast(11) && recognizer is DropGestureRecognizer)
{
dropFound = true;
_dragAndDropDelegate = _dragAndDropDelegate ?? new DragAndDropDelegate(_handler);
if (uIDropInteraction == null && _handler.PlatformView != null)
{
var interaction = new UIDropInteraction(_dragAndDropDelegate);
_handler.PlatformView.AddInteraction(interaction);
}
}
}
if (PlatformVersion.IsAtLeast(11))
{
if (!dragFound && uIDragInteraction != null && _handler.PlatformView != null)
{
_handler.PlatformView.RemoveInteraction(uIDragInteraction);
}
if (!dropFound && uIDropInteraction != null && _handler.PlatformView != null)
{
_handler.PlatformView.RemoveInteraction(uIDropInteraction);
}
}
var toRemove = new List <IGestureRecognizer>();
foreach (var key in _gestureRecognizers.Keys)
{
if (!ElementGestureRecognizers.Contains(key))
{
toRemove.Add(key);
}
}
for (int i = 0; i < toRemove.Count; i++)
{
IGestureRecognizer gestureRecognizer = toRemove[i];
var uiRecognizer = _gestureRecognizers[gestureRecognizer];
_gestureRecognizers.Remove(gestureRecognizer);
if (_platformView != null)
{
_platformView.RemoveGestureRecognizer(uiRecognizer);
}
uiRecognizer.Dispose();
}
}
