public void SetElement(TElement element)
{
var oldElement = Element;
Element = element;
Performance.Start(out string reference);
if (oldElement != null)
{
oldElement.PropertyChanged -= _propertyChangedHandler;
}
if (element != null)
{
if (element.BackgroundColor != Color.Default || (oldElement != null && element.BackgroundColor != oldElement.BackgroundColor))
{
SetBackgroundColor(element.BackgroundColor);
}
UpdateClipToBounds();
if (_tracker == null)
{
_tracker = new VisualElementTracker(this);
_tracker.NativeControlUpdated += (sender, e) => UpdateNativeWidget();
}
if (AutoPackage && _packager == null)
{
_packager = new VisualElementPackager(this);
_packager.Load();
}
if (AutoTrack && _events == null)
{
_events = new EventTracker(this);
_events.LoadEvents(this);
}
element.PropertyChanged += _propertyChangedHandler;
}
OnElementChanged(new ElementChangedEventArgs <TElement>(oldElement, element));
if (element != null)
{
SendVisualElementInitialized(element, this);
}
EffectUtilities.RegisterEffectControlProvider(this, oldElement, element);
if (Element != null && !string.IsNullOrEmpty(Element.AutomationId))
{
SetAutomationId(Element.AutomationId);
}
SetAccessibilityLabel();
SetAccessibilityHint();
SetIsAccessibilityElement();
Performance.Stop(reference);
}
protected override void Dispose(bool disposing)
{
if (disposing && !_disposed)
{
_disposed = true;
if (_gestureListener != null)
{
_gestureListener.Dispose();
_gestureListener = null;
}
if (_visualElementTracker != null)
{
_visualElementTracker.Dispose();
_visualElementTracker = null;
}
if (_visualElementPackager != null)
{
_visualElementPackager.Dispose();
_visualElementPackager = null;
}
if (Element != null)
Element.PropertyChanged -= OnElementPropertyChanged;
}
base.Dispose(disposing);
}
protected virtual void OnElementChanged(ElementChangedEventArgs<Frame> e)
{
ElementChanged?.Invoke(this, new VisualElementChangedEventArgs(e.OldElement, e.NewElement));
if (e.OldElement != null)
{
e.OldElement.PropertyChanged -= OnElementPropertyChanged;
UnsubscribeGestureRecognizers(e.OldElement);
}
if (e.NewElement != null)
{
if (_visualElementTracker == null)
{
SetOnClickListener(this);
SetOnTouchListener(this);
UpdateGestureRecognizers(true);
_visualElementTracker = new VisualElementTracker(this);
_visualElementPackager = new VisualElementPackager(this);
_visualElementPackager.Load();
}
e.NewElement.PropertyChanged += OnElementPropertyChanged;
UpdateShadow();
UpdateBackgroundColor();
SubscribeGestureRecognizers(e.NewElement);
}
}
public void SetElement(VisualElement element)
{
_requestedScroll = null;
var oldElement = Element;
Element = element;
if (oldElement != null)
{
oldElement.PropertyChanged -= HandlePropertyChanged;
((ScrollView)oldElement).ScrollToRequested -= OnScrollToRequested;
}
if (element != null)
{
element.PropertyChanged += HandlePropertyChanged;
((ScrollView)element).ScrollToRequested += OnScrollToRequested;
if (_packager == null)
{
_packager = new VisualElementPackager(this);
_packager.Load();
_tracker = new VisualElementTracker(this);
_tracker.NativeControlUpdated += OnNativeControlUpdated;
_events = new EventTracker(this);
_events.LoadEvents(this);
_insetTracker = new KeyboardInsetTracker(this, () => Window, insets =>
{
ContentInset = ScrollIndicatorInsets = insets;
},
point =>
{
var offset = ContentOffset;
offset.Y += point.Y;
SetContentOffset(offset, true);
}, this);
}
UpdateDelaysContentTouches();
UpdateContentSize();
UpdateBackgroundColor();
UpdateIsEnabled();
UpdateVerticalScrollBarVisibility();
UpdateHorizontalScrollBarVisibility();
OnElementChanged(new VisualElementChangedEventArgs(oldElement, element));
EffectUtilities.RegisterEffectControlProvider(this, oldElement, element);
if (element != null)
{
element.SendViewInitialized(this);
}
if (!string.IsNullOrEmpty(element.AutomationId))
{
AccessibilityIdentifier = element.AutomationId;
}
}
}
