protected override void OnElementChanged(ElementChangedEventArgs <ContentView> e)
{
base.OnElementChanged(e);
if (e.NewElement != null && e.OldElement == null)
{
var pancake = (Element as CanvasView);
// HACK: When there are no children we add a Grid element to trigger DrawChild.
// This should be improved upon, but I haven't found out a nice way to be able to clip
// the children and add the border on top without using DrawChild.
if (pancake.Content == null)
{
pancake.Content = new Grid();
}
Validate(pancake);
this.SetBackground(_drawable = new CanvasDrawable(pancake, Context.ToPixels));
SetupShadow(pancake);
}
}
protected override void OnElementPropertyChanged(object sender, PropertyChangedEventArgs e)
{
var pancake = Element as CanvasView;
Validate(pancake);
base.OnElementPropertyChanged(sender, e);
if (e.PropertyName == CanvasView.BorderColorProperty.PropertyName ||
e.PropertyName == CanvasView.BorderThicknessProperty.PropertyName ||
e.PropertyName == CanvasView.BorderIsDashedProperty.PropertyName ||
e.PropertyName == CanvasView.BorderDrawingStyleProperty.PropertyName ||
e.PropertyName == CanvasView.BorderGradientAngleProperty.PropertyName ||
e.PropertyName == CanvasView.BorderGradientEndColorProperty.PropertyName ||
e.PropertyName == CanvasView.BorderGradientStartColorProperty.PropertyName ||
e.PropertyName == CanvasView.BorderGradientStopsProperty.PropertyName)
{
Invalidate();
}
else if (e.PropertyName == CanvasView.SidesProperty.PropertyName ||
e.PropertyName == CanvasView.OffsetAngleProperty.PropertyName ||
e.PropertyName == CanvasView.HasShadowProperty.PropertyName ||
e.PropertyName == CanvasView.ElevationProperty.PropertyName)
{
SetupShadow(pancake);
}
else if (e.PropertyName == CanvasView.CornerRadiusProperty.PropertyName)
{
Invalidate();
SetupShadow(pancake);
}
else if (e.PropertyName == VisualElement.BackgroundColorProperty.PropertyName)
{
_drawable.Dispose();
this.SetBackground(_drawable = new CanvasDrawable(pancake, Context.ToPixels));
}
}