// the user asked for the size
private void OnGetCanvasSize(object sender, GetPropertyValueEventArgs <SKSize> e)
{
e.Value = Control?.CanvasSize ?? SKSize.Empty;
}
// the user asked for the current GRContext
private void OnGetGRContext(object sender, GetPropertyValueEventArgs <GRContext> e)
{
e.Value = Control?.GRContext;
}