//------------------------------------------------------
//
// Public Properties
//
//------------------------------------------------------
private static void ImageSourcePropertyChanged(DependencyObject d, DependencyPropertyChangedEventArgs e)
{
// The first change to the default value of a mutable collection property (e.g. GeometryGroup.Children)
// will promote the property value from a default value to a local value. This is technically a sub-property
// change because the collection was changed and not a new collection set (GeometryGroup.Children.
// Add versus GeometryGroup.Children = myNewChildrenCollection). However, we never marshalled
// the default value to the compositor. If the property changes from a default value, the new local value
// needs to be marshalled to the compositor. We detect this scenario with the second condition
// e.OldValueSource != e.NewValueSource. Specifically in this scenario the OldValueSource will be
// Default and the NewValueSource will be Local.
if (e.IsASubPropertyChange &&
(e.OldValueSource == e.NewValueSource))
{
return;
}
ImageBrush target = ((ImageBrush)d);
ImageSource oldV = (ImageSource)e.OldValue;
ImageSource newV = (ImageSource)e.NewValue;
System.Windows.Threading.Dispatcher dispatcher = target.Dispatcher;
if (dispatcher != null)
{
DUCE.IResource targetResource = (DUCE.IResource)target;
using (CompositionEngineLock.Acquire())
{
int channelCount = targetResource.GetChannelCount();
for (int channelIndex = 0; channelIndex < channelCount; channelIndex++)
{
DUCE.Channel channel = targetResource.GetChannel(channelIndex);
Debug.Assert(!channel.IsOutOfBandChannel);
Debug.Assert(!targetResource.GetHandle(channel).IsNull);
target.ReleaseResource(oldV, channel);
target.AddRefResource(newV, channel);
}
}
}
target.PropertyChanged(ImageSourceProperty);
}
