WPF WebView PresentationSourceChanged

WebView.cs

public WebView()
{
	PresentationSource.AddSourceChangedHandler(this, PresentationSourceChanged);
}

private void PresentationSourceChanged(object sender, SourceChangedEventArgs args)
{
	if (args.NewSource == null)
	{
		if (source != null && sourceHook != null)
		{
			source.RemoveHook(sourceHook);
			source = null;
		}
		PresentationSource.RemoveSourceChangedHandler(this, PresentationSourceChanged);
	}
	else
	{
		source = (HwndSource)args.NewSource;
	
		if (source != null)
		{
			matrix = source.CompositionTarget.TransformToDevice;
	        	sourceHook = SourceHook;
	        	source.AddHook(sourceHook);
	    	}
	}
}

Replace AddSourceHookIfNotAlreadyPresent with PresentationSource.AddSourceChangedHandler so we're notified of when PresentationSource changes (added or removed).

When SourceChangedEventArgs.NewSource == null the source is no longer available so remove the source hook