/// <summary>
/// Handles changes to the ScrollEventListeners DependencyProperty.
/// </summary>
/// <param name="o">DependencyObject that changed.</param>
/// <param name="e">Event data for the DependencyPropertyChangedEvent.</param>
private static void OnScrollEventListenersChanged(DependencyObject o, DependencyPropertyChangedEventArgs e)
{
FrameworkElement el = o as FrameworkElement;
if (null != el)
{
el.Loaded +=
(s, e2) =>
{
var element = FindChild <ScrollViewer>(o);
if (null != element)
{
ScrollEventListenerCollection oldListeners = e.OldValue as ScrollEventListenerCollection;
ScrollEventListenerCollection newListeners = e.NewValue as ScrollEventListenerCollection;
if (null != oldListeners)
{
oldListeners.Target = null;
}
if (null != newListeners)
{
newListeners.Target = element;
}
}
};
}
}
/// <summary>
/// Gets a ScrollEventListener property for the provided DependencyObject, creates a new one if necessary.
/// </summary>
/// <param name="obj">The DependencyObject whose ScrollEventListener you would like to get.</param>
/// <returns>The ScrollEventListener associated with the provided DependencyObject</returns>
public static ScrollEventListenerCollection GetScrollEventListeners(DependencyObject obj)
{
if (null == obj)
{
throw new ArgumentNullException("obj");
}
else
{
ScrollEventListenerCollection listeners =
(obj.GetValue(ScrollEventListenersProperty) as ScrollEventListenerCollection) ?? new ScrollEventListenerCollection();
obj.SetValue(ScrollEventListenersProperty, listeners);
return(listeners);
}
}