/// <summary>
/// Gets the next event handler to invoke for the current element.
/// </summary>
/// <param name="element">The element for which event handlers are being invoked.</param>
/// <param name="evt">A <see cref="RoutedEvent"/> which identifies the routed event for which handlers are being invoked.</param>
/// <param name="index">The index of the handler to invoke; this value is incremented by one when this method returns.</param>
/// <param name="handler">The metadata for the handler that corresponds to the specified index within the handler list.</param>
/// <returns><see langword="true"/> if a handler was retrieved for the specified index; otherwise, <see langword="false"/>.</returns>
private static Boolean GetEventHandler(DependencyObject element, RoutedEvent evt, ref Int32 index, ref RoutedEventHandlerMetadata handler)
{
var indexTemp = index;
var classHandlers = RoutedEventClassHandlers.GetClassHandlers(element.GetType(), evt);
if (classHandlers != null)
{
lock (classHandlers)
{
if (indexTemp >= 0 && indexTemp < classHandlers.Count)
{
handler = classHandlers[indexTemp];
index++;
return(true);
}
indexTemp -= classHandlers.Count;
}
}
var uiElement = element as UIElement;
if (uiElement != null)
{
var instanceHandlers = uiElement.GetHandlers(evt);
if (instanceHandlers == null)
{
return(false);
}
lock (instanceHandlers)
{
if (indexTemp >= instanceHandlers.Count)
{
return(false);
}
handler = instanceHandlers[indexTemp];
index++;
}
return(true);
}
else
{
return(false);
}
}
/// <summary>
/// Registers a class handler for a routed event.
/// </summary>
/// <param name="classType">The type of the class that is declaring class handling.</param>
/// <param name="routedEvent">A <see cref="RoutedEvent"/> which identifies the event to handle.</param>
/// <param name="handler">The delegate that represents the class handler to register.</param>
/// <param name="handledEventsToo">A value indicating whether to invoke the handler even if it has already been handled.</param>
public static void RegisterClassHandler(Type classType, RoutedEvent routedEvent, Delegate handler, Boolean handledEventsToo)
{
RoutedEventClassHandlers.RegisterClassHandler(classType, routedEvent, handler, handledEventsToo);
}
/// <summary>
/// Registers a class handler for a routed event.
/// </summary>
/// <param name="classType">The type of the class that is declaring class handling.</param>
/// <param name="routedEvent">A <see cref="RoutedEvent"/> which identifies the event to handle.</param>
/// <param name="handler">The delegate that represents the class handler to register.</param>
public static void RegisterClassHandler(Type classType, RoutedEvent routedEvent, Delegate handler)
{
RoutedEventClassHandlers.RegisterClassHandler(classType, routedEvent, handler);
}