/// <summary>
/// Checks if the component has the listener or any of component's ancestors
/// have listeners for the supplied event type
/// </summary>
/// <param name="eventType"></param>
/// <param name="target"></param>
/// <returns></returns>
internal static bool HasBubblingEventListener(string eventType, DisplayListMember target)
{
/**
* 0) Get parent chain
* */
List <DisplayListMember> parentChain = ComponentUtil.GetParentChain(target, true);
parentChain.Add(target); // add myself
/**
* 1) Look for at least one subscribed component
* */
foreach (DisplayListMember component in parentChain)
{
if (component.HasEventListener(eventType))
{
return(true);
}
}
return(false); // no subscribed components
}
/// <summary>
/// Bubbles event through 3 phases
/// <see cref="http://www.w3.org/TR/DOM-Level-2-Events/events.html#Events-flow-capture"/>
/// </summary>
/// <param name="e"></param>
internal static void BubbleEvent(Event e)
{
if (e.Canceled)
{
return;
}
/**
* 0) Get parent chain
* */
List <DisplayListMember> parentChain = ComponentUtil.GetParentChain((DisplayListMember)e.Target, true); // true for reversing
/**
* 1) Capture phase
* */
e.Phase = EventPhase.Capture;
foreach (DisplayListMember d in parentChain)
{
// set current target
e.CurrentTarget = d;
// execute listeners on current target
// any of the listeners my cancel the event, that's handled by ExecuteListeners method internally
d.ExecuteListeners(e);
// all the listeners (or part of the listeners, in the case of cancelation)
// on current target have been executed.
// if event canceled or propagation stopped, go no further
if (!e.Bubbles || e.Canceled)
{
return;
}
}
/**
* 2) Target phase
* */
e.Phase = EventPhase.Target;
e.CurrentTarget = e.Target;
((EventDispatcher)e.Target).ExecuteListeners(e); //, EventPhase.Target); // executing target listeners
// if event canceled or propagation stopped, go no further
if (!e.Bubbles || e.Canceled)
{
return;
}
/**
* 3) Bubbling phase
* */
e.Phase = EventPhase.Bubbling;
parentChain.Reverse(); // reversing the parent chain & starting to bubble
foreach (DisplayListMember d in parentChain)
{
// set current target
e.CurrentTarget = d;
// execute listeners on current target
// any of the listeners my cancel the event, that's handled by ExecuteListeners method internally
d.ExecuteListeners(e);
// all the listeners (or part of the listeners, in the case of cancelation)
// on current target have been executed.
// if event canceled or propagation stopped, go no further
if (!e.Bubbles || e.Canceled)
{
return;
}
}
/**
* Cleanup
* */
if (e is IDisposable)
{
((IDisposable)e).Dispose();
}
}
