/// <summary>
/// Enqueues an event, to be handled by subscribers sometime later.
/// There is no guarantee that the event will end up being handled
/// (e.g. suspended or shut down queues silently ignore events,
/// or the application may be terminated beforehand).
/// </summary>
/// <param name="eventQueue">The event queue to add the event to.</param>
/// <param name="evnt">The event to enqueue.</param>
/// <param name="onHandled">An optional delegate to invoke sometime after the event finished being handled. It may not get called, if the event queue is suspended or being shut down. Check the return value to know whether you can reasonably expect it.</param>
/// <param name="file">The source file of the caller.</param>
/// <param name="member">The method or property name of the caller to this method.</param>
/// <param name="line">The line number in <paramref name="file"/>.</param>
/// <returns><c>true</c> if the event was enqueued successfully and you can expect a callback once it's done being handled; otherwise, <c>false</c>.</returns>
public static bool Enqueue(
this IEventQueue eventQueue,
EventBase evnt,
EventHandledDelegate onHandled,
[CallerFilePath] string file = "",
[CallerMemberName] string member = "",
[CallerLineNumber] int line = 0)
{
if (onHandled.NullReference())
{
return(eventQueue.Enqueue(evnt, file, member, line));
}
var finishedEvent = new FinishedEvent(evnt);
var finishedListener = new FinishedEventHandler(eventQueue, finishedEvent.Index, onHandled);
eventQueue.Subscribers.Add(finishedListener, weakRef: false);
var eventsAdded = eventQueue.Enqueue(evnt, file, member, line) &&
eventQueue.Enqueue(finishedEvent, file, member, line); // doesn't even get called if the first one fails, which is what we want.
if (!eventsAdded)
{
eventQueue.Subscribers.Remove(finishedListener);
}
return(eventsAdded);
}
private void OnRaiseFinished(ObjectArgs e)
{
FinishedEventHandler handler = AllFinished;
if (handler != null)
{
handler(this, e);
}
}
private void OnRaiseFinished(object sender, PaperInfoFinishArgs e)
{
FinishedEventHandler handler = ReportFinished;
if (handler != null)
{
handler(sender, e);
}
}
public void OnFinished(FinishedEventHandler handler)
{
e_finished += new FinishedEventHandler(handler);
}
