Consider using simple callbacks, instead
of the event model.
The ActionScript 3.0 event model is based on the concept of object
dispatching. The event model is object-oriented and optimized for
code reuse. The
dispatchEvent()
method loops through
the list of listeners and calls the event handler method on each
registered object. However, one of the drawbacks of the event model
is that you are likely to create many objects over the lifetime of
your application.
Imagine that you must dispatch an event from the timeline, indicating
the end of an animation sequence. To accomplish the notification,
you can dispatch an event from a specific frame in the timeline,
as the following code illustrates:
dispatchEvent( new Event ( Event.COMPLETE ) );
The Document class can listen for this event with the following
line of code:
addEventListener( Event.COMPLETE, onAnimationComplete );
Although this approach is correct, using the native event model
can be slower and consume more memory than using a traditional callback
function. Event objects must be created and allocated in memory,
which creates a performance slowdown. For example, when listening
to the Event.ENTER_FRAME event, a new event object is created on
each frame for the event handler. Performance can be especially
slow for display objects, due to the capture and bubbling phases, which
can be expensive if the display list is complex.
