Event object type: mx.events.FlexEvent
FlexEvent.type property = mx.events.FlexEvent.ADD

Dispatched when the component is added to a container as a content child by using the addChild() or addChildAt() method. If the component is added to the container as a noncontent child by using the rawChildren.addChild() or rawChildren.addChildAt() method, the event is not dispatched.

The FlexEvent.ADD constant defines the value of the type property of the event object for an add event.