Flex 4: Component move event

I have a CustomTextInput component based on TextInput (Spark) component. The instance of this class is placed on a popup window (TitleWindow).

How can I capture the p开发者_如何学Goopup move (dragging the title) event inside CustomTextInput implementation?

MoveEvent.MOVE event of the CustomTextInput itself doesn't work. Of course, I can't access the parent popup window inside the component implementation, because it's a common component that can be used not only on the popup windows.

Couldn't the parent title window notify the inner component? It would require making a custom TitleWindow component, but it seems the most logical way to implement this behavior.