[flexcoders] Transition when reverting to the base state

[triggersoftware]

I know how to get a component removal transition to work when I'm
actively calling mx:RemoveChild, but I'm not sure how to get a removal
transition to work when components are removed by Flex to undo the
calls to mx:AddChild which moved us into the current state in the
first place.

Okay, that probably doesn't make much sense, so here's a simple
example.  How do I get the mx:Fade transition to be applied to the
label so that when the user clicks on the "Base State" button the
label fades out?


<?xml version="1.0" encoding="utf-8"?>
<mx:Application xmlns:mx="http://www.adobe.com/2006/mxml";
layout="vertical">
        <mx:HBox>
                <mx:Button label="State A" click="currentState = 'A'"/>
                <mx:Button label="Base State" click="currentState = ''"/>       
        
        </mx:HBox>
        <mx:HBox id="placeholder"/>
        
        <mx:states>
                <mx:State name="A">
                        <mx:AddChild relativeTo="{placeholder}">
                                <mx:Label id="lblMessage" text="I am now in 
state A!"/>
                        </mx:AddChild>
                </mx:State>
        </mx:states>
        
        <mx:transitions>                
                <mx:Transition fromState="" toState="A">
                        <mx:Glow target="{lblMessage}" alphaFrom="1" alphaTo="0"
duration="2000"/> 
                </mx:Transition>
                <mx:Transition fromState="A" toState="">                        
                        <mx:Fade target="{lblMessage}" alphaFrom="1.0" 
alphaTo="0.0"
duration="2000"/>        
                </mx:Transition>                
        </mx:transitions>
        
</mx:Application>