<?xml version="1.0" encoding="utf-8"?>
<!-- http://blog.flexexamples.com/2007/08/25/enabling-and-disabling-specific-tabs-in-a-tabbar-control/ -->
<mx:Application xmlns:mx="http://www.adobe.com/2006/mxml"
        layout="vertical" 
        verticalAlign="middle" 
        backgroundColor="white">

    <mx:ApplicationControlBar dock="true">
        <mx:CheckBox id="tabBarEnabled" 
                label="TabBar.enabled" 
                selected="true" 
                width="25%" />

        <mx:CheckBox id="tab1Enabled" 
                label="Tab1.enabled" 
                selected="true" 
                width="25%" />

        <mx:CheckBox id="tab2Enabled" 
                label="Tab2.enabled" 
                selected="true" 
                width="25%" />

        <mx:CheckBox id="tab3Enabled" 
                label="Tab3.enabled" 
                selected="true" 
                width="25%" />
    </mx:ApplicationControlBar>

    <mx:VBox verticalGap="0">
        <mx:TabBar id="tabBar" 
                width="400" 
                dataProvider="{viewStack}" 
                enabled="{tabBarEnabled.selected}" />
        
        <mx:ViewStack id="viewStack" width="400" height="100">
            <mx:VBox id="tab1"
                    label="Tab1" 
                    backgroundColor="haloGreen" 
                    enabled="{tab1Enabled.selected}">
                <mx:Label text="Label 1" />
            </mx:VBox>

            <mx:VBox id="tab2"
                    label="Tab2" 
                    backgroundColor="haloBlue" 
                    enabled="{tab2Enabled.selected}">
                <mx:Label text="Label 2" />
            </mx:VBox>

            <mx:VBox id="tab3" 
                    label="Tab3" 
                    backgroundColor="haloOrange" 
                    enabled="{tab3Enabled.selected}">
                <mx:Label text="Label 3" />
            </mx:VBox>
        </mx:ViewStack>
    </mx:VBox>

</mx:Application>