s:TabBar is a downgrade because it doesn't support disabled tabs.
Here's an example:
<?xml version="1.0" encoding="utf-8"?>
<s:Application xmlns:fx="http://ns.adobe.com/mxml/2009"
xmlns:s="library://ns.adobe.com/flex/spark"
xmlns:mx="library://ns.adobe.com/flex/mx">
<s:controlBarContent>
<s:CheckBox id="tab1Enabled"
label="Tab1.enabled"
selected="true"/>
<s:CheckBox id="tab2Enabled"
label="Tab2.enabled"
selected="false"/>
</s:controlBarContent>
<mx:VBox verticalGap="0"
verticalCenter="0"
horizontalCenter="0">
<mx:TabBar dataProvider="{viewStack}"/>
<s:TabBar dataProvider="{viewStack}"/>
<mx:ViewStack id="viewStack"
width="200"
height="100">
<s:NavigatorContent id="tab1"
label="Tab1"
enabled="{tab1Enabled.selected}"
backgroundColor="red">
<s:Label text="Label 1" />
</s:NavigatorContent>
<s:NavigatorContent id="tab2"
label="Tab2"
enabled="{tab2Enabled.selected}"
backgroundColor="blue">
<s:Label text="Label 2" />
</s:NavigatorContent>
</mx:ViewStack>
</mx:VBox>
</s:Application>
Thanks for the simple, complete code sample. I have filed a bug for this here: http://bugs.adobe.com/jira/browse/SDK-31873