buttonbarhack.mxml

	<mx:Script>
		<![CDATA[
			import mx.controls.Button;
			import models.UndoRedoModel;
			
			[Inject][Bindable]
			public var urModel:UndoRedoModel;
			
			private function toggleButton(bar:ButtonBar, index:int, enabled:Boolean) : void {
				
				Button(bar.getChildAt(index)).enabled = enabled;
				
			}
			
		]]>
	</mx:Script>


		<mx:ButtonBar id="urBar">
			<mx:dataProvider>
				<mx:Object toolTip="Undo" icon="@Embed('assets/images/command_undo.png')" update="{toggleButton(urBar, 0, urModel.canUndo)}" />
				<mx:Object toolTip="Redo" icon="@Embed('assets/images/command_redo.png')" update="{toggleButton(urBar, 1, urModel.canRedo)}" />
			</mx:dataProvider>
		</mx:ButtonBar>