TabBar current button click

I have a TabbedViewNavigatorApplication with three tabs.

I want to call a function when the current active button tab is clicked again.

How can it be done?

Here is several ways to resolve this task, on of them please see below:

<?xml version="1.0" encoding="utf-8"?>
<s:TabbedViewNavigatorApplication 
    xmlns:fx="http://ns.adobe.com/mxml/2009"
    creationComplete="handler_creationCompleteHandler(event)"
    xmlns:s="library://ns.adobe.com/flex/spark" applicationDPI="160">
<fx:Script>
    <![CDATA[
        import mx.events.FlexEvent;

        import spark.components.ButtonBarButton;

        protected function handler_creationCompleteHandler(event:FlexEvent):void
        {
            var lastTabbedButtonIdex:uint = this.tabbedNavigator.tabBar.selectedIndex;

            this.tabbedNavigator.tabBar.addEventListener(MouseEvent.CLICK, handler_onTabBarClick);

            function handler_onTabBarClick(event:MouseEvent):void
            {
                if(lastTabbedButtonIdex == (event.target as ButtonBarButton).itemIndex)
                {
                    trace("Click on selected button");
                }
                else
                {
                    trace("Select other button");
                }

                lastTabbedButtonIdex = (event.target as ButtonBarButton).itemIndex;
            }

            this.removeEventListener(FlexEvent.CREATION_COMPLETE, handler_creationCompleteHandler);
        }

    ]]>
</fx:Script>
<s:ViewNavigator label="About" width="100%" height="100%" firstView="views.AboutView"/>
<s:ViewNavigator label="Test" width="100%" height="100%" firstView="views.TestView"/>
<s:ViewNavigator label="Feed" width="100%" height="100%" firstView="views.FeedView"/>
<fx:Declarations>
    <!-- Place non-visual elements (e.g., services, value objects) here -->
</fx:Declarations>
</s:TabbedViewNavigatorApplication>