<?xml version="1.0" encoding="utf-8"?>
<mx:Application xmlns:mx="http://www.adobe.com/2006/mxml">
 
    <mx:Script>
        <![CDATA[
            import mx.managers.ToolTipManager;
 
            protected function bBar_rollOverHandler(evt:MouseEvent):void {
                ToolTipManager.enabled = false;
            }
 
            protected function bBar_rollOutHandler(event:MouseEvent):void {
                ToolTipManager.enabled = true;
            }
        ]]>
    </mx:Script>
 
    <mx:ButtonBar id="bBar"
            width="400"
            rollOver="bBar_rollOverHandler(event);"
            rollOut="bBar_rollOutHandler(event);">
        <mx:dataProvider>
            <mx:ArrayCollection source="[The quick brown fox,Quick brown fox jumps,Brown fox jumps over,Fox jumps over the]" />
        </mx:dataProvider>
    </mx:ButtonBar>
 
    <mx:Button label="The quick brown fox jumps over the" width="100" />
 
</mx:Application>

<?xml version="1.0" encoding="utf-8"?>
<mx:Application xmlns:mx="http://www.adobe.com/2006/mxml"
        xmlns:comps="comps.*"
        layout="vertical"
        verticalAlign="middle"
        backgroundColor="white">
 
    <mx:Array id="arr">
        <mx:Object label="The quick brown fox" foo="One" />
        <mx:Object label="Quick brown fox jumps" foo="two" />
        <mx:Object label="Brown fox jumps over" foo="three" />
        <mx:Object label="Fox jumps over the" foo="fopir" />
        <mx:Object label="Jumps over the lazy" foo="five" />
        <mx:Object label="Over the lazy dog" foo="six" />
    </mx:Array>
 
    <mx:Form>
        <mx:FormItem label="default ButtonBar:">
            <mx:ButtonBar id="bBar" dataProvider="{arr}" width="400" />
        </mx:FormItem>
        <mx:FormItem label="CustomButtonBar:">
            <comps:CustomButtonBar id="cBBar" dataProvider="{arr}" width="400" />
        </mx:FormItem>
    </mx:Form>
 
</mx:Application>

package comps {
    import comps.CustomButtonBarButton;
 
    import mx.controls.ButtonBar;
    import mx.core.ClassFactory;
    import mx.core.mx_internal;
 
    public class CustomButtonBar extends ButtonBar {
        public function CustomButtonBar() {
            super();
            mx_internal::navItemFactory = new ClassFactory(CustomButtonBarButton);
        }
    }
}

package comps {
    import mx.controls.buttonBarClasses.*;
 
    public class CustomButtonBarButton extends ButtonBarButton {
        public function CustomButtonBarButton() {
            super();
        }
 
        override protected function updateDisplayList(unscaledWidth:Number, unscaledHeight:Number):void {
            super.updateDisplayList(unscaledWidth, unscaledHeight);
            super.toolTip = null;
        }
    }
}