     //---------------------------------- 
     
     /**
-     *  Defines the layout of the titleGroup.
+     *  Defines the layout of titleGroup and titleDisplay.
+     * 
+     *  <p>If titleContent is null, titleDisplay is displayed in place of
+     *  titleGroup. In this case, titleDisplay is positioned with
+     *  padded using paddingLeft and paddingRight properties of
+     *  titleLayout if defined.
      *
      *  @default HorizontalLayout
+     *  @see #titleContent
      *  
      *  @langversion 3.0
      *  @playerversion Flash 10

 * 
 *   <strong>Styles</strong>
 *    backgroundAlpha="1.0"
 *    titleAlign="start"
 * 
 *  &lt;
 *  </pre>

     *  ActionBar. The location and appearance of the navigationGroup of the
     *  ActionBar container is determined by the
     *  spark.skins.mobile.ActionBarSkin.
     *  
     *  <p>The default ActionBarSkin class defines the navigationGroup to appear
     *  to the left of the titleGroup area of the ActionBar.
     *  
     *  <p>Create a custom skin to change the default location and appearance of
     *  the navigationGroup.
     *  
     *  @default null
