Bug 136256 Enhance the message builder
Please see the spec attached in 133995 for detail.
UI/org.eclipse.birt.report.designer.ui.lib.explorer/src/org/eclipse/birt/report/designer/ui/lib/explorer/LibraryExplorerTreeViewPage.java
return Messages.getString( "LibraryExplorerTreeViewPage.toolTips.DragAndDrapOutline" );
			}
			else if ( object instanceof ReportItemHandle
					|| object instanceof ThemeHandle )
			{
				return Messages.getString( "LibraryExplorerTreeViewPage.toolTips.DragAndDrapLayout" );
			}
			if ( object instanceof LibraryHandle )
			{
				return ( (LibraryHandle) object ).getFileName( );
			}
		}
		return ""; 
	}
	/**
	 * The <code>Page</code> implementation of this <code>IPage</code>
	 * method disposes of this page's control (if it has one and it has not
	 * already been disposed). Disposes the visitor of the element
	 */
	public void dispose( )
	{		
		if ( reportPreferenceNode != null )
			reportPreferenceNode.removePreferenceChangeListener( this );
		super.dispose( );
	}
	protected boolean isDisposed( )
	{
		Control ctrl = getControl( );
		return ( ctrl == null || ctrl.isDisposed( ) );
	}