viewer.hookRefreshListener( getRefreshManager( ) );
	protected void createGraphicalViewer( Composite parent )	{		DeferredGraphicalViewer viewer = new DeferredGraphicalViewer( );		viewer.hookRefreshListener( getRefreshManager( ) );		viewer.createControl( parent );		setGraphicalViewer( viewer );		configureGraphicalViewer( );		hookGraphicalViewer( );		initializeGraphicalViewer( );		// addAction ( new ToggleRulerVisibilityAction(		// this.getGraphicalViewer() ));		// suport the mediator		SessionHandleAdapter.getInstance( ).getMediator( ).addColleague( this );	}