Bug 154814 Use library, add library, delete library selection can't be found on Library right click menu in Library explorer
Details: Use library, add library, delete library selection can't be found on Library right click menu in Library explorer Step: 1.New a library and publish to resource folder. 2.New a report design and open library explorer. 3.Right click on the library in library explorer to use the library. Actual result: The selection of use, add ,delete library cannot be found. Exception result: Do can use the right click menu to use, add, delete library.
UI/org.eclipse.birt.report.designer.ui.lib.explorer/src/org/eclipse/birt/report/designer/ui/lib/explorer/LibraryExplorerTreeViewPage.java
Control ctrl = getControl( );
		return ( ctrl == null || ctrl.isDisposed( ) );
	}
	/*
	 * (non-Javadoc)
	 * 
	 * @see org.eclipse.birt.report.model.api.validators.IValidationListener#elementValidated(org.eclipse.birt.report.model.api.DesignElementHandle,
	 *      org.eclipse.birt.report.model.api.validators.ValidationEvent)
	 */
	public void elementValidated( DesignElementHandle targetElement,
			ValidationEvent ev )
	{
		treeViewer.refresh( );
	}
	public void refreshRoot( )
	{
		LibDirectoryNodeModel rootModel = new LibDirectoryNodeModel(
				ReportPlugin.getDefault( ).getResourcePreference( ) );
		treeViewer.setInput( rootModel );
		SessionHandleAdapter.getInstance( ).getSessionHandle( )
				.addResourceChangeListener( this );
	}
	/*
	 * (non-Javadoc)
	 * 
	 * @see org.eclipse.core.runtime.preferences.IEclipsePreferences$IPreferenceChangeListener#preferenceChange(org.eclipse.core.runtime.preferences.IEclipsePreferences.PreferenceChangeEvent)
	 */
	public void preferenceChange( PreferenceChangeEvent event )
	{
		if ( ReportPlugin.RESOURCE_PREFERENCE.equals( event.getKey( ) ) )