Bug 275910 [Widgets] PaintListener on Tree not invoked when item count is 0
bundles/org.eclipse.ui.ide/src/org/eclipse/ui/internal/views/markers/ExtendedMarkersView.java
private void addSelectionListener() {
		viewer.addSelectionChangedListener(new ISelectionChangedListener() {
			public void selectionChanged(SelectionChangedEvent event) {
				ISelection selection = event.getSelection();
				if (selection instanceof IStructuredSelection){
					updateStatusLine((IStructuredSelection)selection);
				}
			}
		});
	}
	/**
	 * 
	 */
	private void addHelpListener() {
		
		viewer.getControl().addHelpListener(new HelpListener() {
			/*
			 * (non-Javadoc)
			 * 
			 * @see
			 * org.eclipse.swt.events.HelpListener#helpRequested(org.eclipse
			 * .swt.events.HelpEvent)
			 */
			public void helpRequested(HelpEvent e) {
				Object provider = getAdapter(IContextProvider.class);
				if (provider == null)
					return;
				IContext context = ((IContextProvider) provider)
						.getContext(viewer.getControl());
				PlatformUI.getWorkbench().getHelpSystem().displayHelp(context);