Bug 120691 [Markers] Expanded categories not persisted between sessions
build I20051213 - in the Problems view in hierarchical mode, with many problems showing, - expand a few categories, select some leaf problems - shutdown / restart - the tree is collapsed Users will expect that the work they did to expand/collapse categories to see the problems they care most about will be persisted between sessions.
bundles/org.eclipse.ui.ide/src/org/eclipse/ui/internal/views/markers/ExtendedMarkersView.java
removeExpandedCategory((MarkerCategory) e.item.getData());
			}
			/*
			 * (non-Javadoc)
			 * 
			 * @see org.eclipse.swt.events.TreeAdapter#treeExpanded(org.eclipse.swt.events.TreeEvent)
			 */
			public void treeExpanded(TreeEvent e) {
				addExpandedCategory((MarkerCategory) e.item.getData());
			}
		});
		
		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);
			}
		});
		registerContextMenu();
	}
	/**