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
private ISelectionListener pageSelectionListener;
	private IPartListener2 partListener;
	private IMemento memento;
	private String[] defaultGeneratorIds = new String[0];
	/**
	 * Return a new instance of the receiver.
	 * @param contentGeneratorId the id of the generator to load.
	 */
	public ExtendedMarkersView(String contentGeneratorId) {
		super();
		instanceCount++;
		defaultGeneratorIds = new String[] {contentGeneratorId};
		preferenceListener = new IPropertyChangeListener() {
			/*
			 * (non-Javadoc)
			 * 
			 * @see org.eclipse.jface.util.IPropertyChangeListener#propertyChange(org.eclipse.jface.util.PropertyChangeEvent)
			 */
			public void propertyChange(PropertyChangeEvent event) {
				String propertyName = event.getProperty();
				if (propertyName
						.equals(IDEInternalPreferences.USE_MARKER_LIMITS)
						|| propertyName
								.equals(IDEInternalPreferences.MARKER_LIMITS_VALUE)) {
					viewer.refresh();
					updateTitle();
				}
			}
		};
		IDEWorkbenchPlugin.getDefault().getPreferenceStore()