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
.addPropertyChangeListener(preferenceListener);
	}
	/**
	 * Add all concrete {@link MarkerItem} elements associated with the receiver
	 * to allMarkers.
	 * 
	 * @param markerItem
	 * @param allMarkers
	 */
	private void addAllConcreteItems(MarkerItem markerItem,
			Collection allMarkers) {
		if (markerItem.isConcrete()) {
			allMarkers.add(markerItem);
			return;
		}
		MarkerItem[] children = markerItem.getChildren();
		for (int i = 0; i < children.length; i++) {
			addAllConcreteItems(children[i], allMarkers);
		}
	}
	/**
	 * Add the category to the list of expanded categories.
	 * 
	 * @param category
	 */
	void addExpandedCategory(MarkerCategory category) {
		categoriesToExpand.add(category.getName());
	}
	/**
	 * Add all of the markers in markerItem recursively.