Bug 241209 [Markers] [Problems View] Changing columns in the preferences makes errors disappear from the view
bundles/org.eclipse.ui.ide/src/org/eclipse/ui/internal/views/markers/ExtendedMarkersView.java
openMarkerInEditor(marker, page);
		}
	}
	/**
	 * Restore the expanded categories.
	 * 
	 * @param builder
	 */
	void reexpandCategories(final CachedMarkerBuilder builder) {
		if (!getCategoriesToExpand().isEmpty() && builder.isShowingHierarchy()) {
			MarkerItem[] items = builder.getElements();
			for (int i = 0; i < items.length; i++) {
				String name = ((MarkerCategory) items[i]).getName();
				if (getCategoriesToExpand().contains(name))
					viewer.expandToLevel(items[i], 2);
			}
		}
	}
	/**
	 * Register the context menu for the receiver so that commands may be added
	 * to it.
	 */
	private void registerContextMenu() {
		MenuManager contextMenu = new MenuManager();
		contextMenu.setRemoveAllWhenShown(true);
		getSite().registerContextMenu(contextMenu, viewer);
		
		if (!getSite().getId().equals(MarkerSupportRegistry.MARKERS_ID))
			getSite().registerContextMenu(MarkerSupportRegistry.MARKERS_ID,
					contextMenu, viewer);