Bug 194209 [CommonNavigator] ProblemsLabelDecorator does not scale well with Project Explorer
When opening a project, The ProblemsLabelDecorator fires a LabelProviderChangedEvent for all resources contained in this project. While in a ProblemTreeViewer, like the Package Explorer, this is handled in an optimized way by filtering out updates to resources which are not realized in the tree view, the Common Navigator has no such means. The result is that for a project with e.g. 50000 resources, a label update for 50000 elements is triggered even though the project is not even expanded in the view.
bundles/org.eclipse.ui.navigator/src/org/eclipse/ui/navigator/CommonNavigator.java
/**
	 * <p>
	 * The Common Navigator Manager handles the setup of the Common Navigator
	 * Menu, manages updates to the ActionBars from
	 * {@link CommonActionProvider}&nbsp; extensions as the user's selection
	 * changes, and also updates the status bar based on the current selection.
	 * 
	 * @return The Common Navigator Manager class which handles menu population
	 *         and ActionBars
	 *         
	 * @since 3.4        
	 */
	protected CommonNavigatorManager createCommonManager() {
		return new CommonNavigatorManager(this, memento);
	}
	/**
	 * <p>
	 * The ActionGroup is used to populate the ActionBars of Common Navigator
	 * View Part, and the returned implementation will have an opportunity to
	 * fill the ActionBars of the view as soon as it is created. ({@link ActionGroup#fillActionBars(org.eclipse.ui.IActionBars)}.
	 * </p>
	 * <p>
	 * The default implementation returns an action group which will add the
	 * following actions:
	 * <ul>
	 * <li>
	 * <p>
	 * Link with editor support. Allows the user to toggling linking the current
	 * selection with the active editors.
	 * </p>