Bug 5492 Open in Hierarchy method list is enabled even when nothing is selected
206 1) Ensure no item is selected in the hierachy view's member list 2) Right click - not on an item 3) Open is present and enabled 4) Select Open, nothing happens
org.eclipse.jdt.ui/ui/org/eclipse/jdt/internal/ui/typehierarchy/MethodsViewer.java
* @see IProblemChangedListener#problemsChanged
	 */
	public void problemsChanged(final Set changed) {
		Control control= getControl();
		if (control != null && !control.isDisposed()) {
			control.getDisplay().asyncExec(new Runnable() {
				public void run() {
					fProblemItemMapper.problemsChanged(changed, (ILabelProvider)getLabelProvider());
				}
			});
		}
	}
		
	/*
	 * @see StructuredViewer#associate(Object, Item)
	 */
	protected void associate(Object element, Item item) {
		if (item.getData() != element) {
			fProblemItemMapper.addToMap(element, item);	
		}
		super.associate(element, item);		
	}
	/*
	 * @see StructuredViewer#disassociate(Item)
	 */
	protected void disassociate(Item item) {
		fProblemItemMapper.removeFromMap(item.getData(), item);
		super.disassociate(item);	
	}
}