Bug 12336 Java Browsing views get cleared in combination with type hierarchy
1. Add Type Hierarchy view to Java Browsing perspective 2. Select a type in the type hierarchy ==> Java Browsing views show correct state 3. Click on a Java Browsing view "Types" or "Packages" ==> Java Browsing views get cleared.
org.eclipse.jdt.ui/ui/org/eclipse/jdt/internal/ui/typehierarchy/SelectionProviderMediator.java
Assert.isNotNull(viewers);
		fViewers= viewers;
		fListener= new InternalListener();
		fSelectionChangedListeners= new ListenerList(4);
		fViewerInFocus= null;		
		for (int i= 0; i < fViewers.length; i++) {
			Viewer viewer= fViewers[i];
			viewer.addSelectionChangedListener(fListener);
			Control control= viewer.getControl();
			control.addFocusListener(fListener);	
		}
	}
	
	
	private void doFocusChanged(Widget control) {
	    	for (int i= 0; i < fViewers.length; i++) {
	    		if (fViewers[i].getControl() == control) {
	    			propagateFocusChanged(fViewers[i]);
	    			return;
	    		}
	    	}		
	}
	
	private void doSelectionChanged(SelectionChangedEvent event) {
			ISelectionProvider provider= event.getSelectionProvider();
			if (provider == fViewerInFocus) {
				fireSelectionChanged();
			}
	}