Bug 216811 [Markers] ExtendedMarkersView#setFocus doesn't
The result is that focus is lost if you drag the view to another stack... The most common implementation seems to be 'viewer.getControl().setFocus()... To test: select an element in the Problems or Tasks view. Drag the view to a new location (could be in an existing stack or a new one) notice that while the view is the active view the arrow keys don't navigate...
bundles/org.eclipse.ui.ide/src/org/eclipse/ui/internal/views/markers/ExtendedMarkersView.java
* (non-Javadoc)
			 * 
			 * @see org.eclipse.swt.events.HelpListener#helpRequested(org.eclipse.swt.events.HelpEvent)
			 */
			public void helpRequested(HelpEvent e) {
				Object provider = getAdapter(IContextProvider.class);
				if (provider == null)
					return;
				IContext context = ((IContextProvider) provider)
						.getContext(viewer.getControl());
				PlatformUI.getWorkbench().getHelpSystem().displayHelp(context);
			}
		});
		registerContextMenu();
	}
	/**
	 * Return a part listener for the receiver.
	 * 
	 * @return IPartListener2
	 */
	private IPartListener2 getPartListener() {
		return new IPartListener2() {
			/*
			 * (non-Javadoc)
			 * 
			 * @see org.eclipse.ui.IPartListener2#partActivated(org.eclipse.ui.IWorkbenchPartReference)
			 */
			public void partActivated(IWorkbenchPartReference partRef) {
				
			}