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.jface.util.IPropertyChangeListener#propertyChange(org.eclipse.jface.util.PropertyChangeEvent)
			 */
			public void propertyChange(PropertyChangeEvent event) {
				String propertyName = event.getProperty();
				if (propertyName
						.equals(IDEInternalPreferences.USE_MARKER_LIMITS)
						|| propertyName
								.equals(IDEInternalPreferences.MARKER_LIMITS_VALUE)) {
					viewer.refresh();
					updateTitle();
				}
			}
		};
		IDEWorkbenchPlugin.getDefault().getPreferenceStore()
				.addPropertyChangeListener(preferenceListener);
	}
	/**
	 * Add all concrete {@link MarkerItem} elements associated with the receiver
	 * to allMarkers.
	 * 
	 * @param markerItem
	 * @param allMarkers
	 */
	private void addAllConcreteItems(MarkerItem markerItem,
			Collection allMarkers) {
		if (markerItem.isConcrete()) {
			allMarkers.add(markerItem);
			return;