/**
* Creates and adds the listeners needed to track the focus.
* @param controller the controller which will be observed
*/
private void initFocusListeners( DockController controller ){
controller.addDockableFocusListener( new DockableFocusListener(){
public void dockableFocused( DockableFocusEvent event ) {
Dockable oldFocused = event.getOldFocusOwner();
Dockable newFocused = event.getNewFocusOwner();
if( oldFocused != null && oldFocused instanceof CommonDockable ){