@Override
 public void inputChanged(Viewer viewer, Object oldInput, Object newInput) {
   this.treeViewer = (TreeViewer) viewer;
   if (fEditor != null) {
     this.resolver = PathResolverProvider.getResolver(fEditor.getEditorInput());
   }
   super.inputChanged(viewer, oldInput, newInput);
 }
 @Override
 public void dispose() {
   try {
     InstanceScope.INSTANCE
         .getNode(HTMLPlugin.PLUGIN_ID)
         .removePreferenceChangeListener(preferenceListener);
   } finally {
     super.dispose();
   }
 }