@Override
 @Nullable
 public Object getData(String dataId) {
   if (DATA_KEY.is(dataId)) {
     return this;
   }
   final SimpleNode simpleNode = getTree().getSelectedNode();
   if (simpleNode instanceof AbstractDomElementNode) {
     final DomElement domElement = ((AbstractDomElementNode) simpleNode).getDomElement();
     if (domElement != null && domElement.isValid()) {
       if (CommonDataKeys.NAVIGATABLE.is(dataId)) {
         final XmlElement tag = domElement.getXmlElement();
         if (tag instanceof Navigatable) {
           return tag;
         }
       }
     }
   }
   return null;
 }
 protected boolean isRightFile(final VirtualFile file) {
   return myRootElement == null
       || (myRootElement.isValid()
           && file.equals(DomUtil.getFile(myRootElement).getVirtualFile()));
 }