@Override
  protected void onDispose() {
    if (myFileListener != null)
      VirtualFileManager.getInstance().removeVirtualFileListener(myFileListener);

    for (Document document : getDocuments()) {
      document.removeDocumentListener(myDocumentListener);
    }
    super.onDispose();
  }
  @Override
  protected void onInit() {
    super.onInit();
    if (myFileListener != null)
      VirtualFileManager.getInstance().addVirtualFileListener(myFileListener);

    for (Document document : getDocuments()) {
      document.addDocumentListener(myDocumentListener);
    }
  }