private void installListener(@NotNull LightEditorInfo editorInfo) {
    FileEditor fileEditor = editorInfo.getFileEditor();
    if (fileEditor instanceof TextEditor) {
      Editor editor = ((TextEditor)fileEditor).getEditor();
      if (editor instanceof EditorEx) {
        ((EditorEx)editor).addFocusListener(new FocusChangeListener() {
          @Override
          public void focusGained(@NotNull Editor editor) {
            checkUpdate(editor);
          }
        }, this);
      }
    }
  }
private void installListener(@NotNull LightEditorInfo editorInfo)