docs: public void doAddListener(BaseListener listener)
      {
          if (m_listener != null)
              m_listener.doAddListener((FileListener)listener);
          else
              m_listener = (FileListener)listener;
          boolean bOldState = listener.setEnabledListener(false);   // To disable recursive forever loop!
          listener.setOwner(this);
          listener.setEnabledListener(bOldState);        // Renable the listener to eliminate echos
      }