public void key_dump_info () {
    System.out.println ("input focus: " + focus);
    System.out.println ("mouse at: " + root.query_pointer ().root_position ());

    if (!argument_present) return; // `dump-basic-info'

    if (argument_negative) {    // `dump-hidden-windows'"
      System.out.println ("all hidden clients: ");

      for (Iterator it=clients.iterator (); it.hasNext ();) {
        Client c = (Client) it.next ();
        
        if (c.state == HIDDEN)
          System.out.println (c);
      }

    } else                      // `dump-all-windows'
      System.out.println ("all clients: " + clients);
  }