/** @see Editor#addSelectorForm() */
  @Override
  public void addSelectorForm() {
    JComboBox<Bus> jcbBus;
    Bus[] buses = Bus.getBusArray(this);
    if (isDeleteOperation) {
      jcbBus = new JComboBox<Bus>();
      jcbBus.setPreferredSize(fieldSize);
      for (Bus b : buses) {
        if (b.id != item.id) {
          jcbBus.addItem(b);
        }
      }
    } else {
      jcbBus = new JComboBox<Bus>(buses);
      jcbBus.setPreferredSize(fieldSize);
      jcbBus.setSelectedIndex(-1);
      if (item != null) {
        for (int i = 0; i < buses.length; i++) {
          if (buses[i].id == item.id) {
            jcbBus.setSelectedIndex(i);
          }
        }
      }
    }

    model = jcbBus;
    addField(TABLE_BUS_BUSID, model);
  }