private void scrollBy(int delta) {
    final int size = getComboBox().getModel().getSize();
    if (delta == 0 || size == 0) return;
    int next = getComboBox().getSelectedIndex() + delta;
    if (next < 0 || next >= size) {
      if (!UISettings.getInstance().getCycleScrolling()) {
        return;
      }
      next = (next + size) % size;
    }
    getComboBox().setSelectedIndex(next);
  }
private void scrollBy(int delta)