private void fireRollOverUpdated(int newIndex) {
    if (rollOverIndex >= 0 && rollOverIndex < getModel().getSize()) {
      JCheckBox oldRollover = getModel().getElementAt(rollOverIndex);
      oldRollover.getModel().setRollover(false);
    }

    rollOverIndex = newIndex;

    if (rollOverIndex >= 0) {
      JCheckBox newRollover = getModel().getElementAt(rollOverIndex);
      newRollover.getModel().setRollover(true);
    }
    UIUtil.repaintViewport(this);
  }
private void fireRollOverUpdated(int newIndex)