Swing/SortColumnColor のバックアップ(No.7)

JTable table = new JTable(model) {
  private final Color evenColor = new Color(255, 250, 250);
  @Override public Component prepareRenderer(
      TableCellRenderer tcr, int row, int column) {
    Component c = super.prepareRenderer(tcr, row, column);
    if (isRowSelected(row)) {
      c.setForeground(getSelectionForeground());
      c.setBackground(getSelectionBackground());
    } else {
      c.setForeground(getForeground());
      c.setBackground(isSortingColumn(column) ? evenColor
                                              : getBackground());
    }
    return c;
  }
  private boolean isSortingColumn(int column) {
    RowSorter<? extends TableModel> sorter = getRowSorter();
    if (Objects.nonNull(sorter)) {
      List<? extends RowSorter.SortKey> keys = sorter.getSortKeys();
      if (keys.isEmpty()) {
        return false;
      }
      if (column == convertColumnIndexToView(keys.get(0).getColumn())) {
        return true;
      }
    }
    return false;
  }
};