JTableの日付セルエディタとしてJTableで作成したカレンダーを使用する

class DateEditor extends AbstractCellEditor implements TableCellEditor, ActionListener {
  private static final String EDIT = "edit";
  private final JButton button = new JButton();
  private final DateFormat formatter = DateFormat.getDateInstance();
  private final CalenderPanel dateChooser = new CalenderPanel();
  private JPopupMenu popup;
  private JTable table;

  protected DateEditor() {
    super();
    button.setActionCommand(EDIT);
    button.addActionListener(this);
    button.setContentAreaFilled(false);
    button.setFocusPainted(false);
    button.setBorder(BorderFactory.createEmptyBorder(1, 1, 1, 1));
    button.setHorizontalAlignment(SwingConstants.LEFT);
    button.setHorizontalTextPosition(SwingConstants.RIGHT);
  }

  @Override public void actionPerformed(ActionEvent e) {
    if (EDIT.equals(e.getActionCommand()) && table != null) {
      int row = table.getSelectedRow();
      int col = table.getSelectedColumn();
      Rectangle rect = table.getCellRect(row, col, true);
      Point p = new Point(rect.x, (int) rect.getMaxY());
      if (popup == null) {
        popup = new JPopupMenu();
        popup.add(dateChooser);
        popup.pack();
      }
      popup.show(table, p.x, p.y);
      dateChooser.requestFocusInWindow();
    }
  }

  @Override public boolean isCellEditable(EventObject e) {
    return e instanceof MouseEvent && ((MouseEvent) e).getClickCount() >= 2;
  }

  @Override public Object getCellEditorValue() {
    LocalDate d = dateChooser.getLocalDate();
    return Date.from(d.atStartOfDay(ZoneId.systemDefault()).toInstant());
  }

  @Override public Component getTableCellEditorComponent(
      JTable table, Object value, boolean isSelected, int row, int column) {
    if (value instanceof Date) {
      Date date = (Date) value;
      button.setText(formatter.format(date));
      button.setOpaque(true);
      // button.setForeground(table.getSelectionForeground());
      Color fgc = table.getSelectionForeground();
      button.setForeground(new Color(fgc.getRGB()));
      button.setBackground(table.getSelectionBackground());
      ZonedDateTime dateTime = date.toInstant().atZone(ZoneId.systemDefault());
      dateChooser.setLocalDate(dateTime.toLocalDate());
      this.table = table;
    }
    return button;
  }

  private final class CalenderPanel extends JPanel {
     // ...
  }

  private static final class MonthTable extends JTable {
     // ...
  }

  private static class CalendarTableRenderer extends DefaultTableCellRenderer {
     // ...
  }
}