Create a range selectable calendar with JList

• download example.jar
• download src.zip
• repository

Code

public final LocalDate realLocalDate = LocalDate.now();
public LocalDate currentLocalDate;
public final Dimension size = new Dimension(40, 26);

// ...
JLabel yearMonthLabel = new JLabel("", SwingConstants.CENTER);
JList<LocalDate> monthList = new JList<LocalDate>(new CalendarViewListModel(realLocalDate)) {
  @Override public void updateUI() {
    setCellRenderer(null);
    super.updateUI();
    setLayoutOrientation(JList.HORIZONTAL_WRAP);
    setVisibleRowCount(CalendarViewListModel.ROW_COUNT); // ensure 6 rows in the list
    setFixedCellWidth(size.width);
    setFixedCellHeight(size.height);
    setCellRenderer(new CalendarListRenderer<>());
    getSelectionModel().setSelectionMode(ListSelectionModel.SINGLE_INTERVAL_SELECTION);
  }
};

// ...
class CalendarViewListModel extends AbstractListModel<LocalDate> {
  public static final int ROW_COUNT = 6;
  private final LocalDate startDate;
  private final WeekFields weekFields = WeekFields.of(Locale.getDefault());
  protected CalendarViewListModel(LocalDate date) {
    super();
    LocalDate firstDayOfMonth = YearMonth.from(date).atDay(1);
    int dowv = firstDayOfMonth.get(weekFields.dayOfWeek()) - 1;
    startDate = firstDayOfMonth.minusDays(dowv);
  }

  @Override public int getSize() {
    return DayOfWeek.values().length * ROW_COUNT;
  }

  @Override public LocalDate getElementAt(int index) {
    return startDate.plusDays(index);
  }
}

References

• Create a range selectable calendar with JList(Japanese)
• Java Swing Tips: Apply LocalDate considering Locale to JTable and display calendar