Swing/SpinnerLocalDateTimeModel のバックアップ(No.1)

class SpinnerLocalDateTimeModel extends AbstractSpinnerModel {
  private Comparable<ChronoLocalDateTime<?>> start, end;
  private LocalDateTime value;
  private TemporalUnit temporalUnit;

  public SpinnerLocalDateTimeModel(
      LocalDateTime value, Comparable<ChronoLocalDateTime<?>> start,
      Comparable<ChronoLocalDateTime<?>> end, TemporalUnit temporalUnit) {
    super();
    if (value == null) {
      throw new IllegalArgumentException("value is null");
    }
    if (!(start == null || start.compareTo(value) <= 0)
        && (end == null || end.compareTo(value) >= 0)) {
      throw new IllegalArgumentException("(start <= value <= end) is false");
    }
    this.value = value;
    this.start = start;
    this.end = end;
    this.temporalUnit = temporalUnit;
  }

  public void setStart(Comparable<ChronoLocalDateTime<?>> start) {
    if (start == null ? this.start != null : !start.equals(this.start)) {
      this.start = start;
      fireStateChanged();
    }
  }

  public Comparable<ChronoLocalDateTime<?>> getStart() {
    return start;
  }

  public void setEnd(Comparable<ChronoLocalDateTime<?>> end) {
    if (end == null ? this.end != null : !end.equals(this.end)) {
      this.end = end;
      fireStateChanged();
    }
  }

  public Comparable<ChronoLocalDateTime<?>> getEnd() {
    return end;
  }

  public void setTemporalUnit(TemporalUnit temporalUnit) {
    if (temporalUnit != this.temporalUnit) {
      this.temporalUnit = temporalUnit;
      fireStateChanged();
    }
  }

  public TemporalUnit getTemporalUnit() {
    return temporalUnit;
  }

  @Override public Object getNextValue() {
    //Calendar cal = Calendar.getInstance();
    //cal.setTime(value.getTime());
    //cal.add(calendarField, 1);
    //Date next = cal.getTime();
    LocalDateTime next = value.plus(1, temporalUnit);
    return end == null || end.compareTo(next) >= 0 ? next : null;
  }

  @Override public Object getPreviousValue() {
    //Calendar cal = Calendar.getInstance();
    //cal.setTime(value.getTime());
    //cal.add(calendarField, -1);
    //Date prev = cal.getTime();
    LocalDateTime prev = value.minus(1, temporalUnit);
    return start == null || start.compareTo(prev) <= 0 ? prev : null;
  }

  public LocalDateTime getLocalDateTime() {
    return value;
  }

  @Override public Object getValue() {
    return value;
  }

  @Override public void setValue(Object value) {
    if (!(value instanceof LocalDateTime)) {
      throw new IllegalArgumentException("illegal value");
    }
    if (!value.equals(this.value)) {
      this.value = (LocalDateTime) value;
      fireStateChanged();
    }
  }
}