Refreshing Issue, if not the list pattern: year - month - day

[maerlynflagg]

hello,

there is something like a refreshing issue on custom picker model. i worte a custom model from your DatePickerModel. year-month-day is not a use case in our region. so i swapped left und right list of your model to have day-month-year.

Model with swapped left/right:

class CubeDatePickerModel extends CommonPickerModel {
  late DateTime maxTime;
  late DateTime minTime;
  final List<int> _leapYearMonths = const <int>[1, 3, 5, 7, 8, 10, 12];

  CubeDatePickerModel({DateTime? currentTime, DateTime? maxTime, DateTime? minTime, required LocaleType locale}) : super(locale: locale) {
    this.maxTime = maxTime ?? DateTime.now().add(const Duration(days: 3650));
    this.minTime = minTime ?? DateTime(1600, 1, 1);

    this.currentTime = currentTime ?? DateTime.now();

    if (this.currentTime.compareTo(this.maxTime) > 0) {
      this.currentTime = this.maxTime;
    } else if (this.currentTime.compareTo(this.minTime) < 0) {
      this.currentTime = this.minTime;
    }

    _fillLeftLists();
    _fillMiddleLists();
    _fillRightLists();
    final int _minMonth = _minMonthOfCurrentYear();
    final int _minDay = _minDayOfCurrentMonth();

    final int _leftIdx = this.currentTime.day - _minDay;

    super.setLeftIndex(_leftIdx);

    final int _middleIdx = this.currentTime.month - _minMonth;
    super.setMiddleIndex(_middleIdx);

    final int _rightIdx = this.currentTime.year - this.minTime.year;
    super.setRightIndex(_rightIdx);
  }

  void _fillRightLists() {
    rightList = List.generate(maxTime.year - minTime.year + 1, (int index) {
      return '${minTime.year + index}${_localeYear()}';
    });
  }

  int _maxMonthOfCurrentYear() {
    return currentTime.year == maxTime.year ? maxTime.month : 12;
  }

  int _minMonthOfCurrentYear() {
    return currentTime.year == minTime.year ? minTime.month : 1;
  }

  int _maxDayOfCurrentMonth() {
    final int _dayCount = calcDateCount(currentTime.year, currentTime.month);
    return currentTime.year == maxTime.year && currentTime.month == maxTime.month ? maxTime.day : _dayCount;
  }

  int _minDayOfCurrentMonth() {
    return currentTime.year == minTime.year && currentTime.month == minTime.month ? minTime.day : 1;
  }

  void _fillMiddleLists() {
    final int _minMonth = _minMonthOfCurrentYear();
    final int _maxMonth = _maxMonthOfCurrentYear();

    middleList = List.generate(_maxMonth - _minMonth + 1, (int index) {
      return '${_localeMonth(_minMonth + index)}';
    });
  }

  void _fillLeftLists() {
    final int _maxDay = _maxDayOfCurrentMonth();
    final int _minDay = _minDayOfCurrentMonth();

    leftList  = List.generate(_maxDay - _minDay + 1, (int index) {
      return '${_minDay + index}${_localeDay()}';
    });
  }

  @override
  void setLeftIndex(int index) {
    super.setLeftIndex(index);

    final int _minDay = _minDayOfCurrentMonth();
    currentTime = currentTime.isUtc
        ? DateTime.utc(
            currentTime.year,
            currentTime.month,
            _minDay + index,
          )
        : DateTime(
            currentTime.year,
            currentTime.month,
            _minDay + index,
          );
  }

  @override
  void setMiddleIndex(int index) {
    super.setMiddleIndex(index);
    //adjust right
    final int _minMonth = _minMonthOfCurrentYear();
    final int _destMonth = _minMonth + index;

    //change date time
    final int _dayCount = calcDateCount(currentTime.year, _destMonth);
    final DateTime _newTime = currentTime.isUtc
        ? DateTime.utc(
            currentTime.year,
            _destMonth,
            currentTime.day <= _dayCount ? currentTime.day : _dayCount,
          )
        : DateTime(
            currentTime.year,
            _destMonth,
            currentTime.day <= _dayCount ? currentTime.day : _dayCount,
          );
    //min/max check
    if (_newTime.isAfter(maxTime)) {
      currentTime = maxTime;
    } else if (_newTime.isBefore(minTime)) {
      currentTime = minTime;
    } else {
      currentTime = _newTime;
    }

    _fillLeftLists();
    final int _minDay = _minDayOfCurrentMonth();
    final int _leftIdx = currentTime.day - _minDay;
    super.setLeftIndex(_leftIdx);
  }

  @override
  void setRightIndex(int index) {
    super.setRightIndex(index);

    //adjust middle
    final int _destYear = index + minTime.year;
    int _minMonth = _minMonthOfCurrentYear();
    DateTime _newTime;
    //change date time
    if (currentTime.month == 2 && currentTime.day == 29) {
      _newTime = currentTime.isUtc
          ? DateTime.utc(
              _destYear,
              currentTime.month,
              calcDateCount(_destYear, 2),
            )
          : DateTime(
              _destYear,
              currentTime.month,
              calcDateCount(_destYear, 2),
            );
    } else {
      _newTime = currentTime.isUtc
          ? DateTime.utc(
              _destYear,
              currentTime.month,
              currentTime.day,
            )
          : DateTime(
              _destYear,
              currentTime.month,
              currentTime.day,
            );
    }
    //min/max check
    if (_newTime.isAfter(maxTime)) {
      currentTime = maxTime;
    } else if (_newTime.isBefore(minTime)) {
      currentTime = minTime;
    } else {
      currentTime = _newTime;
    }

    _fillMiddleLists();
    _fillLeftLists();
    _minMonth = _minMonthOfCurrentYear();
    final int _minDay = _minDayOfCurrentMonth();

    final int _middleIdx = currentTime.month - _minMonth;
    super.setMiddleIndex(_middleIdx);

    final int _leftIdx = currentTime.day - _minDay;
    super.setLeftIndex(_leftIdx);
  }

  @override
  String? leftStringAtIndex(int index) {
    if (index >= 0 && index < leftList.length) {
      return leftList[index];
    } else {
      return null;
    }
  }

  @override
  String? middleStringAtIndex(int index) {
    if (index >= 0 && index < middleList.length) {
      return middleList[index];
    } else {
      return null;
    }
  }

  @override
  String? rightStringAtIndex(int index) {
    if (index >= 0 && index < rightList.length) {
      return rightList[index];
    } else {
      return null;
    }
  }

  String _localeYear() {
    if (locale == LocaleType.zh || locale == LocaleType.jp) {
      return '年';
    } else if (locale == LocaleType.ko) {
      return '년';
    } else {
      return '';
    }
  }

  String _localeMonth(int month) {
    if (locale == LocaleType.zh || locale == LocaleType.jp) {
      return '$month月';
    } else if (locale == LocaleType.ko) {
      return '$month월';
    } else {
      final List _monthStrings = i18nObjInLocale(locale)['monthLong'] as List<String>;

      return _monthStrings[month - 1];
    }
  }

  String _localeDay() {
    if (locale == LocaleType.zh || locale == LocaleType.jp) {
      return '日';
    } else if (locale == LocaleType.ko) {
      return '일';
    } else {
      return '';
    }
  }

  @override
  DateTime finalTime() {
    return currentTime;
  }

  int calcDateCount(int year, int month) {
    if (_leapYearMonths.contains(month)) {
      return 31;
    } else if (month == 2) {
      if ((year % 4 == 0 && year % 100 != 0) || year % 400 == 0) {
        return 29;
      }
      return 28;
    }
    return 30;
  }
}

so there is nothing special. but there is now a issue.

example

minDate: 2021-6-24

so the month list in this year has 7 entries. September has in this list the index 3.

good. if i change the year to 2022, the month list get 12 entries and September has index 8. the issue is now, that the month list jumped to April, cause April has index 3. the picker uses also the old index, not the new computed one, which can i see in the PickerModel in debugger mode. the new computed list of 12 entries is used.

something like that is between day and month, so that if i changed the month, the days not everytime correct. so some month have so 30 days and not 31.

is there something what i forgot for custom picker models to work or is this a refreshing bug?

[maerlynflagg]

i found the root issue, why it not worked and not correctly refreshed. the widget keys was incorrect. so two widget have the same key.

some parts from current plugin version.

widget.pickerModel.layoutProportions()[0] > 0
                ? _renderColumnView(
                    ValueKey(widget.pickerModel.currentLeftIndex()),
                    theme,

widget.pickerModel.layoutProportions()[1] > 0
                ? _renderColumnView(
                    ValueKey(widget.pickerModel.currentLeftIndex()),
                    theme,

 widget.pickerModel.layoutProportions()[2] > 0
                ? _renderColumnView(
                    ValueKey(widget.pickerModel.currentMiddleIndex() * 100 + widget.pickerModel.currentLeftIndex()),
                    theme,

i changed it to every column has his own key. i created a pull request #251 . this included #244 , cause i forked from https://github.com/AlexHartford/flutter_datetime_picker.git.