m_calendar 1.4.0

A customizable and lightweight Flutter calendar widget package supporting day and list-based selections with user-defined decorations.

📆 m_calendar

A customizable, lightweight Flutter calendar package with monthly, weekly, and horizontal layouts, single/range date selection, marked dates, and a built-in month/year picker.

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🖼️ Previews

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✨ Features

Feature	Monthly	Weekly	Horizontal
Single-date selection	✅	✅	✅
Range selection	✅	—	—
Marked dates	✅	—	✅
Month/year picker	✅	—	✅
Custom cell decoration	✅	✅	✅
Custom cell widget	✅	✅	✅
Auto-scroll to date	—	—	✅

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🚀 Installation

Add to your pubspec.yaml:

dependencies:
  m_calendar: ^1.4.0

Then run:

flutter pub get

Import in your Dart file:

import 'package:m_calendar/m_calendar.dart';

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📖 Usage

Monthly calendar (default)

MCalendar(
  selectedMonth: DateTime.now(),
  onUserPicked: (List<DateTime> dates) {
    // Single selection → list contains one date.
    print(dates);
  },
)

Monthly calendar with range selection

MCalendar(
  selectedMonth: DateTime.now(),
  isRangeSelection: true,
  onUserPicked: (List<DateTime> dates) {
    // Range → list contains every date in the selected range.
    // The callback fires only once both range endpoints are picked.
    print('From ${dates.first} to ${dates.last}');
  },
)

Monthly calendar with marked dates

MCalendar(
  selectedMonth: DateTime.now(),
  markedDaysList: [
    MarkedDaysModel(
      selectedDateList: [
        DateTime(2025, 6, 10),
        DateTime(2025, 6, 15),
      ],
      decoration: BoxDecoration(
        color: Colors.blue.withOpacity(0.3),
        shape: BoxShape.circle,
      ),
    ),
  ],
  onUserPicked: (dates) => print(dates),
)

Monthly calendar with month/year picker

MCalendar(
  selectedMonth: DateTime.now(),
  showMonthYearPicker: true, // tap the header to open the picker
  onUserPicked: (dates) => print(dates),
)

Note: MCalendar.monthly(...) defaults showMonthYearPicker to true.
The MCalendar(...) shorthand defaults it to false. Explicitly set it to your preference.

Programmatic control with MCalendarController

Control navigation and programmatic selections from outside the calendar:

final controller = MCalendarController();

MCalendar(
  controller: controller,
  selectedMonth: DateTime(2026, 3),
  onUserPicked: (dates) => print(dates),
)

// Imperative controls:
controller.nextMonth();
controller.previousMonth();
controller.setMonth(DateTime(2026, 6));
controller.selectDate(DateTime(2026, 6, 15));
controller.selectRange(DateTime(2026, 6, 10), DateTime(2026, 6, 18));
controller.clearSelection();

// Query selection:
print(controller.selectedDates);

Custom day cell builder (dayBuilder)

Render custom widgets with event dots, badges, or icons inside day cells:

MCalendar(
  selectedMonth: DateTime.now(),
  dayBuilder: (context, date, state) {
    if (state.isDisabled) {
      return Center(child: Text('${date.day}', style: const TextStyle(color: Colors.grey)));
    }
    if (state.isToday) {
      return Column(
        mainAxisAlignment: MainAxisAlignment.center,
        children: [
          Text('${date.day}', style: const TextStyle(fontWeight: FontWeight.bold)),
          const Icon(Icons.circle, size: 4, color: Colors.blue),
        ],
      );
    }
    return null; // return null to fall back to default rendering
  },
  onUserPicked: (dates) => print(dates),
)

Disabling dates (minDate, maxDate, isDateDisabled)

Prevent selection of past dates, weekends, or specific days:

MCalendar(
  selectedMonth: DateTime.now(),
  minDate: DateTime.now(), // past dates disabled
  maxDate: DateTime.now().add(const Duration(days: 60)), // max 60 days ahead
  isDateDisabled: (date) => date.weekday == DateTime.sunday, // disable Sundays
  disabledDecoration: BoxDecoration(
    color: Colors.grey.shade200,
    borderRadius: BorderRadius.circular(6),
  ),
  onUserPicked: (dates) => print(dates),
)

---

Weekly calendar

MCalendar.weekly(
  selectedMonth: DateTime.now(),
  startDay: Day.sunday, // first day of the week; defaults to Day.saturday
  onUserPicked: (List<DateTime> dates) {
    // Returns [firstDayOfSelectedWeek].
    print(dates);
  },
)

The weekly view shows a scrollable table with one row per month (last 6 months) and up to 6 week columns. Months that span 6 calendar weeks (e.g. September 2023 with a Saturday week start) are displayed correctly without data loss.

---

Horizontal calendar

// Wrap in a SizedBox or Expanded to give the view a bounded height.
SizedBox(
  width: double.infinity,
  height: 120,
  child: MCalendar.horizontal(
    selectedMonth: DateTime.now(),
    onUserPicked: (DateTime date) {
      // Always a single date.
      print(date);
    },
  ),
)

The horizontal view callback is void Function(DateTime) — not a List — because the horizontal view only supports single-date selection.

Horizontal calendar with date range and auto-scroll

SizedBox(
  width: double.infinity,
  height: 120,
  child: MCalendar.horizontal(
    selectedMonth: DateTime.now(),
    initialDate: DateTime.now(),                       // scroll-to target
    endDate: DateTime.now().add(const Duration(days: 30)), // last selectable day
    autoScroll: true,                                  // default: true
    onUserPicked: (date) => print(date),
  ),
)

initialDate is also the first selectable date. Dates before initialDate and after endDate are shown greyed-out and cannot be tapped.

Assertion: passing initialDate after endDate throws an assertion error in debug mode with a clear message.

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🎨 Styling

Cell decoration & child

MCalendar(
  selectedMonth: DateTime.now(),
  // Default (unselected) cell decoration
  decoration: BoxDecoration(
    color: Colors.grey.shade100,
    borderRadius: BorderRadius.circular(8),
  ),
  // Selected cell decoration
  userPickedDecoration: BoxDecoration(
    color: Colors.teal,
    borderRadius: BorderRadius.circular(8),
  ),
  // Custom widget inside the selected cell (overrides the default day number)
  userPickedChild: const Icon(Icons.check, color: Colors.white),
  // Cell padding
  cellPadding: const EdgeInsets.all(8),
  onUserPicked: (dates) => print(dates),
)

Header & week-label styling

MCalendar(
  selectedMonth: DateTime.now(),
  showMonthYearPicker: true,
  // Header text (month + year label)
  weekNameHeaderStyle: const TextStyle(
    fontWeight: FontWeight.bold,
    color: Colors.indigo,
  ),
  onUserPicked: (dates) => print(dates),
)

Month/year picker customization (horizontal view example)

MCalendar.horizontal(
  selectedMonth: DateTime.now(),
  showMonthYearPicker: true,
  monthYearPickerSelectedMonthColor: Colors.teal,
  monthYearPickerUnselectedMonthColor: Colors.grey.shade200,
  monthYearPickerCrossAxisCount: 4,
  monthYearPickerChildAspectRatio: 2.0,
  onUserPicked: (date) => print(date),
)

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📦 Public API

MCalendar (monthly, default)

Parameter	Type	Default	Description
selectedMonth	DateTime	required	Month to display. Day/time components are ignored.
onUserPicked	void Function(List<DateTime>)	required	Fires with selected dates.
isRangeSelection	bool	false	Enables range selection.
showMonthYearPicker	bool	false	Shows the month/year picker header.
markedDaysList	List<MarkedDaysModel>?	null	Dates to visually mark.
decoration	BoxDecoration?	null	Default cell decoration.
userPickedDecoration	BoxDecoration?	null	Selected-cell decoration.
userPickedChild	Widget?	null	Widget inside the selected cell.
defaultChild	Widget?	null	Widget inside unselected cells.
cellPadding	EdgeInsets?	null	Padding inside each cell.
controller	MCalendarController?	null	Controller for programmatic navigation and selection.
dayBuilder	CalendarDayBuilder?	null	Custom widget builder for day cells.
minDate	DateTime?	null	Earliest selectable date.
maxDate	DateTime?	null	Latest selectable date.
isDateDisabled	bool Function(DateTime)?	null	Predicate to disable specific dates.
disabledDecoration	BoxDecoration?	null	Decoration for disabled day cells.
disabledTextStyle	TextStyle?	null	Text style for disabled day cell numbers.

MCalendar.weekly

Same as above plus:

Parameter	Type	Default	Description
startDay	Day	Day.saturday	First day of the week.

MCalendar.horizontal

Parameter	Type	Default	Description
selectedMonth	DateTime	required	Month to display.
onUserPicked	void Function(DateTime)	required	Fires with selected date.
initialDate	DateTime?	null	First selectable date; auto-scroll target.
endDate	DateTime?	null	Last selectable date.
autoScroll	bool	true	Scroll to initialDate on first build.
showMonthYearPicker	bool	false	Shows the month/year picker header.
showWeekDays	bool	true	Show weekday labels under dates.
markedDaysList	List<MarkedDaysModel>?	null	Dates to visually mark.
decoration	BoxDecoration?	null	Default cell decoration.
userPickedDecoration	BoxDecoration?	null	Selected-cell decoration.
headerHeight	double?	320	Height of the picker bottom sheet.
headerIconColor	Color?	null	Color for header arrow icons.
headerTextStyle	TextStyle?	null	Style for header month/year text.
dateTextStyle	TextStyle?	null	Style for the day number.
weekDaysTextStyle	TextStyle?	null	Style for the weekday label.
selectedDateTextStyle	TextStyle?	null	Day number style when selected.
selectedWeekDaysTextStyle	TextStyle?	null	Weekday label style when selected.

MarkedDaysModel

MarkedDaysModel(
  selectedDateList: [DateTime(2025, 6, 10)],
  decoration: BoxDecoration(color: Colors.amber, shape: BoxShape.circle),
  child: const Icon(Icons.star, size: 12), // optional overlay widget
)

Day enum

Used for MCalendar.weekly(startDay: ...):

Day.monday  Day.tuesday  Day.wednesday  Day.thursday
Day.friday  Day.saturday  Day.sunday

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⚠️ Migration Guide

1.3.x → 1.4.0

No breaking changes. All existing code continues to work.

Typo fix — provider class names (non-breaking, additive)

The internal providers were misspelled. The corrected names are now exported:

Old name (deprecated)	New name
MonthlyCalenderTableProvider	MonthlyCalendarTableProvider
WeeklyCalenderTableProvider	WeeklyCalendarTableProvider

The old names still compile (they are @Deprecated typedef aliases) but will be removed in a future major release. Migrate by renaming:

// Before
MonthlyCalenderTableProvider()

// After
MonthlyCalendarTableProvider()

Barrel exports (non-breaking, additive)

MarkedDaysModel and Day are now re-exported from m_calendar.dart. You can remove separate imports if you had them:

// Before
import 'package:m_calendar/m_calendar.dart';
import 'package:m_calendar/model/marked_date_model.dart';
import 'package:m_calendar/provider/weekly_calendar_table_provider.dart';

// After
import 'package:m_calendar/m_calendar.dart'; // MarkedDaysModel and Day included

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🔍 Frequently Asked Questions

Q: Why does the range callback fire only when both endpoints are selected?
A: The callback fires once the range is complete (two taps). During the first tap, rangeStart is set internally; the callback fires on the second tap with the full sorted date list.

Q: What happens if I tap the same date twice in range mode?
A: A single-date range is returned: [date].

Q: What happens if I tap a third date after completing a range?
A: The old range is cleared and a new range starts from the third tap.

Q: Can I use DateTime values with time components for markedDaysList?
A: Yes. Date matching always ignores the time component — only year, month, and day are compared.

Q: Can I show more than one decoration model on the same date?
A: The first matching MarkedDaysModel wins. Ensure no two models share the same date if you want distinct decorations.

Q: Why does MCalendar.weekly show up to 6 week columns?
A: Depending on startDay, some months span 6 calendar weeks (e.g. September 2023 with a Saturday start). Previous versions silently dropped the 6th week; 1.4.0 renders it correctly.

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📄 License

MIT © Muntasir Asif