✨ Handle daily & weekly reoccurrence events

Author: Shubham Jitiya

example/lib/constants.dart

@@ -5,6 +5,8 @@ import 'app_colors.dart';
 class AppConstants {
   AppConstants._();
 
+  static final List<String> weekTitles = ["M", "T", "W", "T", "F", "S", "S"];
+
   static OutlineInputBorder inputBorder = OutlineInputBorder(
     borderRadius: BorderRadius.circular(7),
     borderSide: BorderSide(

example/lib/main.dart

@@ -41,11 +41,19 @@ List<CalendarEventData> _events = [
     description: "Today is project meeting.",
     startTime: DateTime(_now.year, _now.month, _now.day, 18, 30),
     endTime: DateTime(_now.year, _now.month, _now.day, 22),
+    recurrenceSettings: RecurrenceSettings(
+      _now.add(Duration(days: 1)),
+      frequency: RepeatFrequency.daily,
+    ),
   ),
   CalendarEventData(
     date: _now.add(Duration(days: 1)),
     startTime: DateTime(_now.year, _now.month, _now.day, 18),
     endTime: DateTime(_now.year, _now.month, _now.day, 19),
+    recurrenceSettings: RecurrenceSettings(
+      _now.add(Duration(days: 1)),
+      frequency: RepeatFrequency.weekly,
+    ),
     title: "Wedding anniversary",
     description: "Attend uncle's wedding anniversary.",
   ),

example/lib/widgets/add_event_form.dart

@@ -28,6 +28,8 @@ class _AddOrEditEventFormState extends State<AddOrEditEventForm> {
 
   DateTime? _startTime;
   DateTime? _endTime;
+  RepeatFrequency? _selectedFrequency;
+  List<bool> _selectedDays = List.filled(7, false);
 
   Color _color = Colors.blue;
 
@@ -43,6 +45,7 @@ class _AddOrEditEventFormState extends State<AddOrEditEventForm> {
     super.initState();
 
     _setDefaults();
+    _setInitialWeekday();
   }
 
   @override
@@ -102,7 +105,9 @@ class _AddOrEditEventFormState extends State<AddOrEditEventForm> {
                     }
 
                     _startDate = date.withoutTime;
-
+                    // Reset weekday from new start date
+                    _selectedDays.fillRange(0, _selectedDays.length, false);
+                    _selectedDays[date.weekday - 1] = true;
                     if (mounted) {
                       setState(() {});
                     }
@@ -247,6 +252,103 @@ class _AddOrEditEventFormState extends State<AddOrEditEventForm> {
               hintText: "Event Description",
             ),
           ),
+          Align(
+            alignment: Alignment.centerLeft,
+            child: Text(
+              "Repeat",
+              style: TextStyle(
+                color: AppColors.black,
+                fontWeight: FontWeight.w500,
+                fontSize: 17,
+              ),
+            ),
+          ),
+          Column(
+            crossAxisAlignment: CrossAxisAlignment.start,
+            children: [
+              Row(
+                children: [
+                  Radio<RepeatFrequency>(
+                    value: RepeatFrequency.doNotRepeat,
+                    groupValue: _selectedFrequency,
+                    onChanged: (value) {
+                      setState(
+                        () => _selectedFrequency = value,
+                      );
+                    },
+                  ),
+                  Text(
+                    "Do not repeat",
+                    style: TextStyle(
+                      color: AppColors.black,
+                      fontSize: 17,
+                    ),
+                  ),
+                ],
+              ),
+              Row(
+                children: [
+                  Radio<RepeatFrequency>(
+                    value: RepeatFrequency.daily,
+                    groupValue: _selectedFrequency,
+                    onChanged: (value) {
+                      setState(
+                        () => _selectedFrequency = value,
+                      );
+                    },
+                  ),
+                  Text(
+                    "Daily",
+                    style: TextStyle(
+                      color: AppColors.black,
+                      fontSize: 17,
+                    ),
+                  )
+                ],
+              ),
+              Row(
+                children: [
+                  Radio<RepeatFrequency>(
+                    value: RepeatFrequency.weekly,
+                    groupValue: _selectedFrequency,
+                    onChanged: (value) {
+                      setState(
+                        () => _selectedFrequency = value,
+                      );
+                    },
+                  ),
+                  Text(
+                    "Weekly",
+                    style: TextStyle(
+                      color: AppColors.black,
+                      fontSize: 17,
+                    ),
+                  ),
+                ],
+              )
+            ],
+          ),
+          if (_selectedFrequency == RepeatFrequency.weekly) ...[
+            Wrap(
+              children: List<Widget>.generate(AppConstants.weekTitles.length,
+                  (int index) {
+                return ChoiceChip(
+                  label: Text(AppConstants.weekTitles[index]),
+                  showCheckmark: false,
+                  selected: _selectedDays[index],
+                  onSelected: (bool selected) {
+                    setState(() {
+                      _selectedDays[index] = selected;
+                      if (!_selectedDays.contains(true)) {
+                        _selectedDays[_startDate.weekday - 1] = true;
+                      }
+                    });
+                  },
+                  shape: CircleBorder(),
+                );
+              }).toList(),
+            ),
+          ],
           SizedBox(
             height: 15.0,
           ),
@@ -286,19 +388,40 @@ class _AddOrEditEventFormState extends State<AddOrEditEventForm> {
     _form.currentState?.save();
 
     final event = CalendarEventData(
-      date: _startDate,
-      endTime: _endTime,
-      startTime: _startTime,
-      endDate: _endDate,
-      color: _color,
-      title: _titleController.text.trim(),
-      description: _descriptionController.text.trim(),
-    );
+        date: _startDate,
+        endTime: _endTime,
+        startTime: _startTime,
+        endDate: _endDate,
+        color: _color,
+        title: _titleController.text.trim(),
+        description: _descriptionController.text.trim(),
+        recurrenceSettings: RecurrenceSettings(
+          _startDate,
+          frequency: _selectedFrequency ?? RepeatFrequency.daily,
+          weekdays: _selectedIndexes,
+        ));
 
     widget.onEventAdd?.call(event);
     _resetForm();
   }
 
+  /// Get list of weekdays in indices from the selected days
+  List<int> get _selectedIndexes {
+    List<int> selectedIndexes = [];
+    for (int i = 0; i < _selectedDays.length; i++) {
+      if (_selectedDays[i] == true) {
+        selectedIndexes.add(i);
+      }
+    }
+    return selectedIndexes;
+  }
+
+  /// Set initial selected week to start date
+  void _setInitialWeekday() {
+    final currentWeekday = DateTime.now().weekday - 1;
+    _selectedDays[currentWeekday] = true;
+  }
+
   void _setDefaults() {
     if (widget.event == null) return;
 

lib/src/calendar_event_data.dart

@@ -44,6 +44,9 @@ class CalendarEventData<T extends Object?> {
   /// Define style of description.
   final TextStyle? descriptionStyle;
 
+  /// Define reoccurrence settings
+  final RecurrenceSettings? recurrenceSettings;
+
   /// {@macro calendar_event_data_doc}
   CalendarEventData({
     required this.title,
@@ -55,6 +58,7 @@ class CalendarEventData<T extends Object?> {
     this.endTime,
     this.titleStyle,
     this.descriptionStyle,
+    this.recurrenceSettings,
     DateTime? endDate,
   })  : _endDate = endDate?.withoutTime,
         date = date.withoutTime;
@@ -119,6 +123,7 @@ class CalendarEventData<T extends Object?> {
         "title": title,
         "description": description,
         "endDate": endDate,
+        "recurrenceSettings": recurrenceSettings,
       };
 
   /// Returns new object of [CalendarEventData] with the updated values defined

lib/src/enumerations.dart

@@ -48,3 +48,12 @@ enum LineStyle {
   /// Dashed line
   dashed,
 }
+
+/// Defines reoccurrence of event: Daily, weekly, monthly or yearly
+enum RepeatFrequency {
+  doNotRepeat,
+  daily,
+  weekly,
+  monthly,
+  yearly,
+}

lib/src/event_controller.dart

@@ -7,6 +7,7 @@ import 'dart:collection';
 import 'package:flutter/material.dart';
 
 import 'calendar_event_data.dart';
+import 'enumerations.dart';
 import 'extensions.dart';
 import 'typedefs.dart';
 
@@ -137,9 +138,46 @@ class EventController<T extends Object?> extends ChangeNotifier {
       {bool includeFullDayEvents = true}) {
     //ignore: deprecated_member_use_from_same_package
     if (_eventFilter != null) return _eventFilter!.call(date, this.events);
-
-    return _calendarData.getEventsOnDay(date.withoutTime,
+    final events = _calendarData.getEventsOnDay(date.withoutTime,
         includeFullDayEvents: includeFullDayEvents);
+    events.addAll(getRepeatedEvents(date));
+    return events;
+  }
+
+  /// Filters list of repeated events to show in the cell for given date
+  /// from all the repeated events.
+  /// Event reoccurrence will only show after today's date and event's day.
+  List<CalendarEventData<T>> getRepeatedEvents(DateTime date) {
+    if (!date.isAfter(DateTime.now())) {
+      return [];
+    }
+    final repeatedEvents = _calendarData.repeatedEvents;
+    List<CalendarEventData<T>> events = [];
+    for (final event in repeatedEvents) {
+      if (!date.isAfter(event.date)) {
+        continue;
+      }
+      switch (event.recurrenceSettings!.frequency) {
+        case RepeatFrequency.daily:
+          events.add(event);
+          break;
+        case RepeatFrequency.weekly:
+          if (event.recurrenceSettings!.weekdays.contains(date.weekday - 1)) {
+            events.add(event);
+          }
+          break;
+        case RepeatFrequency.monthly:
+          // TODO: Handle this case.
+          break;
+        case RepeatFrequency.yearly:
+          // TODO: Handle this case.
+          break;
+        case RepeatFrequency.doNotRepeat:
+          // TODO: Handle this case.
+          break;
+      }
+    }
+    return events;
   }
 
   /// Returns full day events on given day.
@@ -179,6 +217,10 @@ class CalendarData<T extends Object?> {
   /// available in this list as global itemList of all events).
   final _eventList = <CalendarEventData<T>>[];
 
+  /// If recurrence settings exist then get all the repeated events
+  List<CalendarEventData<T>> get repeatedEvents =>
+      _eventList.where((event) => event.recurrenceSettings != null).toList();
+
   UnmodifiableListView<CalendarEventData<T>> get events =>
       UnmodifiableListView(_eventList);
 
@@ -249,7 +291,6 @@ class CalendarData<T extends Object?> {
 
     // TODO: improve this...
     if (_eventList.contains(event)) return;
-
     if (event.isFullDayEvent) {
       addFullDayEvent(event);
     } else if (event.isRangingEvent) {
@@ -329,7 +370,6 @@ class CalendarData<T extends Object?> {
     if (includeFullDayEvents) {
       events.addAll(getFullDayEvent(date));
     }
-
     return events;
   }
 

lib/src/modals.dart

@@ -83,3 +83,36 @@ class LiveTimeIndicatorSettings {
         showBullet: false,
       );
 }
+
+/// Set `frequency = RepeatFrequency.daily` to repeat every day after current date & event day.
+/// Set `frequency = RepeatFrequency.weekly` & provide list of weekdays to repeat on.
+/// [startDate]: Defines start date of repeating events.
+/// [endDate]: Defines end date of repeating events.
+/// [interval]: Defines repetition of event after given [interval] in days.
+/// [frequency]: Defines repeat daily, weekly, monthly or yearly.
+/// [weekdays]: Contains list of weekdays to repeat on.
+/// By default weekday of event is considered if not provided.
+class RecurrenceSettings {
+  final DateTime startDate;
+  final DateTime? endDate;
+  final int? interval;
+  final RepeatFrequency frequency;
+  final List<int> weekdays;
+
+  RecurrenceSettings(
+    this.startDate, {
+    this.endDate,
+    this.interval,
+    this.frequency = RepeatFrequency.weekly,
+    List<int>? weekdays,
+  }) : weekdays = weekdays ?? [startDate.weekday];
+
+  @override
+  String toString() {
+    return "start date: ${startDate}, "
+        "end date: ${endDate}, "
+        "interval: ${interval}, "
+        "frequency: ${frequency} "
+        "weekdays: ${weekdays.toString()}";
+  }
+}

lib/src/month_view/month_view.dart

@@ -699,6 +699,7 @@ class _MonthPageBuilder<T> extends StatelessWidget {
         shrinkWrap: true,
         itemBuilder: (context, index) {
           final events = controller.getEventsOnDay(monthDays[index]);
+
           return GestureDetector(
             onTap: () => onCellTap?.call(events, monthDays[index]),
             onLongPress: () => onDateLongPress?.call(monthDays[index]),