fix: allow clearing the duration from the pause dialog

packages/flutter_availability/lib/src/ui/view_models/break_view_model.dart

@@ -7,7 +7,7 @@ class BreakViewModel {
   const BreakViewModel({
     this.startTime,
     this.endTime,
-    this.duration,
+    this.submittedDuration,
   });
 
   /// Create a [BreakViewModel] from a [AvailabilityBreakModel]
@@ -17,7 +17,7 @@ class BreakViewModel {
       BreakViewModel(
         startTime: TimeOfDay.fromDateTime(data.startTime),
         endTime: TimeOfDay.fromDateTime(data.endTime),
-        duration: data.duration,
+        submittedDuration: data.submittedDuration,
       );
 
   /// The start time for this break
@@ -26,20 +26,18 @@ class BreakViewModel {
   /// The end time for this break
   final TimeOfDay? endTime;
 
-  /// The full duration of the actual break.
+  /// The full duration of the actual break. This is filled in by the users and
+  /// stays null if the user has not filled it in.
   ///
   /// This is allowed to diverge from the difference between [startTime] and
   /// [endTime] to indicate that the break is somewhere between [startTime] and
   /// [endTime]
-  final Duration? duration;
+  final Duration? submittedDuration;
 
-  /// Get the duration in minutes
+  /// Get the duration of the break
   /// If the duration is null, return the difference between the start and end
   /// time in minutes
-  int get durationInMinutes =>
+  Duration get duration => submittedDuration ?? toBreak().duration;
-      duration?.inMinutes ??
-      ((endTime!.hour * 60 + endTime!.minute) -
-          (startTime!.hour * 60 + startTime!.minute));
 
   /// Returns true if the break is valid
   /// The start is before the end and the duration is equal or lower than the
@@ -54,11 +52,11 @@ class BreakViewModel {
     if (startDateTime.isAfter(endDateTime)) {
       return false;
     }
-    if (duration == null) {
+    if (submittedDuration == null) {
       return true;
     }
     var actualDuration = endDateTime.difference(startDateTime);
-    return duration! <= actualDuration;
+    return submittedDuration! <= actualDuration;
   }
 
   /// Whether the save/next button should be enabled
@@ -66,21 +64,22 @@ class BreakViewModel {
 
   /// Convert to [AvailabilityBreakModel] for saving
   AvailabilityBreakModel toBreak() => AvailabilityBreakModel(
-        startTime: DateTime(0, 0, 0, startTime!.hour, startTime!.minute),
+        startTime:
-        endTime: DateTime(0, 0, 0, endTime!.hour, endTime!.minute),
+            DateTime(0, 0, 0, startTime?.hour ?? 0, startTime?.minute ?? 0),
-        duration: duration,
+        endTime: DateTime(0, 0, 0, endTime?.hour ?? 0, endTime?.minute ?? 0),
+        submittedDuration: submittedDuration,
       );
 
   /// Create a copy with new values
   BreakViewModel copyWith({
     TimeOfDay? startTime,
     TimeOfDay? endTime,
-    Duration? duration,
+    Duration? submittedDuration,
   }) =>
       BreakViewModel(
         startTime: startTime ?? this.startTime,
         endTime: endTime ?? this.endTime,
-        duration: duration ?? this.duration,
+        submittedDuration: submittedDuration ?? this.submittedDuration,
       );
 
   /// compareto method to order two breaks based on their start time
@@ -92,4 +91,11 @@ class BreakViewModel {
         other.startTime!.minute;
     return difference;
   }
+
+  /// Clear the duration of the break
+  BreakViewModel clearDuration() => BreakViewModel(
+        startTime: startTime,
+        endTime: endTime,
+        submittedDuration: null,
+      );
 }

packages/flutter_availability/lib/src/ui/widgets/input_fields.dart

@@ -67,7 +67,7 @@ class DurationInputField extends StatelessWidget {
   final Duration? initialValue;
 
   ///
-  final void Function(Duration) onDurationChanged;
+  final void Function(Duration?) onDurationChanged;
 
   @override
   Widget build(BuildContext context) {
@@ -79,6 +79,8 @@ class DurationInputField extends StatelessWidget {
       var duration = int.tryParse(value);
       if (duration != null) {
         onDurationChanged(Duration(minutes: duration));
+      } else {
+        onDurationChanged(null);
       }
     }
 

packages/flutter_availability/lib/src/ui/widgets/pause_selection.dart

@@ -146,7 +146,7 @@ class BreakDisplay extends StatelessWidget {
       breakModel.endTime!,
     );
 
-    var breakDuration = breakModel.durationInMinutes;
+    var breakDuration = breakModel.duration.inMinutes;
 
     return InkWell(
       onTap: onClick,
@@ -246,9 +246,14 @@ class _AvailabilityBreakSelectionDialogState
     var translations = options.translations;
     var spacing = options.spacing;
 
-    void onUpdateDuration(Duration duration) {
+    void onUpdateDuration(Duration? duration) {
       setState(() {
-        _breakViewModel = _breakViewModel.copyWith(duration: duration);
+        if (duration != null) {
+          _breakViewModel =
+              _breakViewModel.copyWith(submittedDuration: duration);
+        } else {
+          _breakViewModel = _breakViewModel.clearDuration();
+        }
       });
     }
 
@@ -317,7 +322,7 @@ class _AvailabilityBreakSelectionDialogState
                 Expanded(
                   flex: 2,
                   child: DurationInputField(
-                    initialValue: _breakViewModel.duration,
+                    initialValue: _breakViewModel.submittedDuration,
                     onDurationChanged: onUpdateDuration,
                   ),
                 ),

packages/flutter_availability_data_interface/lib/src/models/availability.dart

@@ -60,8 +60,8 @@ class AvailabilityBreakModel {
   const AvailabilityBreakModel({
     required this.startTime,
     required this.endTime,
-    Duration? duration,
+    this.submittedDuration,
-  }) : _duration = duration;
+  });
 
   /// Parses a break from a map.
   ///
@@ -74,7 +74,7 @@ class AvailabilityBreakModel {
             DateTime.fromMillisecondsSinceEpoch((map["startTime"] ?? 0) as int),
         endTime:
             DateTime.fromMillisecondsSinceEpoch((map["endTime"] ?? 0) as int),
-        duration: map["duration"] != null
+        submittedDuration: map["duration"] != null
             ? Duration(minutes: map["duration"] as int)
             : null,
       );
@@ -83,35 +83,36 @@ class AvailabilityBreakModel {
   ///
   /// If duration is not the same as the difference between [startTime] and
   /// [endTime], the [startTime] is considered the start of the period of which
-  /// a break of [_duration] can be held.
+  /// a break of [submittedDuration] can be held.
   final DateTime startTime;
 
   /// The end time for this break
   ///
   /// If duration is not the same as the difference between [startTime] and
   /// [endTime], the [endTime] is considered the end of the period of which
-  /// a break of [_duration] can be held.
+  /// a break of [submittedDuration] can be held.
   final DateTime endTime;
 
-  /// The full duration of the actual break.
+  /// The full duration of the actual break. This is filled in by the users and
+  /// stays null if the user has not filled it in.
   ///
   /// This is allowed to diverge from the difference between [startTime] and
   /// [endTime] to indicate that the break is somewhere between [startTime] and
   /// [endTime]
-  final Duration? _duration;
+  final Duration? submittedDuration;
 
   /// Results in the set duration, or the difference between [startTime] and
   /// [endTime] if no duration is set.
-  Duration get duration => _duration ?? period;
+  Duration get duration => submittedDuration ?? period;
 
   /// The period in which the break will take place.
   ///
-  /// Will be the same as [duration] if the initial [_duration] is null
+  /// Will be the same as [duration] if the initial [submittedDuration] is null
   Duration get period => endTime.difference(startTime);
 
   /// Whether the duration of the break matches the difference between
   /// [startTime] and [endTime]
-  bool get isTight => _duration == null || _duration == period;
+  bool get isTight => submittedDuration == null || submittedDuration == period;
 
   /// Copies the current properties into a new instance of
   /// [AvailabilityBreakModel], except for the properties provided
@@ -119,12 +120,12 @@ class AvailabilityBreakModel {
   AvailabilityBreakModel copyWith({
     DateTime? startTime,
     DateTime? endTime,
-    Duration? duration,
+    Duration? submittedDuration,
   }) =>
       AvailabilityBreakModel(
         startTime: startTime ?? this.startTime,
         endTime: endTime ?? this.endTime,
-        duration: duration ?? _duration,
+        submittedDuration: submittedDuration ?? this.submittedDuration,
       );
 
   /// Returns a map variant of this object.
@@ -135,6 +136,6 @@ class AvailabilityBreakModel {
   Map<String, dynamic> toMap() => <String, dynamic>{
         "startTime": startTime.millisecondsSinceEpoch,
         "endTime": endTime.millisecondsSinceEpoch,
-        "duration": _duration?.inMinutes,
+        "duration": submittedDuration?.inMinutes,
       };
 }

packages/flutter_availability_data_interface/lib/src/models/templates.dart

@@ -331,7 +331,8 @@ class DayTemplateData implements TemplateData {
               AvailabilityBreakModel(
                 startTime: date.mergeTime(templateBreak.startTime),
                 endTime: date.mergeTime(templateBreak.endTime),
-                duration: templateBreak.isTight ? null : templateBreak.duration,
+                submittedDuration:
+                    templateBreak.isTight ? null : templateBreak.duration,
               ),
             ],
           ],

packages/flutter_availability_data_interface/test/models_templates_test.dart

@@ -12,7 +12,7 @@ void main() {
             AvailabilityBreakModel(
               startTime: asTime(startHour),
               endTime: asTime(startHour + 1),
-              duration: const Duration(minutes: 30),
+              submittedDuration: const Duration(minutes: 30),
             );
 
         DayTemplateData createTemplate(int startHour) => DayTemplateData(