specialRegions property Null safety

List<TimeRegion>? specialRegions

Defines the collection of special TimeRegion for SfCalendar.

It is used to highlight time slots on day, week, work week and timeline views based on TimeRegion start and end time.

It also used to restrict interaction on time slots.

 Widget build(BuildContext context) {
   return Container(
     child: SfCalendar(
       view: CalendarView.week,
       specialRegions: _getTimeRegions(),

 List<TimeRegion> _getTimeRegions() {
   final List<TimeRegion> regions = <TimeRegion>[];
       startTime: DateTime.now(),
       endTime: DateTime.now().add(Duration(hours: 1)),
       enablePointerInteraction: false,
       color: Colors.grey.withOpacity(0.2),
       text: 'Break'));

   return regions;


final List<TimeRegion>? specialRegions;