Populating a list view with a custom widget in flutter - flutter

Question

I created a Calendar widget.
I have 7 users and I would like to create 7 personal calendars.
For this purpose, I am using a list view builder.
import 'package:flutter/cupertino.dart';
import 'package:flutter/material.dart';
import 'package:test_honours/model/doctors.dart';
import '../core/booking_calendar.dart';
import '../model/booking_service.dart';
import '../model/enums.dart';
import 'appointment_screen.dart';
class BookingCalendarDemoApp extends StatelessWidget {
BookingCalendarDemoApp({Key? key}) : super(key: key);
final now = DateTime.now();
late BookingModel bookingCalendarModel;
List<BookingModel> bookingList = [];
void createBooking() {
for (var i = 0; i < doctorsList.length; i++) {
Doctor doctor = doctorsList[i];
bookingList.add(bookingCalendarModel = new BookingModel(
apptName: 'Mock Service',
apptDuration: doctor.duration,
bookingEnd: doctor.endHour,
bookingStart: doctor.startHour));
}
}
Stream<dynamic>? getBookingStreamMock(
{required DateTime end, required DateTime start}) {
return Stream.value([]);
}
Future<dynamic> uploadBookingMock({required BookingModel newBooking}) async {
await Future.delayed(const Duration(seconds: 1));
converted.add(DateTimeRange(
start: newBooking.bookingStart, end: newBooking.bookingEnd));
print('${newBooking.toJson()} has been uploaded');
}
List<DateTimeRange> converted = [];
List<DateTimeRange> convertStreamResultMock({required dynamic streamResult}) {
///here you can parse the streamresult and convert to [List<DateTimeRange>]
///take care this is only mock, so if you add today as disabledDays it will still be visible on the first load
///disabledDays will properly work with real data
DateTime first = now;
DateTime tomorrow = now.add(Duration(days: 1));
DateTime second = now.add(const Duration(minutes: 55));
DateTime third = now.subtract(const Duration(minutes: 240));
DateTime fourth = now.subtract(const Duration(minutes: 500));
converted.add(
DateTimeRange(start: first, end: now.add(const Duration(minutes: 30))));
converted.add(DateTimeRange(
start: second, end: second.add(const Duration(minutes: 23))));
converted.add(DateTimeRange(
start: third, end: third.add(const Duration(minutes: 15))));
converted.add(DateTimeRange(
start: fourth, end: fourth.add(const Duration(minutes: 50))));
//book whole day example
converted.add(DateTimeRange(
start: DateTime(tomorrow.year, tomorrow.month, tomorrow.day, 5, 0),
end: DateTime(tomorrow.year, tomorrow.month, tomorrow.day, 23, 0)));
return converted;
}
List<DateTimeRange> generatePauseSlots() {
return [
DateTimeRange(
start: DateTime(now.year, now.month, now.day, 12, 0),
end: DateTime(now.year, now.month, now.day, 14, 0))
];
}
#override
Widget build(BuildContext context) {
double h = MediaQuery.of(context).size.height;
return Container(
height: h,
child: ListView.builder(
shrinkWrap: true,
scrollDirection: Axis.horizontal,
itemCount: bookingList.length,
itemBuilder: (context, index) {
return Column(
children: [
BookingCalendar(
bookingService: bookingCalendarModel,
convertStreamResultToDateTimeRanges:
convertStreamResultMock,
getBookingStream: getBookingStreamMock,
uploadBooking: uploadBookingMock,
pauseSlots: generatePauseSlots(),
hideBreakTime: false,
loadingWidget: const Text('Fetching data...'),
uploadingWidget: const CircularProgressIndicator(),
locale: 'en_US',
startingDayOfWeek: CalendarDays.monday,
wholeDayIsBookedWidget:
const Text('Fully booked! Choose another day'),
disabledDates: [DateTime(2023, 1, 20)],
disabledDays: [6, 7])
],
);
}),
);
}
}
When i run the app the whole screen is black. And I am getting this error:
The following assertion was thrown during paint():
RenderBox was not laid out: RenderRepaintBoundary#557e1 NEEDS-PAINT
'package:flutter/src/rendering/box.dart':
Failed assertion: line 2001 pos 12: 'hasSize'
Could you please give me any suggestions what is wrong? In addition, this class should be opened after the user click on a button.

Answer 1

Use Expanded()
Expanded(
child: ListView.builder()
),

Answer 2

Try to set width too, not only height, to Container parent of ListView.builder(