sort_user_code.dart

class User {
  final String firstName;

  User(this.firstName);

  static List<User> dummyUsers() {
    return [
      User('veli'),
      User('bora'),
    ];
  }
}

class SortingView extends StatefulWidget {
  const SortingView({Key? key}) : super(key: key);

  @override
  State<SortingView> createState() => _SortingViewState();
}

class _SortingViewState extends State<SortingView> {
  final List<User> _users = User.dummyUsers();
  bool _isAcending = true;

  void _sortByUsers(bool isAscending) {
    setState(() {
      _users.sort((first, second) => compareAsciiUpperCase(
          isAscending ? first.firstName : second.firstName, isAscending ? second.firstName : first.firstName));
    });
  }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      floatingActionButtonLocation: FloatingActionButtonLocation.endTop,
      floatingActionButton: FloatingActionButton(
        child: const Icon(Icons.change_circle),
        onPressed: () {
          _changeAndSort();
        },
      ),
      body: Padding(
        padding: const EdgeInsets.all(8.0),
        child: ListView.builder(
          itemBuilder: (context, index) => Card(child: Text(_users[index].firstName)),
          itemCount: _users.length,
        ),
      ),
    );
  }

  void _changeAndSort() {
    setState(() {
      _isAcending = !_isAcending;
    });
    _sortByUsers(_isAcending);
  }
}