import 'package:flutter_web/material.dart';

void main() => runApp(MaterialApp(home: ReoderList(),));


class ReoderList extends StatefulWidget {
  @override
  _ReoderListState createState() => _ReoderListState();
}

class _ReoderListState extends State<ReoderList> {
  bool isSort = false;
  static final _items = <String>[
    'A',
    'B',
    'C',
    'D',
    'E',
    'F',
    'G',
    'H',
    'I',
    'J',
    'K',
    'L',
    'M',
    'N',
  ];

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      floatingActionButton: FloatingActionButton(
        child: Icon(Icons.sort_by_alpha),
        onPressed: () {
          setState(() {
            isSort = !isSort;
            _items.sort((a, b) => isSort ? a.compareTo(b) : b.compareTo(a));
          });
        },
      ),
      body: ReorderableListView(
        onReorder: (int oldIndex, int newIndex) {
          setState(() {
            if (newIndex > oldIndex) {
              newIndex -= 1;
            }
            final moveItem = _items.removeAt(oldIndex);
            _items.insert(newIndex, moveItem);
          });
        },
        children: _items
            .map((item) => ListTile(
                  key: Key(item),
                  title: Text('this is represents $item'),
                  subtitle: Text('Item : $item'),
                  leading: Icon(Icons.drag_handle),
                ))
            .toList(),
      ),
    );
  }
}