ReorderableList

sample.packages.flutter.lib.src.material.reorderable_list.203.

  
import 'package:flutter/material.dart';

void main() => runApp(const ReorderableApp());

class ReorderableApp extends StatelessWidget {
  const ReorderableApp({Key? key}) : super(key: key);

  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      home: Scaffold(
        appBar: AppBar(title: const Text('ReorderableListView Sample')),
        body: const ReorderableExample(),
      ),
    );
  }
}

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

  @override
  State createState() => _ReorderableExampleState();
}

class _ReorderableExampleState extends State {
  final List _items = List.generate(50, (int index) => index);

  @override
  Widget build(BuildContext context) {
    final ColorScheme colorScheme = Theme.of(context).colorScheme;
    final Color oddItemColor = colorScheme.primary.withOpacity(0.05);
    final Color evenItemColor = colorScheme.primary.withOpacity(0.15);

    return ReorderableListView(
      buildDefaultDragHandles: false,
      children: [
        for (int index = 0; index < _items.length; index++)
          Container(
            key: Key('$index'),
            color: _items[index].isOdd ? oddItemColor : evenItemColor,
            child: Row(
              children: [
                Container(
                  width: 64,
                  height: 64,
                  padding: const EdgeInsets.all(8),
                  child: ReorderableDragStartListener(
                    index: index,
                    child: Card(
                      color: colorScheme.primary,
                      elevation: 2,
                    ),
                  ),
                ),
                Text('Item ${_items[index]}'),
              ],
            ),
          ),
      ],
      onReorder: (int oldIndex, int newIndex) {
        setState(() {
          if (oldIndex < newIndex) {
            newIndex -= 1;
          }
          final int item = _items.removeAt(oldIndex);
          _items.insert(newIndex, item);
        });
      },
    );
  }
}