flutter ReorderableListView with Slidable

my_file.dart

class MyFile{
  int? index;
  String name;
  String path;

  MyFile({required this.name, required this.path, this.index});

  Map<String, dynamic> toJson() => {
    'name': name,
    'path': path
  };

  MyFile.fromJson(Map<String, dynamic> json)
    : name = json['name'],
      path = json['path'];
}

extension IndexedIterable<E> on Iterable<E> {
  Iterable<T> mapIndexed<T>(T Function(E value, int index) f) {
    var index = 0;
    return map((element) => f(element, index++));
  }
}

widget.dart

body: ReorderableListView(
  children: playList.mapIndexed((value, index){
    value.index = index;
    return value;
  }).toList().map((file) => 
      Slidable(
        key: ObjectKey(file.path),
        actions: <Widget>[
          IconSlideAction(
            icon: Icons.delete,
            caption: 'Delete',
            color: Colors.red,
            onTap: () {
              setState(() {
                playList.removeAt(file.index!);
              });
            }
          ),
        ],
        actionPane: SlidableDrawerActionPane(),
        child: ListTile(
          key: ObjectKey(file.path),
          title: Text(file.name),
          trailing: Icon(Icons.drag_handle)
        )
    )
    ).toList(),
  onReorder: (int start, int current) {
    // dragging from top to bottom
    if (start < current) {
      int end = current - 1;
      MyFile startItem = playList[start];
      int i = 0;
      int local = start;
      do {
        playList[local] = playList[++local];
        i++;
      } while (i < end - start);
      playList[end] = startItem;
    }
    // dragging from bottom to top
    else if (start > current) {
      MyFile startItem = playList[start];
      for (int i = start; i > current; i--) {
        playList[i] = playList[i - 1];
      }
      playList[current] = startItem;
    }
    setState(() {});
  },
),