When changing the order of categories, things don’t work as expected. ReorderableListView is used to change the order, but instead of changing the order normally, new data is created. I defined the object as immutable using frozen, but I think giving up immutable would be the way to go. Is there a better way?

The code is below:

Future<void> reorderCategory(int oldIndex, int newIndex) async {
    final categories = await getCategories();
    await isar.writeTxn(() async {
      final targetOrder = categories[newIndex].order!;
      final sourceOrder = categories[oldIndex].order!;
      await isar.categorys.put(categories[oldIndex].setOrder(targetOrder));
      await isar.categorys.put(categories[newIndex].setOrder(sourceOrder));
    });
  }

@freezed
@Collection(ignore: {'copyWith'})
class Category with _$Category {
  Category._();

  factory Category({
    required String name,
    int? order,
  }) = _Category;

  Id get id => Isar.autoIncrement;

  final memos = IsarLinks<Memo>();
}

extension MutableCategory on Category {
  Category setOrder(int order) {
    return copyWith(order: order);
  }
}