Firebase Collection into ReorderableListView

I have a Firebase collection in Flutter that I want to have in a reorderableListView. The documents in the collection have a 'position' field that should determine the order of the list and be updated onReorder of the list.

I've worked it out myself finally.

onReorder: (oldIndex, newIndex) {
  setState(() {
    List<MyObjectClass> objectList =
        myObjects
            .data;
    if (newIndex > oldIndex) {
      newIndex -= 1;
    }

    final MyObjectClass
        myObject = objectList.removeAt(oldIndex);
    objectList.insert(newIndex, myObject);

    for (MyObjectClass o in objectList) {
      o.position = objectList.indexOf(o);
      DatabaseService()
          .updateMyObjects(
              o);
    }
  });
}

This is assuming you've got a function in a DatabaseService() class that maps a Firestore Collection to objects, and then have the ReorderableListView in a StreamBuilder that passes it a snapshot of said objects 'myObjects'.