Implementing a playlist

[t-m-z]

When trying to implement a playlist I found a solution at
https://discord.com/channels/509714518008528896/533299043686940692/threads/990854105394216970
which led me to the following code:

import 'dart:async';
import 'package:audioplayers/audioplayers.dart';
...
void main() {
  runApp(const MaterialApp(home: PlaylistApp()));
}

class PlaylistApp extends StatefulWidget {
  const PlaylistApp({super.key});

  @override
  _PlaylistAppState createState() => _PlaylistAppState();
}

class _PlaylistAppState extends StatefulWidget {

  var player = AudioPlayer(playerId: Uuid().v4(),);
  
  List<AssetSource> _playlist = [];
  int _index = 0;

  void playSound(int index) {
    if (index < _playlist.length) {
      player.play(_playlist[index]);
      if (index + 1 < _playlist.length) {
        StreamSubscription<void> subscription = player.onPlayerComplete.listen((event) => 0);
        subscription = player.onPlayerComplete.listen((event) {
          index++;
          playSound(index,);
          subscription.cancel();
        });
      }
    }
  }

...

@override
  Widget build(BuildContext context){
...
      IconButton(
        icon: Icons.play_arrow,
        onPressed: () {
          _index = 0;
          
          if (_playlist.length > 0)
            playSound(_index);
        },
      )   
...	  
  }
}