Automated animated discs project inspired by Dartpad sample project

animated_discs.dart

import 'package:flutter/material.dart';
import 'dart:math';
import 'dart:async';

const Color darkBlue = Color.fromARGB(255, 18, 32, 47);

void main() {
  runApp(MyApp());
}

class MyApp extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return const MaterialApp(
      home: DiscScaffold(noOfDiscs: 40),
    );
  }
}

class Disc {
  static final _random = Random();
  final double size;
  final Alignment alignment;
  final Color color;
  Disc()
      : size = _random.nextDouble() * 40 + 10,
        color = Color.fromRGBO(
          _random.nextInt(255),
          _random.nextInt(255),
          _random.nextInt(255),
          _random.nextDouble(),
        ),
        alignment = Alignment(
          _random.nextDouble() * 2 - 1,
          _random.nextDouble() * 2 - 1,
        );
}

class DiscScaffold extends StatefulWidget {
  final int noOfDiscs;
  const DiscScaffold({Key? key, this.noOfDiscs = 20}) : super(key: key);
  @override
  State<DiscScaffold> createState() => _DiscScaffoldState();
}

class _DiscScaffoldState extends State<DiscScaffold> {
  List<Disc> discs = [];
  late final Timer _timer;
  final Duration _duration = const Duration(milliseconds: 600);

  void _createDiscs() {
    discs.clear();
    for (var i = 0; i < widget.noOfDiscs; i++) {
      discs.add(Disc());
    }
  }

  @override
  void initState() {
    _createDiscs();
    _timer = Timer.periodic(
        Duration(milliseconds: _duration.inMilliseconds + 100), (timer) {
      setState(_createDiscs);
    });

    super.initState();
  }

  @override
  void dispose() {
    _timer.cancel();
    super.dispose();
  }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      backgroundColor: darkBlue,
      body: Stack(
        children: [
          for (var disc in discs)
            Positioned.fill(
              child: AnimatedAlign(
                duration: _duration,
                alignment: disc.alignment,
                child: AnimatedContainer(
                  decoration: BoxDecoration(
                    shape: BoxShape.circle,
                    color: disc.color,
                  ),
                  duration: _duration,
                  height: disc.size,
                  width: disc.size,
                ),
              ),
            ),
        ],
      ),
    );
  }
}