flutter challenge 01

challenge01.dart

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

class AnimatedListExample extends StatefulWidget {
  @override
  _AnimatedListExampleState createState() => _AnimatedListExampleState();
}

class _AnimatedListExampleState extends State<AnimatedListExample> with SingleTickerProviderStateMixin {
  final List<String> _items = [];
  final StreamController<List<String>> _streamController = StreamController<List<String>>();
  Timer? _timer;
  late AnimationController _animationController;

  @override
  void initState() {
    super.initState();
    _animationController = AnimationController(
      duration: const Duration(seconds: 1),
      vsync: this,
    );

    _timer = Timer.periodic(Duration(seconds: 2), (timer) {
      _items.add('Item ${_items.length + 1}');
      _streamController.add(_items);
    });
  }

  @override
  void dispose() {
    _timer?.cancel();
    _streamController.close();
    _animationController.dispose();
    super.dispose();
  }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        title: Text('Animated List Example'),
      ),
      body: StreamBuilder<List<String>>(
        stream: _streamController.stream,
        builder: (context, snapshot) {
          if (!snapshot.hasData) {
            return Center(child: CircularProgressIndicator());
          }

          return ListView.builder(
            itemCount: snapshot.data!.length,
            itemBuilder: (context, index) {
              _animationController.forward(from: 0.0);
              return FadeTransition(
                opacity: _animationController,
                child: ListTile(
                  title: Text(snapshot.data![index]),
                ),
              );
            },
          );
        },
      ),
    );
  }
}

void main() => runApp(MaterialApp(home: AnimatedListExample()));