stateful list item example

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

void main() {
  runApp(
    MyApp(
      items: List<String>.generate(10000, (i) => 'Item $i'),
    ),
  );
}

class MyApp extends StatelessWidget {
  final List<String> items;

  const MyApp({Key? key, required this.items}) : super(key: key);

  @override
  Widget build(BuildContext context) {
    const title = 'Long List';

    return MaterialApp(
      title: title,
      home: StatefulList(items: items),
    );
  }
}

class StatefulList extends StatefulWidget {
  final List items;
  const StatefulList({Key? key, required this.items}) : super(key: key);

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

class _StatefulListState extends State<StatefulList> {
  bool some = false;

  @override
  Widget build(BuildContext context) {
    const title = 'Long List';
    return Scaffold(
      appBar: AppBar(
        title: const Text(title),
      ),
      floatingActionButton: FloatingActionButton(
        onPressed: _toggle,
      ),
      body: ListView.builder(
        itemCount: widget.items.length,
        itemBuilder: (context, index) {
          return StatefulItem(child: some ? Text('$index') : Text('test'));
        },
      ),
    );
  }

  void _toggle() {
    setState(() {
      some = !some;
    });
  }
}

class StatefulItem extends StatefulWidget {
  final Widget child;
  const StatefulItem({Key? key, required this.child}) : super(key: key);

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

class _StatefulItemState extends State<StatefulItem> {
  @override
  Widget build(BuildContext ctx) => ListTile(
        title: widget.child,
      );
}