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

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

class MyApp extends StatelessWidget {
  const MyApp({super.key});

  // This widget is the root of your application.
  @override
  Widget build(BuildContext context) {
    final renderBinding = RendererBinding.instance;
    if (!renderBinding.semanticsEnabled) {
      renderBinding.ensureSemantics();
    }
    return MaterialApp(
      title: 'Flutter Demo',
      theme: ThemeData(
        colorScheme: ColorScheme.fromSeed(seedColor: Colors.deepPurple),
        useMaterial3: true,
      ),
      home: const MyHomePage(title: 'Flutter Demo Home Page'),
    );
  }
}

class MyHomePage extends StatefulWidget {
  const MyHomePage({super.key, required this.title});

  final String title;

  @override
  State<MyHomePage> createState() => _MyHomePageState();
}

class _MyHomePageState extends State<MyHomePage> {
  int _counter = 0;

  void _incrementCounter() {
    setState(() {
      _counter++;
    });
  }

  @override
  Widget build(BuildContext context) {
    const divider = 100;
    return Scaffold(
      appBar: AppBar(
        backgroundColor: Theme.of(context).colorScheme.inversePrimary,
        title: Text(widget.title),
      ),
      body: Center(
        child: Column(
          mainAxisAlignment: MainAxisAlignment.center,
          children: <Widget>[
            const Text(
              'You have pushed the button this many times:',
            ),
            Text('$_counter'),
            Slider(
              autofocus: true,
              value: _counter / divider,
              onChanged: (value) => setState(
                () => _counter = (value * divider).round(),
              ),
              label: 'Screen readers will not pick up this label',
            ),
            Slider(
              value: _counter / divider,
              onChanged: (value) => setState(
                () => _counter = (value * divider).round(),
              ),
              label: 'Screen readers will not speak this label either',
              semanticFormatterCallback: (value) =>
                  'Screen readers will show this value. Counter is $_counter',
            ),
            MergeSemantics(
              // I use `MergeSemantics` to prevent NVDA from recognising a group.
              child: Semantics(
                label: 'This works perfectly',
                child: Slider(
                  value: _counter / divider,
                  onChanged: (value) => setState(
                    () => _counter = (value * divider).round(),
                  ),
                  label:
                      'We just need to wrap the `Slider` widget in a `MergeSemantics` and a `Semantics` widget and everything will be fixed',
                ),
              ),
            )
          ],
        ),
      ),
      floatingActionButton: FloatingActionButton(
        onPressed: _incrementCounter,
        tooltip: 'Increment',
        child: const Icon(Icons.add),
      ),
    );
  }
}