DeviceOrientation web

main.dart

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

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

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

  @override
  Widget build(context) => const MaterialApp(
        home: MyHomePage(),
      );
}

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

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

class _MyHomePageState extends State<MyHomePage> {
  late final ValueNotifier<DeviceOrientation> _valueNotifier;

  @override
  void initState() {
    _valueNotifier = ValueNotifier(DeviceOrientation.portraitUp);
    super.initState();
  }

  @override
  void dispose() {
    _valueNotifier.dispose();
    super.dispose();
  }

  void _next() {
    var next = DeviceOrientation.values.indexOf(_valueNotifier.value) + 1;
    if (!(next < DeviceOrientation.values.length)) {
      next = 0;
    }
    setState(() => _valueNotifier.value = DeviceOrientation.values[next]);
  }

  @override
  Widget build(context) => ValueListenableBuilder(
        valueListenable: _valueNotifier,
        builder: (context, orientation, _) => FakeDeviceOrientationWidget(
          orientation: orientation,
          child: Scaffold(
            body: Center(
              child: Text(orientation.name),
            ),
            floatingActionButton: FloatingActionButton(
              onPressed: _next,
              tooltip: 'next',
              child: const Icon(Icons.rotate_90_degrees_cw),
            ),
          ),
        ),
      );
}

class FakeDeviceOrientationWidget extends StatelessWidget {
  final DeviceOrientation orientation;
  final Widget child;
  const FakeDeviceOrientationWidget({
    super.key,
    required this.orientation,
    required this.child,
  });

  @override
  Widget build(context) => RotatedBox(
        quarterTurns: switch (orientation) {
          DeviceOrientation.portraitUp => 0,
          DeviceOrientation.portraitDown => 2,
          DeviceOrientation.landscapeLeft => 1,
          DeviceOrientation.landscapeRight => 3
        },
        child: child,
      );
}