How to set the highest refresh rate on Android in Flutter using `flutter_displaymode`?

main.dart

///
/// [Author] Alex (https://github.com/AlexV525)
/// [Date] 2022/03/07 23:25
///
import 'dart:async';
import 'dart:io';

import 'package:device_info_plus/device_info_plus.dart';
import 'package:flutter/gestures.dart';
import 'package:flutter/material.dart';
import 'package:flutter_displaymode/flutter_displaymode.dart';

void main() async {
  WidgetsFlutterBinding.ensureInitialized();
  if (Platform.isAndroid) {
    DeviceUtil.androidInfo = await DeviceInfoPlugin().androidInfo;
  }
  DeviceUtil.setHighestRefreshRate();
  runApp(const App());
}

class App extends StatefulWidget {
  const App({Key? key}) : super(key: key);

  @override
  State<App> createState() => AppState();
}

class AppState extends State<App> with WidgetsBindingObserver {
  @override
  void initState() {
    super.initState();
    DeviceUtil.setHighestRefreshRate();
  }

  @override
  void didChangeAppLifecycleState(AppLifecycleState state) {
    if (state == AppLifecycleState.resumed) {
      DeviceUtil.setHighestRefreshRate();
    }
  }

  @override
  Widget build(BuildContext context) {
    return const MaterialApp(home: SizedBox.shrink());
  }
}


class DeviceUtil {
  const DeviceUtil._();

  static AndroidDeviceInfo? androidInfo;
  static DisplayMode? _highestRefreshRateMode;

  static Future<void> setHighestRefreshRate() async {
    if (!Platform.isAndroid || androidInfo?.version.sdkInt == null) {
      return;
    }
    // Apply only on Android 23+.
    final int sdkInt = DeviceUtil.androidInfo!.version.sdkInt!;
    if (sdkInt < 23) {
      return;
    }
    // Delay 1 second since bindings will need to reconnect.
    await Future.delayed(const Duration(seconds: 1));
    final DisplayMode current = await FlutterDisplayMode.active;
    // Search for the highest refresh rate and save.
    if (_highestRefreshRateMode == null) {
      final List<DisplayMode> modes = await FlutterDisplayMode.supported;
      modes.removeWhere(
        (DisplayMode e) =>
            e.width != current.width || e.height != current.height,
      );
      if (modes.isNotEmpty) {
        modes.sort(
          (DisplayMode a, DisplayMode b) =>
              a.refreshRate.compareTo(b.refreshRate),
        );
        _highestRefreshRateMode = modes.lastOrNull;
      }
    }
    final DisplayMode? highest = _highestRefreshRateMode;
    if (highest == null) {
      return;
    }
    // Apply when the current refresh rate is lower than the highest.
    if (current.refreshRate < highest.refreshRate) {
      print(
        'Setting a higher refresh rate '
        'from ${current.refreshRate} '
        'to ${highest.refreshRate}.',
      );
      await FlutterDisplayMode.setPreferredMode(highest);
      final DisplayMode newMode = await FlutterDisplayMode.active;
      // Only apply resampling when the refresh rate has been updated.
      if (newMode.refreshRate > current.refreshRate) {
        GestureBinding.instance.resamplingEnabled = true;
      }
    }
  }
}