Flutter Universal Platform Check - That Works on Web too

platform_is.dart

import 'universal_platform_web.dart'
    if (dart.library.io) 'universal_platform_vm.dart';

/// A universal platform checker.
///
/// Can be used to check active physical Flutter platform on all platforms.
///
/// To check what host platform the app is running on use:
///
/// * PlatformIs.android
/// * PlatformIs.iOS
/// * PlatformIs.macOS
/// * PlatformIs.windows
/// * PlatformIs.linux
/// * PlatformIs.fuchsia
///
/// To check the device type use:
///
/// * PlatformIs.mobile  (Android or iOS)
/// * PlatformIs.desktop (Windows, macOS or Linux)
///
/// Currently Fuchsia is not considered mobile nor desktop, even if it
/// might be so in the future.
///
/// To check if the Flutter application is running on Web you can use:
///
/// * PlatformIs.web
///
/// Alternatively the Flutter foundation compile time constant kIsWeb also
/// works well for that.
///
/// The platform checks are supported independently on web. You can use
/// PlatformIs windows, iOS, macOS, Android and Linux to check what the host
/// platform is when you are running a Flutter Web application.
///
/// Checking if we are running on Fuchsia host in a Web browser, is not yet
/// supported. If running in a Web browser on PlatformIs.web will be true, but
/// PlatformIs.fuchsia will still be false.
class PlatformIs {
  PlatformIs._();
  static bool get web => UniversalPlatform.web;
  static bool get macOS => UniversalPlatform.macOS;
  static bool get windows => UniversalPlatform.windows;
  static bool get linux => UniversalPlatform.linux;
  static bool get android => UniversalPlatform.android;
  static bool get iOS => UniversalPlatform.iOS;
  static bool get fuchsia => UniversalPlatform.fuchsia;
  static bool get mobile => PlatformIs.iOS || PlatformIs.android;
  static bool get desktop =>
      PlatformIs.macOS || PlatformIs.windows || PlatformIs.linux;
}

universal_platform_vm.dart

import 'dart:io';
// NOTE:
// Never import this library directly in the application. The PlatformIs
// class and library uses conditional imports to only import this file on
// VM platform builds.

// UniversalPlatform for Flutter VM builds.
//
// We are using Dart VM builds, so we use dart:io Platform to
// get the current platform.
class UniversalPlatform {
  UniversalPlatform._();
  static bool get web => false;
  static bool get macOS => Platform.isMacOS;
  static bool get windows => Platform.isWindows;
  static bool get linux => Platform.isLinux;
  static bool get android => Platform.isAndroid;
  static bool get iOS => Platform.isIOS;
  static bool get fuchsia => Platform.isFuchsia;
}

universal_platform_web.dart

// ignore: avoid_web_libraries_in_flutter
import 'dart:html' as html;

// NOTE:
// Never import this library directly in the application. The PlatformIs
// class and library uses conditional imports to only import this file on
// Web platform builds.

final html.Navigator _nav = html.window.navigator;

// UniversalPlatform for Flutter WEB build.
//
// We can use dart:html Navigator to get the current platform.
//
// This function is borrowed, with minor modifications, from GetX utils library with MIT license.
// Credits for it belong to its author Jonny Borges https://github.com/jonataslaw
// https://github.com/jonataslaw/getx/blob/master/lib/get_utils/src/platform/platform_web.dart
//
class UniversalPlatform {
  UniversalPlatform._();
  static bool get web => true;
  static bool get macOS => _nav.appVersion.contains('Mac OS') && !iOS;
  static bool get windows => _nav.appVersion.contains('Win');
  static bool get linux =>
      (_nav.appVersion.contains('Linux') || _nav.appVersion.contains('x11')) &&
      !android;
  // Source: https://developer.chrome.com/multidevice/user-agent
  static bool get android => _nav.appVersion.contains('Android ');
  static bool get iOS {
    // maxTouchPoints is needed to separate iPad iOS13 vs new MacOS
    return _hasMatch(_nav.platform, '/iPad|iPhone|iPod/') ||
        (_nav.platform == 'MacIntel' && _nav.maxTouchPoints! > 1);
  }

  // Theoretically we could be in a Web browser on Fuchsia too, but
  // we have no info on how to get that info yet, so we return false.
  static bool get fuchsia => false;
}

bool _hasMatch(String? value, String pattern) {
  // ignore: avoid_bool_literals_in_conditional_expressions
  return (value == null) ? false : RegExp(pattern).hasMatch(value);
}