cd example
flutter pub get
flutter build windows -v

cd example
flutter create . 
flutter build windows

if (brightness == InterfaceBrightness.dark) {
                            brightness = InterfaceBrightness.light;
                          } else if (brightness == InterfaceBrightness.light) {
                            brightness = InterfaceBrightness.dark;
                          } else {
                            brightness = InterfaceBrightness.dark;
                          }
                          bool v = brightness == InterfaceBrightness.dark;
                          // aboutBloc.setForceDark(v);
                          if (v) {
                            Get.changeTheme(themeDataDark);
                          } else {
                            Get.changeTheme(themeData);
                          }
                          print('[brightness] crt brightness: ${brightness}');
                          this.setWindowEffect(WindowEffect.acrylic,
                              brightness == InterfaceBrightness.dark);

...

void setWindowEffect(WindowEffect value, bool dark) {
    Window.setEffect(
      effect: value,
      color: this.color,
      dark: dark,
    );
    if (Platform.isMacOS) {
      if (brightness != InterfaceBrightness.auto) {
        Window.overrideMacOSBrightness(
            dark: brightness == InterfaceBrightness.dark);
      }
    }
    this.setState(() => this.effect = value);
  }

flutter doctor -v                                        
[✓] Flutter (Channel stable, 3.0.0, on macOS 12.3.1 21E258 darwin-arm, locale en-DE)
    • Flutter version 3.0.0 at /Users/mlamers/fvm/versions/stable
    • Upstream repository https://github.com/flutter/flutter.git
    • Framework revision ee4e09cce0 (9 days ago), 2022-05-09 16:45:18 -0700
    • Engine revision d1b9a6938a
    • Dart version 2.17.0
    • DevTools version 2.12.2

[✓] Android toolchain - develop for Android devices (Android SDK version 31.0.0)
    • Android SDK at /Users/mlamers/Library/Android/sdk
    • Platform android-31, build-tools 31.0.0
    • Java binary at: /Applications/Android Studio.app/Contents/jre/Contents/Home/bin/java
    • Java version OpenJDK Runtime Environment (build 11.0.12+0-b1504.28-7817840)
    • All Android licenses accepted.

[✓] Xcode - develop for iOS and macOS (Xcode 13.3.1)
    • Xcode at /Applications/Xcode.app/Contents/Developer
    • CocoaPods version 1.11.3

[✓] Android Studio (version 2021.2)
    • Android Studio at /Applications/Android Studio.app/Contents
    • Flutter plugin can be installed from:
      🔨 https://plugins.jetbrains.com/plugin/9212-flutter
    • Dart plugin can be installed from:
      🔨 https://plugins.jetbrains.com/plugin/6351-dart
    • Java version OpenJDK Runtime Environment (build 11.0.12+0-b1504.28-7817840)

[✓] IntelliJ IDEA Ultimate Edition (version 2021.3.2)
    • IntelliJ at /Users/mlamers/Applications/JetBrains Toolbox/IntelliJ IDEA Ultimate.app
    • Flutter plugin can be installed from:
      🔨 https://plugins.jetbrains.com/plugin/9212-flutter
    • Dart plugin can be installed from:
      🔨 https://plugins.jetbrains.com/plugin/6351-dart

[✓] IntelliJ IDEA Ultimate Edition (version 2021.3.2)
    • IntelliJ at /Users/mlamers/Library/Application Support/JetBrains/Toolbox/apps/IDEA-U/ch-0/213.6777.52/IntelliJ IDEA.app
    • Flutter plugin can be installed from:
      🔨 https://plugins.jetbrains.com/plugin/9212-flutter
    • Dart plugin can be installed from:
      🔨 https://plugins.jetbrains.com/plugin/6351-dart

[✓] IntelliJ IDEA Ultimate Edition (version 2021.3.1)
    • IntelliJ at /Users/mlamers/Library/Application Support/JetBrains/Toolbox/apps/IDEA-U/ch-0/213.6461.79/IntelliJ IDEA.app
    • Flutter plugin can be installed from:
      🔨 https://plugins.jetbrains.com/plugin/9212-flutter
    • Dart plugin can be installed from:
      🔨 https://plugins.jetbrains.com/plugin/6351-dart

[✓] VS Code (version 1.67.2)
    • VS Code at /Applications/Visual Studio Code.app/Contents
    • Flutter extension version 3.40.0

[✓] Connected device (1 available)
    • macOS (desktop) • macos • darwin-arm64 • macOS 12.3.1 21E258 darwin-arm

[✓] HTTP Host Availability
    • All required HTTP hosts are available

• No issues found!

  DeviceInfoPlugin deviceInfo = DeviceInfoPlugin();

  void getWindowEffect() async {
    if (Platform.isWindows) {
      var sysProductName = await deviceInfo.windowsInfo;
      var pn = sysProductName.productName;
      print("--- windows information:::: ${pn}");
      if (pn.contains("Windows 10")) {
        setState(() {
          this.effect = WindowEffect.disabled;
        });

        print("effect set to: ${this.effect}");
      } else {
        this.effect = WindowEffect.acrylic;
      }
    } else {
      this.effect = WindowEffect.acrylic;
    }
  }

flutter_acrylic/FlutterAcrylicPlugin.swift:471: Fatal error: Unexpectedly found nil while unwrapping an Optional value

Future<void> main() async {
  WidgetsFlutterBinding.ensureInitialized();
  await Window.initialize();
  if (Platform.isWindows) {
    await Window.hideWindowControls();
  }

  initializeDateFormatting().then((_) => runApp(MyApp()));

  if (Platform.isWindows) {
    doWhenWindowReady(() {
      appWindow
        ..minSize = Size(640, 360)
        ..size = Size(720, 540)
        ..alignment = Alignment.center
        ..show();
    });
  }
}

/E:/flutter/.pub-cache/hosted/pub.dartlang.org/bitsdojo_window_windows-0.1.0/lib/src/window.dart(72,36): error GF1577525: 'Size' is imported from both 'dart:ffi' and 'dart:ui'. [E:\Playground\Flutter\flutter_acrylic\example\build\windows\flutter\flutter_assemble.vcxproj]
/E:/flutter/.pub-cache/hosted/pub.dartlang.org/bitsdojo_window_windows-0.1.0/lib/src/window.dart(84,12): error GF1577525: 'Size' is imported from both 'dart:ffi' and 'dart:ui'. [E:\Playground\Flutter\flutter_acrylic\example\build\windows\flutter\flutter_assemble.vcxproj]
/E:/flutter/.pub-cache/hosted/pub.dartlang.org/bitsdojo_window_windows-0.1.0/lib/src/window.dart(126,12): error GF1577525: 'Size' is imported from both 'dart:ffi' and 'dart:ui'. [E:\Playground\Flutter\flutter_acrylic\example\build\windows\flutter\flutter_assemble.vcxproj]
/E:/flutter/.pub-cache/hosted/pub.dartlang.org/bitsdojo_window_windows-0.1.0/lib/src/window.dart(133,12): error GF1577525: 'Size' is imported from both 'dart:ffi' and 'dart:ui'. [E:\Playground\Flutter\flutter_acrylic\example\build\windows\flutter\flutter_assemble.vcxproj]
/E:/flutter/.pub-cache/hosted/pub.dartlang.org/bitsdojo_window_windows-0.1.0/lib/src/window.dart(140,12): error GF1577525: 'Size' is imported from both 'dart:ffi' and 'dart:ui'. [E:\Playground\Flutter\flutter_acrylic\example\build\windows\flutter\flutter_assemble.vcxproj]
/E:/flutter/.pub-cache/hosted/pub.dartlang.org/bitsdojo_window_windows-0.1.0/lib/src/window.dart(199,22): error GF1577525: 'Size' is imported from both 'dart:ffi' and 'dart:ui'. [E:\Playground\Flutter\flutter_acrylic\example\build\windows\flutter\flutter_assemble.vcxproj]

Flutter 2.10.3 • channel stable • https://github.com/flutter/flutter.git
Framework • revision 7e9793dee1 (13 days ago) • 2022-03-02 11:23:12 -0600
Engine • revision bd539267b4
Tools • Dart 2.16.1 • DevTools 2.9.2

2021-11-01 09:43:20.415804+0100 new_flutter_project[64015:19213583] NSWindow warning: adding an unknown subview: <NSVisualEffectView: 0x7fe74ef4d490>. Break on NSLog to debug.
2021-11-01 09:43:20.423862+0100 new_flutter_project[64015:19213583] Call stack:
(
	0   AppKit                              0x00007ff80b5daa26 -[NSThemeFrame addSubview:] + 112
	1   AppKit                              0x00007ff80b61d281 -[NSView replaceSubview:with:] + 154
	2   flutter_acrylic                     0x000000010b5fbc2a $s15flutter_acrylic28MainFlutterWindowManipulatorC11setMaterial8materialySo014NSVisualEffectH0V_tFZ + 1322
	3   flutter_acrylic                     0x000000010b5fbdf5 $s15flutter_acrylic28MainFlutterWindowManipulatorC9setEffect8materialySo08NSVisualH8MaterialV_tFZ + 37
	4   flutter_acrylic                     0x000000010b5fcb1a $s15flutter_acrylic20FlutterAcrylicPluginC6handle_6resultySo0C10MethodCallC_yypSgctF + 1050
	5   flutter_acrylic                     0x000000010b5fd9b6 $s15flutter_acrylic20FlutterAcrylicPluginC6handle_6resultySo0C10MethodCallC_yypSgctFTo + 118
	6   FlutterMacOS                        0x000000010e4190ad __56-[FlutterEngineRegistrar addMethodCallDelegate:channel:]_block_invoke + 45
	7   FlutterMacOS                        0x000000010f006a97 __45-[FlutterMethodChannel setMethodCallHandler:]_block_invoke + 119
	8   FlutterMacOS                        0x000000010e41b6a1 -[FlutterEngine engineCallbackOnPlatformMessage:] + 289
	9   FlutterMacOS                        0x000000010e419eac _ZL17OnPlatformMessagePK22FlutterPlatformMessageP13FlutterEngine + 44
	10  FlutterMacOS                        0x000000010ec52fbd _ZNSt3__110__function6__funcIZ23FlutterEngineInitializeE4$_49NS_9allocatorIS2_EEFvNS_10unique_ptrIN7flutter15PlatformMessageENS_14default_deleteIS7_EEEEEEclEOSA_ + 141
	11  FlutterMacOS                        0x000000010ec6420a _ZN7flutter20PlatformViewEmbedder21HandlePlatformMessageENSt3__110unique_ptrINS_15PlatformMessageENS1_14default_deleteIS3_EEEE + 74
	12  FlutterMacOS                        0x000000010e9beb84 _ZNSt3__110__function6__funcIN3fml8internal14CopyableLambdaIZN7flutter5Shell29OnEngineHandlePlatformMessageENS_10unique_ptrINS5_15PlatformMessageENS_14default_deleteIS8_EEEEE4$_16EENS_9allocatorISD_EEFvvEEclEv + 132
	13  FlutterMacOS                        0x000000010ec61522 _ZN7flutter18EmbedderTaskRunner8PostTaskEy + 738
	14  FlutterMacOS                        0x000000010ec4957c FlutterEngineRunTask + 44
	15  FlutterMacOS                        0x000000010e41c807 __60-[FlutterEngine postMainThreadTask:targetTimeInNanoseconds:]_block_invoke + 71
	16  libdispatch.dylib                   0x000000010bb29634 _dispatch_call_block_and_release + 12
	17  libdispatch.dylib                   0x000000010bb2a874 _dispatch_client_callout + 8
	18  libdispatch.dylib                   0x000000010bb3aea9 _dispatch_main_queue_callback_4CF + 1129
	19  CoreFoundation                      0x00007ff808ca13b8 __CFRUNLOOP_IS_SERVICING_THE_MAIN_DISPATCH_QUEUE__ + 9
	20  CoreFoundation                      0x00007ff808c629a6 __CFRunLoopRun + 2760
	21  CoreFoundation                      0x00007ff808c61809 CFRunLoopRunSpecific + 567
	22  HIToolbox                           0x00007ff811cce3e1 RunCurrentEventLoopInMode + 292
	23  HIToolbox                           0x00007ff811cce137 ReceiveNextEventCommon + 587
	24  HIToolbox                           0x00007ff811ccded5 _BlockUntilNextEventMatchingListInModeWithFilter + 70
	25  AppKit                              0x00007ff80b5b38f0 _DPSNextEvent + 886
	26  AppKit                              0x00007ff80b5b1f5c -[NSApplication(NSEvent) _nextEventMatchingEventMask:untilDate:inMode:dequeue:] + 1411
	27  AppKit                              0x00007ff80b5a4359 -[NSApplication run] + 586
	28  AppKit                              0x00007ff80b5781f8 NSApplicationMain + 816
	29  new_flutter_project                 0x0000000102f016f9 main + 9
	30  dyld                                0x00000002030da4fe start + 462
	31  ???                                 0x0000000000000003 0x0 + 3

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

Future<void> main() async {
  WidgetsFlutterBinding.ensureInitialized();
  await Window.initialize();
  await Window.setEffect(
    effect: WindowEffect.acrylic,
    color: const Color(0xCC222222),
  );
  // await Window.enterFullscreen();
  runApp(MyApp());
}

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

  // This widget is the root of your application.
  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      title: 'Flutter Demo',
      theme: ThemeData(
        // This is the theme of your application.
        //
        // Try running your application with "flutter run". You'll see the
        // application has a blue toolbar. Then, without quitting the app, try
        // changing the primarySwatch below to Colors.green and then invoke
        // "hot reload" (press "r" in the console where you ran "flutter run",
        // or simply save your changes to "hot reload" in a Flutter IDE).
        // Notice that the counter didn't reset back to zero; the application
        // is not restarted.
        primarySwatch: Colors.blue,
        visualDensity: VisualDensity.adaptivePlatformDensity,
        backgroundColor: Colors.transparent
      ),
      home: const MyHomePage(title: 'Flutter Demo Home Page')
    );
  }
}

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

  // This widget is the home page of your application. It is stateful, meaning
  // that it has a State object (defined below) that contains fields that affect
  // how it looks.

  // This class is the configuration for the state. It holds the values (in this
  // case the title) provided by the parent (in this case the App widget) and
  // used by the build method of the State. Fields in a Widget subclass are
  // always marked "final".

  final String title;

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

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

  void _incrementCounter() {
    setState(() {
      // This call to setState tells the Flutter framework that something has
      // changed in this State, which causes it to rerun the build method below
      // so that the display can reflect the updated values. If we changed
      // _counter without calling setState(), then the build method would not be
      // called again, and so nothing would appear to happen.
      _counter++;
    });
  }

  @override
  Widget build(BuildContext context) {
    // This method is rerun every time setState is called, for instance as done
    // by the _incrementCounter method above.
    //
    // The Flutter framework has been optimized to make rerunning build methods
    // fast, so that you can just rebuild anything that needs updating rather
    // than having to individually change instances of widgets.
    return Scaffold(
      // appBar: AppBar(
      //   // Here we take the value from the MyHomePage object that was created by
      //   // the App.build method, and use it to set our appbar title.
      //   title: Text(widget.title),
      // ),
      body: Center(
        // Center is a layout widget. It takes a single child and positions it
        // in the middle of the parent.
        child: Column(
          // Column is also a layout widget. It takes a list of children and
          // arranges them vertically. By default, it sizes itself to fit its
          // children horizontally, and tries to be as tall as its parent.
          //
          // Invoke "debug painting" (press "p" in the console, choose the
          // "Toggle Debug Paint" action from the Flutter Inspector in Android
          // Studio, or the "Toggle Debug Paint" command in Visual Studio Code)
          // to see the wireframe for each widget.
          //
          // Column has various properties to control how it sizes itself and
          // how it positions its children. Here we use mainAxisAlignment to
          // center the children vertically; the main axis here is the vertical
          // axis because Columns are vertical (the cross axis would be
          // horizontal).
          mainAxisAlignment: MainAxisAlignment.center,
          children: <Widget>[
            const Text(
              'You have pushed the button this many times:',
            ),
            Text(
              '$_counter',
              style: Theme.of(context).textTheme.headline4,
            ),
          ],
        ),
      ),
      floatingActionButton: FloatingActionButton(
        onPressed: _incrementCounter,
        tooltip: 'Increment',
        child: const Icon(Icons.add),
      ),
      backgroundColor: Colors.transparent,
    );
  }
}

// main.cpp  removed BDW_CUSTOM_FRAME
auto bdw = bitsdojo_window_configure( BDW_HIDE_ON_STARTUP );