Mica does not react to window blurring when title bar is hidden

[beta]

Hi, I'm using flutter_acrylic together with window_manager. My main() function writes as shown below.

Future<void> main() async {
  WidgetsFlutterBinding.ensureInitialized();

  await Window.initialize();

  await windowManager.ensureInitialized();
  const windowOptions = WindowOptions(
    title: _appName,
    size: Size(800, 600),
    center: true,
    // titleBarStyle: TitleBarStyle.hidden, // <- this line is the case
  );
  await windowManager.waitUntilReadyToShow(windowOptions, () async {
    await windowManager.show();
    await windowManager.focus();
  });

  runApp(const GalleryApp());
}

And in my app widget's initState():

  @override
  void initState() {
    super.initState();

    Window.setEffect(
      effect: WindowEffect.mica,
      dark: FluffApp.dark,
    );
  }

With titleBarStyle: TitleBarStyle.normal (the default value), mica works perfectly and turns solid properly when the window is blurred (losing focus).

• Focused
  
• Blurred
  

However after I set titleBarStyle: TitleBarStyle.hidden, the mica background does not react to focus changes any more.

• Focused
  
• Blurred. The focus is in the terminal app, but tbe mica background is still transparent.
  

Please help to look into this problem, and let me know if I'm doing anything wrong. Thanks in advance.

[beta]

Environment: Flutter 3.3.8 (Channel stable) and Windows 11 22H2 (22621.819)

[alexmercerind]

I can't say anything unfortunately without getting into depth. I will still suspect package:window_manager. Window behaviour is closely tied with native Win32 calls.

[beta]

Tested with bitsdojo_window and the background is working correctly. I will close this issue and dig into the code of window_manager to see why.