[Important] [Windows] Distortion of window while starting up

[KRTirtho]

After upgrading to Flutter 3.22.1, Window manager is causing the entire UI to be glitched out (distorted) initially after launch.

This is how it looks

If I turn off/comment out windowManager.ensureInitialized and windowManager.waitUntilReadyToShow function calls, the app shows up completely fine except the Title bar is visible (as expected).

There are no errors/exceptions being thrown at the Console. So, I guess this is caused any embedder change in Flutter engine?

Reverting back to Flutter 3.19.x fixes the issue though

Upstream issue: KRTirtho/spotube#1553

Thanks for your amazing work and the plugin @lijy91 ❤️
Please fix this as soon as possible. Lots of users are affected by it.

[KRTirtho]

There were lots of changes in the Windows embeder EGL which probably lead to this kind of issues.
Special focus: https://docs.flutter.dev/release/release-notes/release-notes-3.22.0#desktop

[Linij]

I encountered the same problem, but I found a solution that requires modifying the size in the main.cpp default file to be the same as the set minimum value to fix it。

[KRTirtho]

I tried your fix but the issue comes back after opening the app 2/3 times.

[KRTirtho]

There's a workaround suggested by Far Se on Flutter Discord that allows to use Flutter v3.22.x with window_manager in Windows

    WidgetsBinding.instance.addPostFrameCallback((Duration timeStamp) async {
      if (Theme.of(context).platform != TargetPlatform.windows) return;
      await Future<void>.delayed(const Duration(milliseconds: 100), () {
        windowManager.getSize().then((Size value) {
          windowManager.setSize(
            Size(value.width + 1, value.height + 1),
          );
        });
      });
    });

Add following in the root App's (the very first widget where MaterialApp or CupertinoApp gets returned) initState method

[Linij]

OK，I will try this. Thinks.

[Linij]

This method is feasible, but I think it may be better。

WidgetsBinding.instance.addPostFrameCallback((Duration timeStamp) async {
      if (Theme.of(context).platform != TargetPlatform.windows) return;
      await Future<void>.delayed(const Duration(milliseconds: 100), () {
        windowManager.getSize().then((Size value) {
          windowManager.setSize(
            Size(value.width + 1, value.height + 1),
          );
          windowManager.setSize(
            Size(value.width, value.height),
          );
        });
      });
    });  

[maznnwell]

I also encountered this issue, but the suggested solution didn't worked for me - on Flutter 3.24.3.

Somewhere in the widget tree, after creating the MaterialApp, a Lottie was being played using a controller - but it was rendering only when it was done loading from the asset file. So I decided to have something rendering while the lottie was loading and it worked.

[KRTirtho]

hey @lijy91 if you can look into this issue when you get time? Lots of users are suffering for this.
I'm also not finding any clue why this might happen.

[leeys0207]

I found a hacky solution.

  @override
  void initState() {
    WidgetsBinding.instance.addPostFrameCallback((timeStamp) async {
      await windowManager.maximize();
      await windowManager.unmaximize();
    });
    super.initState();
  }

[Xazin]

We also have this issue in AppFlowy, we ended up switching to bitsdojo on windows rather than window_manager.

I want to switch back, but the workarounds are hacky (and not usable for all cases) and ends up with a bad user experience.