Respect system theme on an iOS app splash screen

[terrakok]

User report:

When running iOS app in dark mode, I see a white flash every time I enter a view that is using Compose MP. It appears to me that the UIView(Controller) and/or Skiko view is clearing with white even in dark mode. Would be nice if it at least used .systemBackground...

[elijah-semyonov]

I believe it should have been fixed

[terrakok]

The issue should be fixed. If it's not, provide a reproducer here, please, and reopen the issue

[tylerwilson]

After more testing, I have determined this is likely a byproduct of our apps feature that allows you to set the light/dark theme from within the app. That is, if the app light/dark theme differs from the currently set OS theme, this is when we see the flash.

We are adjusting the app theme via this magic line of code:

UIApplication.shared.windows.first(where: \.isKeyWindow)?.overrideUserInterfaceStyle = .dark

So I suspect that the Compose or Skiko layer of code is checking or watching the trait value, which may not have changed, though the app is rendering in a different mode.

I am unsure if this is a case you need to want to handle, though it would be convenient for me. :-/ We may simply disable this feature until such time as it can be handled better.

Thank you!