Very dummy question… Why `isSystemInDarkTheme()` i...

# compose

[nglauber]

Very dummy question… Why isSystemInDarkTheme() is always returning true even when I switch to light mode? 🤔

[nglauber]

More info: here’s my activity code:

setContent {
    MyAppTheme {
        ProvideWindowInsets {
            Surface(color = AppTheme.colors.background) {
                AppNavHost(
                    initialRoute = initRoute.route,
                    sharedViewModel = sharedViewModel,
                    onFinishRequest = { finish() },
                    hasAccounts = hasAccount
                )
            }
        }
    }
}

[nglauber]

and my activity is using a theme extending from Theme.MaterialComponents.DayNight.DarkActionBar

[iamthevoid]

how do you switch to light mode?

[nglauber]

via status bar panel option.

[Andrew Neal]

Can you show us MyAppTheme? There's nothing particularly of note in the snippet you posted.

[iamthevoid]

hmm, sounds strange. isSystemInDarkTheme() should returns true when dark theme enabled android-system-wide and false if doesn’t. Maybe it is device specific bug?

[nglauber]

@Composable
fun MyAppTheme(
    darkTheme: Boolean = isSystemInDarkTheme(),
    content: @Composable () -> Unit
) {
    Log.d("NGVL", "darkTheme: $darkTheme ----- ${isSystemInDarkTheme()}")

@Andrew Neal this log is printing… true 😕

[nglauber]

@iamthevoid i’m testing on an emulator, but another app is working… not sure what I did wrong…

[iamthevoid]

this log printing

darkTheme: true ----- true

or

darkTheme: true ----- false

?

I am not sure that darkTheme param changing same way

[nglauber]

both are true 😕

[Andrew Neal]

Sounds like less of a Compose thing and more of a general Android thing, just based on your snippets. What's your emulator look like? What version of Android are you running, etc? isSystemInDarkThem is just checking the Configuration flags.

@Composable
@ReadOnlyComposable
internal actual fun _*isSystemInDarkTheme*(): Boolean {
val uiMode = LocalConfiguration.current.uiMode
return (uiMode and Configuration.UI_MODE_NIGHT_MASK) == Configuration.UI_MODE_NIGHT_YES
}

[nglauber]

sorry… both are false

[nglauber]

actually, it gets the initial value and are not updated

[nglauber]

@Andrew Neal is API 30 and the device theme is changing. and as I mentioned, other app (using compose) is working fine 😕

[nglauber]

I just trying to figure it out what I did wrong on this app

[Andrew Neal]

Hmm. Yeah, hard to say. You may try testing it on a different emulator. But as far as calling isSystemInDarkTheme like you are goes, that looks good.

[iamthevoid]

Just for confidence: try to clean-build, sometimes studio glitches)

[louiscad]

Different version of AppCompat?

[nglauber]

i’m using app compat 1.4.0-alpha01

[Lucien Guimaraes]

in your manifest have you added this to your activity: android:configChanges="uiMode" ? Without it, the theme won't be updated at runtime when you switch darkMode from the statusbar panel

[nglauber]

I guess it’s the opposite… adding that you’re saying the activity should not be recreated when the uiMode changes… 😕

[Adam Powell]

@Louis Pullen-Freilich [G]

[Lucien Guimaraes]

@nglauber if you go for a single activity / compose app you can add everything into configChanges: https://kotlinlang.slack.com/archives/CJLTWPH7S/p1618760507089400?thread_ts=1618691113.058800&cid=CJLTWPH7S

[nglauber]

@Lucien Guimaraes, thanks but didn’t work for me… I’m not using it in the other app which is working…

[nglauber]

I must be doing something very wrong… 😩
I put this in my Activity

setContent {
    Log.d("NGVL", "isSystemInDarkTheme = ${isSystemInDarkTheme()}")

When I toggle dark/light mode, it is printed, but just the original value is displayed. I mean, if I open the app in dark mode, it’s always show true, otherwise always show false. 😞

[nglauber]

Ok. I found the problem, but now I have another one 😅
In my app class, I’m overriding the attachBaseContext to configure the application language.
So the context returned by createConfigurationContext is not working…

val locale = Locale(language)
Locale.setDefault(locale)
val configuration = Configuration(context.resources.configuration)
configuration.setLocale(locale)
return context.createConfigurationContext(configuration)

Suggestions?

[nglauber]

I think it’s common issue 😅 Let me see if any workaround works…
https://stackoverflow.com/questions/55265834/change-locale-not-work-after-migrate-to-androidx/58004553#58004553

[tad]

Huh, I thought LocaleList.getDefault would return the correct value

[nglauber]

Ok. New update… 😄
I was overriding both onAttachBaseContext on both app and activity. When I left just in the activity, it’s working… I’ll test language change to check if it’s set.

[tad]

I hooked up cashapp/copper to update a MutableState whenever the locale changes, but that's probably unnecessary if Compose can pull it from the Configuration