There doesn’t seem to exist a CompositionLocal for...

# compose

[Stylianos Gakis]

There doesn’t seem to exist a CompositionLocal for Locale in compose right? I can see Locale is there, which only gives you a way to fetch the locale, not to update it, and looking at the implementation it doesn’t seem to use the AppCompatDelegate.setApplicationLocales aka the Per-App Language Preferences API.
Oh and also it doesn’t give a java.util.Locale so there’s that.
Am I missing something here? How do you folks typically fetch the proper locale in your composables aside from just passing it down the chain all the way through?

[ephemient]

LocalContext.current.resources.configuration.locales

[ephemient]

although that doesn't really help if you want to change it or react to changes

[Albert Chang]

You should use LocalConfiguration.current.locales.

[Albert Chang]

And by using that you can subscribe to configuration changes.

[Stylianos Gakis]

Right, so I should use LocalConfiguration.current.locales instead of LocalContext… right? Not in addition to it I assume.
Also with that said, I assume both of these do not interact with the per-app language APIs, do they? Like if I use those APIs to manage my locale, do you know if that will update the locales inside LocalConfiguration?

[Stylianos Gakis]

Oh uhmm, lint says LocalConfiguration.current.locales requires API 24 or newer though 😵 Is this fixable in some way, with coreLibraryDesugaring or something like that? If not I guess I need to make my own LocalLocale and make sure I am also subscribing to LocalConfiguration.current myself to react to such config changes.

[Stylianos Gakis]

Okay this was silly by me, apparently .locale works fine but is deprecated over .locales which is >API24 only. Anyway, gonna use the deprecated one then.

[Albert Chang]

ConfigurationCompat.getLocales(LocalConfiguration.current)
And I believe per-app language API should also update the configuration.

[Stylianos Gakis]

Quite a verbose thing to write, but yeah the solution sounds like it will be this

val locale = ConfigurationCompat.getLocales(LocalConfiguration.current)[0]

This seems to cover all Android versions and I will just double check that it follows the per-app language APIs too.