Platform.localeName always returns 'en_US'

[zzzev]

Steps to Reproduce

1. Start an android emulator
2. Change the locale (Settings > Languages & input > Languages, then either add a non-english one or sort a non-English one to the top of the list).
3. Start a flutter app that includes the line print(Platform.localeName);, note that the output is always 'en_US'

Expected behavior

Platform.localeName should return the locale string that is associated with the language at the top of the list in the settings app.

A MaterialApp's localizationsDelegate does (eventually) load the correct locale, so it is available there, but there shouldn't be a discrepancy between the values (even at this later point, where the localizationsDelegate is passed the correct locale, Platform.localeName still returns 'en_US').

[eseidelGoogle]

Is this a Dart library bug then?

[zzzev]

Sorry, you're right that's probably the right place; I'll close this in favor of this existing issue which is related: dart-lang/sdk#29211

[Hixie]

Flutter uses window.locale and window.onLocaleChanged (from dart:ui).
We'll eventually be adding window.locales as well (to get the user's whole list).
I guess it would make sense to have Platform.localeName match window.locale's toString() output. Does Dart allow us to configure that from the engine?

[eseidelGoogle]

@zanderso might know.

[zanderso]

There is currently no callback that the engine can set up to control the result of Platform.localeName, but it shouldn't be too much work to add one. I'll updated dart-lang/sdk#29211 and use it to track.

[zanderso]

The above fix should be live.

[github-actions]

This thread has been automatically locked since there has not been any recent activity after it was closed. If you are still experiencing a similar issue, please open a new bug, including the output of flutter doctor -v and a minimal reproduction of the issue.