Switching language of Firebase phone sign-in UI on Android #1742
Description
I am developing and Android native application that allows the user to choose the UI language in the first page. All other pages are then displayed in the chosen UI.
The third page of the app requires the user to sign-in using the Firebase phone auth UI (version com.google.firebase:firebase-auth:19.2.0). Unfortunately, the phone auth UI always seems to display in the phone / system language. In other words, if the language of the phone is English, the phone auth UI is always displayed in English. Even if the user has chosen Hindi as the preferred language in the first page, I couldn't find a way to instruct the Firebase phone auth UI to display in Hindi.
This issue is to request a feature to add a locale parameter to the the Firebase phone auth UI, so that the app can specify the language in which the phone auth UI is displayed. For more details, please see this post: https://groups.google.com/forum/#!topic/firebase-talk/Xfkk83y0FHw
The code for switching the locale of an activity is pretty straightforward (albeit non-intuitive). Essentially, in the base activity of all the phone auth UI activities, the locale of the configuration in the context attached to the activity needs to be changed by overriding attachBaseContext. A snippet of this code is shown below:
// See https://proandroiddev.com/change-language-programmatically-at-runtime-on-android-5e6bc15c758 @Override protected void attachBaseContext(Context newBase) { // getLocale() is some method that returns the locale chosen by the user for this activity Locale newLocale = getLocale(); Locale.setDefault(newLocale); Resources resources = newBase.getResources(); Configuration configuration = new Configuration(resources.getConfiguration()); if (Build.VERSION.SDK_INT >= 17) { configuration.setLocale(newLocale); configuration.setLayoutDirection(newLocale); newBase = newBase.createConfigurationContext(configuration); } else { configuration.locale = newLocale; resources.updateConfiguration(configuration, resources.getDisplayMetrics()); } super.attachBaseContext(newBase); } // See https://stackoverflow.com/questions/55265834/change-locale-not-work-after-migrate-to-androidx @Override public void applyOverrideConfiguration(Configuration overrideConfiguration) { if (overrideConfiguration != null) { int uiMode = overrideConfiguration.uiMode; overrideConfiguration.setTo(getBaseContext().getResources().getConfiguration()); overrideConfiguration.uiMode = uiMode; } super.applyOverrideConfiguration(overrideConfiguration); } @Override protected void onCreate(@Nullable Bundle savedInstanceState) { super.onCreate(savedInstanceState); // Do other stuff here resetTitle(); } // See https://proandroiddev.com/change-language-programmatically-at-runtime-on-android-5e6bc15c758 private void resetTitle() { // Required to correctly set the title after language change try { int label = getPackageManager().getActivityInfo(getComponentName(), GET_META_DATA).labelRes; if (label != 0) setTitle(label); } catch (PackageManager.NameNotFoundException e) { // Nothing much can be done - just log the exception logException(e); } }