Automatically adapt Mapbox Streets–sourced layers for user preferred language

[1ec5]

When a user adjusts the Preferred Language Order setting in the Language & Region section of Settings to a language supported by the Mapbox Streets source, any style based on the Mapbox Streets source should automatically adjust by localizing the labels.

MGLMapView can observe NSCurrentLocaleDidChangeNotification and respond by obtaining NSLocale.autoupdatingCurrentLocale, determining the identifiers of the sources whose URL matches mapbox://mapbox.mapbox-streets-v*, and replacing {name*} tokens in the textField of any MGLSymbolStyleLayer whose sourceIdentifier is one of those source identifiers. We already do something similar in iosapp on demand: #6819.

We could also offer a way to extend this feature to arbitrary sources, by allowing the developer to specify which fields in the source correspond to which languages (see also mapbox/DEPRECATED-mapbox-gl#21).

Iterating over all the sources and style layers will require #6097. Discovering whether a source is Mapbox Streets will require #6584. #7030 would rely on a similar mechanism.

/ref #1108
/cc @incanus @pveugen @boundsj @frederoni

[1ec5]

We should expose an option on MGLStyle that allows the developer to turn automatic localization on and off (for supported sources). I think it should be on by default, for parity with MapKit and the Google Maps SDK, but there definitely needs to be a way to turn the feature off, in case the developer wants a specific language to be displayed.

[1ec5]

Note that macosapp already performs this automatic localization, as of #6097 and #7398, so this ticket tracks upstreaming that code to the iOS and macOS SDKs.

[evgzor]

Are any estimations when the issue would be fixed?

[boundsj]

This was done in #9582 on the release-ios-v3.6.0-android-v5.1.0 branch and is expected to be in the 3.6.2 release. cc @fabian-guerra

[evgzor]

@boundsj Could u please provide any estimation when 3.6.2 would be released?

[boundsj]

@evgzor patch releases for v3.6.x are going out every 2 to three weeks so it should be this week or next.

[evgzor]

@boundsj please look:

Localization still does not work on iOS for German language.

[fabian-guerra]

Hi @evgzor did you set mapView.style.localizesLabels to YES?

[friedbunny]

did you set mapView.style.localizesLabels to YES?

Additionally, this should be done in -[MGLMapViewDelegate mapView:didFinishLoadingStyle:] or later.

[evgzor]

@friedbunny @fabian-guerra on iOS all good but on Android Mapbox 5.1.3 still an issue:

Could u help me and tell what could be wrong?

[Guardiola31337]

Hey @evgzor 👋

That feature is not included in the Android binding and the idea to cover that functionality is implementing it as a plugin.
👀 mapbox/mapbox-plugins-android#36

That ticket is still opened so in the meantime you could do it manually:

• Listen to locale config changes 👀 android:configChanges
• Get the current language in device

Locale.getDefault().getDisplayLanguage();

• Change label language dynamically

Layer mapText = map.getLayer("place-city-lg-n");
mapText.setProperties(textField("{name_ru}"));

If you know the language in advance you could directly change label language as shown above ☝️

For further information check Change your map’s label language and the language switch example.

Contributions are more than welcome so I encourage you to take a stab at mapbox/mapbox-plugins-android#36 and send a PR fixing it (follow the steps mentioned above) 😛

Thanks Eugene!