Seventeen languages, done properly: how Googly Player handles translation, RTL and plurals

A user switches an app to Arabic. The menus come back in Arabic, but the line that says how many videos they have puts the number on the wrong side of the label. Another user picks Hindi on a phone set to English, and the picker quietly keeps showing English. There is no crash and nothing in the logs. A third changes language and the notification for the music playing in the background stays in the old one.

None of these failures shows up in a demo on a developer's phone, because a developer's phone usually has every resource installed and runs in the language the app was written in. They show up for real users, on phones bought from a shop, in a language the team does not read. An in-app language picker that half works is worse than none: it promises a choice and then ignores it.

Googly Player is our Android app for videos, music and photos, and it ships in 17 languages through a picker of its own, separate from the system language. This is how we built that picker so that it holds up on a real device, and what each decision protects against.

Seventeen languages, chosen inside the app

Googly Player has a full in-app language picker that works independently of the language the phone itself is set to. A phone can stay in English for everything else while Googly Player runs in Bengali, or the other way round. The languages available are:

• English, Hindi (हिन्दी), Spanish (Español), Arabic (العربية), French (Français), Bengali (বাংলা)
• Portuguese (Português), Russian (Русский), Urdu (اردو), Indonesian (Bahasa Indonesia), German (Deutsch)
• Japanese (日本語), Turkish (Türkçe), Vietnamese (Tiếng Việt), Korean (한국어), Italian (Italiano), Gujarati (ગુજરાતી)

That set mixes Latin, Devanagari, Bengali, Gujarati, Cyrillic, Arabic, Japanese and Korean scripts, and two right-to-left languages. Each of those brings its own way to break an Android app, which is why the list matters less than what we did to make every entry on it behave. The sections below take those problems one at a time.

A picker that names each language in its own script

A language picker is used by exactly the person who cannot yet read the app. If it lists "Gujarati" in English, a Gujarati speaker whose app is currently in English has to know the English word for their own language to find it. So every entry in our picker leads with the language's endonym, its own name in its own script, as the primary label, with the English name underneath for everyone else.

Seventeen entries is long enough to scroll past, so the picker is searchable. It also opens with a Suggested section built from the device locale: the language the phone is already set to is the most likely candidate, and it sits at the top rather than somewhere in the middle of an alphabetical list.

Right-to-left from the first screen

Arabic and Urdu read right to left, and Googly Player has full RTL support for both. That includes a detail most pickers miss: the language names inside the picker itself are anchored correctly. A list where العربية and اردو hang off the left edge like English words looks broken to the people it is meant for, and it is the very first screen they see in their language.

RTL also reaches into places that look like plain text. A label followed by a number is a layout decision as much as a translation, and in Arabic and Urdu the number belongs on the other side. We handle that with formatted strings rather than string concatenation, which comes up again below with the rest of the number handling, because it is the most common way an otherwise well-translated app reads wrong in a right-to-left language.

One setting that reaches services, notifications and dialogs

Changing the locale of an activity changes what that screen shows. It does not change the text a background service builds, and a media app does a great deal of work outside its screens. Googly Player plays audio in the background through a foreground service and posts a media notification for it. If the language choice stopped at the activities, that notification and any dialog raised outside them would stay in the previous language.

So the choice is applied process-wide through AppCompatDelegate.setApplicationLocales. That covers services, notifications and dialogs as well as activities, which means the whole app speaks one language at a time.

On Android 13 and later we go one step further and hand the choice to the platform. The selected language then also appears under Settings › Apps › Googly Player › Language, where Android itself manages it. A user can change it from there without opening the app, and the system's own view of the app's language agrees with ours.

The failure that never crashes: App Bundle language splits

This is the bug we most want other Android teams to know about. An App Bundle lets Google Play split resources by language and install only the ones matching the phone's system language. For most apps that is a sensible saving. For an app with its own language picker it is a trap: a user on an English phone who chooses Japanese in the app has no Japanese resources installed, and Android falls back to the default strings.

The result is a picker that appears to work and renders everything in English. Nothing crashes, nothing is written to the logs, and on a development device with everything installed it never reproduces. We deliberately disable language splits in the App Bundle so that every translation ships in the base APK, which is what makes the picker honour any of the 17 choices on any phone.

Numbers and plurals that read correctly

Media apps are full of counts: how many videos, how many tracks, how many photos. The quick way to write one is to join a label and a number, "Total Videos: " + n. In Arabic and Urdu that puts the number on the wrong side of the label, because the code has fixed the order that only the translation should decide. We never concatenate counts. Every one is a format string, "Total Videos: %d", and each translation places the number where its language puts it.

Format strings fix the position of a number but not the grammar around it. English has a singular and a plural; Arabic needs six grammatical forms for a number and Russian needs four, and a single format string cannot express that. So every count with a noun attached uses Android plural resources, which let each translation supply as many forms as its language actually has. The result is a count that reads like it was written in the language, rather than translated around a number.

Who it is for and what it needs

The language support is for anyone who wants Googly Player in a language other than the one their phone runs in, or who simply reads one of these 17 languages more comfortably than English: a household sharing a phone, a user who keeps the system in English for work, a reader of Arabic or Urdu who expects the app to run right to left properly. For engineers and technical buyers, it is a worked example of what a language picker needs beyond translated strings.

Googly Player runs on Android. The in-app picker is part of the app on every device it supports; the system-level entry under Settings › Apps › Googly Player › Language needs Android 13 or later, because that is where we hand the choice to the platform. Every translation ships in the base APK, so nothing extra downloads when a user switches language.

1. Open the language picker

   Googly Player has its own picker, separate from the phone's language setting. Changing it affects only Googly Player.

2. Pick from Suggested or search

   The Suggested section reflects the device locale. Otherwise, search the list; each language is shown by its own name, with the English name below it.

3. Use it everywhere in the app

   The choice applies across the whole app, including background playback notifications and dialogs. Arabic and Urdu switch the app to right-to-left.

4. On Android 13+, manage it from Settings

   The same choice appears under Settings › Apps › Googly Player › Language and can be changed there without opening the app.

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