How Googly Player switches between 17 languages without silently falling back to English

Your Android app has a language picker. A user whose phone is set to English would rather read your app in Hindi, so they pick Hindi, and the app stays in English. Nothing crashes. Nothing appears in the logs. Or the screens switch correctly but the playback notification and the confirmation dialogs carry on in the system language. Or a count that reads fine in English sits on the wrong side of its label in Arabic.

None of these are translation problems. The strings can be translated perfectly and still never reach the device, reach only part of the app, or be stitched together in an order the language does not use. They are engineering problems: how the app is packaged, how the chosen locale is applied, and how strings with numbers in them are built.

Googly Player is our Android app for videos, music and photos, and it runs in 17 languages chosen from its own in-app picker, independent of the system language. This is how we built that language support, the specific failures we closed off, and what it needs to run.

Seventeen languages, chosen inside the app

The picker offers these languages, each shown by its own name in its own script, with the English name alongside. The choice is entirely separate from the system language, so a phone can stay in one language while Googly Player runs in another.

That independence matters to real people in an ordinary way. Shared phones, work phones set up in English, and households that read one script more comfortably than another all produce someone who wants the app in a language their system is not set to. A picker that only works when it agrees with the system language is not doing a job.

A picker that reads in your own script

Each language is listed by its endonym, the name a language uses for itself, as the primary label, with the English name underneath. Someone looking for Bengali scans for বাংলা, the word they recognise at a glance, rather than hunting for an English word they may not expect to need. The English line underneath helps anyone choosing on someone else's behalf.

The list is searchable, and it opens with a Suggested section built from the device locale, so the most likely choices are at the top before anyone types. For Arabic and Urdu the picker has full right-to-left support, down to the language names themselves being correctly anchored in the list rather than pushed against the wrong edge, which is the first thing an Arabic or Urdu reader would notice.

One choice, applied everywhere the app speaks

A media player does not only talk through its screens. Background playback runs in a service, the media notification is drawn outside any activity, and confirmations arrive as dialogs. If the locale is set per activity, those other surfaces fall back to the system language and the app ends up speaking two languages at once.

We apply the choice process-wide through AppCompatDelegate.setApplicationLocales. Because the locale belongs to the whole process, services, notifications and dialogs pick it up along with every activity. A user who chose Turkish gets Turkish in the player, in the notification that controls it, and in any prompt that appears along the way.

Handing the choice to Android on 13 and later

From Android 13, the platform has its own notion of a per-app language, and we hand Googly Player's choice to it. The practical effect is that the language a user picked inside the app also shows up under Settings › Apps › Googly Player › Language, and can be read or changed from there.

This keeps the two places in agreement. A user who changes the language from system Settings sees the app follow, and a user who changed it inside the app finds the same answer when they look in Settings. On those versions there is one setting with two doors, rather than two settings that can disagree.

The App Bundle setting that silently breaks every translation

This is the failure from the opening paragraph, and it is the hardest one to see. When an app is published as an App Bundle, Play can split resources by language and deliver only the ones matching the device's system language. For most apps that is a saving. For an app with an in-app picker it is a trap: the user picks Hindi, the Hindi strings were never installed, and Android falls back to the defaults.

The result is a picker that silently renders everything in English. There is no crash and nothing in the logs, so it does not show up in crash reporting or in testing on a device whose system language already matches. We deliberately disable language splits in the App Bundle so every translation ships in the base APK, and every language in the picker is actually on the device when it is chosen.

Numbers belong where the language puts them

The quickest way to put a count on screen is to glue it to a label: "Total Videos: " plus the number. In English that reads correctly. In Arabic and Urdu, which run right to left, concatenation puts the number on the wrong side of the label, and the sentence reads backwards to the person it was translated for.

So in Googly Player counts are formatted, never concatenated. The string is written as "Total Videos: %d", one resource with a placeholder, and each translation carries the whole phrase with the placeholder wherever that language puts it. The code supplies the number; the translation decides where it goes.

Plurals that a format string cannot express

A placeholder fixes position but not grammar. English gets by with a singular and a plural, which tempts teams into a single format string and an "(s)". Other languages change the noun depending on the number in ways one string cannot carry: Arabic needs six grammatical forms for a number, and Russian needs four.

Googly Player uses proper plural resources for these. Each language supplies as many forms as its grammar has, and Android selects the right one for the count at runtime. A Russian reader sees the form Russian uses for that particular number, and an Arabic reader sees one of six, not a single phrase bent to fit every quantity.

What it takes to run, and how to switch

Googly Player is an Android app, and the language picker is part of it on every device it runs on, independent of whatever language the system uses. The one version-dependent piece is system integration: on Android 13 and later the choice is handed to the platform and appears in Settings, as described above. Arabic and Urdu run right to left throughout, including in the picker. No separate download is needed per language, because every translation ships in the base APK.

1. Open the language picker

   It lives inside the app, so it works the same whatever the phone's own language is.

2. Find your language

   Check the Suggested section first, which is based on the device locale, or search the list. Languages appear in their own script with the English name underneath.

3. Pick it once

   The choice applies across the whole app, including background playback, the media notification and dialogs.

4. Change it from Settings, if you prefer

   On Android 13 and later the same choice is available under Settings › Apps › Googly Player › Language.

For teams weighing us for their own Android work, this is the kind of detail we treat as part of shipping a feature rather than polish after it: the packaging flag that decides whether translations exist on the device, the API that decides how far a locale reaches, and the string rules that decide whether a translated sentence reads correctly.

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