Fix app locale synchronization, missing translations and audio routing guards

automotive/src/main/AndroidManifest.xml

@@ -17,6 +17,7 @@
         android:fullBackupContent="@xml/backup_rules"
         android:icon="@mipmap/ic_launcher"
         android:label="@string/app_name"
+        android:localeConfig="@xml/locales_config"
         android:roundIcon="@mipmap/ic_launcher_round"
         android:supportsRtl="true"
         android:theme="@style/Theme.Xcertplay">

common/src/main/java/com/shilapi/xcertplay/AppLocale.kt

@@ -1,12 +1,17 @@
 // SPDX-License-Identifier: AGPL-3.0-only
 package com.shilapi.xcertplay
 
+import android.app.Activity
+import android.app.AlertDialog
+import android.app.LocaleManager
+import android.os.Build
+import android.os.LocaleList
 import android.content.Context
 import android.content.res.Configuration
 import com.shilapi.xcertplay.host.R
 import java.util.Locale
 
-/** Persisted app language (system / en / zh / ar / ru / es) applied through configuration contexts. */
+/** Platform app locales on Android 13+, with a persisted context override on older Android. */
 object AppLocale {
     const val SYSTEM = "system"
     const val ENGLISH = "en"
@@ -20,16 +25,45 @@ object AppLocale {
     private const val PREFS = "diplay"
     private const val KEY_LANGUAGE = "app_language"
 
-    fun preference(context: Context): String =
-        context.getSharedPreferences(PREFS, Context.MODE_PRIVATE).getString(KEY_LANGUAGE, SYSTEM) ?: SYSTEM
+    private const val KEY_MIGRATED = "app_language_platform_migrated"
+
+    fun preference(context: Context): String {
+        if (Build.VERSION.SDK_INT >= 33) {
+            val locales = context.getSystemService(LocaleManager::class.java).applicationLocales
+            return if (locales.isEmpty) SYSTEM else locales[0].language
+        }
+        return context.getSharedPreferences(PREFS, Context.MODE_PRIVATE)
+            .getString(KEY_LANGUAGE, SYSTEM)?.takeIf { it in ALL } ?: SYSTEM
+    }
 
     fun save(context: Context, language: String) {
         require(language in ALL)
-        context.getSharedPreferences(PREFS, Context.MODE_PRIVATE).edit().putString(KEY_LANGUAGE, language).apply()
+        if (Build.VERSION.SDK_INT >= 33) {
+            context.getSystemService(LocaleManager::class.java).applicationLocales =
+                locale(language)?.let { LocaleList(it) } ?: LocaleList.getEmptyLocaleList()
+            context.getSharedPreferences(PREFS, Context.MODE_PRIVATE).edit()
+                .putBoolean(KEY_MIGRATED, true).remove(KEY_LANGUAGE).apply()
+        } else {
+            context.getSharedPreferences(PREFS, Context.MODE_PRIVATE).edit()
+                .putString(KEY_LANGUAGE, language).apply()
+        }
     }
 
-    /** Wraps [context] so resource lookups resolve against the chosen language; system stays as-is. */
+    /** On Android 13+, the OS is the single source of truth for the app language. */
     fun wrap(context: Context): Context {
+        if (Build.VERSION.SDK_INT >= 33) {
+            val prefs = context.getSharedPreferences(PREFS, Context.MODE_PRIVATE)
+            if (!prefs.getBoolean(KEY_MIGRATED, false)) {
+                val manager = context.getSystemService(LocaleManager::class.java)
+                val previous = locale(prefs.getString(KEY_LANGUAGE, SYSTEM) ?: SYSTEM)
+                // Never overwrite a language already chosen through Android Settings.
+                if (manager.applicationLocales.isEmpty && previous != null) {
+                    manager.applicationLocales = LocaleList(previous)
+                }
+                prefs.edit().putBoolean(KEY_MIGRATED, true).remove(KEY_LANGUAGE).apply()
+            }
+            return context
+        }
         val locale = locale(preference(context)) ?: return context
         val configuration = Configuration(context.resources.configuration).apply {
             setLocale(locale)
@@ -38,6 +72,25 @@ object AppLocale {
         return context.createConfigurationContext(configuration)
     }
 
+    fun showPicker(activity: Activity) {
+        var selected = ALL.indexOf(preference(activity)).coerceAtLeast(0)
+        AlertDialog.Builder(activity)
+            .setTitle(R.string.language_app_language)
+            .setSingleChoiceItems(ALL.map { displayName(activity, it) }.toTypedArray(), selected) { _, index ->
+                selected = index
+            }
+            .setPositiveButton(R.string.language_apply) { _, _ ->
+                val next = ALL[selected]
+                if (next != preference(activity)) {
+                    save(activity, next)
+                    // LocaleManager recreates activities itself on Android 13+.
+                    if (Build.VERSION.SDK_INT < 33) activity.recreate()
+                }
+            }
+            .setNegativeButton(R.string.common_cancel, null)
+            .show()
+    }
+
     /** Names stay in their native form for every language; only "system default" is localized. */
     fun displayName(context: Context, language: String): String = when (language) {
         SYSTEM -> context.getString(R.string.language_system_default)

common/src/main/java/com/shilapi/xcertplay/CarPlayHostActivity.kt

@@ -566,7 +566,7 @@ class CarPlayHostActivity : ComponentActivity() {
     override fun onResume() {
         super.onResume()
         val languagePreference = AppLocale.preference(this)
-        if (languagePreference != languagePreferenceAtCreate) {
+        if (Build.VERSION.SDK_INT < 33 && languagePreference != languagePreferenceAtCreate) {
             languagePreferenceAtCreate = languagePreference
             recreate()
             return
@@ -1362,6 +1362,12 @@ class CarPlayHostActivity : ComponentActivity() {
             ).apply { topMargin = dp(12) },
         )
 
+        content.addView(Button(this).apply {
+            text = getString(R.string.language_app_language)
+            isAllCaps = false
+            setOnClickListener { AppLocale.showPicker(this@CarPlayHostActivity) }
+        }, LinearLayout.LayoutParams(-1, -2).apply { topMargin = dp(12) })
+
         val scroll = ScrollView(this).apply {
             isFillViewport = true
             addView(

common/src/main/java/com/shilapi/xcertplay/DiPlayActivity.kt

@@ -71,12 +71,15 @@ class DiPlayActivity : ComponentActivity() {
         if (uri != null) exportDiagnostics(uri)
     }
 
+    private var languagePreferenceAtCreate = AppLocale.SYSTEM
+
     override fun attachBaseContext(newBase: Context) {
         super.attachBaseContext(AppLocale.wrap(newBase))
     }
 
     override fun onCreate(savedInstanceState: Bundle?) {
         super.onCreate(savedInstanceState)
+        languagePreferenceAtCreate = AppLocale.preference(this)
         com.shilapi.xcertplay.hud.BydNavigationOutputs.onAppOpened(applicationContext)
         WindowCompat.setDecorFitsSystemWindows(window, true)
         window.statusBarColor = BG; window.navigationBarColor = BG
@@ -108,7 +111,12 @@ class DiPlayActivity : ComponentActivity() {
     override fun onSaveInstanceState(outState: Bundle) { outState.putString("page", page); outState.putBoolean("pending_car_hotspot", pendingCarHotspotSetup); super.onSaveInstanceState(outState) }
     override fun onConfigurationChanged(newConfig: Configuration) { super.onConfigurationChanged(newConfig); render() }
     override fun onResume() {
-        super.onResume(); handler.removeCallbacks(tick); handler.post(tick)
+        super.onResume()
+        if (Build.VERSION.SDK_INT < 33 && AppLocale.preference(this) != languagePreferenceAtCreate) {
+            recreate()
+            return
+        }
+        handler.removeCallbacks(tick); handler.post(tick)
         // Back from the car settings: refresh the car hotspot reminder on the home page.
         if (!initialLaunch && (page == "home" || page == "settings" || page == "connection")) render()
         if (initialLaunch) {
@@ -315,14 +323,14 @@ class DiPlayActivity : ComponentActivity() {
                     card.addView(button(getString(R.string.automatic_map_setup_adb), false) { showClusterAccessSetup() }, matchButton(10, 56))
                     if (!automatic) {
                         val themes = DiLink51ClusterLayout.Theme.entries
-                        choice(card, getString(R.string.instrument_theme), themes.map { it.label }, themes.indexOf(DiLink51ClusterLayout.theme(this))) {
+                        choice(card, getString(R.string.instrument_theme), themes.map { it.localizedLabel(this) }, themes.indexOf(DiLink51ClusterLayout.theme(this))) {
                             DiLink51ClusterLayout.saveTheme(this, themes[it])
                             reconnectForClusterMap()
                         }
                         card.addView(label(getString(R.string.manual_mode_match_the_cluster_theme_here_the_map_cannot_fo), 14, MUTED))
                     }
                     val contrasts = DiLink51ClusterLayout.Contrast.entries
-                    choice(card, getString(R.string.instrument_contrast), contrasts.map { it.label }, contrasts.indexOf(DiLink51ClusterLayout.contrast(this))) {
+                    choice(card, getString(R.string.instrument_contrast), contrasts.map { it.localizedLabel(this) }, contrasts.indexOf(DiLink51ClusterLayout.contrast(this))) {
                         DiLink51ClusterLayout.saveContrast(this, contrasts[it])
                         reconnectForClusterMap()
                     }
@@ -481,7 +489,7 @@ class DiPlayActivity : ComponentActivity() {
     private fun storedSsid() = AirPlayPersistence.loadManualHotspotSsid(this)
     private fun storedPassword() = AirPlayPersistence.loadManualHotspotPassphrase(this)
     private fun hotspotError(ssid: String, password: String) =
-        com.shilapi.xcertplay.orchestration.ManualHotspotValidation.validate(ssid, password)
+        com.shilapi.xcertplay.orchestration.ManualHotspotValidation.error(ssid, password)?.let { getString(it.messageResource()) }
 
     private fun saveHotspotCredentials(ssid: String, password: String) {
         AirPlayPersistence.saveManualHotspotSsid(this, ssid)
@@ -621,7 +629,7 @@ class DiPlayActivity : ComponentActivity() {
     private fun carPlaySizeControl(parent: LinearLayout) {
         val sizes = com.shilapi.xcertplay.airplay.CarPlaySize.entries
         val current = com.shilapi.xcertplay.airplay.CarPlaySize.fromWidthMillimeters(AirPlayPersistence.loadWidthPhysicalMm(this))
-        choice(parent, getString(R.string.carplay_size), sizes.map { it.label }, sizes.indexOf(current)) {
+        choice(parent, getString(R.string.carplay_size), sizes.map { it.localizedLabel(this) }, sizes.indexOf(current)) {
             AirPlayPersistence.saveWidthPhysicalMm(this, sizes[it].widthMillimeters)
         }
         parent.addView(label(getString(R.string.changes_the_size_of_carplay_icons_and_text_applying_a_size), 14, MUTED).apply {
@@ -853,23 +861,23 @@ class DiPlayActivity : ComponentActivity() {
         toneStop = null
         testToneTrack?.let { runCatching { it.stop(); it.release() } }
         testToneTrack = null
+        var candidate: AudioTrack? = null
+        val track = try {
             val pcm = assets.open("navigation_test.pcm").use { it.readBytes() }
-        val track = AudioTrack(
-            streamType,
-            44100,
-            AudioFormat.CHANNEL_OUT_MONO,
-            AudioFormat.ENCODING_PCM_16BIT,
-            pcm.size,
-            AudioTrack.MODE_STREAM
-        )
-        if (track.state != AudioTrack.STATE_INITIALIZED) {
-            Log.w("DiPlay", "playTestTone streamType=$streamType state=${track.state}")
-            track.release()
-                toast(getString(R.string.audio_stream_unavailable, streamType, track.state))
+            AudioTrack(streamType, 44100, AudioFormat.CHANNEL_OUT_MONO,
+                AudioFormat.ENCODING_PCM_16BIT, pcm.size, AudioTrack.MODE_STREAM).also {
+                candidate = it
+                check(it.state == AudioTrack.STATE_INITIALIZED)
+                check(it.write(pcm, 0, pcm.size) == pcm.size)
+                it.play()
+            }
+        } catch (error: Exception) {
+            val state = candidate?.state ?: AudioTrack.STATE_UNINITIALIZED
+            candidate?.let { runCatching { it.release() } }
+            Log.w("DiPlay", "playTestTone streamType=$streamType unavailable", error)
+            toast(getString(R.string.audio_stream_unavailable, streamType, state))
             return
         }
-        track.write(pcm, 0, pcm.size)
-        track.play()
         Log.i("DiPlay", "playTestTone streamType=$streamType state=${track.state} playState=${track.playState}")
         testToneTrack = track
         val stop = Runnable {
@@ -937,21 +945,7 @@ class DiPlayActivity : ComponentActivity() {
             card.addView(label(getString(R.string.language_hint), 14, MUTED))
             val current = AppLocale.preference(this)
             val languageButton = button("${getString(R.string.language_app_language)} · ${AppLocale.displayName(this, current)}", false) { }
-            languageButton.setOnClickListener {
-                var selected = AppLocale.ALL.indexOf(AppLocale.preference(this)).coerceAtLeast(0)
-                val labels = AppLocale.ALL.map { AppLocale.displayName(this, it) }.toTypedArray()
-                AlertDialog.Builder(this).setTitle(getString(R.string.language_app_language))
-                    .setSingleChoiceItems(labels, selected) { _, index -> selected = index }
-                    .setPositiveButton(getString(R.string.language_apply)) { _, _ ->
-                        val next = AppLocale.ALL[selected]
-                        if (next != AppLocale.preference(this)) {
-                            AppLocale.save(this, next)
-                            recreate()
-                        }
-                    }
-                    .setNegativeButton(getString(R.string.common_cancel), null)
-                    .show()
-            }
+            languageButton.setOnClickListener { AppLocale.showPicker(this) }
             card.addView(languageButton, matchButton(12, 60))
         }
     }

common/src/main/java/com/shilapi/xcertplay/LocalizedOptions.kt

@@ -0,0 +1,31 @@
+package com.shilapi.xcertplay
+
+import android.content.Context
+import com.shilapi.xcertplay.airplay.CarPlaySize
+import com.shilapi.xcertplay.host.R
+import com.shilapi.xcertplay.orchestration.ManualHotspotValidation
+
+internal fun CarPlaySize.localizedLabel(context: Context): String = context.getString(when (this) {
+    CarPlaySize.LARGE -> R.string.option_size_large
+    CarPlaySize.MEDIUM -> R.string.option_size_medium
+    CarPlaySize.SMALL -> R.string.option_size_small
+})
+
+internal fun DiLink51ClusterLayout.Theme.localizedLabel(context: Context): String = context.getString(when (this) {
+    DiLink51ClusterLayout.Theme.SCENARIO -> R.string.option_theme_scenario
+    DiLink51ClusterLayout.Theme.MAP -> R.string.option_theme_map
+    DiLink51ClusterLayout.Theme.SIMPLE -> R.string.option_theme_simple
+})
+
+internal fun DiLink51ClusterLayout.Contrast.localizedLabel(context: Context): String = context.getString(when (this) {
+    DiLink51ClusterLayout.Contrast.DEFAULT -> R.string.option_contrast_default
+    DiLink51ClusterLayout.Contrast.LIGHT -> R.string.option_contrast_light
+    DiLink51ClusterLayout.Contrast.DARK -> R.string.option_contrast_dark
+})
+
+internal fun ManualHotspotValidation.Error.messageResource(): Int = when (this) {
+    ManualHotspotValidation.Error.EMPTY_NAME -> R.string.hotspot_error_empty_name
+    ManualHotspotValidation.Error.LONG_NAME -> R.string.hotspot_error_long_name
+    ManualHotspotValidation.Error.INVALID_CHARACTER -> R.string.hotspot_error_invalid_character
+    ManualHotspotValidation.Error.PASSWORD_LENGTH -> R.string.hotspot_error_password_length
+}

common/src/main/res/values-ar/strings.xml

@@ -387,4 +387,17 @@
     <string name="your_phone_your_drive">هاتفك. رحلتك.</string>
     <string name="your_report_was_saved_to_the_selected_location">تم حفظ تقريرك في الموقع المحدد.</string>
     <string name="cluster_waiting_for_map">DiPlay · بانتظار خريطة CarPlay</string>
+    <string name="option_size_large">كبير</string>
+    <string name="option_size_medium">متوسط</string>
+    <string name="option_size_small">صغير</string>
+    <string name="option_theme_scenario">المشهد · خريطة جانبية</string>
+    <string name="option_theme_map">الخريطة · خريطة كاملة</string>
+    <string name="option_theme_simple">بسيط · خريطة جانبية</string>
+    <string name="option_contrast_default">إعداد المظهر الافتراضي</string>
+    <string name="option_contrast_light">خلفية فاتحة · عدادات داكنة</string>
+    <string name="option_contrast_dark">خلفية داكنة · عدادات فاتحة</string>
+    <string name="hotspot_error_empty_name">أدخل اسم نقطة اتصال السيارة</string>
+    <string name="hotspot_error_long_name">يجب ألا يتجاوز اسم نقطة الاتصال 32 بايت</string>
+    <string name="hotspot_error_invalid_character">يحتوي الاسم أو كلمة المرور على محرف غير صالح</string>
+    <string name="hotspot_error_password_length">يجب أن تتكون كلمة مرور نقطة الاتصال من 8 إلى 63 محرفًا</string>
 </resources>

common/src/main/res/values-es/strings.xml

@@ -387,4 +387,17 @@
     <string name="your_phone_your_drive">TU TELÉFONO. TU TRAYECTO.</string>
     <string name="your_report_was_saved_to_the_selected_location">Tu informe se guardó en la ubicación seleccionada.</string>
     <string name="cluster_waiting_for_map">DiPlay · esperando el mapa de CarPlay</string>
+    <string name="option_size_large">Grande</string>
+    <string name="option_size_medium">Mediano</string>
+    <string name="option_size_small">Pequeño</string>
+    <string name="option_theme_scenario">Escenario · mapa lateral</string>
+    <string name="option_theme_map">Mapa · mapa completo</string>
+    <string name="option_theme_simple">Simple · mapa lateral</string>
+    <string name="option_contrast_default">Predeterminado del tema</string>
+    <string name="option_contrast_light">Fondo claro · instrumentos oscuros</string>
+    <string name="option_contrast_dark">Fondo oscuro · instrumentos claros</string>
+    <string name="hotspot_error_empty_name">Introduce el nombre del punto de acceso del coche</string>
+    <string name="hotspot_error_long_name">El nombre del punto de acceso no debe superar los 32 bytes</string>
+    <string name="hotspot_error_invalid_character">El nombre o la contraseña contiene un carácter no válido</string>
+    <string name="hotspot_error_password_length">La contraseña del punto de acceso debe tener entre 8 y 63 caracteres</string>
 </resources>

common/src/main/res/values-ru/strings.xml

@@ -387,4 +387,17 @@
     <string name="your_phone_your_drive">ВАШ ТЕЛЕФОН. ВАША ПОЕЗДКА.</string>
     <string name="your_report_was_saved_to_the_selected_location">Отчёт сохранён в выбранном месте.</string>
     <string name="cluster_waiting_for_map">DiPlay · ожидание карты CarPlay</string>
+    <string name="option_size_large">Большой</string>
+    <string name="option_size_medium">Средний</string>
+    <string name="option_size_small">Маленький</string>
+    <string name="option_theme_scenario">Сценарий · карта сбоку</string>
+    <string name="option_theme_map">Карта · полная карта</string>
+    <string name="option_theme_simple">Простой · карта сбоку</string>
+    <string name="option_contrast_default">По умолчанию для темы</string>
+    <string name="option_contrast_light">Светлый фон · тёмные приборы</string>
+    <string name="option_contrast_dark">Тёмный фон · светлые приборы</string>
+    <string name="hotspot_error_empty_name">Введите имя точки доступа автомобиля</string>
+    <string name="hotspot_error_long_name">Имя точки доступа не должно превышать 32 байта</string>
+    <string name="hotspot_error_invalid_character">Имя или пароль содержит недопустимый символ</string>
+    <string name="hotspot_error_password_length">Пароль точки доступа должен содержать от 8 до 63 символов</string>
 </resources>

common/src/main/res/values-zh-rCN/strings.xml

@@ -398,4 +398,17 @@
     <string name="your_phone_your_drive">你的手机，畅享旅程。</string>
     <string name="your_report_was_saved_to_the_selected_location">报告已保存到所选位置。</string>
     <string name="cluster_waiting_for_map">DiPlay · 等待 CarPlay 地图</string>
+    <string name="option_size_large">大</string>
+    <string name="option_size_medium">中</string>
+    <string name="option_size_small">小</string>
+    <string name="option_theme_scenario">场景 · 侧边地图</string>
+    <string name="option_theme_map">地图 · 全屏地图</string>
+    <string name="option_theme_simple">简约 · 侧边地图</string>
+    <string name="option_contrast_default">主题默认</string>
+    <string name="option_contrast_light">浅色背景 · 深色仪表</string>
+    <string name="option_contrast_dark">深色背景 · 浅色仪表</string>
+    <string name="hotspot_error_empty_name">请输入车载热点名称</string>
+    <string name="hotspot_error_long_name">热点名称不能超过32字节</string>
+    <string name="hotspot_error_invalid_character">名称或密码包含无效字符</string>
+    <string name="hotspot_error_password_length">热点密码长度必须为8至63个字符</string>
 </resources>

common/src/main/res/values/strings.xml

@@ -398,4 +398,17 @@
     <string name="your_phone_your_drive">YOUR PHONE. YOUR DRIVE.</string>
     <string name="your_report_was_saved_to_the_selected_location">Your report was saved to the selected location.</string>
     <string name="cluster_waiting_for_map">DiPlay · waiting for the CarPlay map</string>
+    <string name="option_size_large">Large</string>
+    <string name="option_size_medium">Medium</string>
+    <string name="option_size_small">Small</string>
+    <string name="option_theme_scenario">Scenario · side map</string>
+    <string name="option_theme_map">Map · full map</string>
+    <string name="option_theme_simple">Simple · side map</string>
+    <string name="option_contrast_default">Theme default</string>
+    <string name="option_contrast_light">Light background · dark instruments</string>
+    <string name="option_contrast_dark">Dark background · light instruments</string>
+    <string name="hotspot_error_empty_name">Enter the car hotspot name</string>
+    <string name="hotspot_error_long_name">The hotspot name must be at most 32 bytes</string>
+    <string name="hotspot_error_invalid_character">The name or password contains an invalid character</string>
+    <string name="hotspot_error_password_length">The hotspot password must be 8–63 characters</string>
 </resources>

common/src/test/java/com/shilapi/xcertplay/AppLocaleTest.kt

@@ -0,0 +1,62 @@
+package com.shilapi.xcertplay
+
+import android.app.LocaleManager
+import android.content.Context
+import android.os.LocaleList
+import android.view.View
+import org.junit.Assert.*
+import org.junit.Test
+import org.junit.runner.RunWith
+import org.robolectric.RobolectricTestRunner
+import org.robolectric.RuntimeEnvironment
+import org.robolectric.annotation.Config
+import java.util.Locale
+
+@RunWith(RobolectricTestRunner::class)
+@Config(sdk = [33], manifest = Config.NONE)
+class AppLocaleTest {
+    private val context get() = RuntimeEnvironment.getApplication()
+    private val manager get() = context.getSystemService(LocaleManager::class.java)
+
+    @Test fun pickerAndSystemSettingsShareTheSamePreference() {
+        AppLocale.save(context, AppLocale.ARABIC)
+        assertEquals("ar", manager.applicationLocales.toLanguageTags())
+        manager.applicationLocales = LocaleList.forLanguageTags("es")
+        assertEquals(AppLocale.SPANISH, AppLocale.preference(context))
+        assertSame(context, AppLocale.wrap(context))
+        AppLocale.save(context, AppLocale.SYSTEM)
+        assertTrue(manager.applicationLocales.isEmpty)
+        assertEquals(AppLocale.SYSTEM, AppLocale.preference(context))
+    }
+
+    @Test fun oldPreferenceMigratesOnceAndCannotOverrideLaterSystemChanges() {
+        context.getSharedPreferences("diplay", Context.MODE_PRIVATE).edit()
+            .putString("app_language", "ar").commit()
+        AppLocale.wrap(context)
+        assertEquals("ar", manager.applicationLocales.toLanguageTags())
+        manager.applicationLocales = LocaleList.getEmptyLocaleList()
+        AppLocale.wrap(context)
+        assertEquals(AppLocale.SYSTEM, AppLocale.preference(context))
+    }
+
+    @Test fun existingSystemChoiceWinsOverLegacyPreference() {
+        context.getSharedPreferences("diplay", Context.MODE_PRIVATE).edit()
+            .putString("app_language", "ar").commit()
+        manager.applicationLocales = LocaleList.forLanguageTags("zh-CN")
+        AppLocale.wrap(context)
+        assertEquals(AppLocale.SIMPLIFIED_CHINESE, AppLocale.preference(context))
+        assertEquals("zh-CN", manager.applicationLocales.toLanguageTags())
+    }
+
+    @Test @Config(sdk = [28, 32])
+    fun olderAndroidWrapsArabicAndReturnsToSystemWithoutChangingGlobalResources() {
+        val original = context.resources.configuration.locales.toLanguageTags()
+        AppLocale.save(context, AppLocale.ARABIC)
+        val wrapped = AppLocale.wrap(context)
+        assertEquals(Locale("ar"), wrapped.resources.configuration.locales[0])
+        assertEquals(View.LAYOUT_DIRECTION_RTL, wrapped.resources.configuration.layoutDirection)
+        assertEquals(original, context.resources.configuration.locales.toLanguageTags())
+        AppLocale.save(context, AppLocale.SYSTEM)
+        assertSame(context, AppLocale.wrap(context))
+    }
+}

shared/src/main/java/com/shilapi/xcertplay/media/AndroidMediaSink.kt

@@ -641,7 +641,7 @@ private class AudioRenderer(
         bytesPerSecond = format.sampleRate * frameBytes
         val built: AudioTrack
         var routeLabel: String
-        if (advancedAudioChannelMapping) {
+        if (!AudioChannelMapper.usesNavigationStream(format.audioType, format.payloadType, advancedAudioChannelMapping)) {
             val attributes = audioAttributes()
             routeLabel = "usage"
             built = AudioTrack.Builder()
@@ -653,26 +653,24 @@ private class AudioRenderer(
         } else {
             val streamType = streamType()
             routeLabel = "streamType=$streamType"
-            var candidate = AudioTrack(
-                streamType,
-                format.sampleRate,
-                channelMask,
-                encoding,
-                plan.trackBufferBytes,
-                AudioTrack.MODE_STREAM,
-            )
-            if (candidate.state != AudioTrack.STATE_INITIALIZED) {
-                candidate.release()
-                candidate = AudioTrack.Builder()
+            built = LegacyAudioFallback.build(
+                createLegacy = {
+                    AudioTrack(streamType, format.sampleRate, channelMask, encoding,
+                        plan.trackBufferBytes, AudioTrack.MODE_STREAM)
+                },
+                isInitialized = { it.state == AudioTrack.STATE_INITIALIZED },
+                release = { it.release() },
+                createFallback = {
+                    routeLabel = "streamType=$streamType(fallback=usage)"
+                    Log.w(TAG, "streamType=$streamType rejected by this ROM; falling back to usage-based track")
+                    AudioTrack.Builder()
                         .setAudioAttributes(audioAttributes())
                         .setAudioFormat(pcmFormat(encoding, channelMask))
                         .setTransferMode(AudioTrack.MODE_STREAM)
                         .setBufferSizeInBytes(plan.trackBufferBytes)
                         .build()
-                routeLabel = "streamType=$streamType(fallback=usage)"
-                Log.w(TAG, "streamType=$streamType rejected by this ROM; falling back to usage-based track")
-            }
-            built = candidate
+                },
+            )
         }
         track = built
         val capacityBytes = built.bufferSizeInFrames * frameBytes

shared/src/main/java/com/shilapi/xcertplay/media/AudioChannelMapping.kt

@@ -51,6 +51,9 @@ internal object AudioChannelMapper {
         }
     }
 
+    fun usesNavigationStream(audioType: String, payloadType: Int, advanced: Boolean): Boolean =
+        !advanced && map(audioType, payloadType, AudioChannelMappingMode.MOBILE_COMPATIBLE).channel == AudioChannel.NAVIGATION
+
     private fun mapMobileCompatible(
         audioType: String,
         payloadType: Int,

shared/src/main/java/com/shilapi/xcertplay/media/LegacyAudioFallback.kt

@@ -0,0 +1,18 @@
+package com.shilapi.xcertplay.media
+
+/** A ROM can reject a legacy stream by throwing or returning an uninitialized track. */
+internal object LegacyAudioFallback {
+    fun <T> build(
+        createLegacy: () -> T,
+        isInitialized: (T) -> Boolean,
+        release: (T) -> Unit,
+        createFallback: () -> T,
+    ): T {
+        val candidate = try { createLegacy() } catch (_: RuntimeException) { null }
+        if (candidate != null) {
+            if (isInitialized(candidate)) return candidate
+            release(candidate)
+        }
+        return createFallback()
+    }
+}

shared/src/main/java/com/shilapi/xcertplay/orchestration/ManualHotspotValidation.kt

@@ -6,12 +6,21 @@ object ManualHotspotValidation {
     fun securityFor(passphrase: String): ManualHotspotSecurity =
         if (passphrase.isEmpty()) ManualHotspotSecurity.OPEN else ManualHotspotSecurity.WPA2
 
-    /** Returns a message for the user, or null when the name and password can be used. */
-    fun validate(ssid: String, passphrase: String): String? = when {
-        ssid.isBlank() -> "Enter the car hotspot name"
-        ssid.encodeToByteArray().size > 32 -> "The hotspot name must be at most 32 bytes"
-        '\u0000' in ssid || '\u0000' in passphrase -> "The name or password contains an invalid character"
-        passphrase.isNotEmpty() && passphrase.length !in 8..63 -> "The hotspot password must be 8–63 characters"
+    enum class Error(val message: String) {
+        EMPTY_NAME("Enter the car hotspot name"),
+        LONG_NAME("The hotspot name must be at most 32 bytes"),
+        INVALID_CHARACTER("The name or password contains an invalid character"),
+        PASSWORD_LENGTH("The hotspot password must be 8–63 characters"),
+    }
+
+    fun error(ssid: String, passphrase: String): Error? = when {
+        ssid.isBlank() -> Error.EMPTY_NAME
+        ssid.encodeToByteArray().size > 32 -> Error.LONG_NAME
+        '\u0000' in ssid || '\u0000' in passphrase -> Error.INVALID_CHARACTER
+        passphrase.isNotEmpty() && passphrase.length !in 8..63 -> Error.PASSWORD_LENGTH
         else -> null
     }
+
+    /** English diagnostic text retained for non-UI callers. */
+    fun validate(ssid: String, passphrase: String): String? = error(ssid, passphrase)?.message
 }

shared/src/test/java/com/shilapi/xcertplay/media/LegacyAudioFallbackTest.kt

@@ -0,0 +1,48 @@
+package com.shilapi.xcertplay.media
+
+import org.junit.Assert.*
+import org.junit.Test
+
+class LegacyAudioFallbackTest {
+    @Test fun constructorRejectionStillCreatesUsageTrack() {
+        val fallback = Any()
+        val result = LegacyAudioFallback.build(
+            createLegacy = { throw IllegalArgumentException("Unsupported stream") },
+            isInitialized = { _: Any -> fail("No candidate should exist"); false },
+            release = { fail("No candidate should exist") },
+            createFallback = { fallback },
+        )
+        assertSame(fallback, result)
+    }
+
+    @Test fun uninitializedCandidateIsReleasedBeforeFallback() {
+        val events = mutableListOf<String>()
+        val result = LegacyAudioFallback.build(
+            createLegacy = { "legacy" }, isInitialized = { false },
+            release = { events += "release:$it" },
+            createFallback = { events += "fallback"; "usage" },
+        )
+        assertEquals("usage", result)
+        assertEquals(listOf("release:legacy", "fallback"), events)
+    }
+
+    @Test fun workingLegacyTrackDoesNotFallBackOrRelease() {
+        assertEquals("legacy", LegacyAudioFallback.build(
+            createLegacy = { "legacy" }, isInitialized = { true },
+            release = { fail("Working track must remain open") },
+            createFallback = { fail("No fallback needed"); "usage" },
+        ))
+    }
+
+    @Test fun onlyGuidanceUsesLegacyStreams() {
+        for (type in listOf("telephony", "speechRecognition", "media")) {
+            assertFalse(type, AudioChannelMapper.usesNavigationStream(type, 100, false))
+        }
+        for (type in listOf("default", "alert", "compatibility")) {
+            assertTrue(type, AudioChannelMapper.usesNavigationStream(type, 100, false))
+            assertFalse(type, AudioChannelMapper.usesNavigationStream(type, 100, true))
+        }
+        assertFalse(AudioChannelMapper.usesNavigationStream("unknown", 102, false))
+        assertTrue(AudioChannelMapper.usesNavigationStream("unknown", 100, false))
+    }
+}