feat(settings): add in-app language switcher (#439)

.github/workflows/analyze.yml

@@ -5,12 +5,18 @@ on:
       - '**.dart'
       - 'pubspec.yaml'
       - 'analysis_options.yaml'
+      - 'lib/l10n/**'
+      - 'ios/Runner/Info.plist'
+      - 'android/app/src/main/res/xml/locales_config.xml'
   pull_request:
     branches: [ master, ]
     paths:
       - '**/*.dart'
       - 'pubspec.yaml'
       - 'analysis_options.yaml'
+      - 'lib/l10n/**'
+      - 'ios/Runner/Info.plist'
+      - 'android/app/src/main/res/xml/locales_config.xml'
       - '.github/actions/flutter-common/action.yml'
       - '.github/workflows/analyze.yml'
   workflow_call:
@@ -34,3 +40,6 @@ jobs:
 
       - name: Analyze
         run: flutter analyze --no-fatal-infos --no-fatal-warnings
+
+      - name: Check locale lists are in sync
+        run: dart run tool/check_locales.dart

ios/Podfile.lock

@@ -2,6 +2,8 @@ PODS:
   - camera_avfoundation (0.0.1):
     - Flutter
   - Flutter (1.0.0)
+  - flutter_native_splash (2.4.3):
+    - Flutter
   - flutter_zxing (0.0.1):
     - Flutter
   - image_picker_ios (0.0.1):
@@ -49,6 +51,7 @@ PODS:
 DEPENDENCIES:
   - camera_avfoundation (from `.symlinks/plugins/camera_avfoundation/ios`)
   - Flutter (from `Flutter`)
+  - flutter_native_splash (from `.symlinks/plugins/flutter_native_splash/ios`)
   - flutter_zxing (from `.symlinks/plugins/flutter_zxing/ios`)
   - image_picker_ios (from `.symlinks/plugins/image_picker_ios/ios`)
   - integration_test (from `.symlinks/plugins/integration_test/ios`)
@@ -68,6 +71,8 @@ EXTERNAL SOURCES:
     :path: ".symlinks/plugins/camera_avfoundation/ios"
   Flutter:
     :path: Flutter
+  flutter_native_splash:
+    :path: ".symlinks/plugins/flutter_native_splash/ios"
   flutter_zxing:
     :path: ".symlinks/plugins/flutter_zxing/ios"
   image_picker_ios:
@@ -90,6 +95,7 @@ EXTERNAL SOURCES:
 SPEC CHECKSUMS:
   camera_avfoundation: 968a9a5323c79a99c166ad9d7866bfd2047b5a9b
   Flutter: cabc95a1d2626b1b06e7179b784ebcf0c0cde467
+  flutter_native_splash: c32d145d68aeda5502d5f543ee38c192065986cf
   flutter_zxing: fe1338b6d79b8a455d209a28381e336b6cfb4161
   image_picker_ios: e0ece4aa2a75771a7de3fa735d26d90817041326
   integration_test: 4a889634ef21a45d28d50d622cf412dc6d9f586e

ios/Runner/Info.plist

@@ -12,6 +12,45 @@
 		<string>$(PRODUCT_BUNDLE_IDENTIFIER)</string>
 		<key>CFBundleInfoDictionaryVersion</key>
 		<string>6.0</string>
+		<key>CFBundleLocalizations</key>
+		<array>
+			<string>am</string>
+			<string>ar</string>
+			<string>ca</string>
+			<string>cs</string>
+			<string>de</string>
+			<string>el</string>
+			<string>en</string>
+			<string>es</string>
+			<string>fa</string>
+			<string>fil</string>
+			<string>fr</string>
+			<string>he</string>
+			<string>hi</string>
+			<string>hr</string>
+			<string>hu</string>
+			<string>id</string>
+			<string>it</string>
+			<string>ja</string>
+			<string>ko</string>
+			<string>mk</string>
+			<string>nb</string>
+			<string>nl</string>
+			<string>pl</string>
+			<string>pt</string>
+			<string>pt-BR</string>
+			<string>pt-PT</string>
+			<string>ro</string>
+			<string>ru</string>
+			<string>sk</string>
+			<string>ta</string>
+			<string>th</string>
+			<string>tr</string>
+			<string>uk</string>
+			<string>ur</string>
+			<string>zh</string>
+			<string>zh-Hant</string>
+		</array>
 		<key>CFBundleName</key>
 		<string>wger</string>
 		<key>CFBundlePackageType</key>

lib/helpers/consts.dart

@@ -64,6 +64,7 @@ const PREFS_INGREDIENTS = 'ingredientData';
 const PREFS_WORKOUT_UNITS = 'workoutUnits';
 const PREFS_USER = 'userData';
 const PREFS_USER_DARK_THEME = 'userDarkMode';
+const PREFS_USER_LOCALE = 'userLocale';
 const PREFS_LAST_SERVER = 'lastServer';
 
 const DEFAULT_ANIMATION_DURATION = Duration(milliseconds: 200);

lib/helpers/locale.dart

@@ -34,3 +34,19 @@ Locale? resolveLocale(List<Locale>? locales, Iterable<Locale> supportedLocales)
   }
   return null;
 }
+
+/// Stable string encoding for a [Locale], matching the keys generated by
+/// Flutter's AppLocalizations (e.g. `pt_BR`, `zh_Hant`, `pl`). [scriptCode]
+/// takes precedence over [countryCode] so locales like `zh_Hant` round-trip
+/// distinctly from plain `zh`.
+String encodeLocale(Locale locale) {
+  final script = locale.scriptCode;
+  if (script != null && script.isNotEmpty) {
+    return '${locale.languageCode}_$script';
+  }
+  final country = locale.countryCode;
+  if (country != null && country.isNotEmpty) {
+    return '${locale.languageCode}_$country';
+  }
+  return locale.languageCode;
+}

lib/l10n/app_en.arb

@@ -1160,6 +1160,14 @@
   "darkMode": "Always dark mode",
   "lightMode": "Always light mode",
   "systemMode": "System settings",
+  "appLanguage": "App language",
+  "@appLanguage": {
+    "description": "Label for the in-app language selector in settings"
+  },
+  "appLanguageSystem": "System default",
+  "@appLanguageSystem": {
+    "description": "Dropdown entry that follows the device system language"
+  },
   "productNotFoundOpenFoodFacts": "You can add this product to Open Food Facts to help the community!",
   "@productNotFoundOpenFoodFacts": {
   "description": "Label shown when product is not found to encourage users to go on Open Food Facts and add it themselves"

lib/l10n/app_pl.arb

@@ -833,6 +833,8 @@
     "darkMode": "Zawsze używaj trybu ciemnego",
     "lightMode": "Zawsze używaj trybu jasnego",
     "systemMode": "Ustawienia systemu",
+    "appLanguage": "Język aplikacji",
+    "appLanguageSystem": "Domyślny systemu",
     "fitInWeek": "Dopasuj w tygodniu",
     "dayTypeAmrap": "Tak dużo rund jak to możliwe",
     "trophies": "Trofea",

lib/l10n/language_native_names.dart

@@ -0,0 +1,57 @@
+/*
+ * This file is part of wger Workout Manager <https://github.com/wger-project>.
+ * Copyright (c) 2026 - 2026 wger Team
+ *
+ * wger Workout Manager is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+/// Native display names for each supported locale, keyed by the locale name
+const Map<String, String> languageNativeNames = {
+  'am': 'አማርኛ',
+  'ar': 'العربية',
+  'ca': 'Català',
+  'cs': 'Čeština',
+  'de': 'Deutsch',
+  'el': 'Ελληνικά',
+  'en': 'English',
+  'es': 'Español',
+  'fa': 'فارسی',
+  'fil': 'Filipino',
+  'fr': 'Français',
+  'he': 'עברית',
+  'hi': 'हिन्दी',
+  'hr': 'Hrvatski',
+  'hu': 'Magyar',
+  'id': 'Bahasa Indonesia',
+  'it': 'Italiano',
+  'ja': '日本語',
+  'ko': '한국어',
+  'mk': 'Македонски',
+  'nb': 'Norsk bokmål',
+  'nl': 'Nederlands',
+  'pl': 'Polski',
+  'pt': 'Português',
+  'pt_BR': 'Português (Brasil)',
+  'pt_PT': 'Português (Portugal)',
+  'ro': 'Română',
+  'ru': 'Русский',
+  'sk': 'Slovenčina',
+  'ta': 'தமிழ்',
+  'th': 'ไทย',
+  'tr': 'Türkçe',
+  'uk': 'Українська',
+  'ur': 'اردو',
+  'zh': '中文',
+  'zh_Hant': '繁體中文',
+};

lib/main.dart

@@ -249,6 +249,7 @@ class MainApp extends StatelessWidget {
                     highContrastTheme: wgerLightThemeHc,
                     highContrastDarkTheme: wgerDarkThemeHc,
                     themeMode: user.themeMode,
+                    locale: user.userLocale,
                     home: _getHomeScreen(auth),
                     routes: {
                       DashboardScreen.routeName: (ctx) => const DashboardScreen(),

lib/providers/user.dart

@@ -23,7 +23,9 @@ import 'package:collection/collection.dart';
 import 'package:flutter/material.dart';
 import 'package:shared_preferences/shared_preferences.dart';
 import 'package:wger/helpers/consts.dart';
+import 'package:wger/helpers/locale.dart';
 import 'package:wger/helpers/shared_preferences.dart';
+import 'package:wger/l10n/generated/app_localizations.dart';
 import 'package:wger/models/user/profile.dart';
 import 'package:wger/providers/base_provider.dart';
 
@@ -63,12 +65,14 @@ class DashboardItem {
 
 class UserProvider with ChangeNotifier {
   ThemeMode themeMode = ThemeMode.system;
+  Locale? userLocale;
   final WgerBaseProvider baseProvider;
   late SharedPreferencesAsync prefs;
 
   UserProvider(this.baseProvider, {SharedPreferencesAsync? prefs}) {
     this.prefs = prefs ?? PreferenceHelper.asyncPref;
     _loadThemeMode();
+    _loadUserLocale();
     _loadDashboardConfig();
   }
 
@@ -96,6 +100,38 @@ class UserProvider with ChangeNotifier {
     notifyListeners();
   }
 
+  /// Load saved user locale override from SharedPreferences. A null value means
+  /// the app should follow the system locale.
+  Future<void> _loadUserLocale() async {
+    final raw = await prefs.getString(PREFS_USER_LOCALE);
+    userLocale = _matchSupportedLocale(raw);
+    notifyListeners();
+  }
+
+  /// Match a stored locale tag (`languageCode` or `languageCode_subtag`) against
+  /// the app's [AppLocalizations.supportedLocales]. Returns the exact supported
+  /// instance to keep dropdown identity stable, or null when no match is found.
+  static Locale? _matchSupportedLocale(String? raw) {
+    if (raw == null || raw.isEmpty) {
+      return null;
+    }
+    for (final locale in AppLocalizations.supportedLocales) {
+      if (encodeLocale(locale) == raw) {
+        return locale;
+      }
+    }
+    // Fallback: match by language only (e.g. stored "pl" picks the only pl).
+    final lang = raw.split('_').first;
+    for (final locale in AppLocalizations.supportedLocales) {
+      if (locale.languageCode == lang &&
+          (locale.countryCode == null || locale.countryCode!.isEmpty) &&
+          (locale.scriptCode == null || locale.scriptCode!.isEmpty)) {
+        return locale;
+      }
+    }
+    return null;
+  }
+
   // Dashboard configuration
   List<DashboardItem> _dashboardItems = DashboardWidget.values
       .map((w) => DashboardItem(w))
@@ -193,6 +229,20 @@ class UserProvider with ChangeNotifier {
     notifyListeners();
   }
 
+  /// Override the app locale. Passing `null` clears the override and falls
+  /// back to the system locale via `localeListResolutionCallback`.
+  Future<void> setUserLocale(Locale? locale) async {
+    userLocale = locale;
+
+    if (locale == null) {
+      await prefs.remove(PREFS_USER_LOCALE);
+    } else {
+      await prefs.setString(PREFS_USER_LOCALE, encodeLocale(locale));
+    }
+
+    notifyListeners();
+  }
+
   /// Fetch the current user's profile
   Future<void> fetchAndSetProfile() async {
     final userData = await baseProvider.fetch(baseProvider.makeUrl(PROFILE_URL));

lib/widgets/core/settings.dart

@@ -22,6 +22,7 @@ import 'package:wger/screens/settings_plates_screen.dart';
 
 import './settings/exercise_cache.dart';
 import './settings/ingredient_cache.dart';
+import './settings/language.dart';
 import './settings/theme.dart';
 
 class SettingsPage extends StatelessWidget {
@@ -44,6 +45,7 @@ class SettingsPage extends StatelessWidget {
           const SettingsIngredientCache(),
           ListTile(title: Text(i18n.others, style: Theme.of(context).textTheme.headlineSmall)),
           const SettingsTheme(),
+          const SettingsLanguage(),
           ListTile(
             title: Text(i18n.selectAvailablePlates),
             onTap: () {

lib/widgets/core/settings/language.dart

@@ -0,0 +1,66 @@
+/*
+ * This file is part of wger Workout Manager <https://github.com/wger-project>.
+ * Copyright (c) 2026 - 2026 wger Team
+ *
+ * wger Workout Manager is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+import 'package:flutter/material.dart';
+import 'package:provider/provider.dart';
+import 'package:wger/helpers/locale.dart';
+import 'package:wger/l10n/generated/app_localizations.dart';
+import 'package:wger/l10n/language_native_names.dart';
+import 'package:wger/providers/user.dart';
+
+String _displayNameFor(Locale locale) {
+  return languageNativeNames[encodeLocale(locale)] ??
+      languageNativeNames[locale.languageCode] ??
+      encodeLocale(locale);
+}
+
+class SettingsLanguage extends StatelessWidget {
+  const SettingsLanguage({super.key});
+
+  @override
+  Widget build(BuildContext context) {
+    final i18n = AppLocalizations.of(context);
+    final userProvider = Provider.of<UserProvider>(context);
+
+    final supported = [...AppLocalizations.supportedLocales]
+      ..sort((a, b) => _displayNameFor(a).compareTo(_displayNameFor(b)));
+
+    return ListTile(
+      title: Text(i18n.appLanguage),
+      trailing: DropdownButton<Locale?>(
+        key: const ValueKey('appLanguageDropdown'),
+        value: userProvider.userLocale,
+        onChanged: (Locale? newValue) {
+          userProvider.setUserLocale(newValue);
+        },
+        items: <DropdownMenuItem<Locale?>>[
+          DropdownMenuItem<Locale?>(
+            value: null,
+            child: Text(i18n.appLanguageSystem),
+          ),
+          ...supported.map(
+            (locale) => DropdownMenuItem<Locale?>(
+              value: locale,
+              child: Text(_displayNameFor(locale)),
+            ),
+          ),
+        ],
+      ),
+    );
+  }
+}