Added functionality of language in setting.

lib/widgets/settings.dart

@@ -1,11 +1,94 @@
 import 'package:flutter/material.dart';
-
+import 'app.dart';
 import '../generated/l10n/zulip_localizations.dart';
 import '../model/settings.dart';
 import 'app_bar.dart';
 import 'page.dart';
 import 'store.dart';
 
+class LanguageOption {
+  final String name;
+  final String englishName;
+  final Locale locale;
+
+  const LanguageOption(this.name, this.englishName, this.locale);
+}
+
+final List<LanguageOption> _languageOptions = const [
+  LanguageOption('English', 'English', Locale('en')),
+  LanguageOption('English (UK)', 'English (UK)', Locale('en', 'GB')),
+  LanguageOption('English (US)', 'English (US)', Locale('en', 'US')),
+  LanguageOption('Afrikaans', 'Afrikaans', Locale('af')),
+  LanguageOption('العربية', 'Arabic', Locale('ar')),
+  LanguageOption('Հայերեն', 'Armenian', Locale('hy')),
+  LanguageOption('Azərbaycanca', 'Azerbaijani', Locale('az')),
+  LanguageOption('Беларуская', 'Belarusian', Locale('be')),
+  LanguageOption('বাংলা', 'Bengali', Locale('bn')),
+  LanguageOption('Bosanski', 'Bosnian', Locale('bs')),
+  LanguageOption('Български', 'Bulgarian', Locale('bg')),
+  LanguageOption('Català', 'Catalan', Locale('ca')),
+  LanguageOption('中文 (简体)', 'Chinese (Simplified)', Locale('zh', 'CN')),
+  LanguageOption('中文 (繁體)', 'Chinese (Traditional)', Locale('zh', 'TW')),
+  LanguageOption('Hrvatski', 'Croatian', Locale('hr')),
+  LanguageOption('Čeština', 'Czech', Locale('cs')),
+  LanguageOption('Dansk', 'Danish', Locale('da')),
+  LanguageOption('Nederlands', 'Dutch', Locale('nl')),
+  LanguageOption('Eesti', 'Estonian', Locale('et')),
+  LanguageOption('Filipino', 'Filipino', Locale('fil')),
+  LanguageOption('Suomi', 'Finnish', Locale('fi')),
+  LanguageOption('Français', 'French', Locale('fr')),
+  LanguageOption('Français (Canada)', 'French (Canada)', Locale('fr', 'CA')),
+  LanguageOption('Galego', 'Galician', Locale('gl')),
+  LanguageOption('ქართული', 'Georgian', Locale('ka')),
+  LanguageOption('Deutsch', 'German', Locale('de')),
+  LanguageOption('Ελληνικά', 'Greek', Locale('el')),
+  LanguageOption('ગુજરાતી', 'Gujarati', Locale('gu')),
+  LanguageOption('עברית', 'Hebrew', Locale('he')),
+  LanguageOption('हिन्दी', 'Hindi', Locale('hi')),
+  LanguageOption('Magyar', 'Hungarian', Locale('hu')),
+  LanguageOption('Íslenska', 'Icelandic', Locale('is')),
+  LanguageOption('Bahasa Indonesia', 'Indonesian', Locale('id')),
+  LanguageOption('Gaeilge', 'Irish', Locale('ga')),
+  LanguageOption('Italiano', 'Italian', Locale('it')),
+  LanguageOption('日本語', 'Japanese', Locale('ja')),
+  LanguageOption('ಕನ್ನಡ', 'Kannada', Locale('kn')),
+  LanguageOption('Қазақ', 'Kazakh', Locale('kk')),
+  LanguageOption('ភាសាខ្មែរ', 'Khmer', Locale('km')),
+  LanguageOption('한국어', 'Korean', Locale('ko')),
+  LanguageOption('ລາວ', 'Lao', Locale('lo')),
+  LanguageOption('Latviešu', 'Latvian', Locale('lv')),
+  LanguageOption('Lietuvių', 'Lithuanian', Locale('lt')),
+  LanguageOption('Македонски', 'Macedonian', Locale('mk')),
+  LanguageOption('Malayalam', 'Malayalam', Locale('ml')),
+  LanguageOption('Bahasa Melayu', 'Malay', Locale('ms')),
+  LanguageOption('Монгол', 'Mongolian', Locale('mn')),
+  LanguageOption('नेपाली', 'Nepali', Locale('ne')),
+  LanguageOption('Norsk Bokmål', 'Norwegian (Bokmål)', Locale('nb')),
+  LanguageOption('فارسی', 'Persian', Locale('fa')),
+  LanguageOption('Polski', 'Polish', Locale('pl')),
+  LanguageOption('Português (Brasil)', 'Portuguese (Brazil)', Locale('pt', 'BR')),
+  LanguageOption('Português (Portugal)', 'Portuguese (Portugal)', Locale('pt', 'PT')),
+  LanguageOption('ਪੰਜਾਬੀ', 'Punjabi', Locale('pa')),
+  LanguageOption('Română', 'Romanian', Locale('ro')),
+  LanguageOption('Русский', 'Russian', Locale('ru')),
+  LanguageOption('Српски', 'Serbian', Locale('sr')),
+  LanguageOption('Slovenčina', 'Slovak', Locale('sk')),
+  LanguageOption('Slovenščina', 'Slovenian', Locale('sl')),
+  LanguageOption('Español', 'Spanish', Locale('es')),
+  LanguageOption('Español (Latinoamérica)', 'Spanish (Latin America)', Locale('es', '419')),
+  LanguageOption('Svenska', 'Swedish', Locale('sv')),
+  LanguageOption('தமிழ்', 'Tamil', Locale('ta')),
+  LanguageOption('తెలుగు', 'Telugu', Locale('te')),
+  LanguageOption('ไทย', 'Thai', Locale('th')),
+  LanguageOption('Türkçe', 'Turkish', Locale('tr')),
+  LanguageOption('Українська', 'Ukrainian', Locale('uk')),
+  LanguageOption('اردو', 'Urdu', Locale('ur')),
+  LanguageOption('Oʻzbek', 'Uzbek', Locale('uz')),
+  LanguageOption('Tiếng Việt', 'Vietnamese', Locale('vi')),
+  LanguageOption('Cymraeg', 'Welsh', Locale('cy')),
+  LanguageOption('isiZulu', 'Zulu', Locale('zu')),
+];
+
 class SettingsPage extends StatelessWidget {
   const SettingsPage({super.key});
 
@@ -14,6 +97,18 @@ class SettingsPage extends StatelessWidget {
       context: context, page: const SettingsPage());
   }
 
+  String _getCurrentLanguageName() {
+    final currentLocale = ZulipApp.currentLocale;
+    if (currentLocale == null) return 'System default';
+
+    final option = _languageOptions.firstWhere(
+          (opt) => opt.locale.languageCode == currentLocale.languageCode,
+      orElse: () => const LanguageOption('English', 'English', Locale('en')),
+    );
+
+    return option.englishName;
+  }
+
   @override
   Widget build(BuildContext context) {
     final zulipLocalizations = ZulipLocalizations.of(context);
@@ -23,6 +118,22 @@ class SettingsPage extends StatelessWidget {
       body: Column(children: [
         const _ThemeSetting(),
         const _BrowserPreferenceSetting(),
+        ListTile(
+            leading: const Icon(Icons.language),
+            title: const Text('Language'),
+            trailing: Text(
+              _getCurrentLanguageName(),
+              style: Theme.of(context).textTheme.bodySmall?.copyWith(
+                color: Theme.of(context).hintColor,
+              ),
+            ),
+            onTap: () => Navigator.push<void>(  // Explicitly specify return type
+              context,
+              MaterialPageRoute<void>(  // Explicit type parameter
+                builder: (context) => const LanguageSelectionScreen(),
+              ),
+            ),
+          ),
         if (GlobalSettingsStore.experimentalFeatureFlags.isNotEmpty)
           ListTile(
             title: Text(zulipLocalizations.experimentalFeatureSettingsPageTitle),
@@ -32,6 +143,97 @@ class SettingsPage extends StatelessWidget {
   }
 }
 
+class _LanguageSelectionScreenState extends State<LanguageSelectionScreen> {
+  final TextEditingController _searchController = TextEditingController();
+  List<LanguageOption> _filteredLanguages = [];
+
+  @override
+  void initState() {
+    super.initState();
+    _filteredLanguages = _languageOptions;
+    _searchController.addListener(_filterLanguages);
+  }
+
+  @override
+  void dispose() {
+    _searchController.dispose();
+    super.dispose();
+  }
+
+  void _filterLanguages() {
+    final query = _searchController.text.toLowerCase();
+    setState(() {
+      _filteredLanguages = _languageOptions.where((lang) {
+        return lang.name.toLowerCase().contains(query) ||
+            lang.englishName.toLowerCase().contains(query);
+      }).toList();
+    });
+  }
+
+  @override
+  Widget build(BuildContext context) {
+    return Scaffold(
+      appBar: AppBar(
+        title: const Text('Language'),
+        leading: IconButton(
+          icon: const Icon(Icons.arrow_back),
+          onPressed: () => Navigator.pop(context),
+        ),
+      ),
+      body: Column(
+        children: [
+          Padding(
+            padding: const EdgeInsets.all(16.0),
+            child: TextField(
+              controller: _searchController,
+              decoration: InputDecoration(
+                hintText: 'Search',
+                prefixIcon: const Icon(Icons.search),
+                border: OutlineInputBorder(
+                  borderRadius: BorderRadius.circular(8),
+                ),
+                contentPadding: const EdgeInsets.symmetric(vertical: 12),
+              ),
+            ),
+          ),
+          Expanded(
+            child: ListView.builder(
+              itemCount: _filteredLanguages.length,
+              itemBuilder: (context, index) {
+                final option = _filteredLanguages[index];
+                final isSelected = ZulipApp.currentLocale?.languageCode ==
+                    option.locale.languageCode;
+
+                return ListTile(
+                  title: Column(
+                    crossAxisAlignment: CrossAxisAlignment.start,
+                    children: [
+                      Text(option.name),
+                      Text(
+                        option.englishName,
+                        style: Theme.of(context).textTheme.bodySmall?.copyWith(
+                          color: Theme.of(context).hintColor,
+                        ),
+                      ),
+                    ],
+                  ),
+                  trailing: isSelected
+                      ? const Icon(Icons.check, color: Colors.blue)
+                      : null,
+                  onTap: () {
+                    ZulipApp.setLocale(option.locale);
+                    Navigator.pop(context);
+                  },
+                );
+              },
+            ),
+          ),
+        ],
+      ),
+    );
+  }
+}
+
 class _ThemeSetting extends StatelessWidget {
   const _ThemeSetting();