settings: Support set language

Known issue:
String "Welcome" is shown as default language.

src/ui/flutter_app/lib/common/config.dart

@@ -45,6 +45,7 @@ class Config {
   static bool experimentsEnabled = false;
 
   // Display
+  static String language = "Default";
   static bool standardNotationEnabled = true;
   static bool isPieceCountInHandShown = false;
   static bool isNotationsShown = false;
@@ -105,6 +106,7 @@ class Config {
     Config.experimentsEnabled = settings['ExperimentsEnabled'] ?? false;
 
     // Display
+    Config.language = settings['Language'] ?? "Default";
     Config.standardNotationEnabled =
         settings['StandardNotationEnabled'] ?? true;
     Config.isPieceCountInHandShown =
@@ -185,6 +187,7 @@ class Config {
     settings['ExperimentsEnabled'] = Config.experimentsEnabled;
 
     // Display
+    settings['Language'] = Config.language;
     settings['StandardNotationEnabled'] = Config.standardNotationEnabled;
     settings['IsPieceCountInHandShown'] = Config.isPieceCountInHandShown;
     settings['IsNotationsShown'] = Config.isNotationsShown;

src/ui/flutter_app/lib/l10n/intl_de.arb

@@ -943,5 +943,13 @@
   "ossLicenses": "Open Source Lizenzen",
   "@ossLicenses": {
     "description": "Open source licenses"
+  },
+  "language": "Sprache",
+  "@language": {
+    "description": "Languages"
+  },
+  "defaultLanguage": "Standardsprache",
+  "@defaultLanguage": {
+    "description": "Default language"
   }
 }

src/ui/flutter_app/lib/l10n/intl_en.arb

@@ -943,5 +943,13 @@
   "ossLicenses": "Open source licenses",
   "@ossLicenses": {
     "description": "Open source licenses"
+  },
+  "language": "Language",
+  "@language": {
+    "description": "Languages"
+  },
+  "defaultLanguage": "Default language",
+  "@defaultLanguage": {
+    "description": "Default language"
   }
 }

src/ui/flutter_app/lib/l10n/intl_fa.arb

@@ -943,5 +943,13 @@
   "ossLicenses": "Open Source Lizenzen",
   "@ossLicenses": {
     "description": "مجوزهای منبع آزاد"
+  },
+  "language": "زبان",
+  "@language": {
+    "description": "Languages"
+  },
+  "defaultLanguage": "زبان پیش فرض",
+  "@defaultLanguage": {
+    "description": "Default language"
   }
 }

src/ui/flutter_app/lib/l10n/intl_hu.arb

@@ -943,5 +943,13 @@
   "ossLicenses": "Nyílt forráskódú licencek",
   "@ossLicenses": {
     "description": "Open source licenses"
+  },
+  "language": "Nyelv",
+  "@language": {
+    "description": "Languages"
+  },
+  "defaultLanguage": "Alapértelmezett nyelv",
+  "@defaultLanguage": {
+    "description": "Default language"
   }
 }

src/ui/flutter_app/lib/l10n/intl_ro.arb

@@ -943,5 +943,13 @@
   "ossLicenses": "Licențe open source",
   "@ossLicenses": {
     "description": "Open source licenses"
+  },
+  "language": "Limba",
+  "@language": {
+    "description": "Languages"
+  },
+  "defaultLanguage": "Limba implicita",
+  "@defaultLanguage": {
+    "description": "Default language"
   }
 }

src/ui/flutter_app/lib/l10n/intl_zh.arb

@@ -235,5 +235,7 @@
   "more": "更多",
   "experimental": "此仍属实验性功能。",
   "experiments": "实验性功能",
-  "ossLicenses": "开放源代码许可"
+  "ossLicenses": "开放源代码许可",
+  "language": "显示语言",
+  "defaultLanguage": "默认语言"
 }

src/ui/flutter_app/lib/l10n/resources.dart

@@ -18,6 +18,15 @@
 
 import 'dart:io';
 
+Map<String, String> languageMap = {
+  "de": "Deutsch",
+  "en": "English",
+  "fa": "فارسی",
+  "hu": "Magyar",
+  "ro": "Română",
+  "zh": "简体中文",
+};
+
 /// Interface strings
 abstract class Strings {
   String get tapBackAgainToLeave;

src/ui/flutter_app/lib/widgets/game_page.dart

@@ -1647,24 +1647,34 @@ class _GamePageState extends State<GamePage>
   }
 
   @override
-  void didPush() {
+  void didPush() async {
     final route = ModalRoute.of(context)!.settings.name;
     print('$tag Game Page didPush route: $route');
-    widget.engine.setOptions();
+    await widget.engine.setOptions();
+    if (Config.language != "Default") {
+      S.load(Locale(Config.language));
+      setState(() {});
+    }
   }
 
   @override
-  void didPopNext() {
+  void didPopNext() async {
     final route = ModalRoute.of(context)!.settings.name;
     print('$tag Game Page didPopNext route: $route');
-    widget.engine.setOptions();
+    await widget.engine.setOptions();
+    if (Config.language != "Default") {
+      S.load(Locale(Config.language));
+    }
   }
 
   @override
-  void didPushNext() {
+  void didPushNext() async {
     final route = ModalRoute.of(context)!.settings.name;
     print('$tag Game Page didPushNext route: $route');
-    widget.engine.setOptions();
+    await widget.engine.setOptions();
+    if (Config.language != "Default") {
+      S.load(Locale(Config.language));
+    }
   }
 
   @override

src/ui/flutter_app/lib/widgets/game_settings_page.dart

@@ -505,6 +505,16 @@ class _GameSettingsPageState extends State<GameSettingsPage> {
 
   // Display
 
+  setLanguage(String value) async {
+    setState(() {
+      Config.language = value;
+    });
+
+    print("[config] language: $value");
+
+    Config.save();
+  }
+
   setIsPieceCountInHandShown(bool value) async {
     setState(() {
       Config.isPieceCountInHandShown = value;

src/ui/flutter_app/lib/widgets/personalization_settings_page.dart

@@ -16,10 +16,13 @@
   along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */
 
+import 'dart:io';
+
 import 'package:flutter/material.dart';
 import 'package:flutter_colorpicker/flutter_colorpicker.dart';
 import 'package:sanmill/common/config.dart';
 import 'package:sanmill/generated/l10n.dart';
+import 'package:sanmill/l10n/resources.dart';
 import 'package:sanmill/style/app_theme.dart';
 import 'package:sanmill/widgets/settings_card.dart';
 import 'package:sanmill/widgets/settings_list_tile.dart';
@@ -337,6 +340,14 @@ class _PersonalizationSettingsPageState
       SettingsCard(
         context: context,
         children: <Widget>[
+          SettingsListTile(
+            context: context,
+            titleString: S.of(context).language,
+            trailingString:
+                Config.language == "Default" ? "" : Config.language.toString(),
+            onTap: setLanguage,
+          ),
+          ListItemDivider(),
           SettingsSwitchListTile(
             context: context,
             value: Config.isPieceCountInHandShown,
@@ -454,6 +465,93 @@ class _PersonalizationSettingsPageState
 
   // Display
 
+  setLanguage() async {
+    callback(var lang) async {
+      print("[config] language = $lang");
+
+      Navigator.of(context).pop();
+
+      setState(() {
+        Config.language = lang ?? "Default";
+
+        if (Config.language != "Default") {
+          S.load(Locale(Config.language));
+        } else {
+          S.load(Locale(Platform.localeName.substring(0, 2)));
+        }
+      });
+
+      print("[config] Config.language: ${Config.language}");
+
+      Config.save();
+    }
+
+    showModalBottomSheet(
+      context: context,
+      builder: (BuildContext context) => Column(
+        mainAxisSize: MainAxisSize.min,
+        children: <Widget>[
+          RadioListTile(
+            activeColor: AppTheme.switchListTileActiveColor,
+            title: Text(S.of(context).defaultLanguage),
+            groupValue: Config.language,
+            value: "Default",
+            onChanged: callback,
+          ),
+          ListItemDivider(),
+          RadioListTile(
+            activeColor: AppTheme.switchListTileActiveColor,
+            title: Text(languageMap["de"]!),
+            groupValue: Config.language,
+            value: "de",
+            onChanged: callback,
+          ),
+          ListItemDivider(),
+          RadioListTile(
+            activeColor: AppTheme.switchListTileActiveColor,
+            title: Text(languageMap["en"]!),
+            groupValue: Config.language,
+            value: "en",
+            onChanged: callback,
+          ),
+          ListItemDivider(),
+          RadioListTile(
+            activeColor: AppTheme.switchListTileActiveColor,
+            title: Text(languageMap["fa"]!),
+            groupValue: Config.language,
+            value: "fa",
+            onChanged: callback,
+          ),
+          ListItemDivider(),
+          RadioListTile(
+            activeColor: AppTheme.switchListTileActiveColor,
+            title: Text(languageMap["hu"]!),
+            groupValue: Config.language,
+            value: "hu",
+            onChanged: callback,
+          ),
+          ListItemDivider(),
+          RadioListTile(
+            activeColor: AppTheme.switchListTileActiveColor,
+            title: Text(languageMap["ro"]!),
+            groupValue: Config.language,
+            value: "ro",
+            onChanged: callback,
+          ),
+          ListItemDivider(),
+          RadioListTile(
+            activeColor: AppTheme.switchListTileActiveColor,
+            title: Text(languageMap["zh"]!),
+            groupValue: Config.language,
+            value: "zh",
+            onChanged: callback,
+          ),
+          ListItemDivider(),
+        ],
+      ),
+    );
+  }
+
   setIsPieceCountInHandShown(bool value) async {
     setState(() {
       Config.isPieceCountInHandShown = value;

src/ui/flutter_app/lib/widgets/settings_switch_list_tile.dart

@@ -31,7 +31,7 @@ class SettingsSwitchListTile extends StatelessWidget {
   }) : super(key: key);
 
   final BuildContext context;
-  final bool value;
+  final value;
   final String titleString;
   final String? subtitleString;
   final onChanged;

src/ui/flutter_app/pubspec.yaml

@@ -26,6 +26,7 @@ dependencies:
   devicelocale: ^0.4.1
   double_back_to_close_app: ^2.0.1
   flutter_picker: ^2.0.1
+  #pref: ^2.3.0
   #screen_recorder: ^0.0.2
 
 dev_dependencies: