Add System Language Item

Flow.Launcher.Core/Resource/AvailableLanguages.cs

@@ -25,12 +25,11 @@
         public static Language Norwegian_Bokmal = new Language("nb-NO", "Norsk Bokmål");
         public static Language Slovak = new Language("sk", "Slovenčina");
         public static Language Turkish = new Language("tr", "Türkçe");
         public static Language Czech = new Language("cs", "čeština");
         public static Language Arabic = new Language("ar", "اللغة العربية");
         public static Language Vietnamese = new Language("vi-vn", "Tiếng Việt");
         public static Language Hebrew = new Language("he", "עברית");
 
-
         public static List<Language> GetAvailableLanguages()
         {
             List<Language> languages = new List<Language>
@@ -63,5 +62,38 @@
             };
             return languages;
         }
+
+        public static string GetSystemTranslation(string languageCode)
+        {
+            return languageCode switch
+            {
+                "en" => "System",
+                "zh-cn" => "系统",
+                "zh-tw" => "系統",
+                "uk-UA" => "Система",
+                "ru" => "Система",
+                "fr" => "Système",
+                "ja" => "システム",
+                "nl" => "Systeem",
+                "pl" => "System",
+                "da" => "System",
+                "de" => "System",
+                "ko" => "시스템",
+                "sr" => "Систем",
+                "pt-pt" => "Sistema",
+                "pt-br" => "Sistema",
+                "es" => "Sistema",
+                "es-419" => "Sistema",
+                "it" => "Sistema",
+                "nb-NO" => "System",
+                "sk" => "Systém",
+                "tr" => "Sistem",
+                "cs" => "Systém",
+                "ar" => "النظام",
+                "vi-vn" => "Hệ thống",
+                "he" => "מערכת",
+                _ => "System",
+            };
+        }
     }
 }

Flow.Launcher.Core/Resource/Internationalization.cs

@@ -18,23 +18,52 @@ public class Internationalization
     {
         public Settings Settings { get; set; }
         private const string Folder = "Languages";
+        private const string DefaultLanguageCode = "en";
         private const string DefaultFile = "en.xaml";
         private const string Extension = ".xaml";
         private readonly List<string> _languageDirectories = new List<string>();
         private readonly List<ResourceDictionary> _oldResources = new List<ResourceDictionary>();
+        private readonly string SystemLanguageCode;
 
         public Internationalization()
         {
             AddFlowLauncherLanguageDirectory();
+            SystemLanguageCode = GetSystemLanguageCodeAtStartup();
         }
 
-
         private void AddFlowLauncherLanguageDirectory()
         {
             var directory = Path.Combine(Constant.ProgramDirectory, Folder);
             _languageDirectories.Add(directory);
         }
 
+        private static string GetSystemLanguageCodeAtStartup()
+        {
+            var availableLanguages = AvailableLanguages.GetAvailableLanguages();
+
+            // Retrieve the language identifiers for the current culture.
+            // ChangeLanguage method overrides the CultureInfo.CurrentCulture, so this needs to
+            // be called at startup in order to get the correct lang code of system. 
+            var currentCulture = CultureInfo.CurrentCulture;
+            var twoLetterCode = currentCulture.TwoLetterISOLanguageName;
+            var threeLetterCode = currentCulture.ThreeLetterISOLanguageName;
+            var fullName = currentCulture.Name;
+
+            // Try to find a match in the available languages list
+            foreach (var language in availableLanguages)
+            {
+                var languageCode = language.LanguageCode;
+
+                if (string.Equals(languageCode, twoLetterCode, StringComparison.OrdinalIgnoreCase) ||
+                    string.Equals(languageCode, threeLetterCode, StringComparison.OrdinalIgnoreCase) ||
+                    string.Equals(languageCode, fullName, StringComparison.OrdinalIgnoreCase))
+                {
+                    return languageCode;
+                }
+            }
+
+            return DefaultLanguageCode;
+        }
 
         internal void AddPluginLanguageDirectories(IEnumerable<PluginPair> plugins)
         {
@@ -68,8 +97,18 @@ private void LoadDefaultLanguage()
         public void ChangeLanguage(string languageCode)
         {
             languageCode = languageCode.NonNull();
-            Language language = GetLanguageByLanguageCode(languageCode);
-            ChangeLanguage(language);
+
+            // Get actual language if language code is system
+            var isSystem = false;
+            if (languageCode == Constant.SystemLanguageCode)
+            {
+                languageCode = SystemLanguageCode;
+                isSystem = true;
+            }
+
+            // Get language by language code and change language
+            var language = GetLanguageByLanguageCode(languageCode);
+            ChangeLanguage(language, isSystem);
         }
 
         private Language GetLanguageByLanguageCode(string languageCode)
@@ -87,11 +126,10 @@ private Language GetLanguageByLanguageCode(string languageCode)
             }
         }
 
-        public void ChangeLanguage(Language language)
+        private void ChangeLanguage(Language language, bool isSystem)
         {
             language = language.NonNull();
 
-
             RemoveOldLanguageFiles();
             if (language != AvailableLanguages.English)
             {
@@ -103,7 +141,7 @@ public void ChangeLanguage(Language language)
             CultureInfo.CurrentUICulture = CultureInfo.CurrentCulture;
 
             // Raise event after culture is set
-            Settings.Language = language.LanguageCode;
+            Settings.Language = isSystem ? Constant.SystemLanguageCode : language.LanguageCode;
             _ = Task.Run(() =>
             {
                 UpdatePluginMetadataTranslations();
@@ -167,7 +205,9 @@ private void LoadLanguage(Language language)
 
         public List<Language> LoadAvailableLanguages()
         {
-            return AvailableLanguages.GetAvailableLanguages();
+            var list = AvailableLanguages.GetAvailableLanguages();
+            list.Insert(0, new Language(Constant.SystemLanguageCode, AvailableLanguages.GetSystemTranslation(SystemLanguageCode)));
+            return list;
         }
 
         public string GetTranslation(string key)

Flow.Launcher.Infrastructure/Constant.cs

@@ -52,5 +52,7 @@ public static class Constant
         public const string SponsorPage = "https://github.com/sponsors/Flow-Launcher";
         public const string GitHub = "https://github.com/Flow-Launcher/Flow.Launcher";
         public const string Docs = "https://flowlauncher.com/docs";
+
+        public const string SystemLanguageCode = "system";
     }
 }

Flow.Launcher.Infrastructure/UserSettings/Settings.cs

@@ -13,7 +13,7 @@ namespace Flow.Launcher.Infrastructure.UserSettings
 {
     public class Settings : BaseModel, IHotkeySettings
     {
-        private string language = "en";
+        private string language = Constant.SystemLanguageCode;
         private string _theme = Constant.DefaultTheme;
         public string Hotkey { get; set; } = $"{KeyConstant.Alt} + {KeyConstant.Space}";
         public string OpenResultModifiers { get; set; } = KeyConstant.Alt;