feat: add tray menu localization using system locale (#446)

CONTRIBUTING.md

@@ -219,7 +219,7 @@ Community feedback is essential to keeping Handy the best it can be for everyone
      - How you tested the changes
      - Screenshots/videos if applicable
      - Breaking changes (if any)
-     
+
    **Remember:** PRs with community support are prioritized. If you haven't already, start a [discussion](https://github.com/cjpais/Handy/discussions) to gather feedback before or alongside your PR. It is not explicitly required to gather feedback, but it certainly helps your PR get merged faster.
 
 ### Code Style Guidelines

src-tauri/Cargo.toml

@@ -25,6 +25,8 @@ crate-type = ["staticlib", "cdylib", "rlib"]
 
 [build-dependencies]
 tauri-build = { version = "2", features = [] }
+serde_json = "1"
+serde = { version = "1", features = ["derive"] }
 
 [dependencies]
 once_cell = "1"

src-tauri/build.rs

@@ -2,9 +2,115 @@ fn main() {
     #[cfg(all(target_os = "macos", target_arch = "aarch64"))]
     build_apple_intelligence_bridge();
 
+    generate_tray_translations();
+
     tauri_build::build()
 }
 
+/// Generate tray menu translations from frontend locale files.
+///
+/// Source of truth: src/i18n/locales/*/translation.json
+/// The English "tray" section defines the struct fields.
+fn generate_tray_translations() {
+    use std::collections::BTreeMap;
+    use std::fs;
+    use std::path::Path;
+
+    let out_dir = std::env::var("OUT_DIR").unwrap();
+    let locales_dir = Path::new("../src/i18n/locales");
+
+    println!("cargo:rerun-if-changed=../src/i18n/locales");
+
+    // Collect all locale translations
+    let mut translations: BTreeMap<String, serde_json::Value> = BTreeMap::new();
+
+    for entry in fs::read_dir(locales_dir).unwrap().flatten() {
+        let path = entry.path();
+        if !path.is_dir() {
+            continue;
+        }
+
+        let lang = path.file_name().unwrap().to_str().unwrap().to_string();
+        let json_path = path.join("translation.json");
+
+        println!("cargo:rerun-if-changed={}", json_path.display());
+
+        let content = fs::read_to_string(&json_path).unwrap();
+        let parsed: serde_json::Value = serde_json::from_str(&content).unwrap();
+
+        if let Some(tray) = parsed.get("tray").cloned() {
+            translations.insert(lang, tray);
+        }
+    }
+
+    // English defines the schema
+    let english = translations.get("en").unwrap().as_object().unwrap();
+    let fields: Vec<_> = english
+        .keys()
+        .map(|k| (camel_to_snake(k), k.clone()))
+        .collect();
+
+    // Generate code
+    let mut out = String::from(
+        "// Auto-generated from src/i18n/locales/*/translation.json - do not edit\n\n",
+    );
+
+    // Struct
+    out.push_str("#[derive(Debug, Clone)]\npub struct TrayStrings {\n");
+    for (rust_field, _) in &fields {
+        out.push_str(&format!("    pub {rust_field}: String,\n"));
+    }
+    out.push_str("}\n\n");
+
+    // Static map
+    out.push_str(
+        "pub static TRANSLATIONS: Lazy<HashMap<&'static str, TrayStrings>> = Lazy::new(|| {\n",
+    );
+    out.push_str("    let mut m = HashMap::new();\n");
+
+    for (lang, tray) in &translations {
+        out.push_str(&format!("    m.insert(\"{lang}\", TrayStrings {{\n"));
+        for (rust_field, json_key) in &fields {
+            let val = tray.get(json_key).and_then(|v| v.as_str()).unwrap_or("");
+            out.push_str(&format!(
+                "        {rust_field}: \"{}\".to_string(),\n",
+                escape_string(val)
+            ));
+        }
+        out.push_str("    });\n");
+    }
+
+    out.push_str("    m\n});\n");
+
+    fs::write(Path::new(&out_dir).join("tray_translations.rs"), out).unwrap();
+
+    println!(
+        "cargo:warning=Generated tray translations: {} languages, {} fields",
+        translations.len(),
+        fields.len()
+    );
+}
+
+fn camel_to_snake(s: &str) -> String {
+    s.chars()
+        .enumerate()
+        .fold(String::new(), |mut acc, (i, c)| {
+            if c.is_uppercase() && i > 0 {
+                acc.push('_');
+            }
+            acc.push(c.to_lowercase().next().unwrap());
+            acc
+        })
+}
+
+fn escape_string(s: &str) -> String {
+    s.replace('\\', "\\\\")
+        .replace('"', "\\\"")
+        .replace('\n', "\\n")
+        .replace('\r', "\\r")
+        .replace('\t', "\\t")
+}
+
 #[cfg(all(target_os = "macos", target_arch = "aarch64"))]
 fn build_apple_intelligence_bridge() {
     use std::env;

src-tauri/src/lib.rs

@@ -14,6 +14,7 @@ mod settings;
 mod shortcut;
 mod signal_handle;
 mod tray;
+mod tray_i18n;
 mod utils;
 use specta_typescript::{BigIntExportBehavior, Typescript};
 use tauri_specta::{collect_commands, Builder};
@@ -194,7 +195,7 @@ fn initialize_core_logic(app_handle: &AppHandle) {
     app_handle.manage(tray);
 
     // Initialize tray menu with idle state
-    utils::update_tray_menu(app_handle, &utils::TrayIconState::Idle);
+    utils::update_tray_menu(app_handle, &utils::TrayIconState::Idle, None);
 
     // Get the autostart manager and configure based on user setting
     let autostart_manager = app_handle.autolaunch();

src-tauri/src/settings.rs

@@ -363,7 +363,9 @@ fn default_post_process_enabled() -> bool {
 }
 
 fn default_app_language() -> String {
-    "en".to_string()
+    tauri_plugin_os::locale()
+        .and_then(|l| l.split(['-', '_']).next().map(String::from))
+        .unwrap_or_else(|| "en".to_string())
 }
 
 fn default_post_process_provider_id() -> String {

src-tauri/src/shortcut.rs

@@ -13,6 +13,7 @@ use crate::settings::{
     self, get_settings, ClipboardHandling, LLMPrompt, OverlayPosition, PasteMethod, SoundTheme,
     APPLE_INTELLIGENCE_DEFAULT_MODEL_ID, APPLE_INTELLIGENCE_PROVIDER_ID,
 };
+use crate::tray;
 use crate::ManagedToggleState;
 
 pub fn init_shortcuts(app: &AppHandle) {
@@ -721,9 +722,12 @@ pub fn change_append_trailing_space_setting(app: AppHandle, enabled: bool) -> Re
 #[specta::specta]
 pub fn change_app_language_setting(app: AppHandle, language: String) -> Result<(), String> {
     let mut settings = settings::get_settings(&app);
-    settings.app_language = language;
+    settings.app_language = language.clone();
     settings::write_settings(&app, settings);
 
+    // Refresh the tray menu with the new language
+    tray::update_tray_menu(&app, &tray::TrayIconState::Idle, Some(&language));
+
     Ok(())
 }
 

src-tauri/src/tray.rs

@@ -1,4 +1,5 @@
 use crate::settings;
+use crate::tray_i18n::get_tray_translations;
 use tauri::image::Image;
 use tauri::menu::{Menu, MenuItem, PredefinedMenuItem};
 use tauri::tray::TrayIcon;
@@ -71,12 +72,15 @@ pub fn change_tray_icon(app: &AppHandle, icon: TrayIconState) {
     ));
 
     // Update menu based on state
-    update_tray_menu(app, &icon);
+    update_tray_menu(app, &icon, None);
 }
 
-pub fn update_tray_menu(app: &AppHandle, state: &TrayIconState) {
+pub fn update_tray_menu(app: &AppHandle, state: &TrayIconState, locale: Option<&str>) {
     let settings = settings::get_settings(app);
 
+    let locale = locale.unwrap_or(&settings.app_language);
+    let strings = get_tray_translations(Some(locale.to_string()));
+
     // Platform-specific accelerators
     #[cfg(target_os = "macos")]
     let (settings_accelerator, quit_accelerator) = (Some("Cmd+,"), Some("Cmd+Q"));
@@ -87,23 +91,29 @@ pub fn update_tray_menu(app: &AppHandle, state: &TrayIconState) {
     let version_label = format!("Handy v{}", env!("CARGO_PKG_VERSION"));
     let version_i = MenuItem::with_id(app, "version", &version_label, false, None::<&str>)
         .expect("failed to create version item");
-    let settings_i = MenuItem::with_id(app, "settings", "Settings...", true, settings_accelerator)
+    let settings_i = MenuItem::with_id(
-        .expect("failed to create settings item");
+        app,
+        "settings",
+        &strings.settings,
+        true,
+        settings_accelerator,
+    )
+    .expect("failed to create settings item");
     let check_updates_i = MenuItem::with_id(
         app,
         "check_updates",
-        "Check for Updates...",
+        &strings.check_updates,
         settings.update_checks_enabled,
         None::<&str>,
     )
     .expect("failed to create check updates item");
-    let quit_i = MenuItem::with_id(app, "quit", "Quit", true, quit_accelerator)
+    let quit_i = MenuItem::with_id(app, "quit", &strings.quit, true, quit_accelerator)
         .expect("failed to create quit item");
     let separator = || PredefinedMenuItem::separator(app).expect("failed to create separator");
 
     let menu = match state {
         TrayIconState::Recording | TrayIconState::Transcribing => {
-            let cancel_i = MenuItem::with_id(app, "cancel", "Cancel", true, None::<&str>)
+            let cancel_i = MenuItem::with_id(app, "cancel", &strings.cancel, true, None::<&str>)
                 .expect("failed to create cancel item");
             Menu::with_items(
                 app,

src-tauri/src/tray_i18n.rs

@@ -0,0 +1,36 @@
+//! Tray menu internationalization
+//!
+//! Everything is auto-generated at compile time by build.rs from the
+//! frontend locale files (src/i18n/locales/*/translation.json).
+//!
+//! The English translation.json is the single source of truth:
+//! - TrayStrings struct fields are derived from the English "tray" keys
+//! - All languages are auto-discovered from the locales directory
+//!
+//! To add a new tray menu item:
+//! 1. Add the key to en/translation.json under "tray"
+//! 2. Add translations to other locale files
+//! 3. Update tray.rs to use the new field (e.g., strings.new_field)
+
+use once_cell::sync::Lazy;
+use std::collections::HashMap;
+
+// Include the auto-generated TrayStrings struct and TRANSLATIONS static
+include!(concat!(env!("OUT_DIR"), "/tray_translations.rs"));
+
+/// Get the language code from a locale string (e.g., "en-US" -> "en")
+fn get_language_code(locale: &str) -> &str {
+    locale.split(['-', '_']).next().unwrap_or("en")
+}
+
+/// Get localized tray menu strings based on the system locale
+pub fn get_tray_translations(locale: Option<String>) -> TrayStrings {
+    let lang = locale.as_deref().map(get_language_code).unwrap_or("en");
+
+    // Try requested language, fall back to English
+    TRANSLATIONS
+        .get(lang)
+        .or_else(|| TRANSLATIONS.get("en"))
+        .cloned()
+        .expect("English translations must exist")
+}

src/i18n/locales/de/translation.json

@@ -1,4 +1,10 @@
 {
+  "tray": {
+    "settings": "Einstellungen...",
+    "checkUpdates": "Nach Updates suchen...",
+    "quit": "Beenden",
+    "cancel": "Abbrechen"
+  },
   "sidebar": {
     "general": "Allgemein",
     "advanced": "Erweitert",

src/i18n/locales/en/translation.json

@@ -1,4 +1,10 @@
 {
+  "tray": {
+    "settings": "Settings...",
+    "checkUpdates": "Check for Updates...",
+    "quit": "Quit",
+    "cancel": "Cancel"
+  },
   "sidebar": {
     "general": "General",
     "advanced": "Advanced",

src/i18n/locales/es/translation.json

@@ -1,4 +1,10 @@
 {
+  "tray": {
+    "settings": "Configuración...",
+    "checkUpdates": "Buscar actualizaciones...",
+    "quit": "Salir",
+    "cancel": "Cancelar"
+  },
   "sidebar": {
     "general": "General",
     "advanced": "Avanzado",

src/i18n/locales/fr/translation.json

@@ -1,5 +1,11 @@
 {
   "_comment": "French translation for Handy. Contribute at: https://github.com/cjpais/Handy",
+  "tray": {
+    "settings": "Paramètres...",
+    "checkUpdates": "Rechercher des mises à jour...",
+    "quit": "Quitter",
+    "cancel": "Annuler"
+  },
   "sidebar": {
     "general": "Général",
     "advanced": "Avancé",

src/i18n/locales/it/translation.json

@@ -1,4 +1,10 @@
 {
+  "tray": {
+    "settings": "Impostazioni...",
+    "checkUpdates": "Verifica aggiornamenti...",
+    "quit": "Esci",
+    "cancel": "Annulla"
+  },
   "sidebar": {
     "general": "Generale",
     "advanced": "Avanzate",

src/i18n/locales/ja/translation.json

@@ -1,4 +1,10 @@
 {
+  "tray": {
+    "settings": "設定...",
+    "checkUpdates": "アップデートを確認...",
+    "quit": "終了",
+    "cancel": "キャンセル"
+  },
   "sidebar": {
     "general": "一般",
     "advanced": "詳細設定",

src/i18n/locales/pl/translation.json

@@ -1,4 +1,10 @@
 {
+  "tray": {
+    "settings": "Ustawienia...",
+    "checkUpdates": "Sprawdź aktualizacje...",
+    "quit": "Zamknij",
+    "cancel": "Anuluj"
+  },
   "sidebar": {
     "general": "Ogólne",
     "advanced": "Zaawansowane",

src/i18n/locales/vi/translation.json

@@ -1,5 +1,11 @@
 {
   "_comment": "Vietnamese translation for Handy. Contribute at: https://github.com/cjpais/Handy",
+  "tray": {
+    "settings": "Cài đặt...",
+    "checkUpdates": "Kiểm tra cập nhật...",
+    "quit": "Thoát",
+    "cancel": "Hủy"
+  },
   "sidebar": {
     "general": "Chung",
     "advanced": "Nâng cao",

src/i18n/locales/zh/translation.json

@@ -1,4 +1,10 @@
 {
+  "tray": {
+    "settings": "设置...",
+    "checkUpdates": "检查更新...",
+    "quit": "退出",
+    "cancel": "取消"
+  },
   "sidebar": {
     "general": "通用",
     "advanced": "高级",