W: interface language — German, French, Spanish, Japanese menus and panels

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

ROADMAP.md

@@ -94,6 +94,7 @@ DesignCraft aims at full Adobe InDesign parity — and to be better: faster, ope
 - Transparency flattener (`file.exportPdf {flatten: high|medium|low|ppi}`, Edit ▸ Transparency Flattener Presets): spreads with transparency are rasterised per page in the exported PDF. It doesn't yet keep text and vectors outside transparent areas.
 - Video and sound (place .mp4/.mov/.webm/.mp3/.wav…, `media.options/get`, Media panel): media frames show a poster or placeholder on screen, in print and in PDF, and export as HTML5 `<video>`/`<audio>` in EPUB. No in-app playback or PDF rich media.
 - Right-to-left text (World-Ready basics): right-to-left runs are shaped right to left, lines are reordered by the Unicode Bidirectional Algorithm (matched against the reference implementation), Paragraph Direction (`type.para {direction}`, Paragraph panel, IDML ParagraphDirection, EPUB `dir`). Kashida justification, caret movement in visual order and digit substitution aren't there yet.
+- Interface language (Edit ▸ Interface Language, `app.language`): German, French, Spanish and Japanese menu titles, common menu items and panel names (our own translations); dialogs and the rest of the UI stay English.
 - Drag and drop text editing: drag selected text to move it (Alt copies) with its formatting (`text.release`).
 - Image Import Options: place any page of a multi-page PDF (`file.place {pdfPage}`; the app asks which page), shown on screen and embedded as that page in PDF export.
 - Define Lists: named numbered lists that continue across stories in page order (`list.define`, paragraph `listName` / `startAt`), round-tripped through IDML; `null` in `type.para` / `type.char` now removes an override.

apps/designcraft/src/native_menu.rs

@@ -56,7 +56,7 @@ impl NativeMenu {
         items.insert("dc-discord".into(), ("help.discord".into(), serde_json::Value::Null, Handle::Plain(discord)));
         let _ = menu.append(&app_menu);
         for (title, entries) in menus::menu_tree() {
-            let sub = Submenu::new(title, true);
+            let sub = Submenu::new(designcraft_ui_egui::i18n::tr(&app.ui.language, title), true);
             build(app, &sub, &entries, &mut items, &mut counter);
             let _ = menu.append(&sub);
         }
@@ -103,7 +103,7 @@ fn build(app: &DesignApp, parent: &Submenu, entries: &[Item], items: &mut HashMa
                 let _ = parent.append(&PredefinedMenuItem::separator());
             }
             Item::Sub(label, children) => {
-                let sub = Submenu::new(label, true);
+                let sub = Submenu::new(designcraft_ui_egui::i18n::tr(&app.ui.language, label), true);
                 build(app, &sub, children, items, counter);
                 let _ = parent.append(&sub);
             }
@@ -111,6 +111,7 @@ fn build(app: &DesignApp, parent: &Submenu, entries: &[Item], items: &mut HashMa
                 *counter += 1;
                 let mid = format!("dc{counter}");
                 let sc = if params.is_null() { shortcut.and_then(accel) } else { None };
+                let label = designcraft_ui_egui::i18n::tr(&app.ui.language, label);
                 let handle = if menus::checked(app, id, params).is_some() {
                     let c = CheckMenuItem::with_id(mid.clone(), label, true, false, sc);
                     let _ = parent.append(&c);

crates/ui-egui/src/dock.rs

@@ -95,7 +95,7 @@ pub fn show(app: &mut DesignApp, ui: &mut egui::Ui) {
             for (id, label, icon) in ICON_PANELS {
                 let open = app.ui.open_panel.as_deref() == Some(*id);
                 let floats = app.ui.floating.iter().any(|(p, _)| p == id);
-                if icons::button(ui, icon, 28.0, open || floats, label).clicked() {
+                if icons::button(ui, icon, 28.0, open || floats, &crate::i18n::tr(&app.ui.language, label)).clicked() {
                     if floats {
                         ui.ctx().move_to_top(egui::LayerId::new(egui::Order::Middle, egui::Id::new(("floating_panel", *id))));
                     } else {
@@ -120,7 +120,7 @@ fn dock_header(ui: &mut egui::Ui, t: &Tokens, chevron: &str) {
 pub fn flyout(app: &mut DesignApp, ctx: &egui::Context) {
     let Some(id) = app.ui.open_panel.clone() else { return };
     let t = Tokens::get(ctx);
-    let label = ICON_PANELS.iter().find(|p| p.0 == id).map(|p| p.1).unwrap_or("Panel");
+    let label = crate::i18n::tr(&app.ui.language, ICON_PANELS.iter().find(|p| p.0 == id).map(|p| p.1).unwrap_or("Panel")).into_owned();
     let screen = ctx.content_rect();
     let dock_w = if app.ui.dock_expanded { ctx.memory(|m| m.area_rect(egui::Id::new("dock")).map(|r| r.width())).unwrap_or(280.0) } else { 0.0 };
     let pos = egui::pos2(screen.max.x - 37.0 - dock_w - 262.0, 120.0);
@@ -212,10 +212,10 @@ pub fn dock_panel(app: &mut DesignApp, id: &str) {
 pub fn floating(app: &mut DesignApp, ctx: &egui::Context) {
     let t = Tokens::get(ctx);
     for (id, at) in app.ui.floating.clone() {
-        let label = ICON_PANELS.iter().find(|p| p.0 == id).map(|p| p.1).unwrap_or("Panel");
+        let label = crate::i18n::tr(&app.ui.language, ICON_PANELS.iter().find(|p| p.0 == id).map(|p| p.1).unwrap_or("Panel")).into_owned();
         let mut open = true;
         let mut dock = false;
-        let r = egui::Window::new(label)
+        let r = egui::Window::new(label.clone())
             .id(egui::Id::new(("floating_panel", &id)))
             .title_bar(false)
             .default_pos(egui::pos2(at[0], at[1]))

crates/ui-egui/src/i18n.rs

@@ -0,0 +1,164 @@
+//! Interface language (Edit › Interface Language): translations of menu titles, the most used
+//! menu items and panel names. Untranslated strings stay English. The translations are our own.
+
+/// Supported interface languages: (code, name in that language).
+pub const LANGUAGES: &[(&str, &str)] = &[("", "English"), ("de", "Deutsch"), ("fr", "Français"), ("es", "Español"), ("ja", "日本語")];
+
+/// English → [German, French, Spanish, Japanese].
+const TABLE: &[(&str, [&str; 4])] = &[
+    // Menus.
+    ("File", ["Datei", "Fichier", "Archivo", "ファイル"]),
+    ("Edit", ["Bearbeiten", "Édition", "Edición", "編集"]),
+    ("Layout", ["Layout", "Page", "Maquetación", "レイアウト"]),
+    ("Type", ["Schrift", "Texte", "Texto", "書式"]),
+    ("Object", ["Objekt", "Objet", "Objeto", "オブジェクト"]),
+    ("Table", ["Tabelle", "Tableau", "Tabla", "表"]),
+    ("View", ["Ansicht", "Affichage", "Ver", "表示"]),
+    ("Window", ["Fenster", "Fenêtre", "Ventana", "ウィンドウ"]),
+    ("Help", ["Hilfe", "Aide", "Ayuda", "ヘルプ"]),
+    // File.
+    ("New", ["Neu", "Nouveau", "Nuevo", "新規"]),
+    ("New Document…", ["Neues Dokument …", "Nouveau document…", "Nuevo documento…", "新規ドキュメント…"]),
+    ("Open…", ["Öffnen …", "Ouvrir…", "Abrir…", "開く…"]),
+    ("Close", ["Schließen", "Fermer", "Cerrar", "閉じる"]),
+    ("Save", ["Speichern", "Enregistrer", "Guardar", "保存"]),
+    ("Save As…", ["Speichern unter …", "Enregistrer sous…", "Guardar como…", "別名で保存…"]),
+    ("Save a Copy…", ["Kopie speichern …", "Enregistrer une copie…", "Guardar una copia…", "コピーを保存…"]),
+    ("Revert", ["Zurück zur letzten Version", "Version précédente", "Volver a la versión guardada", "復帰"]),
+    ("Place…", ["Platzieren …", "Importer…", "Colocar…", "配置…"]),
+    ("Export PDF…", ["PDF exportieren …", "Exporter en PDF…", "Exportar PDF…", "PDF を書き出し…"]),
+    ("Print…", ["Drucken …", "Imprimer…", "Imprimir…", "プリント…"]),
+    ("Document Setup…", ["Dokument einrichten …", "Format de document…", "Ajustar documento…", "ドキュメント設定…"]),
+    ("Package…", ["Verpacken …", "Assembler…", "Empaquetar…", "パッケージ…"]),
+    // Edit.
+    ("Undo", ["Rückgängig", "Annuler", "Deshacer", "取り消し"]),
+    ("Redo", ["Wiederholen", "Rétablir", "Rehacer", "やり直し"]),
+    ("Cut", ["Ausschneiden", "Couper", "Cortar", "カット"]),
+    ("Copy", ["Kopieren", "Copier", "Copiar", "コピー"]),
+    ("Paste", ["Einfügen", "Coller", "Pegar", "ペースト"]),
+    ("Clear", ["Löschen", "Effacer", "Borrar", "消去"]),
+    ("Duplicate", ["Duplizieren", "Dupliquer", "Duplicar", "複製"]),
+    ("Select All", ["Alles auswählen", "Tout sélectionner", "Seleccionar todo", "すべてを選択"]),
+    ("Deselect All", ["Auswahl aufheben", "Tout désélectionner", "Deseleccionar todo", "すべての選択を解除"]),
+    ("Find/Change…", ["Suchen/Ersetzen …", "Rechercher/Remplacer…", "Buscar/Cambiar…", "検索と置換…"]),
+    ("Check Spelling…", ["Rechtschreibprüfung …", "Vérifier l'orthographe…", "Revisar ortografía…", "スペルチェック…"]),
+    ("Preferences…", ["Voreinstellungen …", "Préférences…", "Preferencias…", "環境設定…"]),
+    ("Keyboard Shortcuts…", ["Tastaturbefehle …", "Raccourcis clavier…", "Métodos abreviados de teclado…", "キーボードショートカット…"]),
+    ("Interface Language", ["Sprache der Oberfläche", "Langue de l'interface", "Idioma de la interfaz", "インターフェイスの言語"]),
+    // Layout.
+    ("Pages", ["Seiten", "Pages", "Páginas", "ページ"]),
+    ("Margins and Columns…", ["Ränder und Spalten …", "Marges et colonnes…", "Márgenes y columnas…", "マージン・段組…"]),
+    ("Create Guides…", ["Hilfslinien erstellen …", "Créer des repères…", "Crear guías…", "ガイドを作成…"]),
+    (
+        "Numbering & Section Options…",
+        [
+            "Nummerierungs- und Abschnittsoptionen …",
+            "Options de numérotation et de section…",
+            "Opciones de numeración y sección…",
+            "ノンブルとセクション設定…",
+        ],
+    ),
+    // Type.
+    ("Font", ["Schriftart", "Police", "Fuente", "フォント"]),
+    ("Size", ["Schriftgrad", "Corps", "Tamaño", "サイズ"]),
+    ("Character", ["Zeichen", "Caractère", "Carácter", "文字"]),
+    ("Paragraph", ["Absatz", "Paragraphe", "Párrafo", "段落"]),
+    ("Tabs", ["Tabulatoren", "Tabulations", "Tabulaciones", "タブ"]),
+    ("Glyphs", ["Glyphen", "Glyphes", "Glifos", "字形"]),
+    ("Story", ["Textabschnitt", "Article", "Artículo", "ストーリー"]),
+    ("Character Styles", ["Zeichenformate", "Styles de caractère", "Estilos de carácter", "文字スタイル"]),
+    ("Paragraph Styles", ["Absatzformate", "Styles de paragraphe", "Estilos de párrafo", "段落スタイル"]),
+    ("Create Outlines", ["In Pfade umwandeln", "Vectoriser", "Crear contornos", "アウトラインを作成"]),
+    ("Show Hidden Characters", ["Verborgene Zeichen einblenden", "Afficher les caractères masqués", "Mostrar caracteres ocultos", "制御文字を表示"]),
+    // Object.
+    ("Transform", ["Transformieren", "Transformation", "Transformar", "変形"]),
+    ("Arrange", ["Anordnen", "Disposition", "Organizar", "重ね順"]),
+    ("Group", ["Gruppieren", "Grouper", "Agrupar", "グループ"]),
+    ("Ungroup", ["Gruppierung aufheben", "Dissocier", "Desagrupar", "グループ解除"]),
+    ("Lock", ["Sperren", "Verrouiller", "Bloquear", "ロック"]),
+    ("Hide", ["Ausblenden", "Masquer", "Ocultar", "隠す"]),
+    ("Effects", ["Effekte", "Effets", "Efectos", "効果"]),
+    ("Fitting", ["Anpassen", "Ajustement", "Encaje", "オブジェクトサイズの調整"]),
+    ("Text Frame Options…", ["Textrahmenoptionen …", "Options de bloc de texte…", "Opciones de marco de texto…", "テキストフレーム設定…"]),
+    // Table.
+    ("Insert Table…", ["Tabelle einfügen …", "Insérer un tableau…", "Insertar tabla…", "表を挿入…"]),
+    ("Merge Cells", ["Zellen verbinden", "Fusionner les cellules", "Combinar celdas", "セルを結合"]),
+    ("Unmerge Cells", ["Zellverbindung aufheben", "Annuler la fusion des cellules", "Separar celdas", "セルの結合解除"]),
+    ("Insert", ["Einfügen", "Insérer", "Insertar", "挿入"]),
+    ("Delete", ["Löschen", "Supprimer", "Eliminar", "削除"]),
+    // View.
+    ("Zoom In", ["Einzoomen", "Zoom avant", "Acercar", "ズームイン"]),
+    ("Zoom Out", ["Auszoomen", "Zoom arrière", "Alejar", "ズームアウト"]),
+    ("Fit Page in Window", ["Seite in Fenster einpassen", "Page entière", "Encajar página en ventana", "ページ全体"]),
+    ("Fit Spread in Window", ["Druckbogen in Fenster einpassen", "Planche entière", "Encajar pliego en ventana", "スプレッド全体"]),
+    ("Actual Size", ["Originalgröße", "Taille réelle", "Tamaño real", "100%"]),
+    ("Screen Mode", ["Bildschirmmodus", "Mode d'affichage", "Modo de pantalla", "スクリーンモード"]),
+    ("Grids & Guides", ["Raster und Hilfslinien", "Grilles et repères", "Cuadrículas y guías", "グリッドとガイド"]),
+    ("Show Rulers", ["Lineale einblenden", "Afficher les règles", "Mostrar reglas", "定規を表示"]),
+    // Window and panels.
+    ("Properties", ["Eigenschaften", "Propriétés", "Propiedades", "プロパティ"]),
+    ("Layers", ["Ebenen", "Calques", "Capas", "レイヤー"]),
+    ("Links", ["Verknüpfungen", "Liens", "Vínculos", "リンク"]),
+    ("Swatches", ["Farbfelder", "Nuancier", "Muestras", "スウォッチ"]),
+    ("Color", ["Farbe", "Couleur", "Color", "カラー"]),
+    ("Stroke", ["Kontur", "Contour", "Trazo", "線"]),
+    ("Gradient", ["Verlauf", "Dégradé", "Degradado", "グラデーション"]),
+    ("Align", ["Ausrichten", "Alignement", "Alinear", "整列"]),
+    ("Pathfinder", ["Pathfinder", "Pathfinder", "Buscatrazos", "パスファインダー"]),
+    ("Info", ["Info", "Informations", "Información", "情報"]),
+    ("Library", ["Bibliothek", "Bibliothèque", "Biblioteca", "ライブラリ"]),
+    ("Book", ["Buch", "Livre", "Libro", "ブック"]),
+    ("Index", ["Index", "Index", "Índice", "索引"]),
+    ("Hyperlinks", ["Hyperlinks", "Hyperliens", "Hipervínculos", "ハイパーリンク"]),
+    ("Bookmarks", ["Lesezeichen", "Signets", "Marcadores", "ブックマーク"]),
+    ("Articles", ["Artikel", "Articles", "Artículos", "アーティクル"]),
+    ("Tags", ["Tags", "Balises", "Etiquetas", "タグ"]),
+    ("Media", ["Medien", "Média", "Medios", "メディア"]),
+    ("Object States", ["Objektstatus", "États d'objet", "Estados de objeto", "オブジェクトステート"]),
+    ("Buttons and Forms", ["Schaltflächen und Formulare", "Boutons et formulaires", "Botones y formularios", "ボタンとフォーム"]),
+    ("Liquid Layout", ["Flüssiges Layout", "Mise en page liquide", "Maquetación líquida", "リキッドレイアウト"]),
+    ("Workspace", ["Arbeitsbereich", "Espace de travail", "Espacio de trabajo", "ワークスペース"]),
+    ("Split Window", ["Fenster teilen", "Fractionner la fenêtre", "Dividir ventana", "ウィンドウを分割"]),
+    ("New Window", ["Neues Fenster", "Nouvelle fenêtre", "Nueva ventana", "新規ウィンドウ"]),
+    (
+        "Show All Menu Items",
+        ["Alle Menüelemente anzeigen", "Afficher toutes les commandes", "Mostrar todos los elementos de menú", "すべてのメニュー項目を表示"],
+    ),
+];
+
+fn column(lang: &str) -> Option<usize> {
+    match lang {
+        "de" => Some(0),
+        "fr" => Some(1),
+        "es" => Some(2),
+        "ja" => Some(3),
+        _ => None,
+    }
+}
+
+/// `s` in `lang` (English, or the string itself, when there's no translation).
+pub fn tr<'a>(lang: &str, s: &'a str) -> std::borrow::Cow<'a, str> {
+    let Some(c) = column(lang) else { return s.into() };
+    match TABLE.iter().find(|(en, _)| *en == s) {
+        Some((_, t)) => t[c].to_string().into(),
+        None => s.into(),
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn translates_known_strings_and_keeps_the_rest() {
+        assert_eq!(tr("de", "File"), "Datei");
+        assert_eq!(tr("ja", "Swatches"), "スウォッチ");
+        assert_eq!(tr("fr", "Something new"), "Something new");
+        assert_eq!(tr("", "File"), "File");
+        // Every row is unique and complete.
+        for (i, (en, t)) in TABLE.iter().enumerate() {
+            assert!(TABLE[..i].iter().all(|(e, _)| e != en), "duplicate {en}");
+            assert!(t.iter().all(|x| !x.is_empty()), "{en}");
+        }
+    }
+}

crates/ui-egui/src/lib.rs

@@ -11,6 +11,7 @@ pub mod chrome;
 pub mod control;
 pub mod dialogs;
 pub mod dock;
+pub mod i18n;
 pub mod icons;
 pub mod menus;
 pub mod panels;
@@ -102,6 +103,8 @@ pub struct UiState {
     /// Edit › Menus: hidden menu items (`menu/label`), and Show Full Menus.
     pub hidden_menu_items: Vec<String>,
     pub show_full_menus: bool,
+    /// Edit › Interface Language: "" (English), "de", "fr", "es" or "ja".
+    pub language: String,
     /// Edit › Transparency Flattener Presets: "" (none), "high", "medium" or "low" for PDF export.
     pub flattener: String,
     /// View › Separations Preview: a process plate (0–3) and/or an ink limit (total, 0–4).
@@ -171,6 +174,7 @@ impl Default for UiState {
             tagged_frames: false,
             hidden_menu_items: Vec::new(),
             show_full_menus: false,
+            language: String::new(),
             flattener: String::new(),
             separation: None,
             ink_limit: None,

crates/ui-egui/src/menus.rs

@@ -26,6 +26,7 @@ pub const UI_COMMANDS: &[(&str, &str, Option<&str>, &str)] = &[
     ("app.fittingOptions", "Frame Fitting Options…", None, "{} — the dialog for object.fittingOptions"),
     ("app.menus", "Menus…", None, "{} — show or hide menu items"),
     ("window.hideMenuItem", "Hide Menu Item", None, "{item: \"Menu/Label\", hidden?: bool}"),
+    ("app.language", "Interface Language", None, "{lang: \"\"|de|fr|es|ja} — menus and panel names (the macOS menu bar follows on the next launch)"),
     (
         "app.flattener",
         "Transparency Flattener Presets",
@@ -176,6 +177,13 @@ pub const MENUS: &[(&str, &[&str])] = &[
             "cmd:edit.transparencyBlendSpace|Document RGB|{\"space\": \"rgb\"}",
             "cmd:edit.transparencyBlendSpace|Document CMYK|{\"space\": \"cmyk\"}",
             "<",
+            ">Interface Language",
+            "ui:app.language|English|{\"lang\": \"\"}",
+            "ui:app.language|Deutsch|{\"lang\": \"de\"}",
+            "ui:app.language|Français|{\"lang\": \"fr\"}",
+            "ui:app.language|Español|{\"lang\": \"es\"}",
+            "ui:app.language|日本語|{\"lang\": \"ja\"}",
+            "<",
             ">Transparency Flattener Presets",
             "ui:app.flattener|None (keep transparency)|{\"preset\": \"\"}",
             "ui:app.flattener|High Resolution|{\"preset\": \"high\"}",
@@ -703,6 +711,14 @@ pub fn run_ui(app: &mut DesignApp, id: &str, p: &Value) -> Option<Result<Value,
                 None => Ok(Value::Null),
             }
         }
+        "app.language" => {
+            let v = p.get("lang").and_then(Value::as_str).unwrap_or("");
+            if !crate::i18n::LANGUAGES.iter().any(|(c, _)| *c == v) {
+                return Some(Err(format!("unknown language `{v}`")));
+            }
+            app.ui.language = v.to_string();
+            Ok(json!(v))
+        }
         "app.flattener" => {
             let v = p.get("preset").and_then(Value::as_str).unwrap_or("");
             if !["", "high", "medium", "low"].contains(&v) {
@@ -1413,6 +1429,7 @@ pub fn checked(app: &DesignApp, id: &str, params: &Value) -> Option<bool> {
         "changes.track" => app.session.active().is_some_and(|d| d.doc.settings.track_changes),
         "window.controlBar" => app.ui.control_bar,
         "window.split" => app.split,
+        "app.language" => app.ui.language == params.get("lang").and_then(Value::as_str).unwrap_or(""),
         "app.flattener" => app.ui.flattener == params.get("preset").and_then(Value::as_str).unwrap_or(""),
         "window.taskBar" => app.ui.task_bar,
         "window.toolsDoubleColumn" => app.ui.tools_double_column,
@@ -1460,13 +1477,14 @@ pub fn activate(app: &mut DesignApp, id: &str, params: &Value) {
 
 /// The menu bar contents (inside the app bar; macOS uses the native menu instead).
 pub fn menu_bar(app: &mut DesignApp, ui: &mut egui::Ui) {
+    let lang = app.ui.language.clone();
     for (menu, entries) in menu_tree() {
-        ui.menu_button(menu, |ui| {
+        ui.menu_button(crate::i18n::tr(&lang, menu), |ui| {
             ui.set_min_width(240.0);
             let hidden = menu_items(app, ui, &entries, menu);
             if hidden > 0 && !app.ui.show_full_menus {
                 ui.separator();
-                if ui.button("Show All Menu Items").clicked() {
+                if ui.button(crate::i18n::tr(&lang, "Show All Menu Items")).clicked() {
                     app.ui.show_full_menus = true;
                 }
             }
@@ -1489,16 +1507,18 @@ fn menu_items(app: &mut DesignApp, ui: &mut egui::Ui, items: &[Item], path: &str
             }
             Item::Sub(name, children) => {
                 let sub = format!("{path}/{name}");
-                ui.menu_button(name, |ui| {
+                let shown = crate::i18n::tr(&app.ui.language, name).into_owned();
+                ui.menu_button(shown, |ui| {
                     hidden += menu_items(app, ui, children, &sub);
                 });
             }
             Item::Cmd { label, .. } if !app.ui.show_full_menus && app.ui.hidden_menu_items.contains(&menu_key(path, label)) => hidden += 1,
             Item::Cmd { label, id, params, shortcut: _ } => {
+                let label = crate::i18n::tr(&app.ui.language, label);
                 let text = match checked(app, id, params) {
                     Some(true) => format!("✓ {label}"),
                     Some(false) => format!("   {label}"),
-                    None => label.clone(),
+                    None => label.into_owned(),
                 };
                 let mut b = egui::Button::new(text);
                 if let Some(sc) = shortcut_of(app, id) {
@@ -1777,6 +1797,20 @@ mod tests {
         frame(&mut app);
     }
 
+    #[test]
+    fn interface_language_switches_and_validates() {
+        let mut app = crate::DesignApp::new(designcraft_engine::Session::new(), crate::Services::default());
+        run_ui(&mut app, "app.language", &json!({"lang": "de"})).unwrap().unwrap();
+        assert_eq!(app.ui.language, "de");
+        assert_eq!(checked(&app, "app.language", &json!({"lang": "de"})), Some(true));
+        assert_eq!(crate::i18n::tr(&app.ui.language, "Window"), "Fenster");
+        assert!(run_ui(&mut app, "app.language", &json!({"lang": "xx"})).unwrap().is_err());
+        // Every menu title has a translation (Japanese never matches the English).
+        for (title, _) in menu_tree() {
+            assert_ne!(crate::i18n::tr("ja", title), title, "{title}");
+        }
+    }
+
     #[test]
     fn panels_float_and_dock() {
         let mut app = crate::DesignApp::new(designcraft_engine::Session::new(), crate::Services::default());

docs/parity.md

@@ -11,11 +11,11 @@ Each row of the InDesign feature catalogue is scored **D** (done), **P** (partia
 |---|---|---|---|---|---|
 | P0 | 102 | 99 | 3 | 0 | 99% |
 | P1 | 97 | 92 | 5 | 0 | 97% |
-| P2 | 76 | 40 | 28 | 8 | 71% |
+| P2 | 76 | 40 | 29 | 7 | 72% |
 
 | Area | Parity |
 |---|---|
-| Application shell & workspace | 91% |
+| Application shell & workspace | 92% |
 | Documents, pages, spreads | 94% |
 | Layers | 95% |
 | Frames, shapes & paths | 100% |
@@ -56,7 +56,7 @@ Open P0 items: Preferences, Vector/page formats (PDF/AI/SVG/EPS place), Export t
 | Application shell & workspace | Show Full Menus | P2 | D |
 | Application shell & workspace | Recovery / autosave | P0 | D |
 | Application shell & workspace | Preferences | P0 | P |
-| Application shell & workspace | Localization | P2 | M |
+| Application shell & workspace | Localization | P2 | P |
 | Application shell & workspace | Scripting (own API: commands, scripts, MCP) | P2 | D |
 | Documents, pages, spreads | New Document dialog | P0 | D |
 | Documents, pages, spreads | Document Setup | P0 | D |