i18n: make the GUI translatable and add a Simplified Chinese interface

.github/workflows/build.yml

@@ -28,6 +28,9 @@ jobs:
       - name: Check coverage matrix is in sync
         run: python3 tools/coverage_matrix.py --check
 
+      - name: Check translation catalogues are complete
+        run: python3 tools/check-translations.py
+
       # Lua 5.3 is vendored under third_party/lua and built by CMake, so no
       # upstream checkout is needed — the repo is self-contained.
       - name: Install apt dependencies
@@ -51,6 +54,8 @@ jobs:
             qemu-system-arm \
             mono-runtime-sgen mono-mcs libmonosgen-2.0-1 \
             qt6-base-dev \
+            qt6-tools-dev \
+            qt6-l10n-tools \
             libcapstone-dev \
             zlib1g-dev \
             libdw-dev \

.github/workflows/release.yml

@@ -59,6 +59,8 @@ jobs:
             qemu-system-arm \
             mono-runtime-sgen mono-mcs libmonosgen-2.0-1 \
             qt6-base-dev \
+            qt6-tools-dev \
+            qt6-l10n-tools \
             libcapstone-dev \
             zlib1g-dev \
             libdw-dev \

CHANGELOG.md

@@ -36,6 +36,14 @@ reimplementation of Cheat Engine).
   jump range of the hook. The Auto Assembler now says so instead of reporting
   an out-of-range operand or a bare allocation failure. Wine 11.0, legacy Wine
   and Proton are unaffected.
+- The GUI is translated with Qt's translation tools and ships with a Simplified
+  Chinese (zh_CN) catalogue: every menu, dialog, label and message is marked for
+  translation, Settings > Language offers follow the system / English / 简体中文,
+  and the catalogue is embedded in the binaries. A `.qm` file beside the
+  executable or under `translations/` overrides the built-in copy. English
+  remains the source language, so nothing changes without a catalogue. The
+  terminal (`cescan`), messages from the Qt-free core library, and the tutorial
+  games stay in English. See `docs/I18N.md`.
 
 ---
 

CMakeLists.txt

@@ -368,6 +368,7 @@ if(Qt6_FOUND)
         gui/resources.qrc
         gui/main.cpp
         gui/theme.cpp
+        gui/i18n.cpp
         gui/mainwindow.cpp
         gui/processlistdialog.cpp
         gui/gdbconnectiondialog.cpp
@@ -633,6 +634,28 @@ if(Qt6_FOUND)
     else()
         message(STATUS "Global hotkeys: Wayland portal backend disabled (Qt6::DBus not found)")
     endif()
+
+    # ── Translations ──
+    # English is the source language; the catalogue below is embedded in the
+    # binary. A .qm dropped next to the executable or under translations/
+    # overrides the built-in copy, so a translation can be tried without a
+    # rebuild. LinguistTools comes from qt6-tools-dev and qt6-l10n-tools on
+    # Debian/Ubuntu; without them the build still works, in English.
+    find_package(Qt6 COMPONENTS LinguistTools QUIET)
+    if(Qt6LinguistTools_FOUND)
+        # The include path lets lupdate resolve the headers, so member tr()
+        # calls get the namespaced context moc uses at runtime
+        # (ce::gui::MainWindow, not MainWindow).
+        qt_add_translations(cheatengine TS_FILES translations/cheatengine_zh_CN.ts
+            INCLUDE_DIRECTORIES ${CMAKE_SOURCE_DIR})
+        if(TARGET gui_lifecycle_smoke)
+            # The screenshots run honours CE_LANG, so the .qm has to exist.
+            add_dependencies(gui_lifecycle_smoke cheatengine_lrelease)
+        endif()
+        message(STATUS "Translations: enabled (zh_CN)")
+    else()
+        message(STATUS "Translations: disabled (Qt6 LinguistTools not found)")
+    endif()
 else()
     message(STATUS "Qt6 not found — skipping GUI build")
 endif()

README.md

@@ -100,6 +100,7 @@ See [AI agents](docs/MCP.md).
 
 - [Lua scripting reference](docs/SCRIPTING.md) and [examples](examples)
 - [Supported targets and features](docs/COMPATIBILITY.md)
+- [Translating the interface](docs/I18N.md)
 - [Changelog](CHANGELOG.md)
 - [Contributing](CONTRIBUTING.md)
 

docs/I18N.md

@@ -0,0 +1,103 @@
+# Translating the interface
+
+The GUI is built with Qt6, so its interface can be translated with Qt's own
+translation tools. English is the source language: the strings in the code are
+the English text, and a catalogue adds other languages. Without a catalogue the
+program looks exactly as it always has.
+
+Simplified Chinese (zh_CN) ships in `translations/cheatengine_zh_CN.ts` and is
+compiled into the binary. The catalogue is embedded as a resource, so the `.deb`
+and the AppImage carry it without extra files.
+
+## Choosing the language
+
+- With no setting, the interface follows the desktop locale (`LANG`, e.g.
+  `zh_CN.UTF-8`).
+- **Settings > Language** overrides it: follow the system, English, or 简体中文.
+  The choice is stored in `ui/language`; when it changes, Cheat Engine offers to
+  restart itself so the new language takes effect right away.
+- A `.qm` file dropped beside the executable, or under `translations/`, wins over
+  the built-in catalogue. That lets a translator try a file without a rebuild.
+  This does not apply to a privileged install: the `.deb` gives `cheatengine`
+  `cap_sys_ptrace`, which makes it a secure-exec process, and such a binary only
+  uses the built-in catalogue so nobody can replace the strings of its
+  confirmation dialogs. The Qt standard translations are still read from the
+  system location.
+
+The Qt standard strings (stock dialog buttons, native file dialogs) come from
+Qt's own translations. Linux distributions package those separately
+(`qt6-translations-l10n` on Debian/Ubuntu, `qttranslations` on Fedora); install
+it for translated standard buttons. The application's own strings work either
+way.
+
+## What is translated
+
+Everything the GUI shows: menus, actions, window and tab titles, labels,
+buttons, check boxes, tooltips, placeholders, table headers, dialogs, message
+boxes, file dialog filters, and the empty-state hints. Numbers, addresses and
+values are formatted as before.
+
+Not covered, deliberately:
+
+- `cescan` and other terminal output, which has no interface language.
+- Messages produced by the Qt-free `cecore` library (scanner, debugger and
+  process errors) are shown as they are, in English.
+- The tutorial games (`cetutorial`, `cegtutorial`) keep their English text: the
+  tutorial steps describe exact code and instructions in the game.
+- Text stored in cheat tables and Lua scripts is user data, never translated.
+- Lua and agent tool names are part of the scripting API, never translated.
+
+## For translators
+
+Install the Qt translation tools: `qt6-tools-dev` and `qt6-l10n-tools` on
+Debian/Ubuntu. CMake then also builds the catalogues; without them the GUI is
+built in English and a status line says so.
+
+Refresh the catalogue from the sources:
+
+```bash
+cmake --build build --target update_translations
+```
+
+That runs `lupdate` over the GUI sources and merges new strings into the `.ts`
+files, keeping existing translations. Translate with Qt Linguist:
+
+```bash
+linguist translations/cheatengine_zh_CN.ts
+```
+
+or with any editor: the file is plain XML. `cmake --build build` compiles the
+catalogue with `lrelease`.
+
+Add a language:
+
+1. Create `translations/cheatengine_<locale>.ts`, e.g. `cheatengine_de.ts`
+   (`lupdate` knows the language from the file name).
+2. Add it to the `qt_add_translations` call in `CMakeLists.txt`.
+3. Add the language to `SettingsDialog::buildLanguagePage` so it can be picked.
+4. Update this file and the desktop file / AppStream metadata if the release
+   notes should mention it.
+
+Notes for a good translation:
+
+- Keep `%1`, `%2` and `%n` placeholders exactly as they are.
+- Keep HTML tags, URLs, and product names (`Cheat Engine`, `Lua`, `ceserver`,
+  `GDB`, `QEMU`, `Mono`) as they are.
+- Menu items that open a window end in `...`; keep the three dots.
+- Top-level menus carry a `&` mnemonic; use `文件(&F)` style.
+- The screenshot review can render another language; it reads `CE_LANG`:
+
+  ```bash
+  CE_LANG=zh_CN QT_QPA_PLATFORM=offscreen ./build/gui_lifecycle_smoke \
+      --screenshots build/i18n-screenshots
+  ```
+
+  The review finds windows and menu items by their English source text, so it
+  still drives the UI, while every capture is rendered in the chosen language.
+  `CE_LANG` is a hook of the screenshot mode only: the other smoke tests
+  compare English status text, so they are not meant to run with a catalogue
+  loaded.
+
+  The Qt standard translations are read from the system location
+  (`QLibraryInfo::TranslationsPath`), so install the desktop's Qt translation
+  package when the stock dialog buttons should be translated too.

docs/PROGRESS.md

@@ -59,6 +59,25 @@ example owned by root after a `sudo -E` run), scans fell back to `/tmp`, which
 is RAM-backed on many desktops, so a large scan really did fill it. The
 fallback is now the disk-backed `/var/tmp`.
 
+## Simplified Chinese interface and a translation pipeline: 12 November 2026
+
+The GUI is fully translatable and ships with a Simplified Chinese (zh_CN)
+catalogue. Every user-visible string in `gui/` is wrapped in `tr()` (or
+`QCoreApplication::translate` where there is no class context), Settings has a
+new Language page (follow the system, English, 简体中文), and the catalogue is
+embedded in the binary so the `.deb` and the AppImage carry it. A `.qm` dropped
+beside the executable or under `translations/` overrides the built-in copy, so a
+translation can be tested without rebuilding; the loader moved into
+`gui/i18n.cpp` so the screenshot smoke can use it too.
+
+The catalogue is generated with Qt's `lupdate`/`lrelease`; CI installs
+`qt6-tools-dev` and `qt6-l10n-tools` so the release build compiles it. English
+stays the source language, so with no catalogue the interface is unchanged.
+Deliberately out of scope: `cescan` terminal output, messages from the Qt-free
+`cecore` library, and the tutorial games, which quote exact code and step text.
+`docs/I18N.md` documents the workflow for translators; the screenshot review can
+render another language with `CE_LANG=zh_CN`.
+
 ## GUI polish from a full screenshot review: 13 October 2026
 
 `gui_lifecycle_smoke --screenshots DIR` now renders about 180 PNGs: every

gui/advancedoptions.cpp

@@ -16,22 +16,22 @@ namespace ce::gui {
 
 AdvancedOptionsWindow::AdvancedOptionsWindow(ce::ProcessHandle* proc, QWidget* parent)
     : QMainWindow(parent), proc_(proc) {
-    setWindowTitle("Code list/Pause");   // CE AdvancedOptionsUnit caption
+    setWindowTitle(tr("Code list/Pause"));   // CE AdvancedOptionsUnit caption
 
     auto* central = new QWidget;
     setCentralWidget(central);
     auto* v = new QVBoxLayout(central);
 
-    v->addWidget(new QLabel("Code list:"));       // CE Label
+    v->addWidget(new QLabel(tr("Code list:")));       // CE Label
 
     table_ = new QTableWidget(0, 2);               // CE lvCodelist (Address, Name)
-    table_->setHorizontalHeaderLabels({"Address", "Name"});
+    table_->setHorizontalHeaderLabels({tr("Address"), tr("Name")});
     table_->horizontalHeader()->setStretchLastSection(true);
     table_->horizontalHeader()->setSectionResizeMode(0, QHeaderView::ResizeToContents);
     table_->setSelectionBehavior(QAbstractItemView::SelectRows);
     table_->setSelectionMode(QAbstractItemView::SingleSelection);
     styleDataTable(table_);
-    setEmptyHint(table_, "Code found with \"Find out what writes\" can be added here to keep it, disassemble it or replace it with NOPs.");
+    setEmptyHint(table_, tr("Code found with \"Find out what writes\" can be added here to keep it, disassemble it or replace it with NOPs."));
     table_->setContextMenuPolicy(Qt::CustomContextMenu);
     connect(table_, &QWidget::customContextMenuRequested,
             this, &AdvancedOptionsWindow::showContextMenu);
@@ -42,7 +42,7 @@ AdvancedOptionsWindow::AdvancedOptionsWindow(ce::ProcessHandle* proc, QWidget* p
 
     auto* row = new QHBoxLayout;                    // CE Panel1
     row->addStretch();
-    auto* ok = new QPushButton("OK");               // CE Button1
+    auto* ok = new QPushButton(tr("OK"));               // CE Button1
     connect(ok, &QPushButton::clicked, this, &QWidget::close);
     row->addWidget(ok);
     v->addLayout(row);
@@ -76,13 +76,13 @@ void AdvancedOptionsWindow::showContextMenu(const QPoint& pos) {
     const uintptr_t addr = addressAtRow(row);
 
     QMenu m(this);
-    auto* openAct    = m.addAction("Open the disassembler at this location");
+    auto* openAct    = m.addAction(tr("Open the disassembler at this location"));
     m.addSeparator();
-    auto* nopAct     = m.addAction("Replace with code that does nothing");
-    auto* restoreAct = m.addAction("Restore with original code");
+    auto* nopAct     = m.addAction(tr("Replace with code that does nothing"));
+    auto* restoreAct = m.addAction(tr("Restore with original code"));
     m.addSeparator();
-    auto* renameAct  = m.addAction("Rename");
-    auto* removeAct  = m.addAction("Remove from list");
+    auto* renameAct  = m.addAction(tr("Rename"));
+    auto* removeAct  = m.addAction(tr("Remove from list"));
 
     const bool have = (addr != 0);
     for (auto* a : {openAct, nopAct, renameAct, removeAct}) a->setEnabled(have);
@@ -99,15 +99,15 @@ void AdvancedOptionsWindow::showContextMenu(const QPoint& pos) {
     } else if (chosen == nopAct && proc_ && !nopOriginals_.count(addr)) {
         auto orig = ce::nopInstruction(*proc_, addr);
         if (!orig.empty()) nopOriginals_[addr] = orig;
-        else QMessageBox::warning(this, "NOP", "Could not read/patch the instruction.");
+        else QMessageBox::warning(this, "NOP", tr("Could not read/patch the instruction."));
     } else if (chosen == restoreAct && proc_) {
         auto it = nopOriginals_.find(addr);
         if (it != nopOriginals_.end() && ce::restoreBytes(*proc_, addr, it->second))
             nopOriginals_.erase(it);
     } else if (chosen == renameAct && row >= 0) {
         bool ok = false;
         QString cur = table_->item(row, 1) ? table_->item(row, 1)->text() : QString();
-        auto name = QInputDialog::getText(this, "Rename", "Name:", QLineEdit::Normal, cur, &ok);
+        auto name = QInputDialog::getText(this, tr("Rename"), tr("Name:"), QLineEdit::Normal, cur, &ok);
         if (ok) table_->setItem(row, 1, new QTableWidgetItem(name));
     } else if (chosen == removeAct && row >= 0) {
         table_->removeRow(row);