FullscreenUI: Allow changing UI language

src/duckstation-qt/mainwindow.cpp

@@ -1648,32 +1648,29 @@ void MainWindow::setupAdditionalUi()
   }
   updateDebugMenuCropMode();
 
-  const QString current_language(QString::fromStdString(Host::GetBaseStringSettingValue("Main", "Language", "")));
+  const std::string current_language = Host::GetBaseStringSettingValue("Main", "Language", "");
   QActionGroup* language_group = new QActionGroup(m_ui.menuSettingsLanguage);
-  for (const std::pair<QString, QString>& it : QtHost::GetAvailableLanguageList())
+  for (const auto& [language, code] : Host::GetAvailableLanguageList())
   {
-    QAction* action = language_group->addAction(it.first);
+    QAction* action = language_group->addAction(QString::fromUtf8(language));
     action->setCheckable(true);
-    action->setChecked(current_language == it.second);
+    action->setChecked(current_language == code);
 
-    QString icon_filename(QStringLiteral(":/icons/flags/%1.png").arg(it.second));
+    QString icon_filename(QStringLiteral(":/icons/flags/%1.png").arg(QLatin1StringView(code)));
     if (!QFile::exists(icon_filename))
     {
       // try without the suffix (e.g. es-es -> es)
-      const int pos = it.second.lastIndexOf('-');
-      if (pos >= 0)
-        icon_filename = QStringLiteral(":/icons/flags/%1.png").arg(it.second.left(pos));
+      const char* pos = std::strrchr(code, '-');
+      if (pos)
+        icon_filename = QStringLiteral(":/icons/flags/%1.png").arg(QLatin1StringView(pos));
     }
     action->setIcon(QIcon(icon_filename));
 
     m_ui.menuSettingsLanguage->addAction(action);
-    action->setData(it.second);
+    action->setData(QString::fromLatin1(code));
     connect(action, &QAction::triggered, [this, action]() {
       const QString new_language = action->data().toString();
-      Host::SetBaseStringSettingValue("Main", "Language", new_language.toUtf8().constData());
-      Host::CommitBaseSettingChanges();
-      QtHost::InstallTranslator();
-      recreate();
+      Host::ChangeLanguage(new_language.toUtf8().constData());
     });
   }
 

src/duckstation-qt/mainwindow.h

@@ -107,6 +107,7 @@ public Q_SLOTS:
   std::optional<WindowInfo> getWindowInfo();
 
   void checkForUpdates(bool display_message);
+  void recreate();
 
   void* getNativeWindowId();
 
@@ -242,7 +243,6 @@ private:
   void setTheme(const QString& theme);
   void updateTheme();
   void reloadThemeSpecificImages();
-  void recreate();
   void destroySubWindows();
 
   void registerForDeviceNotifications();

src/duckstation-qt/qthost.h

@@ -253,9 +253,6 @@ bool InNoGUIMode();
 /// Executes a function on the UI thread.
 void RunOnUIThread(const std::function<void()>& func, bool block = false);
 
-/// Returns a list of supported languages and codes (suffixes for translation files).
-std::vector<std::pair<QString, QString>> GetAvailableLanguageList();
-
 /// Default language for the platform.
 const char* GetDefaultLanguage();
 

src/duckstation-qt/qttranslations.cpp

@@ -1,6 +1,7 @@
 // SPDX-FileCopyrightText: 2019-2023 Connor McLaughlin <stenzek@gmail.com> and contributors.
 // SPDX-License-Identifier: (GPL-3.0 OR CC-BY-NC-ND-4.0)
 
+#include "mainwindow.h"
 #include "qthost.h"
 
 #include "core/host.h"
@@ -202,24 +203,37 @@ static std::string QtHost::GetFontPath(const GlyphInfo* gi)
   return font_path;
 }
 
-std::vector<std::pair<QString, QString>> QtHost::GetAvailableLanguageList()
+std::span<const std::pair<const char*, const char*>> Host::GetAvailableLanguageList()
 {
-  return {{QStringLiteral("English"), QStringLiteral("en")},
-          {QStringLiteral("Deutsch"), QStringLiteral("de")},
-          {QStringLiteral("Español de Latinoamérica"), QStringLiteral("es")},
-          {QStringLiteral("Español de España"), QStringLiteral("es-ES")},
-          {QStringLiteral("Français"), QStringLiteral("fr")},
-          {QStringLiteral("עברית"), QStringLiteral("he")},
-          {QStringLiteral("日本語"), QStringLiteral("ja")},
-          {QStringLiteral("한국어"), QStringLiteral("ko")},
-          {QStringLiteral("Italiano"), QStringLiteral("it")},
-          {QStringLiteral("Nederlands"), QStringLiteral("nl")},
-          {QStringLiteral("Polski"), QStringLiteral("pl")},
-          {QStringLiteral("Português (Pt)"), QStringLiteral("pt-PT")},
-          {QStringLiteral("Português (Br)"), QStringLiteral("pt-BR")},
-          {QStringLiteral("Русский"), QStringLiteral("ru")},
-          {QStringLiteral("Türkçe"), QStringLiteral("tr")},
-          {QStringLiteral("简体中文"), QStringLiteral("zh-CN")}};
+  static constexpr const std::pair<const char*, const char*> languages[] = {{"English", "en"},
+                                                                            {"Deutsch", "de"},
+                                                                            {"Español de Latinoamérica", "es"},
+                                                                            {"Español de España", "es-ES"},
+                                                                            {"Français", "fr"},
+                                                                            {"עברית", "he"},
+                                                                            {"日本語", "ja"},
+                                                                            {"한국어", "ko"},
+                                                                            {"Italiano", "it"},
+                                                                            {"Nederlands", "nl"},
+                                                                            {"Polski", "pl"},
+                                                                            {"Português (Pt)", "pt-PT"},
+                                                                            {"Português (Br)", "pt-BR"},
+                                                                            {"Русский", "ru"},
+                                                                            {"Türkçe", "tr"},
+                                                                            {"简体中文", "zh-CN"}};
+
+  return languages;
+}
+
+bool Host::ChangeLanguage(const char* new_language)
+{
+  QtHost::RunOnUIThread([new_language = std::string(new_language)]() {
+    Host::SetBaseStringSettingValue("Main", "Language", new_language.c_str());
+    Host::CommitBaseSettingChanges();
+    QtHost::InstallTranslator();
+    g_main_window->recreate();
+  });
+  return true;
 }
 
 const char* QtHost::GetDefaultLanguage()

src/duckstation-qt/setupwizarddialog.cpp

@@ -186,8 +186,8 @@ void SetupWizardDialog::setupLanguagePage()
                                                GeneralSettingsWidget::DEFAULT_THEME_NAME, "InterfaceSettingsWidget");
   connect(m_ui.theme, QOverload<int>::of(&QComboBox::currentIndexChanged), this, &SetupWizardDialog::themeChanged);
 
-  for (const std::pair<QString, QString>& it : QtHost::GetAvailableLanguageList())
-    m_ui.language->addItem(it.first, it.second);
+  for (const auto& [language, code] : Host::GetAvailableLanguageList())
+    m_ui.language->addItem(QString::fromUtf8(language), QString::fromLatin1(code));
   SettingWidgetBinder::BindWidgetToStringSetting(nullptr, m_ui.language, "Main", "Language",
                                                  QtHost::GetDefaultLanguage());
   connect(m_ui.language, QOverload<int>::of(&QComboBox::currentIndexChanged), this,