citra_qt: load translation from resource

src/citra_qt/configuration/config.cpp

@@ -182,6 +182,7 @@ void Config::ReadValues() {
     UISettings::values.gamedir = qt_config->value("gameListRootDir", ".").toString();
     UISettings::values.gamedir_deepscan = qt_config->value("gameListDeepScan", false).toBool();
     UISettings::values.recent_files = qt_config->value("recentFiles").toStringList();
+    UISettings::values.language = qt_config->value("language", "").toString();
     qt_config->endGroup();
 
     qt_config->beginGroup("Shortcuts");
@@ -333,6 +334,7 @@ void Config::SaveValues() {
     qt_config->setValue("gameListRootDir", UISettings::values.gamedir);
     qt_config->setValue("gameListDeepScan", UISettings::values.gamedir_deepscan);
     qt_config->setValue("recentFiles", UISettings::values.recent_files);
+    qt_config->setValue("language", UISettings::values.language);
     qt_config->endGroup();
 
     qt_config->beginGroup("Shortcuts");

src/citra_qt/configuration/configure_audio.cpp

@@ -75,3 +75,7 @@ void ConfigureAudio::updateAudioDevices(int sink_index) {
         ui->audio_device_combo_box->addItem(device.c_str());
     }
 }
+
+void ConfigureAudio::retranslateUi() {
+    ui->retranslateUi(this);
+}

src/citra_qt/configuration/configure_audio.h

@@ -19,6 +19,7 @@ public:
     ~ConfigureAudio();
 
     void applyConfiguration();
+    void retranslateUi();
 
 public slots:
     void updateAudioDevices(int sink_index);

src/citra_qt/configuration/configure_debug.cpp

@@ -24,3 +24,7 @@ void ConfigureDebug::applyConfiguration() {
     Settings::values.gdbstub_port = ui->gdbport_spinbox->value();
     Settings::Apply();
 }
+
+void ConfigureDebug::retranslateUi() {
+    ui->retranslateUi(this);
+}

src/citra_qt/configuration/configure_debug.h

@@ -19,6 +19,7 @@ public:
     ~ConfigureDebug();
 
     void applyConfiguration();
+    void retranslateUi();
 
 private:
     void setConfiguration();

src/citra_qt/configuration/configure_dialog.cpp

@@ -10,6 +10,8 @@
 ConfigureDialog::ConfigureDialog(QWidget* parent) : QDialog(parent), ui(new Ui::ConfigureDialog) {
     ui->setupUi(this);
     this->setConfiguration();
+    connect(ui->generalTab, &ConfigureGeneral::languageChanged, this,
+            &ConfigureDialog::onLanguageChanged);
 }
 
 ConfigureDialog::~ConfigureDialog() {}
@@ -26,3 +28,15 @@ void ConfigureDialog::applyConfiguration() {
     ui->webTab->applyConfiguration();
     Settings::Apply();
 }
+
+void ConfigureDialog::onLanguageChanged(const QString& locale) {
+    emit languageChanged(locale);
+    ui->retranslateUi(this);
+    ui->generalTab->retranslateUi();
+    ui->systemTab->retranslateUi();
+    ui->inputTab->retranslateUi();
+    ui->graphicsTab->retranslateUi();
+    ui->audioTab->retranslateUi();
+    ui->debugTab->retranslateUi();
+    ui->webTab->retranslateUi();
+}

src/citra_qt/configuration/configure_dialog.h

@@ -20,6 +20,12 @@ public:
 
     void applyConfiguration();
 
+private slots:
+    void onLanguageChanged(const QString& locale);
+
+signals:
+    void languageChanged(const QString& locale);
+
 private:
     void setConfiguration();
 

src/citra_qt/configuration/configure_general.cpp

@@ -2,6 +2,7 @@
 // Licensed under GPLv2 or any later version
 // Refer to the license.txt file included.
 
+#include <QDirIterator>
 #include "citra_qt/configuration/configure_general.h"
 #include "citra_qt/ui_settings.h"
 #include "core/core.h"
@@ -12,6 +13,23 @@ ConfigureGeneral::ConfigureGeneral(QWidget* parent)
     : QWidget(parent), ui(new Ui::ConfigureGeneral) {
 
     ui->setupUi(this);
+    ui->language_combobox->addItem(tr("<System>"), QString(""));
+    ui->language_combobox->addItem(tr("English"), QString("en"));
+    QDirIterator it(":/languages", QDirIterator::NoIteratorFlags);
+    while (it.hasNext()) {
+        QString locale = it.next();
+        locale.truncate(locale.lastIndexOf('.'));
+        locale.remove(0, locale.lastIndexOf('/') + 1);
+        QString lang = QLocale::languageToString(QLocale(locale).language());
+        ui->language_combobox->addItem(lang, locale);
+    }
+
+    // Unlike other configuration, interface language change need to be reflect on the interface
+    // immediately. This is done by passing a signal to the main window, and then retranslating when
+    // passing back.
+    connect(ui->language_combobox,
+            static_cast<void (QComboBox::*)(int)>(&QComboBox::currentIndexChanged), this,
+            &ConfigureGeneral::onLanguageChanged);
 
     for (auto theme : UISettings::themes) {
         ui->theme_combobox->addItem(theme.first, theme.second);
@@ -37,6 +55,8 @@ void ConfigureGeneral::setConfiguration() {
     ui->region_combobox->setCurrentIndex(Settings::values.region_value + 1);
 
     ui->theme_combobox->setCurrentIndex(ui->theme_combobox->findData(UISettings::values.theme));
+    ui->language_combobox->setCurrentIndex(
+        ui->language_combobox->findData(UISettings::values.language));
 }
 
 void ConfigureGeneral::applyConfiguration() {
@@ -52,3 +72,14 @@ void ConfigureGeneral::applyConfiguration() {
     Settings::values.use_cpu_jit = ui->toggle_cpu_jit->isChecked();
     Settings::Apply();
 }
+
+void ConfigureGeneral::onLanguageChanged(int index) {
+    if (index == -1)
+        return;
+
+    emit languageChanged(ui->language_combobox->itemData(index).toString());
+}
+
+void ConfigureGeneral::retranslateUi() {
+    ui->retranslateUi(this);
+}

src/citra_qt/configuration/configure_general.h

@@ -19,6 +19,13 @@ public:
     ~ConfigureGeneral();
 
     void applyConfiguration();
+    void retranslateUi();
+
+private slots:
+    void onLanguageChanged(int index);
+
+signals:
+    void languageChanged(const QString& locale);
 
 private:
     void setConfiguration();

src/citra_qt/configuration/configure_general.ui

@@ -6,8 +6,8 @@
    <rect>
     <x>0</x>
     <y>0</y>
-    <width>300</width>
-    <height>377</height>
+    <width>345</width>
+    <height>493</height>
    </rect>
   </property>
   <property name="windowTitle">
@@ -38,6 +38,20 @@
             </property>
            </widget>
           </item>
+          <item>
+           <layout class="QHBoxLayout" name="horizontalLayout_2">
+            <item>
+             <widget class="QLabel" name="language_label">
+              <property name="text">
+               <string>Interface language</string>
+              </property>
+             </widget>
+            </item>
+            <item>
+             <widget class="QComboBox" name="language_combobox"/>
+            </item>
+           </layout>
+          </item>
          </layout>
         </item>
        </layout>

src/citra_qt/configuration/configure_graphics.cpp

@@ -113,3 +113,7 @@ void ConfigureGraphics::applyConfiguration() {
     Settings::values.swap_screen = ui->swap_screen->isChecked();
     Settings::Apply();
 }
+
+void ConfigureGraphics::retranslateUi() {
+    ui->retranslateUi(this);
+}

src/citra_qt/configuration/configure_graphics.h

@@ -19,6 +19,7 @@ public:
     ~ConfigureGraphics();
 
     void applyConfiguration();
+    void retranslateUi();
 
 private:
     void setConfiguration();

src/citra_qt/configuration/configure_input.cpp

@@ -277,3 +277,7 @@ void ConfigureInput::keyPressEvent(QKeyEvent* event) {
     }
     setPollingResult({}, true);
 }
+
+void ConfigureInput::retranslateUi() {
+    ui->retranslateUi(this);
+}

src/citra_qt/configuration/configure_input.h

@@ -33,6 +33,7 @@ public:
 
     /// Save all button configurations to settings file
     void applyConfiguration();
+    void retranslateUi();
 
 private:
     std::unique_ptr<Ui::ConfigureInput> ui;

src/citra_qt/configuration/configure_system.cpp

@@ -167,3 +167,7 @@ void ConfigureSystem::refreshConsoleID() {
     Service::CFG::UpdateConfigNANDSavegame();
     ui->label_console_id->setText("Console ID: 0x" + QString::number(console_id, 16).toUpper());
 }
+
+void ConfigureSystem::retranslateUi() {
+    ui->retranslateUi(this);
+}

src/citra_qt/configuration/configure_system.h

@@ -20,6 +20,7 @@ public:
 
     void applyConfiguration();
     void setConfiguration();
+    void retranslateUi();
 
 public slots:
     void updateBirthdayComboBox(int birthmonth_index);

src/citra_qt/configuration/configure_web.cpp

@@ -100,3 +100,7 @@ void ConfigureWeb::OnLoginVerified() {
                "correctly, and that your internet connection is working."));
     }
 }
+
+void ConfigureWeb::retranslateUi() {
+    ui->retranslateUi(this);
+}

src/citra_qt/configuration/configure_web.h

@@ -20,6 +20,7 @@ public:
     ~ConfigureWeb();
 
     void applyConfiguration();
+    void retranslateUi();
 
 public slots:
     void RefreshTelemetryID();