fix(ui): system translation not being updated

This commit fixes an issue when switching from any language back to English,
the system translations remain to be the last language even if the application
translations have switched back to English.

src/widget/translator.cpp

@@ -28,7 +28,8 @@
 #include <QTranslator>
 #include <algorithm>
 
-QTranslator* Translator::translator{nullptr};
+QTranslator* Translator::core_translator{nullptr};
+QTranslator* Translator::app_translator{nullptr};
 QVector<Translator::Callback> Translator::callbacks;
 QMutex Translator::lock;
 
@@ -39,31 +40,38 @@ void Translator::translate(const QString& localeName)
 {
     QMutexLocker locker{&lock};
 
-    if (!translator)
-        translator = new QTranslator();
+    if (!core_translator)
+        core_translator = new QTranslator();
+
+    if (!app_translator)
+        app_translator = new QTranslator();
+
+    // Remove old translations
+    QCoreApplication::removeTranslator(core_translator);
+    QApplication::removeTranslator(app_translator);
 
     // Load translations
-    QCoreApplication::removeTranslator(translator);
     QString locale = localeName.isEmpty() ? QLocale::system().name().section('_', 0, 0) : localeName;
 
     if (locale != "en") {
-        if (translator->load(locale, ":translations/")) {
+        if (core_translator->load(locale, ":translations/")) {
             qDebug() << "Loaded translation" << locale;
 
-            // system menu translation
-            QTranslator* qtTranslator = new QTranslator();
+            // System menu translation
             QString s_locale = "qt_" + locale;
             QString location = QLibraryInfo::location(QLibraryInfo::TranslationsPath);
-            if (qtTranslator->load(s_locale, location)) {
-                QApplication::installTranslator(qtTranslator);
+            if (app_translator->load(s_locale, location)) {
+                QApplication::installTranslator(app_translator);
                 qDebug() << "System translation loaded" << locale;
             } else {
                 qDebug() << "System translation not loaded" << locale;
             }
+
+            // Application translation
+            QCoreApplication::installTranslator(core_translator);
         } else {
             qDebug() << "Error loading translation" << locale;
         }
-        QCoreApplication::installTranslator(translator);
     }
 
     // After the language is changed from RTL to LTR, the layout direction isn't

src/widget/translator.h

@@ -38,5 +38,6 @@ private:
     using Callback = QPair<void*, std::function<void()>>;
     static QVector<Callback> callbacks;
     static QMutex lock;
-    static QTranslator* translator;
+    static QTranslator* core_translator;
+    static QTranslator* app_translator;
 };