Qt LanguageChange event - find out new language

Question

When I have changeEvent(QEvent* event) with receive type event->type() == QEvent::LanguageChange, how can I get information about what the new language is in my app?

Answer 1

You can compare the translated string with its known translations:

void changeEvent(QEvent *event)
{
    if (event->type() == QEvent::LanguageChange) {
        QString translated = QCoreApplication::translate("some context", "Button");
        if (translated == "Button")
            // language is English
        else if (translated == "Кнопка")
            // language is Russian
        ...
    }
}

Answer 2

Qt don't have any object to represent application langugae. So you should implement it yorself.

Usually changeEvent(QEvent* event) with type QEvent::LanguageChange was caused by installTranslator(QTranslator*) so you should know witch langugae you loaded to translator and store it locally.