How to force QLocale::system to change

c++, localization, qt, qt4

Solution

For testing you can use something like that (just correct main function):

int main(int argc, char **argv) {
    QApplication app(argc, argv);

    QLocale localeUsedToDeterminateTranslators = QLocale::system();
    Q_FOREACH(QString a, app.arguments()) {
        const static localeParam = "-locale:";
        if (a.startsWith(localeParam)) {
           localeUsedToDeterminateTranslators = QLocale(a.mid(sizeof(localeParam)-1));
           break;
        }
    }
    ... // your normal code

Then when you run you app you can just run it with extra parameter: `./yourAppName -locale:nl`. See documentation of QLocale for possible values.

Edit: I've found even better approach, there is a method `QLocale::setDefault`, so this should work even better:

int main(int argc, char **argv) {
    QApplication app(argc, argv);

    Q_FOREACH(QString a, app.arguments()) {
        const static localeParam = "-locale:";
        if (a.startsWith(localeParam)) {
           QLocale::setDefault(QLocale(a.mid(sizeof(localeParam)-1)));
           break;
        }
    }
    ...
    QTranslator app_translator;
    if (!app_translator.load ("app_" + QLocale().name (), app_tr_dir))
         qWarning ("Can't load app translator file for locale %s from %s", qPrintable (QLocale().name()), app_tr_dir.toLocal8Bit().data());
    else
         app.installTranslator (&app_translator);

Problem

I need to test my application translation to non-English language very often, and this is very uncomfortable to change the whole operating system language just to do this simple check. How can i change Qt-detected system language using environment variables for example? or with command-line parameter. I try to change `LANG`, `LANGUAGE` environment variables, but it has no effect. However, under GNOME it has! UPD: code i'm using such code to determine the system locale and load appropriate translation: ``` QTranslator app_translator; if (!app_translator.load ("app_" + QLocale::system ().name (), app_tr_dir)) qWarning ("Can't load app translator file for locale %s from %s", qPrintable (QLocale::system ().name ()), app_tr_dir.toLocal8Bit().data()); else app.installTranslator (&app_translator); ``` P.S. My OS is Kubuntu 13.10, Qt version is 4.8.

Original source

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