Qt/translations

Indicating what to translate

Include QTranslator:

#include <QTranslator>

and wrap any strings with the QApplication::translate() or the QObject::tr() function:

QString message = app->translate("Message displayed while the system is loading", "Loading, Please Wait...");

Providing the translations

First, add each language file to the TRANSLATIONS variable in your *.pro file:

TRANSLATIONS = myApp_en.ts \
               myApp_fr.ts

Run lupdate on the project:

lupdate myApp.pro

Provide the translations:

linguist *.ts

Release the translations:

lrelease myApp.pro

Installing translations

Load the translation file before loading or displaying any translated windows:

QApplication app(argc, argv);
QTranslator translator;
MainWindow *main;
 
if (!translator.load(QString("myApp_") + lang + ".qm")) {
	qDebug("!!! translator.load -> FALSE!!! \n");
} else {
	app->installTranslator(&translator);
}
 
/* it's important that you do things like this AFTER installing the translator */
main = new MainWindow();

Running

Don't forget to copy the *.qm files into the same directory as the application!

cp ../myApp/*.qm .