How to remove accents / diacritic marks from a string in Qt?

Question

How to remove diacritic marks from a string in Qt. For example, this:

QString test = QString::fromUtf8("éçàÖœ");
qDebug() << StringUtil::removeAccents(test);

should output:

ecaOoe

Answer 1

There is not straighforward, built-in solution in Qt. A simple solution, which should work in most cases, is to loop through the string and replace each character by their equivalent:

QString StringUtil::diacriticLetters_;
QStringList StringUtil::noDiacriticLetters_;

QString StringUtil::removeAccents(QString s) {
    if (diacriticLetters_.isEmpty()) {
        diacriticLetters_ = QString::fromUtf8("ŠŒŽšœžŸ¥µÀÁÂÃÄÅÆÇÈÉÊËÌÍÎÏÐÑÒÓÔÕÖØÙÚÛÜÝßàáâãäåæçèéêëìíîïðñòóôõöøùúûüýÿ");
        noDiacriticLetters_ << "S"<<"OE"<<"Z"<<"s"<<"oe"<<"z"<<"Y"<<"Y"<<"u"<<"A"<<"A"<<"A"<<"A"<<"A"<<"A"<<"AE"<<"C"<<"E"<<"E"<<"E"<<"E"<<"I"<<"I"<<"I"<<"I"<<"D"<<"N"<<"O"<<"O"<<"O"<<"O"<<"O"<<"O"<<"U"<<"U"<<"U"<<"U"<<"Y"<<"s"<<"a"<<"a"<<"a"<<"a"<<"a"<<"a"<<"ae"<<"c"<<"e"<<"e"<<"e"<<"e"<<"i"<<"i"<<"i"<<"i"<<"o"<<"n"<<"o"<<"o"<<"o"<<"o"<<"o"<<"o"<<"u"<<"u"<<"u"<<"u"<<"y"<<"y";
    }

    QString output = "";
    for (int i = 0; i < s.length(); i++) {
        QChar c = s[i];
        int dIndex = diacriticLetters_.indexOf(c);
        if (dIndex < 0) {
            output.append(c);
        } else {
            QString replacement = noDiacriticLetters_[dIndex];
            output.append(replacement);
        }
    }

    return output;
}

Note that noDiacriticLetters_ needs to be a QStringList since some characters with diacritic marks can match to two single characters. For example œ => oe