Function discoverAvailableLanguages

source/ControlPanelDialog.cpp:107–153

}

QList<LanguageEntry> discoverAvailableLanguages(const QString& savedOverrideCode) {
    QSet<QString> codes;
    QList<LanguageEntry> entries;

    // English is always available — it's the source language, no .qm needed.
    entries.append({QStringLiteral("en"), buildDisplayName(QStringLiteral("en")), true});
    codes.insert(QStringLiteral("en"));

    static const QRegularExpression qmRegex(
        QStringLiteral("^app_([A-Za-z]{2,3}(?:_[A-Za-z]{2,4})?)\\.qm$"));

    for (const QString& path : translationSearchPaths()) {
        if (path.isEmpty()) continue;
        QDir dir(path);
        if (!dir.exists()) continue;
        const QFileInfoList files = dir.entryInfoList(
            {QStringLiteral("app_*.qm")}, QDir::Files);
        for (const QFileInfo& fi : files) {
            const auto m = qmRegex.match(fi.fileName());
            if (!m.hasMatch()) continue;
            QString raw  = m.captured(1);
            QString code = raw.section('_', 0, 0).toLower();  // "zh_CN" -> "zh"
            if (codes.contains(code)) continue;
            codes.insert(code);
            entries.append({code, buildDisplayName(code), true});
        }
    }

    // Sort: English first, rest alphabetical by display name (locale-aware).
    if (entries.size() > 1) {
        std::sort(entries.begin() + 1, entries.end(),
            [](const LanguageEntry& a, const LanguageEntry& b) {
                return a.displayName.localeAwareCompare(b.displayName) < 0;
            });
    }

    // If the saved override points at a language we didn't find, surface it
    // anyway marked "(not installed)" so the user sees their saved choice.
    if (!savedOverrideCode.isEmpty() && !codes.contains(savedOverrideCode)) {
        entries.append({
            savedOverrideCode,
            QStringLiteral("%1 (not installed)").arg(buildDisplayName(savedOverrideCode)),
            false
        });
    }
    return entries;
}

} // namespace