To avoid this line becoming so long, you could do:

    const QVariantMap tilesVariantMap = variantMap["tiles"].toMap();
    for (it = tilesVariantMap.begin(); it != tilesVariantMap.end(); ++it) {

Since the `tilesVariantMap` is now declared `const`, the compiler will automatically pick the `const` variants of `QMap::begin` and `QMap::end`.