#include <QtWidgets>

int main(int argc, char *argv[])
{
    QApplication a(argc, argv);
    QWidget win;
    auto layout = new QVBoxLayout(&win);

    QAbstractFileIconProvider provider;
    QMap<QString, QIcon> iconMap
    {
        {"Computer", provider.icon(QAbstractFileIconProvider::Computer)},
        {"Desktop", provider.icon(QAbstractFileIconProvider::Desktop)},
        {"Trashcan", provider.icon(QAbstractFileIconProvider::Trashcan)},
        {"Network", provider.icon(QAbstractFileIconProvider::Network)},
        {"Drive", provider.icon(QAbstractFileIconProvider::Drive)},
        {"Folder", provider.icon(QAbstractFileIconProvider::Folder)},
        {"File", provider.icon(QAbstractFileIconProvider::File)},
        {"CSV File", provider.icon(QFileInfo("dummy.csv"))},
        {"JPG File", provider.icon(QFileInfo("dummy.jpg"))},
        {"PDF File", provider.icon(QFileInfo("dummy.pdf"))}
    };

    for (const auto& key : iconMap.keys())
    {
        auto icon = iconMap[key];
        qDebug() << key << "Icon null?:" << icon.isNull();
        layout->addWidget(new QPushButton(icon, key));
    }

    win.show();
    return a.exec();
}