#include <QtWidgets>

int main(int argc, char *argv[])
{
    QApplication app(argc, argv);
    auto createProgressBar = [](int val, Qt::Orientation orientation, bool inverted)
    {
        auto pb = new QProgressBar;
        pb->setMaximum(100);
        pb->setValue(val);
        pb->setOrientation(orientation);
        pb->setInvertedAppearance(inverted);
        return pb;
    };
    auto getLayout = [](QWidget *w, Qt::Orientation orientation) -> QBoxLayout *
    {
        if (orientation == Qt::Horizontal)
            return new QVBoxLayout(w);
        return new QHBoxLayout(w);
    };
    auto createWidget = [&](Qt::Orientation orientation, bool inverted, const char *title)
    {
        QWidget *w = new QWidget;
        w->setWindowTitle(title);
        auto lay = getLayout(w, orientation);
        for (int i : {0, 1, 48, 52, 99, 100})
            lay->addWidget(createProgressBar(i, orientation, inverted));
        w->show();
    };
    createWidget(Qt::Horizontal, false, "Horizontal, normal");
    createWidget(Qt::Vertical, false, "Vertical, normal");
    createWidget(Qt::Horizontal, true, "Horizontal, inverted");
    createWidget(Qt::Vertical, true, "Vertical, inverted");
    return app.exec();
}