#include <QtWidgets>

int main(int argc, char *argv[])
{
    QApplication a(argc, argv);
    QWidget w;
    auto lay = new QGridLayout(&w);
    auto styleComboBox = new QComboBox;
    const QString defaultStyleName = QApplication::style()->objectName();
    QStringList styleNames = QStyleFactory::keys();
    for (int i = 1, size = styleNames.size(); i < size; ++i) {
        if (defaultStyleName.compare(styleNames.at(i), Qt::CaseInsensitive) == 0) {
            styleNames.swapItemsAt(0, i);
            break;
        }
    }
    styleComboBox->addItems(styleNames);
    lay->addWidget(styleComboBox, 0, 1);

    auto cbx = new QComboBox;
    cbx->addItem("Auto");
    cbx->addItem("Light");
    cbx->addItem("Dark");
    lay->addWidget(cbx, 0, 0);
    int row = 0;
    for (bool flat : {true, false}) {
        for (bool enabled : {true, false}) {
            ++row;
            int col = 0;
            {
                auto pb = new QPushButton(QString("Up, flat: %1, enabled: %2").arg(flat).arg(enabled));
                pb->setEnabled(enabled);
                pb->setFlat(flat);
                pb->setDown(false);
                lay->addWidget(pb, row, col++);
            }
            {
                auto pb = new QPushButton(QString("Down, flat: %1, enabled: %2").arg(flat).arg(enabled));
                pb->setEnabled(enabled);
                pb->setFlat(flat);
                pb->setDown(true);
                lay->addWidget(pb, row, col++);
            }
            {
                auto pb = new QPushButton(QString("Checkable + !Checked, flat: %1, enabled: %2").arg(flat).arg(enabled));
                pb->setEnabled(enabled);
                pb->setFlat(flat);
                pb->setCheckable(true);
                pb->setChecked(false);
                lay->addWidget(pb, row, col++);
            }
            {
                auto pb = new QPushButton(QString("Checkable + Checked, flat: %1, enabled: %2").arg(flat).arg(enabled));
                pb->setEnabled(enabled);
                pb->setFlat(flat);
                pb->setCheckable(true);
                pb->setChecked(true);
                lay->addWidget(pb, row, col++);
            }
        }
    }
    for (bool raise : {true, false}) {
        for (bool enabled : {true, false}) {
            ++row;
            int col = 0;
            {
                auto pb = new QToolButton;
                pb->setToolTip(QString("Up, raise: %1, enabled: %2").arg(raise).arg(enabled));
                pb->setEnabled(enabled);
                pb->setAutoRaise(raise);
                pb->setDown(false);
                lay->addWidget(pb, row, col++);
            }
            {
                auto pb = new QToolButton;
                pb->setToolTip(QString("Down, raise: %1, enabled: %2").arg(raise).arg(enabled));
                pb->setEnabled(enabled);
                pb->setAutoRaise(raise);
                pb->setDown(true);
                lay->addWidget(pb, row, col++);
            }
            {
                auto pb = new QToolButton;
                pb->setToolTip(QString("Checkable & !Checked, raise: %1, enabled: %2").arg(raise).arg(enabled));
                pb->setEnabled(enabled);
                pb->setAutoRaise(raise);
                pb->setCheckable(true);
                pb->setChecked(false);
                lay->addWidget(pb, row, col++);
            }
            {
                auto pb = new QToolButton;
                pb->setToolTip(QString("Checkable & Checked, raise: %1, enabled: %2").arg(raise).arg(enabled));
                pb->setEnabled(enabled);
                pb->setAutoRaise(raise);
                pb->setCheckable(true);
                pb->setChecked(true);
                lay->addWidget(pb, row, col++);
            }
        }
    }
    w.show();
    QObject::connect(cbx, &QComboBox::currentIndexChanged, cbx, [](int index) {
        QGuiApplication::styleHints()->setColorScheme(static_cast<Qt::ColorScheme>(index));
        });
    QObject::connect(styleComboBox, &QComboBox::textActivated,
        styleComboBox, [&](const QString & styleName)
    {
        QApplication::setStyle(QStyleFactory::create(styleName));
    });
    return a.exec();
}