#include <QtWidgets>

int main(int argc, char *argv[])
{
    QApplication a(argc, argv);
    auto testWidget = new QWidget;
    auto gridLayout = new QGridLayout(testWidget);

    auto create = [&](int row, int col)
    {
        auto gb = new QGroupBox(testWidget);
        gb->setSizePolicy(QSizePolicy::Expanding, QSizePolicy::Expanding);
        auto lbl = new QLabel(QString("%1/%2").arg(row).arg(col));
        lbl->setStyleSheet("background-color: red");
        auto lay = new QHBoxLayout(gb);
        lay->addWidget(lbl);
        gridLayout->addWidget(gb, row, col, 1, 1);
        return gb;
    };

    {
        auto groupBox = create(0, 0);
        qDebug() << groupBox->alignment();
    }
    {
        auto groupBox = create(1, 0);
        groupBox->setTitle("No alignment");
    }
    {
        auto groupBox = create(2, 0);
        groupBox->setCheckable(true);
    }

    int row = 0;
    for (auto vAlign : {Qt::AlignTop, Qt::AlignVCenter, Qt::AlignBottom}) {
        int col = 1;
        {
            auto groupBox = create(row, col++);
            groupBox->setTitle("AlignLeft");
            groupBox->setCheckable(row == col - 2);
            groupBox->setAlignment(Qt::AlignLeft | vAlign);
        }
        {
            auto groupBox = create(row, col++);
            groupBox->setTitle("AlignHCenter");
            groupBox->setCheckable(row == col - 2);
            groupBox->setAlignment(Qt::AlignHCenter | vAlign);
        }
        {
            auto groupBox = create(row, col++);
            groupBox->setTitle("AlignRight");
            groupBox->setCheckable(row == col - 2);
            groupBox->setAlignment(Qt::AlignRight | vAlign);
        }
        ++row;
    }

    testWidget->show();
    return a.exec();
}