#include <QtCore>
#include <QtGui>
#include <QtWidgets>


int main(int argc, char** argv)
{
    QApplication app(argc, argv);
    app.setStyle(QStyleFactory::create("fusion"));

    // 1: specify a section border and an arrow position
    app.setStyleSheet("QHeaderView::section { border: 1px solid blue; } QHeaderView::up-arrow { right: 1px; }");

    // 2: specify only a section border
    // app.setStyleSheet("QHeaderView::section { border: 1px solid blue; }");

    // 3: specify only an arrow position
    // app.setStyleSheet("QHeaderView::up-arrow { right: 1px; }");

    // 4: specify no stylesheet so only the base fusion style is used

    QStandardItemModel model(3, 3);
    for (auto i = 0u; i < 3; ++i) {
        for (auto j = 0u; j < 3; ++j) {
            model.setData(model.index(i, j), QString("cell(%1, %2)").arg(i).arg(j));
        }
    }

    for (auto j = 0u; j < 3; ++j) {
        model.setHeaderData(j, Qt::Orientation::Horizontal, QString("Column Header %1|").arg(j));
    }

    QTreeView view{};
    view.setModel(&model);
    view.setSortingEnabled(true);

    view.header()->setSortIndicator(1, Qt::SortOrder::AscendingOrder);
    view.header()->setSectionResizeMode(QHeaderView::ResizeMode::Interactive);

    view.show();
    return app.exec();
}