#include <QApplication>
#include <QTreeView>
#include <QItemSelectionModel>
#include <QStringListModel>
#include <QTimer>
#include <QDebug>

int main(int argc, char** argv)
{
    QApplication app(argc, argv);

    QStringListModel model{{"Monday", "Tuesday", "Wednesday", "Thursday"}};

    QTreeView view;
    view.setModel(&model);
    view.show();

    QTimer::singleShot(1000, &app, [&view]{
        auto selm = new QItemSelectionModel(view.model(), &view);
        auto idx = view.model()->index(1, 0);
        selm->select(idx, QItemSelectionModel::Select);
        qDebug() << "Made selection" << idx;
        view.setSelectionModel(selm);
        // view.viewport()->update();
    });

    return app.exec();
}