#include <QApplication>
#include <QTreeWidget>

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

    QTreeWidget widget;
    widget.setColumnCount(1);
    widget.headerItem()->setText(0, "Tree");
    widget.setDragEnabled(true);
    widget.setDragDropMode(QAbstractItemView::InternalMove);
 
    QList<QTreeWidgetItem*> items;
    for(int i = 0; i < 5; ++i)
    {
        items.append(new QTreeWidgetItem((QTreeWidget*)0, {QString("Item: %1").arg(i)}));
    }
    widget.insertTopLevelItems(0, items);
    widget.show();

    return app.exec();
}