CLONE -A QLineEdit embedded in a QGraphicsProxyWidget does not call the Virtual Keyboard when clicked

#include <QtGui>

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

    QGraphicsScene scene;
    QGraphicsView view(&scene);

    scene.addWidget(new QLineEdit("lorem ipsum"));

    view.show();

    return app.exec();
}