Stuff

void MyLabelScene::mouseMoveEvent(QGraphicsSceneMouseEvent *event){    if (event->modifiers().testFlag(Qt::ControlModifier) && is_moved){        QPointF diff = point_buffer - event->scenePos();        point_buffer = event->scenePos();        emit move_viewport(diff); // connected to the translation_requested of the view    }    else QGraphicsScene::mouseMoveEvent(event);}void MyLabelScene::mousePressEvent(QGraphicsSceneMouseEvent *event){    if (event->modifiers().testFlag(Qt::ControlModifier)){        is_moved = true;        point_buffer=  event->scenePos();    }    else QGraphicsScene::mousePressEvent(event);};void MyLabelScene::mouseReleaseEvent(QGraphicsSceneMouseEvent *event){    is_moved = false;    QGraphicsScene::mouseReleaseEvent(event);};void MyLabelView::translation_requested(QPointF p){    qDebug() << p;    this->translate(p.x(), p.y());    this->update();}