void Test::mouseMoveEvent(QGraphicsSceneMouseEvent *event)
{
    
    qDebug()<<"MouseMove"<<event->button();
    if (event->button() != Qt::LeftButton){
          //Always execute
              return;
    }
QGraphicsScene::mouseMoveEvent(event);
}

Output:
MouseMove Qt::NoButton

Why does the QGraphicsSceneMouseEvent :: button () function inside the mouseMoveEvent function return Qt :: Nobutton?
However mousePressEvent and mouseReleaseEvent function work fine :(
Output :
MousePress Qt::LeftButton
MouseMove Qt::NoButton
MouseMove Qt::NoButton
MouseRelease Qt::LeftButton

Thanks!!