C++ (Qt)
void View::mousePressEvent(QMouseEvent *event)
{
    event->ignore();
    qDebug() << "View " << event->pos();
    QGraphicsView::mousePressEvent(event);
}
 

C++ (Qt)
Scene::Scene(QObject *parent) : QGraphicsScene(parent)
{
    addItem(&table);
}
 
void Scene::mousePressEvent(QGraphicsSceneMouseEvent *event)
{
    qDebug() << "Scene" << event->scenePos();
    QGraphicsScene::mousePressEvent(event);
}
 

C++ (Qt)
Table::Table(QGraphicsItem * parent) : QGraphicsItemGroup(parent)
{
    int k = 0;
    for(int i =  0; i < 3; i++){
        for(int j = 0; j < 3; j++){
 
            addToGroup(&cells[i][j]);
            cells[i][j].setPos(0 + i * cells[i][j].boundingRect().width(),
                            0 + j * cells[i][j].boundingRect().height()
                            );
 
            cells[i][j].setnum(k++);
            cells[i][j].setParentItem(this);
        }
    }
}
 
void Table::mousePressEvent(QGraphicsSceneMouseEvent *event)
{
    event->ignore();
    qDebug() << "Table" << event->pos();
    QGraphicsItemGroup::mousePressEvent(event);
}
 

C++ (Qt)
Cell::Cell(QGraphicsItem * parent) : QGraphicsItem(parent)
{
    number = 0;
}
 
void Cell::paint(QPainter *painter, const QStyleOptionGraphicsItem *option, QWidget *widget)
{
    Q_UNUSED(option)
    Q_UNUSED(widget)
 
    painter->drawRect(0, 0, 40, 40);
    painter->drawText(boundingRect() , QString("cell %1").arg(number, 0, 10));
}
 
QRectF Cell::boundingRect() const
{
    return QRectF(0, 0, 40, 40);
}
 
void Cell::mousePressEvent(QGraphicsSceneMouseEvent *event)
{
    qDebug() << number;
}
 

View  QPoint(250,227) 
Scene QPointF(184, 203) 
Table QPointF(84, 103) 
Table QPointF(84, 103) 

C++ (Qt)
void Table::mousePressEvent(QGraphicsSceneMouseEvent *event)
{
 
    //НО ЭТО НЕ ОЧЕНЬ ХОРОШО !!!
    Cell * cell = reinterpret_cast<Cell * >(scene()->itemAt(event->scenePos().rx(), event->scenePos().ry()));
    //
 
    qDebug() << cell->getnumber();
    QGraphicsItemGroup::mousePressEvent(event);
}