QGraphicsRectItem boundingRect() not updating with mousemove event

[sayan275]

I have a QgraphicsRectItem, with a overridden boundingRect().
I try to print the boundingRect(), in ItemChange() with ItemPositionChange flag, but it doesn't update.

TiltBoxItem::itemChange QPointF(-485.063,4.53229)
TiltBoxItem::itemChange boundingRect:: QRectF(728.313,289.567 166.75x90.135)
TiltBoxItem::itemChange m_BOX:: QRectF(728.813,290.067 165.75x89.135)
TiltBoxItem::mouseMoveEvent m_BOX:: QRectF(728.813,290.067 165.75x89.135)

the value which shows for boundingRect and m_box is same as I drawn on scene. After that I have moved it throughout the scene, but the bounding box/m-box is not updated.

the code is like this

QRectF TiltBoxItem::boundingRect() const
{
    return QGraphicsRectItem::boundingRect();
}

QVariant TiltBoxItem::itemChange(QGraphicsItem::GraphicsItemChange change, const QVariant &value)
{
    if(change == QGraphicsItem::ItemPositionChange)
    {
        qInfo()<<__FUNCTION__<<value.toPointF();
        qInfo()<<__FUNCTION__<<"boundingRect::"<<boundingRect();
        qInfo()<<__FUNCTION__<<"m_BOX::"<<m_box;
    }
    return QGraphicsItem::itemChange(change, value);
}

void TiltBoxItem::mouseMoveEvent(QGraphicsSceneMouseEvent *event)
{    
    QGraphicsItem::mouseMoveEvent(event);
    update();
    qInfo()<<__FUNCTION__<<"m_BOX::"<<m_box;
}

m_box is

 QRectF m_box;

//and in ctor we initialize it
m_box = rect;
setRect(m_box);

Why the boundingRect is not updating with the mousemoveEvent?...is there some code required to update the boundingRect ?

Any help is appreciated.

[eyllanesc]

boundingRect does not depend on the position of the item with respect to the scene since it is in coordinates with respect to the item. I recommend you review https://doc.qt.io/qt-5/graphicsview.html so that you understand the different coordinate systems that are handled.