QGraphicsItem doesn't detect its own boundingRect change - qt

Question

// QT 4.8
I've implemented a resizable QGraphicsItem, which works pretty fine.
However, now, I need to include child items in this resizable item.
Child items size/position will obviously depend on parent one.
My problem is to notify childs when parent one is resized.
But so far, the parent itself doesn't detect its own size change (whereas on the scene, everything behave as expected!)
In the parent item (= the resizable one) item I've tried to override
QVariant itemChange(QGraphicsItemChange, QVariant)
in order to dump change events. I can see all events, but itemChange method never get called when item is (being) resized.
Any help greatly appreciated.
NB:
In my resizable QGraphicsItem constructor, I've enabled the flag QGraphicsItem::ItemSendGeometryChange
ResizableGraphicsItem::ResizableGraphicsItem(QGraphicsItem *p_parent,
qreal p_initialWidth,
qreal p_initialHeight)
: QGraphicsItem(p_parent), _width(p_initialWidth),
_height(p_initialHeight), _resized(true)
{
setFlag(ItemSendsGeometryChanges);
...
}
The resize method looks like the following:
void ResizableGraphicsItem::setSize(qreal p_width, qreal p_height)
{
prepareGeometryChange();
if ((_width != p_width) ||
(_height != p_height))
{
_width = p_width;
_height = p_height;
_resized = true;
}
}
with:
QRectF ResizableGraphicsItem::boundingRect() const
{
return QRectF(0, 0, _width, _height);
}