Unsolved centering under mouse on QGraphicsItem when zooming

[lansing]

I have a rectangle QGraphicsItem in a QGraphicsView. When I scroll my mouse, the width of the item will change representing zoom in/zoom out. When the width of the item is longer than the view, a scroll will appear. Now I want the anchor to be under my mouse when scrolling so it stays in the center of viewport in the perspective of the QGraphicsItem.

The document has info about setResizeAnchor(QGraphicsView::AnchorUnderMouse) but that only applies to the coordinate of QGraphicsView, I want it to be centering on the QGraphicsItem instead.