Have someone any idea, dealing with the resizing of a QGraphicsPixmapItem???

Reading the documentation i find many reasons that could introduce problem during the resize:
1)When we resize a QGraphicsRectItem, we work on a QrectF that is more accurate to give us the corners coordinate(QGraphicsPixmapItem work with QRect Object)
2)QGraphicsPixmapItem objects, start drawing its pixmap, starting from the QpointF "offset()", which defines the top-left corner of the pixmap; so i think that if we change the rect of the pixmap, we have to change also the offset() of the current resizing item.

I make a lot of different version of resizing, but i can't find the solution.
I find the right resizing method for the bottom side and the bottom right corner(So i think the problem starts when we modify the top-left corner!!!)

Bottom-side:
Qt Code: 
  1. QRect new_rect(pixmap().rect().topLeft(),
  2. QPoint(pixmap().rect().topRight().x(),event->pos().toPoint().y()));
  3. setPixmap(QPixmap::fromImage(image.scaled(QSize(new_rect.width(),new_rect.height()),Qt::IgnoreAspectRatio,Qt::FastTransformation)));
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Botto-right corner:
Qt Code: 
  1. QRect new_rect(pixmap().rect().topLeft(),QPoint(event->pos().toPoint().x(),
  2. event->pos().toPoint().y()));
  3. setPixmap(QPixmap::fromImage(image.scaled(QSize(new_rect.width(),new_rect.height()),Qt::IgnoreAspectRatio,Qt::FastTransformation)));
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I hope someone will help me.........thanks a lot.