[Qt-jambi-interest] maping & Cooirdinates

[Dawid Sip]

Hi,

Im having a tough time with Rectangle positioning in a scene.
Basicaly I'm using a custom Cursor made from an rectangular image. I 
take the im and get its .rect(), I than make 
graphicsView.mapToScene('the rectangle'), and get a polygon from which i 
create graphicsItem which i add to the scene. I want this item to be 
added at the cursor position which i have in QPoint p, do i do 
polygonItem.moveBy(p.x(), p.y()). Unfortunately this does not place the 
item where the cursor is. This has something to do with the 
graphicsView.mapToScene transformation. When I ommit this transformation 
and create polyItem directrly from the 'rect' and move it by the amount 
in p, all works fine. I cant leave it like this though because i need 
the mapToScene to make the polyItem dimensions appear exactly like the 
cursors. What do i do wrong here?

    protected void markForegroundRegion(QPoint p){
        //p is in scene coords  
   
//        QPolygonF pol = this.view.mapToScene(cursorIm.rect());
        QPolygonF pol = new QPolygonF(new QRectF(cursorIm.rect()));
        QRectF rec = pol.boundingRect();
       
        QGraphicsPolygonItem poIt = new QGraphicsPolygonItem(pol);

        poIt.setPos(-rec.width()/2, -rec.height()/2);
       poIt.moveBy(p.x(), p.y());
        poIt.setBrush(new QBrush(new QColor(228, 18, 28, 228)));

        poIt.setZValue(46);
        this.scene.addItem(poIt);
       
    }



Dave