[Qt-interest] How to update

[Sean Harmer]

Hi,

On Thursday 02 Jul 2009 08:32:16 Sujan Dasmahapatra wrote:
> I have a custom GraphicsItem  Geometry class.
>
> Class Geometry:public  QGraphicsItem
> {
>                 Q_OBJECT
> Public:
>                 Int  numberOfPoints;
>                 QPointF  *points;
> };
>
> Geometry *geometry = new Geometry;
> geometry->setPos(dx+geometry->x(),dy+geometry->y());
>
>  I do a translation on the geometry by setPos() function so the position
> of the geometry is changed.How would I update the 'points' with the new
> coordinate points??? Please tell me someone.
You don't need to update the internal position of the points. Your custom item 
should just draw them in local item coordinates as always. The QGraphocsView 
framework takes care of applying the transformation to your item as a whole. 
Please have a read through the docs on QGraphicsView and coordinate systems:

http://doc.qtsoftware.com/4.5/graphicsview.html#the-graphics-view-coordinate-
system

Sean