[SOLVED] QGraphicsScene Layer

droelf

I want to draw Circles with various depths.

Like this:
http://www.informatik.uni-koeln.de/ls_juenger/fileadmin/projects/geodual/sc04.png

But it happens that they disappear or some seem to not appear at all.

I am using addEllipse() for this.

Does someone know how to handle the layers of a QGraphicsscene properly?

SGaist

Hi,

Isn't setZValue what you are looking for ?

droelf

@SGaist

yep, now i initialized all GraphicItems by using GraphicsEllipseItem instead of adding them directly.
But now i got following problem:
The first layer got zValue 0
The second -1
.....
But somehow my elements on depth -3 wont get painted.
Is there a limit or some sort of event when the GraphicsScene clears itself?

Here is a code snippet:

 if(y!=0){
               QGraphicsEllipseItem* el = new QGraphicsEllipseItem();
               QRect rect4(v_to_paint->pos.x(),v_to_paint->pos.y(),(v_to_paint->yv+y)*2,(v_to_paint->yv+y)*2);
               el->setRect(rect4);
               el->setPen(Pen);
               el->setBrush(Brush);
               el->setZValue(depth);
               painter->addItem(el);
           }

           int type = v_to_paint->type;


           if((type==1||type==2)&&(v_to_paint->isRoot==false)){
           QGraphicsEllipseItem* el1 = new QGraphicsEllipseItem();
           QRect rect(v_to_paint->pos.x()-v_to_paint->yv,v_to_paint->pos.y()-v_to_paint->yv,v_to_paint->yv*2,v_to_paint->yv*2);
           el1->setRect(rect);
           el1->setPen(greenPen);
           el1->setBrush(greenBrush);
           el1->setZValue(-2);
           painter->addItem(el1);

           QGraphicsEllipseItem* el2 = new QGraphicsEllipseItem();
           QRect rect2(v_to_paint->pos.x()-3,v_to_paint->pos.y()-3,6,6);
           el2->setRect(rect2);
           el2->setPen(blackPen);
           el2->setBrush(blackBrush);
           el2->setZValue(-1);
           painter->addItem(el2);

The first one "el" is the one that wont get painted.

SGaist

You should take a look at the Drag and Drop Robot example, the use of setZValue is shown there