title: QGraphicsItem clipping children.
body: <p>My derived class from QGraphicsItem returns a bounding rect of Rect1.</p>
  
  <pre><code>QRectF BaseControl::boundingRect() const {
      return(Rect1);
  }
  </code></pre>
  
  <p>Its many children all clip to Rect1.</p>
  
  <p>Instead, How do I get the children to clip to an inner rect Rect2 defined by me while the boundingRect of my QGraphicsItem remains as Rect1?. </p>