title: PyQt: QGraphicsScene events are not propagated down to GraphicItems
body: <p>I have a GraphicScene inside a QGraphicView populated with many rectangles (items). I would like each rectangle to respond to the mouse click but I'm not able to find the hook to attach the event handler to the correct object and to get the event propagated to it.</p>
  
  <p>I attached an event handler to the scene:</p>
  
  <pre><code>scene.event = myfunction
  </code></pre>
  
  <p>and it worked (it was firing every event) but I was unable to attach the same function to one of its children. Can you give me an insight on where to search for such an entry point?</p>