title: How to handle taps on a custom callout view?
body: <p>I am adding a callout view like this:</p>
  
  <pre><code>func mapView(mapView: MKMapView!,
          didSelectAnnotationView view: MKAnnotationView!) {
      let calloutView = UIView(frame:
          CGRect(x: 0, y: 0, width: 300, height: 120))
  
      calloutView.backgroundColor = UIColor.purpleColor()
      calloutView.center = CGPointMake(CGRectGetWidth(view.bounds) / 2.0, 0.0)
      calloutView.layer.anchorPoint = CGPointMake(0.5, 1.0)
      calloutView.layer.masksToBounds = false
  
      calloutView.userInteractionEnabled = true
      let calloutViewTapRecognizer = UITapGestureRecognizer(target: self,
          action: "onCalloutViewTap")
      calloutView.addGestureRecognizer(calloutViewTapRecognizer)
  
      view.addSubview(calloutView)
  }
  </code></pre>
  
  <p>Though my <code>onCalloutViewTap</code> function is never called... I am curious to understand why and to get something that works to handle interactions with my callout view.</p>