There's a point I wonder, maybe someone could explain me with simple words better than the doc do...
When you want to add an overlay onto a MKMapView, you first add something that follow the MKOverlay protocol.
Then later, (MKOverlayView*)mapView:(MKMapView*)mapView viewForOverlay:(id)overlay
is called and you must return a MKOverlayView or something that inherits it.
What is the role of the overlay added in addOverlay
as it does not display anything ? Why not directly add a subview as it's done with addSubview for views and put "inside it" the needed vars for the display ? Why running with such a 2 part process ?