I'd like to let the user define a region on a map. The region will be represented by a circle defined by a center and its radius.
Here is a picture of the result I'd like to have : 
radius: I want the radius to be define with a small circle that the user will drag to set the radius size (and I'd like to be able to draw a dashed line between the center and the circle as well as showing the distance).
center I want to set the center of the map by letting the user drag the map behind to move the red pin to the desired new center.
I know how to get the blue circle, how to add a gesture to get the new radius and to redraw a circle at run time. What I don't know is how to draw dashed line, small black circle and display / update text inside the MKMapView.
Also, I'm completely lost when it's about setting the center. How can I drag the map around by letting all this object (blue circle, red pin center, dashed line, ...) not moving ?
Should I completely forget about MKMapView and draw everything above it in a UIView and then get coordinate by mapping fake touch on MKMapView ?
