Centering MKMapView on spot N-pixels below pin

Question

Want to center MKMapView on a point N-pixels below a given pin (which may or may not be visible in the current MapRect).

I've been trying to solve this using various plays with -(CLLocationCoordinate2D)convertPoint:(CGPoint)point toCoordinateFromView:(UIView *)view to no success.

Anyone been down this road (no pun intended)?

Answer 1

SWIFT 3 UPDATED

Updated the function with Zoom

func zoomToPos() {

        let span = MKCoordinateSpan(latitudeDelta: 0.1, longitudeDelta:  0.1)

        // Create a new MKMapRegion with the new span, using the center we want.
        let coordinate = moveCenterByOffset(offset: CGPoint(x: 0, y: 100), coordinate: (officeDetail?.coordinate)!)
        let region = MKCoordinateRegion(center: coordinate, span: span)

        mapView.setRegion(region, animated: true)


    }

    func moveCenterByOffset (offset: CGPoint, coordinate: CLLocationCoordinate2D) -> CLLocationCoordinate2D {
        var point = self.mapView.convert(coordinate, toPointTo: self.mapView)
        point.x += offset.x
        point.y += offset.y
        return self.mapView.convert(point, toCoordinateFrom: self.mapView)
    }

Answer 2

For Swift:

import MapKit

extension MKMapView {

func moveCenterByOffSet(offSet: CGPoint, coordinate: CLLocationCoordinate2D) {
    var point = self.convert(coordinate, toPointTo: self)

    point.x += offSet.x
    point.y += offSet.y

    let center = self.convert(point, toCoordinateFrom: self)
    self.setCenter(center, animated: true)
}

func centerCoordinateByOffSet(offSet: CGPoint) -> CLLocationCoordinate2D {
    var point = self.center

    point.x += offSet.x
    point.y += offSet.y

    return self.convert(point, toCoordinateFrom: self)
}
}