swift-sample-region-notification-10.swift

import UIKit
import MapKit
import CoreLocation

class ViewController: UIViewController, MKMapViewDelegate {

    @IBOutlet weak var mapView: MKMapView!
    
    override func viewDidLoad() {
        super.viewDidLoad()
        
        // setup Map View on User Location
        let noLocation = CLLocationCoordinate2D()
        let span = MKCoordinateSpan(latitudeDelta: 0.001, longitudeDelta: 0.001)
        let viewRegion = MKCoordinateRegion(center: noLocation, span: span)
        
        mapView.delegate = self
        mapView.region = viewRegion
        mapView.showsUserLocation = true
        mapView.userTrackingMode = .follow
        
        setupMapView()
    }
    
    func setupMapView(){
        
        var annotationList = [MKPointAnnotation]()
        var circleList = [MKCircle]()
        
        let locationName = "Tokyo Tower"
        let coordiate = CLLocationCoordinate2DMake(35.658626, 139.745471)
        
        // setup annotation
        let annotation = MKPointAnnotation()
        annotation.coordinate = coordiate
        annotation.title = locationName
        
        annotationList.append(annotation)
        
        // setup circle
        let circle = MKCircle(center: coordiate, radius: 50)
        circleList.append(circle)
        
        // add to map view
        mapView.addAnnotations([annotation])
        mapView.addOverlays([circle])
    }
    
    func mapView(_ mapView: MKMapView, didUpdate userLocation: MKUserLocation) {
        
        let span = MKCoordinateSpan(latitudeDelta: 0.001, longitudeDelta: 0.001)
        let region = MKCoordinateRegion(center: userLocation.coordinate, span: span)
        mapView.region = region
    }
    
    func mapView(_ mapView: MKMapView, rendererFor overlay: MKOverlay) -> MKOverlayRenderer {
        
        let circleRenderer = MKCircleRenderer(overlay: overlay)
        circleRenderer.strokeColor = UIColor(red: 66/255, green: 133/255, blue: 244/255, alpha: 0.80)
        circleRenderer.lineWidth = 1.0
        circleRenderer.fillColor = UIColor(red: 66/255, green: 133/255, blue: 244/255, alpha: 0.20)
        
        return circleRenderer
    }
}