Silver Challenge User's location

iOS Programming: The Big Nerd Ranch Guide (6th Edi 6. Programming Views
22

Hi, I am not clear how to show the user’s location after clicking the button. Could you please give more details? Thanks…

24

With all the posts above, I finally come up with the solution with MKMapView only.

/*
You have to set what the location of the simulator actually is:
(1) search for “Edit Scheme” in the help menu
(2) Options → Core Location → Default Location
*/

import UIKit
import MapKit

class MapViewController: UIViewController, MKMapViewDelegate {

var mapView: MKMapView!

override func loadView() {
    // create a map view
    mapView = MKMapView()
    mapView.delegate = self
    mapView.isZoomEnabled = true
    mapView.isScrollEnabled = true
    
    // comment the line below if automatical locating is desired
    // mapView.showsUserLocation = true

    view = mapView
    
    segmentedControlCreation()
    
    userLocationButtonCreation()
}

func segmentedControlCreation() {
    let segmentedControl = UISegmentedControl(items: ["Standard", "Hybrid", "Satellite"])
    segmentedControl.backgroundColor = UIColor.white.withAlphaComponent(0.5)
    segmentedControl.selectedSegmentIndex = 0
    
    segmentedControl.addTarget(self, action: #selector(MapViewController.mapTypeChanged(_:)), for: .valueChanged)
    
    segmentedControl.translatesAutoresizingMaskIntoConstraints = false
    view.addSubview(segmentedControl)
    
    let topConstraint = segmentedControl.topAnchor.constraint(equalTo: view.safeAreaLayoutGuide.topAnchor, constant: 8)
    
    let margins = view.layoutMarginsGuide
            
    let leadingConstraint = segmentedControl.leadingAnchor.constraint(equalTo: margins.leadingAnchor)
    let trailingConstraint = segmentedControl.trailingAnchor.constraint(equalTo: margins.trailingAnchor)
    
    topConstraint.isActive = true
    leadingConstraint.isActive = true
    trailingConstraint.isActive = true
}

@objc func mapTypeChanged(_ segControl: UISegmentedControl) {
    switch segControl.selectedSegmentIndex {
    case 0:
        mapView.mapType = .standard
    case 1:
        mapView.mapType = .hybrid
    case 2:
        mapView.mapType = .satellite
    default:
        break
    }
}

func userLocationButtonCreation() {
    let button: UIButton = UIButton.init(type: .system)
    button.translatesAutoresizingMaskIntoConstraints = false

    button.setTitle("FindMe", for: .normal)

    button.backgroundColor = UIColor.white.withAlphaComponent(0.5)

    button.addTarget(self, action: #selector(showUserLocation(sender:)), for: .touchUpInside)

    view.addSubview(button)
    
    let margins = view.layoutMarginsGuide

    let bottomConstraint = button.bottomAnchor.constraint(equalTo: margins.bottomAnchor)

    let leadingConstraint = button.leadingAnchor.constraint(equalTo: margins.leadingAnchor)

    bottomConstraint.isActive = true
    leadingConstraint.isActive = true
    
}

@objc func showUserLocation(sender: UIButton!) {
    print("Start locating the user...")
    
    // This should be set here to avoid automatically locating
    mapView.showsUserLocation = true
    
    self.mapView(mapView, didUpdate: mapView.userLocation)
}

override func viewDidLoad() {
    super.viewDidLoad()
}

func mapView(_ mapView: MKMapView, didUpdate userLocation: MKUserLocation) {
    let latitude = userLocation.coordinate.latitude
    let longitude = userLocation.coordinate.longitude
    let center = CLLocationCoordinate2D(latitude: latitude, longitude: longitude)
    let span = MKCoordinateSpan(latitudeDelta: 0.05, longitudeDelta: 0.05)
    let region = MKCoordinateRegion(center: center, span: span)

    mapView.setRegion(region, animated: true)
}

}