Handling taps on a map

Question

I have an iOS app where I need to interfere with a map. After searching a bit I came to the conclusion that I have to use an MKMapView object and probably implement the MKMapViewDelegate protocol.

I am now wondering how I can capture the touch point (meaning longitude and lattitude) when the user taps on the map. I suppose there is a much better way than fiddling around with a home made UITapGestureRecognizer.

To make it clear and simple, I have this kind of code to start with:

import UIKit
import CoreLocation
import MapKit

class ViewController: UIViewController, CLLocationManagerDelegate, MKMapViewDelegate {
    let appDelegate = UIApplication.sharedApplication().delegate as! AppDelegate,
    screenSize: CGRect = UIScreen.mainScreen().bounds,
    locationManager = CLLocationManager()
    .........

    override func viewDidLoad() {
        super.viewDidLoad()

        locationManager.delegate = self
        locationManager.desiredAccuracy = kCLLocationAccuracyBest
        .........

        let mapView = MKMapView(frame: CGRect(origin: CGPoint(x: 0.0, y: 20.0),
            size: CGSize(width: screenSize.width,
                height: screenSize.height-70.0)))
        mapView.delegate = self
        self.view.addSubview(mapView)
    }

    .........
}

My question is: what do I have to do to handle the tap of the user on the mapView object? Though I looked for the anwer before writing this post, I came with no clear solution.

There is only one way and it is using `TapGestureRecognizer`. — Nirav D, Dec 02 '16 at 07:14
You mean getting the point with TapGestureRecognizer and then converting to the map coordinates, using the origin and zooming factor of the map? — Michel, Dec 02 '16 at 07:17
Yes I agree too `Nirav D`'s comment , when I try to handle the same scenario, I searched a lot, but finally I gone with `UITapGestureRecognizer` — Karthick Selvaraj, Dec 02 '16 at 07:18
Well, that sounds SAD :). But if that is the way it is. I'll have to do with that. — Michel, Dec 02 '16 at 07:20

Ramkrishna Sharma · Answer 1 · 2017-01-03T14:02:37.313

Please add the UITapGestureRecognizer in viewDidLoad.

    let gestureRecognizer = UITapGestureRecognizer(target: self, action:#selector(ViewController.getCoordinatePressOnMap(sender:)))
    gestureRecognizer.numberOfTapsRequired = 1
    mapView.addGestureRecognizer(gestureRecognizer)

Implementation of getCoordinatePressOnMap method.

@IBAction func getCoordinatePressOnMap(sender: UITapGestureRecognizer) {
    let touchLocation = sender.location(in: mapView)
    let locationCoordinate = mapView.convert(touchLocation, toCoordinateFrom: mapView)
    print("Tapped at lat: \(locationCoordinate.latitude) long: \(locationCoordinate.longitude)")
}

Note :

convert(_:toCoordinateFrom:) : Converts a point in the specified view’s coordinate system to a map coordinate.

Hope it works for you!!!

score 0 · Answer 2 · answered Dec 02 '16 at 07:21

By looking at the documentation, there isn't any method that handles touches.

I think you have to detect touch using UITapGestureRecognizer. touchesBegan doesn't work because I think the map view intercepts that, just like a table view.

After you detected the touch location, use the convert(_:toCoordinateFrom:) method to convert the CGPoint in the map view's coordinate space to a CLLocationCoordinate2D on the map.

If this all sounds too troublesome, you can use Google Maps instead. GMSMapView has a delegate method mapView(_:didTapAt:) method that you can implement.

Handling taps on a map

2 Answers2