I’m writing this for a local university with students who are working on an iOS project to track the locations of an object at a fixed location. I advised them to ensure that the data models input into Realm match those in the script and be cautioned that further work will be required for the mobile app, such as recalculating things as your device location changes in relation to the object you’re tracking.
To track and follow a moving object using Swift, you can use the Core Location framework, specifically the CLLocationManager
class. Here’s an example code snippet that shows how to track and follow a moving object using the CLLocationManager
:
import CoreLocation
class ViewController: UIViewController, CLLocationManagerDelegate {
let locationManager = CLLocationManager()
override func viewDidLoad() {
super.viewDidLoad()
// Request authorization to use location services
locationManager.requestWhenInUseAuthorization()
// Set up location manager
locationManager.delegate = self
locationManager.desiredAccuracy = kCLLocationAccuracyBestForNavigation
locationManager.startUpdatingLocation()
locationManager.startUpdatingHeading()
}
func locationManager(_ manager: CLLocationManager, didUpdateLocations locations: [CLLocation]) {
// Get the current location
guard let currentLocation = locations.last else { return }
// Calculate the distance and bearing to the target location
let targetLocation = CLLocation(latitude: 37.7749, longitude: -122.4194) // target location (e.g., moving object)
let distance = currentLocation.distance(from: targetLocation)
let bearing = currentLocation.bearing(to: targetLocation)
// Rotate the view to point in the direction of the target location
// (assuming that the view is a compass or map view)
let heading = locationManager.heading?.trueHeading ?? 0.0 // get the current heading
let relativeBearing = bearing - heading // calculate the relative bearing
// rotate the view by relativeBearing degrees
// (assuming that the view's orientation is measured in degrees clockwise from true north)
}
}
In this example, we create a CLLocationManager
object and request authorization to use location services. We set the delegate to self
and configure the location manager to use the best available accuracy for navigation. We start updating the location and heading of the device.
In the locationManager(_:didUpdateLocations:)
method, we get the current location from the locations
array. We then calculate the distance and bearing to the target location, which in this case is a fixed location that represents the moving object.
We calculate the relative bearing by subtracting the current heading from the bearing to the target location. We then rotate the view by the relative bearing to point in the direction of the target location.
Note that this is a simplified example and assumes that the target location is a fixed location. If the target location is a moving object, you’ll need to update its location periodically and recalculate the distance and bearing to it. You can do this using a timer or by subscribing to location updates from a remote API.