This lecture investigates using the Google Maps SDK in an iOS application written in the Swift language. There are several inaccuracies / missing steps in the Google documentation at the date this presentation was given, so this guide was designed to help students quickly get up Google Maps up and running in their apps in minimal time. We also take a look at the basic concepts in the iOS CoreLocation framework in obtaining location information in your app in addition to using GeoCoders for forward and reverse lookups. This lecture is part of a course intended to be an intensive and very compressed deep dive into iOS development in Swift. Visit the course web page to get copies of the course outline, lecture notes, sample code, etc. Course website: http://www.themobilemontage.com/2015/05/12/ios-bootcamp-learning-to-create-awesome-apps-on-ios-using-swift/

1. Working with the
iOS Core Location Framework
and Google Maps SDK
Lecture 10
Jonathan R. Engelsma

2. TOPICS
• The Fundamentals.
• Working with CoreLocation
• Working with Google Maps SDK

3. THE CURRENT LOCATION
• The ability to obtain the device’s
current location is a very powerful
feature!
• Enabler for context aware
computing
• App integrates content and
behavior relevant to current
location

4. OBTAININGTHE LOCATION
• Smartphones use a variety of
techniques to locate the device:
• GPS
• Assisted GPS
• Cellular / WiFiTriangulation

5. GLOBAL POSITIONING
SYSTEM
• Space-based satellite system (US Government)
• Requires line of sight to 4+ satellites
• Accuracy: ~ 3 - 15 meters.
• Can take time to get first fix.
• Don’t work well indoors.

6. ASSISTED GPS
• Greatly reduces theTTFF (time to first fix).
• Uses terrestrial radio network to accelerate connection to
satellite.
• Widely used by modern cell phones.

7. WIFI / CELLULAR
TRIANGULATION
• Uses terrestrial cellular
towers and wifi access
points to determine device
location.
• Can be used indoors!

8. OBTAININGTHE LOCATION
• Implication: Location data varies in accuracy.
Accurate Less Accurate

9. TAKES ENERGY!
• Getting a GEO fix takes a
lot of battery!
• device can’t sleep when
GPS receiver is running.
• make sure your apps
don’t misuse or you will
get uninstalled real fast!

10. CORE LOCATION
• CoreLocation Framework
• Provides apps with location coordinate and heading info.
• Can define geographical regions and monitor when user
crosses region boundaries.
• Also supports “beacon” regions with iBeacon devices.

11. LOCATION MANAGER
• CLLocationManager:
var locationManager = CLLocationManager()
locationManager.desiredAccuracy = kCLLocationAccuracyBest
locationManager.distanceFilter = 10.0
Determine how far the device must travel
before a new location update is generated.

12. LOCATION ACCURACY
Accuracy Technology
kCLLocationAccuracyBestForNavigation GPS
kCLLocationAccuracyBest GPS
kCLLocationAccuracyNearestTenMeters GPS
kCLLocationAccuracyHundredMeters
WiFi (GPS in rural
areas)
kCLLocationAccuracyKilometer Cell tower
kCLLocationAccuracyThreeKilometers Cell tower

13. LOCATION MANAGER
• CLLocationManager requires location updates asynchronously.
• View Controller typically implements the
CLLocationManagerDelegate protocol to receive these
updates.

14. LOCATION MANAGER
DELEGATE
func locationManager(manager: CLLocationManager!,
didChangeAuthorizationStatus status: CLAuthorizationStatus)
{
// called when authorization changes.
}
func locationManagerDidResumeLocationUpdates(manager: CLLocationManager!) {
// called when location updates start to arrive.
}

15. LOCATION MANAGER
DELEGATE
func locationManager(manager: CLLocationManager!,
didUpdateLocations locations: [AnyObject]!)
{
var location: CLLocation = locations.first as! CLLocation
// put code to handle location update here.
}

16. CLLOCATION
• CLLocation: represents the data generated by
CLLocationManager. It contains:
• geo coordinates and altitude
• accuracy indicator
• time
• speed and heading.

17. GEO CODING
• CLGeocoder: converts between a lat/long coordinate and a
user-friendly representation of that coordinate.
Lat: 42.963661
Long: -85.677515
Grand Rapids, MI
USA
reverse geo-coding
forward geo-coding

18. GEO-CODING GUIDELINES
• Geocoder requests involve the network and are rate limited:
• send one request per user action.
• cache the results if you do more than one action per loc.
• issue a new geocoding request only if user has moved a
significant distance.
• don’t use it in the background!

19. GOOGLE MAPS SDK
• Google Maps SDK is the alternative of
choice for Apple MapKit!
• Provides more detailed map tiles.
• Includes StreetView!
• Can optionally use Apple’s MapKit
framework
https://developers.google.com/maps/documentation/ios/intro

20. GOOGLE MAPS SDK
• Types: Normal, Satellite, Hybrid,Terrain
• Traffic Layer
• Indoor building maps where available. (Museum navigator!)
• Places API / Place Picker
• Panorama (StreetView)
• Interactive Markers
• Polygons
• Camera view animation

21. DISPLAY MODES
Standard Satellite StreetView

22. CREATING A MAPVIEW
override func viewDidLoad() {
super.viewDidLoad()
locationManager.delegate = self
locationManager.requestWhenInUseAuthorization()
var cameraAllendale = GMSCameraPosition.cameraWithLatitude(42.96356,
longitude: -85.8899, zoom: 14.7)
mapView = GMSMapView.mapWithFrame(CGRectZero, camera: cameraAllendale)
mapView.settings.compassButton = true
self.view = mapView
let marker = GMSMarker()
marker.position = CLLocationCoordinate2DMake(42.96356, -85.8899)
marker.title = "GVSU"
marker.snippet = "Allendale, MI"
marker.icon = UIImage(named: "gvsu")
marker.appearAnimation = kGMSMarkerAnimationPop
marker.map = mapView
}

23. READING ASSIGNMENT
• Chapter 21 in Programming iOS8 by Neuburg
• Google Map SDK Documentation / Example Code
• https://developers.google.com/maps/documentation/ios/