Finding Your Way Around Map Kit

FINDING YOUR WAY AROUND MAPKIT

byRyan�� Johnson

MOBILE DATA SOLUTIONS@_RyanJohnson_Monday, April 16, 12

WHAT WE’LL COVER

Core Location

The Basics

Simulating Location

Geocoding

Map Kit

The Basics

Annotations

Overlays

Advanced Drawing & Animation

Monday, April 16, 12

CORE LOCATIONTHE�� BACKEND


GETTING THE USER’S LOCATIONCLLocationManager


GETTING THE USER’S LOCATION

1. Instantiate a CLLocationManager object: manager = [[CLLocationManager alloc] init];

CLLocationManager




2. Set a delegate: manager.delegate = (id<CLLocationManagerDelegate>)self;

CLLocationManager





3. Set your desired accuracy & start monitoring:manager.desiredAccuracy = kCLLocationAccuracyBest;[manager startUpdatingLocation];

CLLocationManager






4. Location updates are sent to the delegate method:- (void) locationManager:(CLLocationManager *)manager didUpdateToLocation:(CLLocation *)newLocation fromLocation:(CLLocation *)oldLocation;

CLLocationManager






4. Location updates are sent to the delegate method:- (void) locationManager:(CLLocationManager *)manager didUpdateToLocation:(CLLocation *)newLocation fromLocation:(CLLocation *)oldLocation;

CLLocationManager

PROTiP:�� GPS�� hates�� batteries.�� You�� can�� help�� save�� the�� user’s�� battery�� by�� setting�� the�� desired�� accuracy�� to�� what�� you�� actually�� need.�� Less�� accurate�� =�� more�� battery�� life�� =�� better�� UX.

manager.desiredAccuracy = kCLLocationAccuracyThreeKilometers


Geography�� Lesson�� #1:The�� World�� Is�� Round.

Latitude�� =�� the�� east/west

Longitude�� =�� the�� north/south

The�� distance�� or�� direction�� between�� two�� points�� is�� calculated�� over�� the�� sphere�� of�� the�� earth�� not�� a�� straight�� line.


➡ location.coordinate - the CLLocationCoordinate2D struct with the latitude and longitude

➡ location.horizontalAccuracy - the accuracy of the coordinate in meters

➡ location.speed - the user’s speed in meters per second

➡ location.course - the direction the user is headed in degrees

THE LOCATION MODELCLLocation

Y U NO WORK!?Invalid�� Coordinates�� can�� cause�� tough�� to�� debug�� issues.��

You�� can�� validate�� your�� coordinates�� withCLLocationCoordinate2DIsValid(CLLocationCoordinate2D coord)


REGION MONITORING

➡ Easy to use geofencing - lets you know when a user enters or exits a defined circular geographic region.

➡ Can continue to run in the background, relaunching your app when a user enters/exits a region.

➡ Shared system resource (limit, identifiers)

CLRegion

➡ Create a CLRegion to be monitored:CLLocationCoordinate2D regionCenter = {42.443904, -71.122044};CLRegion * region = [[CLRegion alloc] initCircularRegionWithCenter:regionCenter radius:1000 identifier:@"A Monitored Region"];

➡ Send the CLRegion to a CLLocationManager to be monitored[_locationManager startMonitoringForRegion:region desiredAccuracy:50];

➡ Region events are passed to the CLLocationManager delegate’s methods:- (void) locationManager:(CLLocationManager *)manager didEnterRegion:(CLRegion *)region; - (void) locationManager:(CLLocationManager *)manager didExitRegion:(CLRegion *)region;


SIMULATING YOUR LOCATION

➡ Can simulate a pin point location or travel a long a series of points

➡ If you do nothing, the simulator’s default location is in San Francisco.

➡ Three Ways to Simulate Your Location

➡ Default locations in Xcode

➡ A GPX File

➡ UIAutomation - UIATarget setLocation(coordinateDictionary)

PROTIP:�� Only�� simulate�� your�� location�� on�� devices�� dedicated�� to�� development.�� Your�� simulated�� location�� is�� reported�� to�� all�� apps.�� So,�� Maps�� or�� Path�� will�� think�� you’re�� in�� Pyongyang�� when�� you’re�� really�� in�� Eagan.


CODE DEMOBASICS�� AND��

LOCATION�� SIMULATION


Reverse geocoding introduced in iOS 3 with MKReverseGeocoder (now depreciated)

iOS 5 now allows for forward and reverse geocoding in the new CLGeocoder class.

Forward Geocoding - turns an address into a coordinate

Reverse Geocoding - turns a coordinate into an address

GEOCODINGCLGeocoder


CODE DEMOGEOCODING


RUNNING IN THE BACKGROUND

Location services are a permitted background task

Enabled in the Info.plist:<key>UIBackgroundModes</key><array><string>location</string></array>

Region Monitoring does not require the background task permission. Your app will be relaunched in the background to allow for processing the region event.


MAP KITTHE�� FRONT�� END


Geography�� Lesson�� #2:Maps�� are�� flat.�� this�� is�� a�� problem.

There�� are�� a�� lot�� of�� ways�� to�� make�� a�� circle�� flat.��







MKMapView�� uses�� a�� web�� mercator�� projection.





















Mapkit�� uses�� its�� own�� structures�� (MKMapPoint,�� MKMapRect)�� to�� handle�� this�� conversion


The basic way of showing geographic data

Can show the user’s location with out the need for Core Locationmapview.showsUserLocation = YES;[mapView setUserTrackingMode:MKUserTrackingModeFollow animated:YES];

MAPSMKMapView


The basic way of presenting point data on a map

Comes with a disclosure pop-out for additional detail

MKAnnotation is the basic model (really a protocol) and MKAnnotationView is the view. You add the MKAnnotation to the map, and the map is provided a view by the map’s delegate.

ANNOTATIONSMKAnnotation + MKAnnotationView


Allows you to place paths or custom drawing over a map.

Provided basic path types: MKCircle, MKPolyline, MKPolygon

Can create your own view classes to easily draw over a map.

Custom drawing must be done by overriding:- (void)drawMapRect:(MKMapRect)mapRect zoomScale:(MKZoomScale)zoomScaleinContext:(CGContextRef)context;

OVERLAYSMKOverlay + MKOverlayView


CODE DEMOANNOTATIONS�� +�� OVERLAYS


Geospatial Data Abstraction Library

www.gdal.com or brew install gdal

A command line tool to create your own tile images and to convert the projection of images

Essential if you’re going to put your own images on a map

GDAL


http://www.gdal.com

http://www.gdal.com

CODE DEMOTILED�� IMAGES


WWDC Videos & Sample Code -2010 Session - Customizing Maps With Overlays KML https://developer.apple.com/library/ios/samplecode/KMLViewer/Introduction/Intro.html#//apple_ref/doc/uid/DTS40010046

Tiled Images (in the Code Bundle) http://connect.apple.com/cgi-bin/WebObjects/MemberSite.woa/wa/getSoftware?

wosid=aY5boO0HQiIJ3STghf12IbXXhCt&fileID=26713&code=y&source=x

2011 Session - Visualizing Information Graphically With MapKit

Open Source Code -VPPMap (Annotation Clustering)- https://github.com/vicpenap/VPPMapCore Location Utils - https://github.com/100grams/CoreLocationUtils

ADDITIONAL RESOURCES


https://developer.apple.com/itunes/?destination=adc.apple.com.4092349126.04109539109.4144345629?i=1086097872

https://developer.apple.com/itunes/?destination=adc.apple.com.4092349126.04109539109.4144345629?i=1086097872

https://developer.apple.com/library/ios/samplecode/KMLViewer/Introduction/Intro.html#




http://connect.apple.com/cgi-bin/WebObjects/MemberSite.woa/wa/getSoftware?wosid=aY5boO0HQiIJ3STghf12IbXXhCt&fileID=26713&code=y&source=x






https://developer.apple.com/videos/wwdc/2011/includes/visualizing-information-geographically-with-mapkit.html%23visualizing-information-geographically-with-mapkit

https://developer.apple.com/videos/wwdc/2011/includes/visualizing-information-geographically-with-mapkit.html%23visualizing-information-geographically-with-mapkit

https://github.com/vicpenap/VPPMap

https://github.com/vicpenap/VPPMap

https://github.com/100grams/CoreLocationUtils

https://github.com/100grams/CoreLocationUtils

Documents

Finding Your Way Around Map Kit