I've been looking at this for a while. I've found plenty of posts and looked at the documentation but I'm having trouble getting it working. I have core location implemented, and its working with no problems i.e.
NSLog(#"Description: %#\n", [newLocation description]);
The description details are displayed in the log.
I want to capture the current location when the user taps on a button and as they start to move recapture their location intermittently. Using this information I want to calculate the distance between the starting point and the current point.
I know I can use the following:
CLLocationDistance distance = [myLocation distanceFromLocation:restaurantLocation]
to calculate the distance but I'm not sure how to capture the current location.
If anyone could post some sample code that would be great. I close to getting this working, just need a final push over the line.
Regards,
Stephen
Part 2: Since the original post, I've made a bit of progess. Details posted below:
#import "MyCLController.h"
#implementation MyCLController
#synthesize locationManager;
#synthesize delegate;
- (id) init {
self = [super init];
if (self != nil) {
self.locationManager = [[[CLLocationManager alloc] init] autorelease];
self.locationManager.delegate = self; // send loc updates to myself
}
return self;
}
- (void)locationManager:(CLLocationManager *)manager
didUpdateToLocation:(CLLocation *)newLocation
fromLocation:(CLLocation *)oldLocation
{
[self.delegate locationUpdate:newLocation];
CLLocation *item1 = [[CLLocation alloc] initWithLatitude:newLocation.coordinate.latitude longitude:newLocation.coordinate.longitude];
CLLocation *item2 = [[CLLocation alloc] initWithLatitude:oldLocation.coordinate.latitude longitude:oldLocation.coordinate.longitude];
int meters = [item1 getDistanceFrom:item2];
NSLog(#"Distance-d: %d", meters);
[item1 release];
[item2 release];
}
- (void)locationManager:(CLLocationManager *)manager
didFailWithError:(NSError *)error
{
[self.delegate locationError:error];
}
- (void)dealloc {
[self.locationManager release];
[super dealloc];
}
#end
Am I right to calculate the distance here or should I be doing it in NewWorkoutViewController.m, in the locationUpdate method ?
You set a delegate on your location manager which will be called when the location changes. You can control (indirectly) how often it gets called by specifing a distance filter so that you will only get a callback if the location has moved at least that amount.
Related
I'm pretty new to iOS development (my first app) and I faced this issue.
I have an iPhone app that should get user's current location in multiple ViewControllers upon user button touch. To prevent redundant code (implementing locationManager:didFailWithError, locationManager:didUpdateToLocation:fromLocation, etc. multiple times in different view controllers) I decided to create a custom class called LocationManager:
LocationManager.h
#interface LocationManager : NSObject <CLLocationManagerDelegate> {
#private
CLLocationManager *CLLocationManagerInstance;
id<LocationManagerAssigneeProtocol> assignee;
}
-(void) getUserLocationWithDelegate:(id) delegate;
LocationManager.m
#implementation LocationManager
-(id)init {
self = [super init];
if(self) {
CLLocationManagerInstance = [[CLLocationManager alloc] init];
CLLocationManagerInstance.desiredAccuracy = kCLLocationAccuracyBest;
CLLocationManagerInstance.delegate = self;
}
return self;
}
-(void) getUserLocationWithDelegate:(id) delegate {
if([CLLocationManager locationServicesEnabled]) {
assignee = delegate;
[CLLocationManagerInstance startUpdatingLocation];
}
}
#pragma CLLocationManagerDelegate
- (void)locationManager:(CLLocationManager *)manager didFailWithError:(NSError *)error {
...
}
- (void)locationManager:(CLLocationManager *)manager didUpdateToLocation:(CLLocation *)newLocation fromLocation:(CLLocation *)oldLocation {
[CLLocationManagerInstance stopUpdatingLocation];
[assignee didUpdateToLocation:newLocation];
}
and I have a protocol called LocationManagerAssigneeProtocol that my ViewControllers implement
#protocol LocationManagerAssigneeProtocol <NSObject>
#required
-(void) didUpdateToLocation:(CLLocation *) location;
#end
and in my viewcontroller where needed
- (IBAction)getMyLocation:(id)sender {
[locationMgr getUserLocationWithDelegate:self];
}
This code works perfectly, however, I have a feeling that I'm violating some design patterns here by letting LocationManager be able to call a function of the class that itself initiated a call to Location Manager. On the other hand, I don't want to go with implementing CLLocationManagerDelegate for all my viewcontrollers that are supposed to work with locations.
Are there any better solution to this issue?
I agree with #CarlVeazey on this one. Delegate are great for a 1 to 1 relationship existing at any one time, however in your case it seems that you may need multiple viewControllers to respond to location events at any given time. So just remove anything related to your delegate and its associated protocol.
I'd probably make LocationManager class a singleton and modify the methods for updating:
+(LocationManager *)sharedInstance
{
static LocationManager *_sharedInstance = nil;
static dispatch_once_t oncePredicate;
dispatch_once(&oncePredicate, ^{
_sharedInstance = [[self alloc] init];
});
return _sharedInstance;
}
-(void)getUserLocation
{
if ([CLLocationManager locationServicesEnabled])
[CLLocationManager startUpdatingLocation];
}
-(void)locationManager:(CLLocationManager *)manager didUpdateToLocation:(CLLocation *)newLocation fromLocation:(CLLocation *)oldLocation
{
[CLLocationManagerInstance stopUpdatingLocation];
[[NSNotificationCenter defaultCenter] postNotificationWithName:#"LocationManagerDidUpdateLocation" object:newLocation];
}
... Then any viewController that needs to use this class would have something like:
-(void)viewDidLoad
{
[super viewDidLoad];
[[NSNotificationCenter defaultCenter] addObserverForName:#"LocationManagerDidUpdateLocation" object:self queue:[NSOperationQueue mainQueue] usingBlock:^(NSNotification *note) {
CLLocation *location = note.object;
...
}];
}
-(IBAction)getMyLocation:(id)sender {
[[LocationManager sharedInstance] getUserLocation];
}
Hope that helps and makes sense.
I am doing one application.In that i am using the CLLocationManager Class for getting the updated location latitude and longitude details.But i need to use this CLLocationManager in sepaate thread .I written my code like below.
- (void)viewDidLoad
{
[NSThread detachNewThreadSelector:#selector(fetch) toTarget:self withObject:nil];
}
-(void)fetch
{
manager=[[CLLocationManager alloc]init];
manager.delegate=self;
manager.distanceFilter=kCLDistanceFilterNone;
manager.desiredAccuracy = kCLLocationAccuracyBest;
[manager startUpdatingLocation];
}
- (void)locationManager:(CLLocationManager *)manager
didUpdateToLocation:(CLLocation *)newLocation
fromLocation:(CLLocation *)oldLocation
{
NSLog(#"%f",newLocation.coordinate.latitude);
lbl.text=[NSString stringWithFormat:#"%f",newLocation.coordinate.longitude];
}
.But this delegate method is not fired when i run this code.So please guide me how to get the location updates in separate thread.
The methods of your delegate object are called from the thread in which you started the corresponding location services. That thread must itself have an active run loop, like the one found in your application’s main thread. ——from apple document
Could you please tried with this.
dispatch_async(newThread, ^(void) {
[self fetch];
});
hope you'll get solved problem.
in .h file
MainView *ctl;
NSMutableDictionary *dictSubPoses;
- (id)initWithCtl:(MainView*)_ctl;
in .m file
- (id)initWithCtl:(MainView*)_ctl
{
if(self = [super init])
{
ctl = _ctl; //[_ctl retain];
}
return self;
}
- (void)main
{
[ctl performSelector:#selector(yourMethod) withObject:dictSubPoses];
}
in .h file
#import <CoreLocation/CoreLocation.h>
#import <MapKit/MapKit.h>
//Set Delegate
CLLocationManagerDelegate
// Declare
CLLocationManager *locationManager;
in .m file
-(void)ViewDidLoad
{
locationupadate=YES;
locationManager = [[CLLocationManager alloc] init];
locationManager.delegate = self;
locationManager.desiredAccuracy = kCLLocationAccuracyBest;
locationManager.distanceFilter = 100.0f;
[locationManager startUpdatingLocation];
}
- (void)locationManager:(CLLocationManager *)manager
didUpdateToLocation:(CLLocation *)newLocation
fromLocation:(CLLocation *)oldLocation
{
if(locationupadate)
{
NSLog(#"%f",newLocation.coordinate.latitude);
lbl.text=[NSString stringWithFormat:#"%f",newLocation.coordinate.longitude];
}
I was really hesitant to post a fourth question on this subject, but triple-checked everything according to previous answers and still get bad results.
Problem: CLLocationManager does not call didEnterRegion in iOS6.
Setup: iOS6.
Here is the code with all the functions relevant to CLLocationManager
myMapViewController.h
#interface FirstViewController : UIViewController <UIApplicationDelegate,CLLocationManagerDelegate, MKMapViewDelegate, UISearchBarDelegate,RKObjectLoaderDelegate >
{
/* variables */
}
#property (strong, nonatomic) CLLocationManager *locationManager;
myMapViewController.m
- (void)viewDidLoad
{
[super viewDidLoad];
/* other initialization code */
locationManager = [[CLLocationManager alloc] init];
[locationManager setDelegate:self];
[locationManager setDistanceFilter: kCLLocationAccuracyBest];
[locationManager setDesiredAccuracy: kCLLocationAccuracyBest];
}
- (void)objectLoader:(RKObjectLoader*)objectLoader didLoadObjects:(NSArray*)objects {
/* other application code */
Step* step = [_steps lastObject];
CLRegion *tmpReg = [[CLRegion alloc] initCircularRegionWithCenter:step.start_location.coordinate radius:1000 identifier: [step.start_locationLat stringValue] ];
[locationManager startMonitoringForRegion:tmpReg];
NSLog(#"Setting region with latitude %f", tmpReg.center.latitude);
}
- (void)locationManager:(CLLocationManager *)manager didStartMonitoringForRegion:(CLRegion *)region{
NSLog(#"Monitoring region with latitude %f", region.center.latitude);
}
- (void)locationManager:(CLLocationManager *)manager didEnterRegion:(CLRegion *)region{
NSLog(#"ENTERED REGION!");
}
}
- (void) locationManager:(CLLocationManager *)manager didExitRegion:(CLRegion *)region{
NSLog(#"EXITED REGION!");
}
- (void)locationManager:(CLLocationManager *)manager monitoringDidFailForRegion:(CLRegion *)region withError:(NSError *)error
{
NSLog(#"Region monitoring failed with error: %#", [error localizedDescription]);
}
Application runs with zero warnings and here is the log:
2012-12-02 19:31:41.449 myApp[5695:c07] Setting region with latitude 37.785690
2012-12-02 19:31:41.506 myApp[5695:c07] Monitoring region with latitude 37.785690
Have you entered the region? You question doesn't actually say that you are moving your device in and out of the region you are monitoring, or simulating that movement via Xcode.
you did not forget to put [locationManager startUpdatingLocation]; ??
I'm trying to get the app to update the user's location as the user moves, and update POI based on his location. It doesn't work right now (the user's location stays the same even if he moves by a lot). Can anybody help me out?
- (void)viewDidLoad {
[super viewDidLoad];
locationManager = [[CLLocationManager alloc] init];
locationManager.delegate = self;
locationManager.desiredAccuracy = kCLLocationAccuracyHundredMeters;
locationManager.distanceFilter = 1000;
[mapView removeAnnotations: mapView.annotations];
[locationManager startUpdatingLocation];
}
- (void)locationManager:(CLLocationManager *)manager didUpdateToLocation:(CLLocation *)newLocation fromLocation:(CLLocation *)oldLocation {
homeCoordinate = newLocation.coordinate;
if (!home1Annotation) {
home1Annotation = [[MyMapAnnotation alloc] initWithCoordinate:homeCoordinate
title:#"Current Location"
];
[mapView addAnnotation:home1Annotation];
[self adjustMapZoom];
[self loadAndSortPOIs];
for (int j =0 ; j <5 ; j++){
[self displayPOIs];
}
}
}
My Map Annotation
#import "MyMapAnnotation.h"
#implementation MyMapAnnotation
#synthesize coordinate;
#pragma mark initializers
// designated initializer
-(id) initWithCoordinate:(CLLocationCoordinate2D)coordinateQ title:(NSString*) titleQ {
if ( self = [super init]) {
coordinate = coordinateQ;
title = titleQ;
[title retain];
}
return self;
}
-(void) dealloc {
[title release];
[super dealloc];
}
#pragma mark MKAnnotation implementation
-(NSString*) title { return title; }
-(NSString*) subtitle { return nil; }
#end
Two things go wrong:
1) ask for the highest accuracy: kCLLocationAccuracyBest instead of kCLLocationAccuracyHundredMeters. Don't set distanceFilter or set it to zero.
2) in didUpdateToLocation, add a line
NSLog(#"Location update: %#",newLocation);
and watch logfile output. Your if statement makes that the code block below is only run once. I would expect an else block, which will update the POI location in case the home1Annotation already exists. Something like:
} else {
[MyMapAnnotation setCoordinate:homeCoordinate];
}
(but I do not know your class MyMapAnnotation so this is guessing)
There shouldn't be any problems, all will work, but in your case next call about user location changed will be called when user will cane their place from recent detection on distance of 1 kilometer as you specified by this code locationManager.distanceFilter = 1000;
This is the first time I am using CLLocationManager. I am not sure if i am doing the right thing. Correct me if i am wrong.
I initialize the locationManager in my viewDidLoad Method and tell the locationManager to startUpdatingLocation in the same method.
When the delegate receives
-(void)locationManager:(CLLocationManager *)manager didUpdateToLocation:(CLLocation *)newLocation fromLocation:(CLLocation *)oldLocation{
[locationManager stopUpdatingLocation];
//do stuff with the coordinates
}
to avoid repeated calls to this delegate method.
I have a UIButton where users can click to update the location
//called by user action
-(IBAction)updateLocation{
//start updating delegate
locationManager.delegate=self;
[locationManager startUpdatingLocation];
}
However when the location changes and when I click the UIbutton, the location coordinates donot change at all. :(
What am i doing wrong? Is this the right of doing or should i not stop the locationManager at all ?
Help would be appreciated.
CLLocationManager caches your last location and returns it as soon as you call -startUpdatingLocation. So, you are starting updates, receiving the old location, and then stopping updates.
This isn't how -startUpdatingLocation/-stopUpdatingLocation are meant to be used. As I asked above, what's wrong with calling the delegate method multiple times? If you only want to get the location when the user taps a button, leave the CLLocationManager updating, and just check CLLocationManger's location property when the user taps your button.
If the reason you're trying to avoid multiple calls to the delegate method is because you're worried about power consumption, etc., adjust the desiredAccuracy property of the CLLocationManager with something like: locationManager.desiredAccuracy = kCLLocationAccuracyHundredMeters.
All told, it might look something like this...
.h file:
#interface YourController : NSObject <CLLocationManagerDelegate>
#property (nonatomic, retain) CLLocationManager *locationMgr;
#property (nonatomic, retain) CLLocation *lastLocation;
- (IBAction)getNewLocation:(id)sender;
#end
.m file:
#interface YourController
#synthesize locationMgr = _locationMgr;
#synthesize lastLocation = _lastLocation;
- (id)init
{
if (self = [super init]) {
self.locationMgr = [[CLLocationManager alloc] init];
self.locationMgr.desiredAccuracy = kCLLocationAccuracyBest;
self.locationMgr.delegate = self;
}
return self;
}
- (void)locationManager:(CLLocationManager *)manager
didUpdateToLocation:(CLLocation *)newLocation
fromLocation:(CLLocation *)oldLocation
{
if (!self.lastLocation) {
self.lastLocation = newLocation;
}
if (newLocation.coordinate.latitude != self.lastLocation.coordinate.latitude &&
newLocation.coordinate.longitude != self.lastLocation.coordinate.longitude) {
self.lastLocation = newLocation;
NSLog(#"New location: %f, %f",
self.lastLocation.coordinate.latitude,
self.lastLocation.coordinate.longitude);
[self.locationMgr stopUpdatingLocation];
}
}
- (IBAction)getNewLocation:(id)sender
{
[self.locationMgr startUpdatingLocation];
NSLog(#"Old location: %f, %f",
self.lastLocation.coordinate.latitude,
self.lastLocation.coordinate.longitude);
}
- (void)dealloc
{
[self.locationMgr release];
self.locationMgr = nil;
[self.lastLocation release];
self.lastLocation = nil;
[super dealloc];
}
#end
Am assuming you have included #import <CoreLocation/CoreLocation.h> framework to being with. This is the way you start getting location updates.
CLLocationManager *locationMgr = [[CLLocationManager alloc] init];
locationMgr.desiredAccuracy = kCLLocationAccuracyBest;
locationMgr.delegate = self;
[locationMgr startUpdatingLocation];
You are correct here. After this you start getting location updates, here in this delegate-
-(void)locationManager:(CLLocationManager *)manager
didUpdateToLocation:(CLLocation *)newLocation
fromLocation:(CLLocation *)oldLocation
{
// Handle location updates
}
-(void)locationManager:(CLLocationManager *)manager didFailWithError:(NSError *)error
{
// Handle error
}