UULocationManager.m

//
//  UULocationManager.m
//  Useful Utilities - CLLocationManager wrapper
//
//	License:
//  You are free to use this code for whatever purposes you desire. The only requirement is that you smile everytime you use it.
//
//  Contact: @cheesemaker or jon@threejacks.com

#import "UULocationManager.h"

#if __has_feature(objc_arc)
	#define UU_RELEASE(x)		(void)(0)
	#define UU_RETAIN(x)		x
	#define UU_AUTORELEASE(x)	x
	#define UU_BLOCK_RELEASE(x) (void)(0)
	#define UU_BLOCK_COPY(x)    [x copy]
#else
	#define UU_RELEASE(x) [x release]
	#define UU_RETAIN(x) [x retain]
	#define UU_AUTORELEASE(x) [(x) autorelease]
	#define UU_BLOCK_RELEASE(x) Block_release(x)
	#define UU_BLOCK_COPY(x)    Block_copy(x)
#endif

NSString * const UULocationChangedNotification = @"UULocationChangedNotification";
NSString * const UULocationNameChangedNotification = @"UULocationNameChangedNotification";
NSString * const UULocationAuthChangedNotification = @"UULocationAuthChangedNotification";
NSString * const UULocationErrorNotification = @"UULocationErrorNotification";

@interface UULocationManager()
	@property (nonatomic, retain) CLLocationManager* clLocationManager;
	@property (nonatomic, retain) CLLocation* clLocation;
	@property (nonatomic, retain) NSString* locationName;
    @property (nonatomic, retain) NSString* cityName;
    @property (nonatomic, retain) NSString* stateName;
    @property (nonatomic, retain) NSTimer* notificationTimer;
@end

static UULocationManager* theLocationManager = nil;

@implementation UULocationManager

+ (UULocationManager*) sharedInstance
{
    if (theLocationManager == nil)
    {
        theLocationManager = [[UULocationManager alloc] init];
    }
    
    return theLocationManager;
}

+ (void) startTracking
{
	//Just call the accessor...
	[UULocationManager sharedInstance];
}

- (CLLocation*) currentLocation
{
	return self.clLocation;
}

- (NSString*) currentLocationName
{
	return self.locationName;
}

- (NSString*) currentCityName
{
    return self.cityName;
}

- (NSString*) currentStateName
{
    return self.stateName;
}

- (id) init
{
	self = [super init];
	if (self)
	{
        self.distanceThreshold = 10.0f;		// 10 meters
        self.timeThreshold = 1800;			// 30 minutes
        self.monitorLocationName = NO;
        self.delayLocationUpdates = NO;
        self.locationUpdateDelay = 1.0f;	// 1 second
        
		if ([CLLocationManager locationServicesEnabled])
		{
			// Initialize the locationManager
			CLLocationManager* locManager = UU_AUTORELEASE([[CLLocationManager alloc] init]);
			locManager.delegate = self;
            
			locManager.desiredAccuracy = kCLLocationAccuracyBest;
			locManager.distanceFilter = self.distanceThreshold;
			self.clLocationManager = locManager;
		
			//Go!!!
			[self.clLocationManager startUpdatingLocation];
		}	
	}
	return self;
}

- (void) startTracking
{
    [self.clLocationManager startUpdatingLocation];
}

- (void) stopTracking
{
    self.clLocation = nil;
    [self.clLocationManager stopUpdatingLocation];
}

- (void) startTrackingSignificantLocationChanges
{
    [self.clLocationManager startMonitoringSignificantLocationChanges];
}

- (void) stopTrackingSignificantLocationChanges
{
    [self.clLocationManager stopMonitoringSignificantLocationChanges];
}

- (void) setDistanceThreshold:(CLLocationDistance)distanceThreshold
{
    _distanceThreshold = distanceThreshold;
    self.clLocationManager.distanceFilter = distanceThreshold;
}

- (void)locationManager:(CLLocationManager *)manager didUpdateToLocation:(CLLocation *)newLocation fromLocation:(CLLocation *)oldLocation;
{
    if (!self.clLocation ||
		!CLLocationCoordinate2DIsValid(self.clLocation.coordinate) ||
        [self.clLocation distanceFromLocation:newLocation] > self.distanceThreshold ||
        [self.clLocation.timestamp timeIntervalSinceDate:newLocation.timestamp] > self.timeThreshold ||
        newLocation.horizontalAccuracy < self.clLocation.horizontalAccuracy)
	{
		self.clLocation = newLocation;

        if (self.delayLocationUpdates)
        {
            [self.notificationTimer invalidate];
            self.notificationTimer = [NSTimer scheduledTimerWithTimeInterval:self.locationUpdateDelay target:self selector:@selector(postLocationChangedTimer:) userInfo:self.clLocation repeats:NO];
        }
        else
        {
            [[NSNotificationCenter defaultCenter] postNotificationName:UULocationChangedNotification object:self.clLocation];
        }
	
        if (self.monitorLocationName)
        {
            [self queryLocationName:self.clLocation];
        }
	}
}

- (void) postLocationChangedTimer:(NSTimer*)timer
{
    CLLocation* location = timer.userInfo;
    [[NSNotificationCenter defaultCenter] postNotificationName:UULocationChangedNotification object:location];
}

- (void)locationManager:(CLLocationManager *)manager didFailWithError:(NSError *)error
{
    [[NSNotificationCenter defaultCenter] postNotificationName:UULocationErrorNotification object:error];
}

- (void)locationManager:(CLLocationManager *)manager didChangeAuthorizationStatus:(CLAuthorizationStatus)status
{
    [[NSNotificationCenter defaultCenter] postNotificationName:UULocationAuthChangedNotification object:@(status)];
}

- (void) queryLocationName:(CLLocation*)location
{
    CLGeocoder* geoCoder = UU_AUTORELEASE([[CLGeocoder alloc] init]);
    [geoCoder reverseGeocodeLocation:location completionHandler:^(NSArray* placemarks, NSError* error)
     {
         if (error == nil && placemarks != nil && placemarks.count > 0)
         {
             CLPlacemark* info = [placemarks objectAtIndex:0];
             
             NSMutableString* sb = [NSMutableString string];
             if (info.locality != nil)
             {
                 [sb appendString:info.locality];
                 self.cityName = info.locality;
             }
             
             if (info.administrativeArea != nil)
             {
                 if (sb.length > 0)
                 {
                     [sb appendString:@", "];
                 }
                 [sb appendString:info.administrativeArea];
                 self.stateName = info.administrativeArea;
             }
             
             self.locationName = sb;
             [[NSNotificationCenter defaultCenter] postNotificationName:UULocationNameChangedNotification object:sb];
         }
     }];
}

- (bool) hasValidLocation
{
    return ((self.clLocation != nil) && CLLocationCoordinate2DIsValid(self.clLocation.coordinate));
}

@end