LocationManager.m

// Copyright (c) 2009 Imageshack Corp.
// All rights reserved.
// 
// Redistribution and use in source and binary forms, with or without
// modification, are permitted provided that the following conditions
// are met:
// 1. Redistributions of source code must retain the above copyright
//    notice, this list of conditions and the following disclaimer.
// 2. Redistributions in binary form must reproduce the above copyright
//    notice, this list of conditions and the following disclaimer in the
//    documentation and/or other materials provided with the distribution.
// 3. The name of the author may not be used to endorse or promote products
//    derived from this software without specific prior written permission.
// 
// THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
// IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
// OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
// IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
// INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
// NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
// THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
// 

#import "LocationManager.h"
#import "TweetterAppDelegate.h"

static LocationManager *globalLocationManager = nil;
static BOOL initialized = NO;

@implementation LocationManager

@synthesize tinyURL;


+ (LocationManager*)locationManager
{
	if(!globalLocationManager) 
		globalLocationManager = [[LocationManager allocWithZone:nil] init];
	return globalLocationManager;
}

+ (id)allocWithZone:(NSZone *)zone
{
    @synchronized(self)
	{
		if (globalLocationManager == nil) 
			globalLocationManager = [super allocWithZone:zone];
    }
	
    return globalLocationManager;
}

- (id)copyWithZone:(NSZone *)zone
{
    return self;
}


- (id)retain
{
    return self;
}


- (unsigned)retainCount
{
    return UINT_MAX;  //denotes an object that cannot be released
}


- (void)release
{
    //do nothing
}


- (id)autorelease
{
    return self;
}

-(void)reset
{
	locationDefined = NO;
	latitude = 0.f;
	longitude = 0.f;
}

- (id)init
{
	if(initialized)
		return globalLocationManager;
	
	self = [super init];
    if (!self)
	{
		if(globalLocationManager)
			[globalLocationManager release];
		return nil;
	}

	
	locationManager = nil;
	initialized = YES;
	locationDenied = NO;
	[self reset];
    return self;
}

-(void)dealloc
{
	if(locationManager)
		[locationManager release];
	[super dealloc];
}

- (void) stopUpdates
{
	if (locationManager)
	{
		[locationManager stopUpdatingLocation];
	}
	[self reset];
}

- (void) startUpdates
{
	if(![[NSUserDefaults standardUserDefaults] boolForKey:@"UseLocations"])
	{
		[self stopUpdates];
		return;
	}
		
	if (locationManager)
	{
		[locationManager stopUpdatingLocation];
	}
	else
	{
		locationManager = [[CLLocationManager alloc] init];
		locationManager.delegate = self;
		locationManager.distanceFilter = 100;
		locationManager.desiredAccuracy = kCLLocationAccuracyHundredMeters;
	}
	
	locationDefined = NO;
	[locationManager startUpdatingLocation];
}

- (NSString*) urlFormat
{
	return @"http://maps.google.com/maps?q=%+.6f,%+.6f";
}


- (NSString*) longURLWithLatitude:(float)lat  longitude:(float)lon
{
	return [NSString stringWithFormat:[self urlFormat], lat, lon];
}

- (NSString*) longURL
{
	return locationDefined ? [self longURLWithLatitude:latitude  longitude:longitude] : nil;
}

- (NSString*) mapURL
{
	if(!locationDefined) 
		return nil;

	return tinyURL ? tinyURL : [self longURL];
}



- (void)locationManager:(CLLocationManager *)manager didUpdateToLocation:(CLLocation *)newLocation  fromLocation:(CLLocation *)oldLocation
{
	locationDenied = NO;
	if(![[NSUserDefaults standardUserDefaults] boolForKey:@"UseLocations"])
	{
		[self stopUpdates];
		return;
	}

	if(!tinyURL || ![self longURL] || ![[self longURL] isEqualToString:[self longURLWithLatitude:newLocation.coordinate.latitude longitude:newLocation.coordinate.longitude]])
	{
		latitude = newLocation.coordinate.latitude;
		longitude = newLocation.coordinate.longitude;
		locationDefined = YES;
		tinyURL = nil;
		[TweetterAppDelegate increaseNetworkActivityIndicator];
		[NSThread  detachNewThreadSelector:@selector(getTinyURLFromServer:) toTarget:self withObject:[self longURL]];
		[[NSNotificationCenter defaultCenter] postNotificationName: @"UpdateLocationNotification" object: nil];
	}
}

- (BOOL) locationDenied
{
	return locationDenied;
}

- (BOOL) locationServicesEnabled
{
	CLLocationManager* lm = locationManager;
	if(!lm)
		lm = [[[CLLocationManager alloc] init] autorelease];
	return lm.locationServicesEnabled;
}

- (void)locationManager:(CLLocationManager *)manager didFailWithError:(NSError *)error
{
	[self reset];

    if ([error domain] == kCLErrorDomain) 
	{
        switch ([error code]) 
		{
            case kCLErrorDenied:
				locationDenied = YES;
				[self stopUpdates];
                break;
            case kCLErrorLocationUnknown:
                break;
            default:
                break;
        }
	}
	
	[[NSNotificationCenter defaultCenter] postNotificationName: @"UpdateLocationNotification" object: nil];
}

- (BOOL) locationDefined
{
	return locationDefined;
}

- (float) latitude
{
	return latitude;
}

- (float) longitude
{
	return longitude;
}

- (void) setTinyURLOnMainThread:(NSArray*)urls
{
	[TweetterAppDelegate decreaseNetworkActivityIndicator];
	NSString* tiny = [urls objectAtIndex:0] == [NSNull null] ? nil : [urls objectAtIndex:0];
	NSString* full =[urls objectAtIndex:1];
	if([full isEqualToString:[self longURL]] || !self.tinyURL)
		self.tinyURL = tiny;
}

- (void)getTinyURLFromServer:(NSString*)longURL
{
	NSAutoreleasePool *pool = [[NSAutoreleasePool alloc] init];
	NSString *alias = [NSString stringWithFormat:@"y%08x", ((int)time(NULL))];
	
	NSData *page = [NSData dataWithContentsOfURL:
		[NSURL URLWithString:[NSString stringWithFormat:@"http://tinyurl.com/create.php?url=%@&alias=%@", longURL, alias]]];

	id tiny = page ? [NSString stringWithFormat:@"http://tinyurl.com/%@", alias] : [NSNull null];
	NSArray* urls =  [[[NSArray alloc] initWithObjects: tiny, [[longURL copy] autorelease], nil] autorelease];
	[self performSelectorOnMainThread:@selector(setTinyURLOnMainThread:) withObject:urls waitUntilDone:NO];

	[pool release];
}


@end