Device Location (ie latitude,longitude)

I wrote up a handy way to grab the latitude and longitude info off the device when it comes in.
Ideally you make the call a few times to get the best positional data, but here is a one-off:

First, add CoreLocation framework to the project.

Next, extend the app delegate to respond to the location callback

TGBAppDelegate.h

#import <CoreLocation/CoreLocation.h>
#import <CoreLocation/CLLocationManagerDelegate.h>

@interface TGBAppDelegate : NSObject <UIApplicationDelegate,CLLocationManagerDelegate> {
	IBOutlet UIWindow *window;
	CLLocationManager *locmanager;
}

Then the actual callbacks:

TGBAppDelegate.mm (the entire file)

///-----------------------------------------------------------------------------
// Torque Game Engine 
// Copyright (C) GarageGames.com, Inc.
//-----------------------------------------------------------------------------


#import "TGBAppDelegate.h"
#include "platform/platformInput.h"

extern void _iPhoneRunTorqueMain( id appID,  UIView *Window, UIApplication *app );
extern void _iPhoneGameInnerLoop();
extern void _iPhoneGameResignActive();
extern void _iPhoneGameBecomeActive();
extern void _iPhoneGameWillTerminate();
extern void _iPhoneGameChangeOrientation();

extern void _iPhoneGameLogLocationFail();
extern void _iPhoneGameLogLocationSuccess(const char *coords,const char *accuracy);


@implementation TGBAppDelegate

@synthesize window;

- (void)applicationDidFinishLaunching:(UIApplication *)application {
	locmanager = [[CLLocationManager alloc] init];
	[locmanager setDelegate:self];
	[locmanager setDesiredAccuracy:kCLLocationAccuracyBest];
	[locmanager startUpdatingLocation];	
	_iPhoneRunTorqueMain( self, window, application );
}


- (void)applicationWillResignActive:(UIApplication *)application {
	_iPhoneGameResignActive();	
}


- (void)applicationDidBecomeActive:(UIApplication *)application {
	_iPhoneGameBecomeActive();
}

- (void)applicationWillTerminate:(UIApplication *)application {
	_iPhoneGameWillTerminate();
}


- (void)application:(UIApplication *)application didChangeStatusBarOrientation:(UIInterfaceOrientation)oldStatusBarOrientation{
	_iPhoneGameChangeOrientation();
}

- (void) runMainLoop {
	_iPhoneGameInnerLoop();
}

- (void) getDeviceLocation {
	[locmanager startUpdatingLocation];	
}

- (void) locationManager:(CLLocationManager *) manager didUpdateToLocation:(CLLocation *) newLocation fromLocation:(CLLocation *)oldLocation
{
	NSAutoreleasePool * pool = [[NSAutoreleasePool alloc] init];
	
	CLLocationAccuracy hAccuracy = [newLocation horizontalAccuracy];
	CLLocationAccuracy vAccuracy = [newLocation verticalAccuracy];
	NSString *accuracyString = [NSString stringWithFormat:@"%f %f",hAccuracy,vAccuracy];
	const char *strAccuracyString = [accuracyString UTF8String ];
	
	
	CLLocationCoordinate2D loc = [newLocation coordinate];
	NSString *coordString = [NSString stringWithFormat:@"%f %f",loc.latitude,loc.longitude];
	const char *strCoordString = [coordString UTF8String ];
	
	_iPhoneGameLogLocationSuccess(strCoordString,strAccuracyString);
	[pool release];
}

- (void) locationManager:(CLLocationManager *)manager didFailWithError:(NSError *)error
{
	NSLog(@"Error establishing location");
	_iPhoneGameLogLocationFail();
}

- (void)dealloc {
	[locmanager release];
	[window release];
	[super dealloc];
}

@end

Finally, some callbacks in the code, in iPhoneMain.mm

void _iPhoneGameLogLocationFail()
{
	Con::errorf("Location Fail");
	Con::executef( 1, "oniPhoneLogLocationFail" );
}

void _iPhoneGameLogLocationSuccess(const char *coords, const char *accuracy)
{
	char argBuffer1[64];
	dSprintf(argBuffer1, 64, coords);

	char argBuffer2[64];
	dSprintf(argBuffer2, 64, accuracy);

	Con::executef( 3, "oniPhoneLogLocationSuccess",argBuffer1, argBuffer2 );
}

And the relative script callbacks:

function oniPhoneLogLocationSuccess(%loc,%accuracy)
{
   MessageBoxOK("Location Log Success","Success:" @ %loc,"");
    $DeviceLocation = %loc;  //This is a latitude SPC longitude format

}

function oniPhoneLogLocationFail()
{
	MessageBoxOK("Location Log Fail","Fail","");
}

It worked on the iPod, the app requests to use your location (via iPhoneSDK) and if you say yes then it should find you!

Again, the ideal way to do this is to initiate the call a few times, each time can take 10-15 seconds and can use one of 5 different location methods, so you might get better locations with more attempts, examining the accuracy when it comes in.

I got lucky implementing this: it worked the first time or so, so I thought I would share it! Struggling for a few months with the iPhone SDK ended up being useful after all.