Using GPX route or track for testing in Xcode 4.2

Question

Has anyone had any success using a GPX route or track to test location aware apps that depend on movement in Xcode 4.2? I have been able to get it to use a single waypoint in a GPX file or even get it to iterate over a series of waypoints, but I have not been able to have it follow a track in a way that would give speed and course information. I have tried with recorded tracks from driving, hand made routes and tracks, and routes made with Trailrunner.

It may be that this functionality just is not available, but Apple does provide a freeway drive in the simulator. I want to be able to do something similar on device and in a location that I can specify. Anybody have any thoughts?

Answer 1

The best way is to create your own simulator class to read the file and generate CLLocation events, which gives you complete control. GPX files don't contain speed and heading, so you'll have to calculate them yourself. The basic simulation loop I've used is:

Simulate{
  if (!eof) {
    Read the next waypoint
    Calculate distance, dt (delta time), bearing and speed (distance/dt) from the previous waypoint

    Generate a CLLocation object and call the didUpdateToLocation delegate method
    Peek at the next waypoint and calculate next_dt
    Scale next_dt   // as desired for faster playback (e.g. dt/2 would be 2x)
    Start an NSTimer with next_dt as the duration
  }
}

When the timer fires, call Simulate again

Note: Until recently, synthesizing CLLocations was somewhat problematic since CLLocation is immutable and the init method had no way to set speed and heading. This was remedied in iOS 4.2.

Answer 2

The Freeway Drive appears to be defined by a 1.6 MB file in /Developer/Platforms/iPhoneSimulator.platform/Developer/SDKs/iPhoneSimulator5.0.sdk/System/Library/Frameworks/CoreLocation.framework/Support/SimulationScenarios/Freeway Drive.plist. It's a dictionary with two keys, Options and Locations. Options itself is a dictionary with two keys and can probably be reverse engineered. Locations, on the other hand, is a large array (2240 items) of NSData, each one about 724 bytes. The first eight bytes decode to "bplist00", so each of these is a plist. I wrote one to disk, but Xcode's property list editor claims it is corrupted.

The directory where that file is is also where the other canned locations and routes live. I duplicated one of the files and restarted the simulator, and the new file showed up in the Debug menu.

The biggest issue with adding your own files is that a future Xcode update might erase them, but that's not such a big deal if you keep the originals somewhere.

Answer 3

You can plot complex routes using Google Maps and then convert them to a compatible GPX file using https://mapstogpx.com/mobiledev.php