Recipe: User Location Annotations

Recipe 19-6 provided a way to visually track a location event as it focused over time. Recipe 19-7 kicks this idea up a notch to track a device as it moves over time. Instead of sampling locations over time and picking the best result, it employs a far easier approach while achieving similar results. It hands over all responsibility for user location to the map view and its userLocation property, using a timer to check in occasionally and update.

As mentioned in the discussion for Recipe 19-6, enabling the showsUserLocation property automatically tasks Core Location to track the device. Recipe 19-7 leverages this capability by checking that location once every few seconds. It updates the map view to reflect that location, keeping the map centered on the user and adding a custom annotation to the user pin to display the current coordinates.