Programming Android

Chapter 15. Location and Mapping

Ever since mobile phones started to incorporate standalone GPS receivers, developers have foreseen a new era of location-based applications. Location awareness enables a new generation of mobile applications. If your application is looking up restaurants, it’s clearly advantageous if you can restrict your search to the area around you. It’s even better if you can see a map of the restaurants’ locations, and perhaps be able to look up driving or walking directions. If you’re looking for a temporary job, as in the MJAndroid application highlighted in Using the Database API: MJAndroid, it’s definitely a benefit to be able to graphically view job opportunities on a map.

Navigation is really just the first generation of location-based services (LBS). Applications that enable users either to opt in to allow sharing of their location with friends, such as Google Latitude, or to attach importance to geographic sites, such as Foursquare, have begun to arrive in a big way. The world of LBS is really taking off, and as we’ll see, Google’s Android provides powerful features that greatly simplify development of this type of application.

In economic terms, location-based applications are a major factor in mobile telephony, making up a significant portion of the revenue from mobile applications, and growing fast. Because they are based on the ability of the mobile network to locate devices and the relationship of mobility and location, location-based applications ...