Professional Android Sensor Programming

Chapter 2

Determining a Device's Current Location

What's in this chapter?

Introduction to the Android Location API components

Introduction to the different sources of location information in Android

Example usage of the Location API to determine a device's current location

Mobile app developers often have to determine the device's current location. Knowing a device's location enables app developers to add increased functionality to a wide range of apps. Location data is a key component to apps like Google Maps and Google Navigator, and is also used in Google search, Twitter, and Facebook to add another dimension to the data they are already collecting.

For developers who have made the decision to include location data, Android provides a fairly robust API to its location service. Although on the surface this API may seem trivial to use, plenty of details — such as battery life and accuracy of location data — need to be considered.

As an introduction to the topic of location services in Android, this chapter provides a guided tour of the location portions of the API. In addition, the chapter presents an app that answers the most basic Android question (“Where am I?”) and presents location data on the screen. Figure 2.1 shows the app's screen.

Figure 2.1 Current location app

Know Your Tools

This chapter starts the discussion of the location service by first taking a bird's-eye view ...