The following pseudo-UML diagram details the basic structure of the LocationManager framework. The LocationManager framework is composed of the following classes:

• LocationManager - The main class used by the application/activity
• LocationDevice - The abstract class which represents all device descriptors
• LocationProvider - The abstract class which represents all location providers
• LocationException - The root of all exceptions thrown by a location provider
• GPXWriter - Functionality to record streams of locations as a GPX file
• DeviceException - The root of all exceptions thrown by LocationDevice operations

The framework also provides the following devices and providers:

• BuiltInGPSDevice/BuiltInGPSProvider - Interface for the Android built in GPS
• PlaybackDevice/PlaybackProvider - Interface to playback locations from a previously recorded GPX file.

Adding new devices is relatively straight forward. For each new device you must write a new class to be the LocationDevice and write a new class to be the LocationProvider. It is up to the Device to perform detection and verification of the ohysical device, while the Provider is to provide the normalized location updates when they are made available via the physical device.