To create a dynamic and multi-pane user interface on Android, you need to encapsulate
UI components and activity behaviors into modules that you can swap into and out of
your activities. You can create these modules with the
Fragment class, which
behaves somewhat like a nested activity that can define its own layout and manage its own
When a fragment specifies its own layout, it can be configured in different combinations with other fragments inside an activity to modify your layout configuration for different screen sizes (a small screen might show one fragment at a time, but a large screen can show two or more).
This class shows you how to create a dynamic user experience with fragments and optimize your app's user experience for devices with different screen sizes, all while continuing to support devices running versions as old as Android 1.6.