1<html>
2<body>
3<p>
4  The classes in this package are used for development of accessibility service that
5  provide alternative or augmented feedback to the user.
6</p>
7<p>
8  An {@link android.accessibilityservice.AccessibilityService} runs in the background and
9  receives callbacks by the system when {@link android.view.accessibility.AccessibilityEvent}s
10  are fired. Such events denote some state transition in the user interface, for example, the
11  focus has changed, a button has been clicked, etc. Such a service can optionally request the
12  capability for querying the content of the active window. Development of an accessibility
13  service requires extends this class and implements its abstract methods.
14</p>
15<p>
16  An {@link android.accessibilityservice.AccessibilityServiceInfo} describes an
17  {@link android.accessibilityservice.AccessibilityService}. The system notifies an
18  AccessibilityService for {@link android.view.accessibility.AccessibilityEvent}s
19  according to the information encapsulated in this class.
20</p>
21</body>
22</html>
23