The classes in this package are used for development of accessibility service that provide alternative or augmented feedback to the user.

An {@link android.accessibilityservice.AccessibilityService} runs in the background and receives callbacks by the system when {@link android.view.accessibility.AccessibilityEvent}s are fired. Such events denote some state transition in the user interface, for example, the focus has changed, a button has been clicked, etc. Such a service can optionally request the capability for querying the content of the active window. Development of an accessibility service requires extends this class and implements its abstract methods.

An {@link android.accessibilityservice.AccessibilityServiceInfo} describes an {@link android.accessibilityservice.AccessibilityService}. The system notifies an AccessibilityService for {@link android.view.accessibility.AccessibilityEvent}s according to the information encapsulated in this class.