DriveEvent

Base interface implemented by all Drive event types. An application can express interest in receiving events by adding an event listener or declaring an event listener service.

An event listener implements the listener interface for a particular event type and receives a direct callback from the Drive service to the client application that is currently connected. A listener is added by calling the appropriate add<EventType>Listener method on the DriveResource of interest. Listeners are active for the duration of the current connection or until the remove<EventType>Listener method is called on the same entity with the same callback parameter.

An event service must be declared in an application's manifest to indicate that an application is interested in receiving events via bound service AIDL calls on the event service, even if the application is not currently connected or even running.

A subscription is added by calling the appropriate add<EventType>Subscription method on the DriveResource of interest. Subscriptions are active until the remove<EventType>Subscription method is called on the same entity or until the next device reboot. An application that is interested in maintaining any subscriptions across reboots should handle the ACTION_BOOT_COMPLETED intent to add back these subscriptions after the reboot has completed.

Some event types will also support the ability to request event delivery using the ExecutionOptions parameter that is passed to a Drive API call. This will indicate that the requested events be delivered to the event service for as long as the operation is active, i.e. until it has successfully completed or permanently failed.

Events will be delivered to all registered listeners, subscribers, and/or enabled operations that match the event. The same event may be delivered to more than one listener or service when appropriate.