WOSA Device Service events

The WOSA Device Service generates two kind of events: WOSACmdEvent and WOSADevEvent, which are subclasses of WOSAEvent as shown in the following diagram:

Diagram illustrating the hierarchy of the WOSAEvent and its subclasses.

WOSACmdEvent

A command event, WOSACmdEvent, is generated whenever an asynchronous call (other than the startup(), cleanup(), or cancelCmd() method) is completed.

The msgType attribute contains the function type that is being reported, such as WFS_EXECUTE_COMPLETE for an execute() call. The requestID attribute contains the value of the requestID that was returned when the asynchronous call was made.

The WOSACmdEvent also has a WOSAMessageReply (reply) object, representing the reply data, which varies depending on the device, function call, and function parameters. For example, a call to getInfo() with a PrtMediaListRequest object as a parameter generates a command event with a PrtMediaListReply object in the reply field of the event. PrtMediaListReply is a subclass of the WOSAMessageReply class.

WOSADevEvent

A device event, WOSADevEvent, is generated when an unsolicited event from the logical device or the WOSA/XFS stack is generated. Unsolicited events are generated as a consequence of user interaction with the physical device, or another external cause. The possible msgType values are WFS_EXECUTE_EVENT, WFS_SERVICE_EVENT, WFS_USER_EVENT, and WFS_SYSTEM_EVENT.