Image Number 8 for United States Patent #8117304.
Applications generating events, and system facilities generating events, send notifications of the events to a system event sink. The event sink is preferably associated with an operating system, and provides an application programming interface for registering listeners. (In one alternative approach, the event sink operates as a centrally-accessible or network-accessible entity, where it may concurrently interact with more than one client.) Upon receiving a notification of an event, the event sink forwards the notification to any registered listeners. Optionally, filters may be used to specify criteria to be met before a notification is forwarded to the listener. An event does not rely on a particular application for displaying the event to an end user. As one example, notification of a newly-arrived e-mail message might be presented in a chat window of an instant messaging client.