An object encapsulating a user activity supported by this responder.
- macOS 10.10+
By setting the
user property on a responder, the
NSUser object becomes managed by AppKit. You should override
update to write lazily any state data representing the user’s activity to the
user dictionary. User activities managed by AppKit are saved automatically at appropriate times. Multiple responders can share a single
NSUser instance, in which case they all get a callback, such as
update, when the system updates the user activity object.
A responder object can set its
user property to
nil if it no longer wants to participate. Any
NSUser objects that are managed by AppKit but which have no associated responders (or documents) are automatically invalidated.
This property can be used from any thread. It is KVO observable.