Registers the selector of the specified target to implement a single undo operation that the target receives.
Mac Catalyst 13.0+Beta
The target of the undo operation.
The undo manager maintains an unowned reference to target to prevent retain cycles.
The selector for the undo operation.
The argument sent with the selector.
The undo manager maintains a strong reference to anObject.
Use registerUndoWithTarget:selector:object: to register a selector for an undo operation. To register a selector on the undo stack, you also need to make the method available to the Objective-C runtime by applying the @objc attribute to the method. For more on how to create a selector, see Selectors.
Calling this method also clears the redo stack.
The following example demonstrates how to register and use a selector on the undo stack by modeling a Garden class with two methods: plant(flower:) and pluck(flower:). The plant(flower:) method removes a flower from the garden while pluck(flower:) adds a flower such that effectively, the two methods are inverse operations of each other. This inverse quality makes it ideal to register plant(flower:) and pluck(flower:) to be each other's undo operation.
This documentation contains preliminary information about an API or technology in development. This information is subject to change, and software implemented according to this documentation should be tested with final operating system software.