Undo
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UndoController
is a general-purpose recorder of operations for undo and redo.Note
You register an undo operation by specifying the object that’s changing (or the owner of that object), along with a method to invoke to revert its state, and the arguments for that method. When performing undo anUndoController
saves the operations reverted so that you can redo the undos. It differs from Foundation’sNSUndoManager
in that groups are not created automatically for each cycle of the run loop and that each step of a group can be undone rather than just the whole group.Declaration
Swift
@objcMembers @objc(PESDKUndoController) open class UndoController : NSObject