didOpenUndoGroup
An identifier for a message about an undo manager having opened an undo group.
Declaration
static var didOpenUndoGroup: NotificationCenter.BaseMessageIdentifier<UndoManager.DidOpenUndoGroupMessage> { get }Discussion
Use this identifier with NotificationCenter’s addObserver(of:for:using:) or messages(of:for:bufferSize:) methods to observe messages of type UndoManager.DidOpenUndoGroupMessage.