How do I register UndoManager in Swift?

Question

How do I use UndoManager (previously NSUndoManager) in Swift?

Here\'s an Objective-C example I\'ve tried to replicate:

[[un         


        

Answer 1

setValue forKey does the trick for me on OS X if one needs to support 10.10. I couldn't set it directly cause prepareWithInvocationTarget returns a proxy object.

@objc
enum ImageScaling : Int, CustomStringConvertible {
    case FitInSquare
    case None

    var description : String {
        switch self {
        case .FitInSquare: return "FitInSquare"
        case .None: return "None"
        }
    }
}
private var _scaling : ImageScaling = .FitInSquare
dynamic var scaling : ImageScaling {
    get {
        return _scaling
    }
    set(newValue) {
        guard (_scaling != newValue) else { return }
        undoManager?.prepareWithInvocationTarget(self).setValue(_scaling.rawValue, forKey: "scaling")
        undoManager?.setActionName("Change Scaling")
        document?.beginChanges()
        _scaling = newValue
        document?.endChanges()
    }
}