animating button Allowuserinteraction not working

Question

I have a UIbutton created in code in an NSObject class which controls a game in a UIViewController class. The button works fine throughout most of the game, but at a certain point I want the button to fadein/out. Once the fadein/out starts animating the button is no longer interactive. I have set the .AllowUserInteraction option, but still no luck. I am stumped on this one, so any help much appreciated!

Class GameController: NSObject {
var gameView: UIView!
var nextButton: UIButton!

func gameViewSetUp() {
    // create the nextButton
    let imageNextButton = UIImage(named: "rightArrow") as UIImage?
    self.nextButton = UIButton(type: .Custom)
    nextButton.frame = CGRectMake(ScreenWidth-100,ScreenHeight-250,60,60)
    nextButton.setTitle("", forState: UIControlState.Normal)
    nextButton.setImage(imageNextButton, forState: .Normal)
    nextButton.contentMode = .ScaleAspectFill
    nextButton.backgroundColor = UIColor.clearColor()
    nextButton.layer.cornerRadius = 5.0
    nextButton.layer.borderWidth = 2.5
    nextButton.layer.borderColor = UIColor.clearColor().CGColor
    nextButton.addTarget(self, action: "nextPressed", forControlEvents: .TouchUpInside)
    nextButton.userInteractionEnabled = true
    gameView.addSubview(nextButton)

func playStageX() { 
       nextButtonWink()
    }
}

func nextButtonWink() {
    UIView.animateWithDuration(1.5, delay: 0, options: [.AllowUserInteraction, .Repeat, .CurveEaseInOut, .Autoreverse],
        animations: {
 // self.nextButton.userInteractionEnabled = true // I tried this as well but no impact.
            self.nextButton.alpha = 0
        }, completion: nil)
}

class GameViewController: UIViewController {
private var controller: GameController
required init?(coder aDecoder: NSCoder) {
    controller = GameController()
    super.init(coder: aDecoder)
}
override func viewDidLoad() {
    super.viewDidLoad()   
    let gameView = UIView(frame: CGRectMake(0, 0, ScreenWidth, ScreenHeight))
    self.view.addSubview(gameView)
    controller.gameView = gameView

}

Answer 1

Take out self.nextButton.alpha = 0 to test this out, I believe that button events will not fire when alpha is zero. When it comes to animations, the actual object's alpha will get set to zero before the animation starts, and what you are seeing is like a rendered interactive screenshot of your view as it animates

If that is the case, then you need to set the alpha to something like 0.0100000003 or override the button to be interactive at alpha 0