Swift, for some UIViews to their overall controller when clicked

Question

I have a DotBoss:UIViewController

There are a dozen UIView in the scene, Dot:UIView

(Some are direct subviews, some are further down.)

There are even container views in the chain between the highest controller and the Dot items.

The dozen Dot items know if they are tapped...

class Dot:UIView 
    {
    private var tap:UITapGestureRecognizer? = nil
    override func awakeFromNib()
        {
        tap = UITapGestureRecognizer(target:self,
                     action: #selector(SnapDot.handleTap(_:)))
        self.addGestureRecognizer(tap!)
        }
    func handleTap(g:UITapGestureRecognizer)
        {
        print("user tapped on this particular Dot...")
        }
    }

I want DotBoss to know when one of the Dot is tapped.

class DotBoss:UIViewController
  {
  func oneDotWasClicked(d:Dot)
   {
   }
  }

How to do this perfectly in Swift?

---

Note for anyone googling here, this bubbling extension is remarkably useful: https://blog.veloxdb.com/2016/05/12/bubbling-events-using-uiresponder-in-swift/

Answer 1

A Dot (UIView) and its ultimately controlling DotBoss (UIViewController) are both responders, and are links along the responder chain. Therefore, a Dot can call a method in its DotBoss by walking the responder chain until it comes to the DotBoss:

func handleTap(g:UITapGestureRecognizer) {
    // ... other stuff can go here if necessary ...
    var r : UIResponder = self
    repeat { r = r.nextResponder()! } while !(r is DotBoss)
    (r as! DotBoss).oneDotWasClicked(self)
}