     @IBOutlet fileprivate var currentYOffset: NSLayoutConstraint!
     
     open fileprivate(set) weak var activeViewController: UIViewController!
+    
+    public weak var delegate: SwipeNavigationControllerDelegate?
     
     // Mark: View controllers
     open fileprivate(set) var centerViewController: UIViewController!

        if currentXOffset == nil && currentYOffset == nil {
            view.addSubview(centerViewController.view)
            centerViewController.view.translatesAutoresizingMaskIntoConstraints = false
            centerViewController.view.backgroundColor = UIColor.blue
            self.currentXOffset = alignCenterXConstraint(forItem: centerViewController.view, toItem: view, position: .center)
            self.currentYOffset = alignCenterYConstraint(forItem: centerViewController.view, toItem: view, position: .center)
            view.addConstraints([self.currentXOffset, self.currentYOffset])

        currentYOffset.constant = targetOffset.dy
        disappearingViewController?.beginAppearanceTransition(false, animated: true)
        activeViewController.beginAppearanceTransition(true, animated: true)
        delegate?.swipeNavigationController(self, willShowEmbeddedViewForPosition: position)
        UIView.animate(withDuration: swipeAnimateDuration, animations: {
            self.view.layoutIfNeeded()
        }) { (finished) in
            self.delegate?.swipeNavigationController(self, didShowEmbeddedViewForPosition: position)
            self.activeViewController.endAppearanceTransition()
            disappearingViewController?.endAppearanceTransition()
        }
    }
    
    open func isContainerActive(position: Position) -> Bool {
        let targetOffset: CGVector
        switch position {
