class MyPresentationController: UIPresentationController {
  
  let dimmingView = UIView()
  
  override init(presentedViewController: UIViewController, presentingViewController: UIViewController) {
    dimmingView.backgroundColor = UIColor.blackColor().colorWithAlphaComponent(0.4)
    
    super.init(presentedViewController: presentedViewController, presentingViewController: presentingViewController)
  }
  
  override func frameOfPresentedViewInContainerView() -> CGRect {
    if let frame = containerView?.bounds {
      return CGRectInset(frame, 50, 50)
    } else {
      return super.frameOfPresentedViewInContainerView()
    }
  }
  
  override func containerViewWillLayoutSubviews() {
    guard let containerView = containerView else { return }
    dimmingView.frame = containerView.bounds
  }
  
  override func presentationTransitionWillBegin() {
    guard
      let containerView = containerView,
      let presentedView = presentedView(),
      let coordinator = presentingViewController.transitionCoordinator()
      else { return }
    dimmingView.alpha = 0.0
    containerView.addSubview(dimmingView)
    dimmingView.addSubview(presentedView)
    coordinator.animateAlongsideTransition({ (context) -> Void in
      self.dimmingView.alpha = 1.0
      }, completion: nil)
  }
  
  override func presentationTransitionDidEnd(completed: Bool) {
    if !completed {
      dimmingView.removeFromSuperview()
    }
  }
  
  override func dismissalTransitionWillBegin() {
    guard let coordinator = presentedViewController.transitionCoordinator() else { return }
    coordinator.animateAlongsideTransition({ (context) -> Void in
      self.dimmingView.alpha = 0.0
      }, completion: nil)
  }
  
  override func dismissalTransitionDidEnd(completed: Bool) {
    if completed {
      dimmingView.removeFromSuperview()
    }
  }
}

class TransitioningAnimator: NSObject, UIViewControllerAnimatedTransitioning {
  
  func transitionDuration(transitionContext: UIViewControllerContextTransitioning?) -> NSTimeInterval {
    return 1.0
  }
  
  func animateTransition(transitionContext: UIViewControllerContextTransitioning) {
    guard
      let toViewController = transitionContext.viewControllerForKey(UITransitionContextToViewControllerKey),
      let toView = transitionContext.viewForKey(UITransitionContextToViewKey),
      let containerView = transitionContext.containerView()
      else { return }
    
    let finalFrame = transitionContext.finalFrameForViewController(toViewController)
    toView.frame = finalFrame
    toView.transform = CGAffineTransformMakeScale(0.2, 0.2)
    toView.alpha = 0.0
    containerView.addSubview(toView)
    
    UIView.animateWithDuration(transitionDuration(transitionContext), delay: 0, usingSpringWithDamping: 0.5, initialSpringVelocity: 0, options: [], animations: { _ in
      toView.transform = CGAffineTransformIdentity
      toView.alpha = 1.0
      }) { completed -> Void in
        transitionContext.completeTransition(completed)
    }
  }
  
}

class TransitioningDelegate: NSObject, UIViewControllerTransitioningDelegate {
  func presentationControllerForPresentedViewController(presented: UIViewController, presentingViewController presenting: UIViewController, sourceViewController source: UIViewController) -> UIPresentationController? {
    let presentationController = MyPresentationController(presentedViewController: presented, presentingViewController: presenting)
    return presentationController
  }
  
  func animationControllerForPresentedController(presented: UIViewController, presentingController presenting: UIViewController, sourceController source: UIViewController) -> UIViewControllerAnimatedTransitioning? {
    let animator = TransitioningAnimator()
    return animator;
  }
  
}

let vc = MyViewController()
let myTransitioningDelegate = TransitioningDelegate()
transitioningDelegate = myTransitioningDelegate
vc.transitioningDelegate = myTransitioningDelegate
presentViewController(vc, animated: true, completion: nil)

@available(iOS 8.0, *)
public class UIPresentationController : NSObject, UIAppearanceContainer, UITraitEnvironment, UIContentContainer, UIFocusEnvironment {
    
    public var presentingViewController: UIViewController { get }
    public var presentedViewController: UIViewController { get }
    
    public var presentationStyle: UIModalPresentationStyle { get }
    
    // The view in which a presentation occurs. It is an ancestor of both the presenting and presented view controller's views.
    // This view is being passed to the animation controller.
    public var containerView: UIView? { get }
    
    weak public var delegate: UIAdaptivePresentationControllerDelegate?
    
    public init(presentedViewController: UIViewController, presentingViewController: UIViewController)
    
    // By default this implementation defers to the delegate, if one exists, or returns the current presentation style. UIFormSheetPresentationController, and
    // UIPopoverPresentationController override this implementation to return UIModalPresentationStyleFullscreen if the delegate does not provide an
    // implementation for adaptivePresentationStyleForPresentationController:
    public func adaptivePresentationStyle() -> UIModalPresentationStyle
    @available(iOS 8.3, *)
    public func adaptivePresentationStyleForTraitCollection(traitCollection: UITraitCollection) -> UIModalPresentationStyle
    
    public func containerViewWillLayoutSubviews()
    public func containerViewDidLayoutSubviews()
    
    // A view that's going to be animated during the presentation. Must be an ancestor of a presented view controller's view
    // or a presented view controller's view itself.
    // (Default: presented view controller's view)
    public func presentedView() -> UIView?
    
    // Position of the presented view in the container view by the end of the presentation transition.
    // (Default: container view bounds)
    public func frameOfPresentedViewInContainerView() -> CGRect
    
    // By default each new presentation is full screen.
    // This behavior can be overriden with the following method to force a current context presentation.
    // (Default: YES)
    public func shouldPresentInFullscreen() -> Bool
    
    // Indicate whether the view controller's view we are transitioning from will be removed from the window in the end of the
    // presentation transition
    // (Default: NO)
    public func shouldRemovePresentersView() -> Bool
    
    public func presentationTransitionWillBegin()
    public func presentationTransitionDidEnd(completed: Bool)
    public func dismissalTransitionWillBegin()
    public func dismissalTransitionDidEnd(completed: Bool)
    
    // Modifies the trait collection for the presentation controller.
    @NSCopying public var overrideTraitCollection: UITraitCollection?
}