Custom transitioning snippets

TransitioningDelegate.swift

class MyTransitionDelegate : NSObject, UIViewControllerTransitioningDelegate {
    
    func animationControllerForPresentedController(presented: UIViewController, presentingController presenting: UIViewController, sourceController source: UIViewController) -> UIViewControllerAnimatedTransitioning? {
        return MyAnimatedTransitioning(isPresented: true)
    }
    
    func animationControllerForDismissedController(dismissed: UIViewController) -> UIViewControllerAnimatedTransitioning? {
        return MyAnimatedTransitioning(isPresented: false)
    }
    
    func presentationControllerForPresentedViewController(presented: UIViewController, presentingViewController presenting: UIViewController, sourceViewController source: UIViewController) -> UIPresentationController? {
        return MyPresentationC(presentedViewController: presented, presentingViewController: presenting)
    }
}

//----------------
class MyAnimatedTransitioning: NSObject, UIViewControllerAnimatedTransitioning {

    let isPresented: Bool!
    let animationDuration: NSTimeInterval = 1.5
    
    init(isPresented: Bool) {
        self.isPresented = isPresented
        super.init()
    }
    
    func transitionDuration(transitionContext: UIViewControllerContextTransitioning?) -> NSTimeInterval {
        return self.animationDuration
    }
    
    func animateTransition(transitionContext: UIViewControllerContextTransitioning) {
        
        let fromVC: UIViewController? = transitionContext.viewControllerForKey(UITransitionContextFromViewControllerKey)
        let toVC: UIViewController? = transitionContext.viewControllerForKey(UITransitionContextToViewControllerKey)
        let containerView: UIView? = transitionContext.containerView()
        
        if self.isPresented == true {
            self.animatePresentation(transitionContext, fromVC: fromVC, toVC: toVC, containerView: containerView)
        }
        else {
            self.animateDismissal(transitionContext, fromVC: fromVC, toVC: toVC, containerView: containerView)
        }
    }
    
    func animatePresentation(transitionContext: UIViewControllerContextTransitioning?, fromVC: UIViewController?, toVC: UIViewController?, containerView: UIView?) {
        
        toVC?.view.frame = (transitionContext?.finalFrameForViewController(toVC!))!
        
        // we have to add toVC to container. In PresentationController or in this class
        // transitionContext?.completeTransition(true)
    }
    
    func animateDismissal(transitionContext: UIViewControllerContextTransitioning?, fromVC: UIViewController?, toVC: UIViewController?, containerView: UIView?) {
        // transitionContext?.completeTransition(true)
    }
}

//-------------------------

class MyPresentationC : UIPresentationController {
    
    override func presentationTransitionWillBegin() {
        // This should be done in Animated Transition or Presentation Controller!
        self.containerView?.addSubview(self.presentedView()!)
    }
    
    override func frameOfPresentedViewInContainerView() -> CGRect {
        
        // example
        let width: CGFloat = 200.0
        let height: CGFloat = 100.0
        let frame = CGRectMake(self.containerView!.center.x - width/2, CGRectGetMinY(self.containerView!.frame) - height, width, height)
        return frame
    }
}

// In the presented VC
required init?(coder aDecoder: NSCoder) {
        super.init(coder: aDecoder)
        self.presentationSetup()
    }
    
    override init(nibName nibNameOrNil: String?, bundle nibBundleOrNil: NSBundle?) {
        super.init(nibName: nibNameOrNil, bundle: nibBundleOrNil)
        self.presentationSetup()
    }
    
    func presentationSetup() {
        self.transitioningDelegate = self.sidePanelTransitionDelegate
        self.modalPresentationStyle = .Custom
    }