Oscar Oscar - 7 months ago 52
Swift Question

Swift - How to do a custom slide animation?

I've been looking for swift code to make simple custom slide transitions between views (just left to right or right to left, without bounce) but I only found code for complicated animations. Thanks everyone for your help !

Oscar

Answer

I finally found the answer here : http://mathewsanders.com/animated-transitions-in-swift/#custom-transition-animations and adpated it a little bit.

1) Create this Swift NSObject file
class TransitionManager2: NSObject, UIViewControllerAnimatedTransitioning, UIViewControllerTransitioningDelegate {

private var presenting = true
// MARK: UIViewControllerAnimatedTransitioning protocol methods

// animate a change from one viewcontroller to another
func animateTransition(transitionContext: UIViewControllerContextTransitioning) {

    // get reference to our fromView, toView and the container view that we should perform the transition in
    let container = transitionContext.containerView()
    let fromView = transitionContext.viewForKey(UITransitionContextFromViewKey)!
    let toView = transitionContext.viewForKey(UITransitionContextToViewKey)!

    // set up from 2D transforms that we'll use in the animation
    let offScreenRight = CGAffineTransformMakeTranslation(container.frame.width, 0)
    let offScreenLeft = CGAffineTransformMakeTranslation(-container.frame.width, 0)

    // prepare the toView for the animation
    toView.transform = self.presenting ? offScreenRight : offScreenLeft

    // set the anchor point so that rotations happen from the top-left corner
    toView.layer.anchorPoint = CGPoint(x:0, y:0)
    fromView.layer.anchorPoint = CGPoint(x:0, y:0)

    // updating the anchor point also moves the position to we have to move the center position to the top-left to compensate
    toView.layer.position = CGPoint(x:0, y:0)
    fromView.layer.position = CGPoint(x:0, y:0)

    // add the both views to our view controller
    container.addSubview(toView)
    container.addSubview(fromView)

    // get the duration of the animation
    // DON'T just type '0.5s' -- the reason why won't make sense until the next post
    // but for now it's important to just follow this approach
    let duration = self.transitionDuration(transitionContext)

    // perform the animation!
    // for this example, just slid both fromView and toView to the left at the same time
    // meaning fromView is pushed off the screen and toView slides into view
    // we also use the block animation usingSpringWithDamping for a little bounce
    UIView.animateWithDuration(duration, delay: 0.0, usingSpringWithDamping: 1, initialSpringVelocity: 1, options: nil, animations: {

        // slide fromView off either the left or right edge of the screen 
        // depending if we're presenting or dismissing this view
        fromView.transform = self.presenting ? offScreenLeft : offScreenRight
        toView.transform = CGAffineTransformIdentity

        }, completion: { finished in

            // tell our transitionContext object that we've finished animating
            transitionContext.completeTransition(true)

    })

}

// return how many seconds the transiton animation will take
func transitionDuration(transitionContext: UIViewControllerContextTransitioning) -> NSTimeInterval {
    return 0.4
}

// MARK: UIViewControllerTransitioningDelegate protocol methods

// return the animataor when presenting a viewcontroller
// remmeber that an animator (or animation controller) is any object that aheres to the UIViewControllerAnimatedTransitioning protocol
func animationControllerForPresentedController(presented: UIViewController, presentingController presenting: UIViewController, sourceController source: UIViewController) -> UIViewControllerAnimatedTransitioning? {
    // these methods are the perfect place to set our `presenting` flag to either true or false - voila!
    self.presenting = true
    return self
}
// return the animator used when dismissing from a viewcontroller
func animationControllerForDismissedController(dismissed: UIViewController) -> UIViewControllerAnimatedTransitioning? {
    self.presenting = false
    return self
    }
}

2) Change the segue between the 2 ViewControllers to "Custom"

3) Add in the first ViewController this code :

let transitionManager = TransitionManager2()
override func prepareForSegue(segue: UIStoryboardSegue, sender: AnyObject?) {
    // this gets a reference to the screen that we're about to transition to
    let toViewController = segue.destinationViewController as! UIViewController

    // instead of using the default transition animation, we'll ask
    // the segue to use our custom TransitionManager object to manage the transition animation
    toViewController.transitioningDelegate = self.transitionManager

}