completion not called on UIView.animate on ios 10 and ios 12

[armintelker]

the completion is not called on ios 10 and ios 12. this is strange. can you reproduce this?

HalfModalTransitionAnimator.swift

        UIView.animate(withDuration: transitionDuration(using: transitionContext), animations: {
            if self.edge == .maxYEdge {
                from.view.frame.origin.y = 800
            } else {
                from.view.alpha = 0
            }
        }, completion: { _ in
            transitionContext.completeTransition(!transitionContext.transitionWasCancelled)
        })

[punithbm]

@martinnormark Facing same issue here

[apparition47]

Noticed the same issue on my iPhone 6 (10.3.1). iOS 11 and 12 are okay.

Still looking into a proper solution but a temp workaround could be:

// HalfModalTransitionAnimator.swift
// @objc func animateTransition(using transitionContext: UIViewControllerContextTransitioning) {
if #available(iOS 11.0, *) {
    UIView.animate(withDuration: self.transitionDuration(using: transitionContext), animations: {
        from?.view.frame.origin.y = 800
    }) { _ in
        transitionContext.completeTransition(!transitionContext.transitionWasCancelled)
    }
else {
    DispatchQueue.main.asyncAfter(deadline: .now() + 0.4) {
        transitionContext.completeTransition(!transitionContext.transitionWasCancelled)
    }
}

[punithbm]

@apparition47 iOS 12 also has same issue

[apparition47]

For whatever reason the UIPanGestureRecognizer's onPan() selector isn't receiving events and so the transition never completes and my modal is stuck.

//iOS 10 console
finished transition
animating...
start interactive

//iOS 11
//finished transition
//animating...
//start interactive
//animate completed
//dismissal did end: true
//done dismiss animation

Changing this seemed to fix my issue on iOS 10 and allow the transition to complete:

// CardModalTransitioningDelegate.swift
var interactiveDismiss = false

[jsndev]

iOS 10.3 also has same issue
var interactiveDismiss = false
This solved my problem.

tks @apparition47

[pmaksimov]

Have found a solution on this

override func startInteractiveTransition(_ transitionContext: UIViewControllerContextTransitioning) {
super.startInteractiveTransition(transitionContext)
finish()
}

in HalfModalInteractiveTransition.swift

[pmaksimov]

@apparition47 That doesn't solves the issue. It only makes transition non-interactive as far as I see.

[parvshkhan]

Wow great solution I was trouble with this also
var interactiveDismiss = false
fixed it.