Completion closure never called when animating showing/hiding

[nico75005]

UIView.animateWithDuration(0.5, animations: {
subview.hidden = false
}, completion: { finished in
// never called when changing hidden property of a subview of TZStackView
})

[nico75005]

A workaround is to use a CATransaction:

CATransaction.begin()

CATransaction.setCompletionBlock( {
    // code to call once the animation is over
} )

subview.hidden = false

CATransaction.commit()

[EliaCereda]

I’ve encountered this problem too, nice workaround! Is the completion block never called in your experience? In my case it works the first time, but not on subsequent calls.

I suspect the cause is this line in the code of TZStackView.observeValueForKeyPath(…):

UIView.setAnimationDelegate(self)

It’s just a guess, but I think UIView implements the completion callback by setting some internal object as the delegate of the animation. Which then brings the question, does calling UIView.setAnimationDelegate inside a CATransaction result in the correct behavior? Could you do a quick test and see if TZStackView.hiddenAnimationStopped is called in your code?

EDIT: it seems issue #50 is referring to the same problem, this definitely needs to be looked into. Unfortunately it’s going to be a while before I’m able to do it myself, but I will if it hasn’t been fixed yet.

[CosynPa]

Fixed in #72