When animating view with UIView.animate other views are also needlessly animated

Question

I'm wondering why views in my custom TableViewCells are affected by animation which should animate only 2 views in my floating pager (which is even not in TableView's view hierarchy..

UIView.animate(withDuration: 0.3) {
    self.stateIndicator.isHiddenInStackView = true
    self.loaderIndicator.isHiddenInStackView = false
}

When I comment out animation block everything stops animating.

Attached GIF describes everything (Blue views gets animated corner radius, badges 'flies in' instead of just appearing):

UIView.animate strange behavior

Any help or hint will be appreciated :).

Regards Tom.

What is `isHiddenInStackView`? Is this property's setter doing something? — mag_zbc, Jun 07 '18 at 11:13
It's only "safe-hide-unhide" var isHiddenInStackView: Bool { get { return isHidden } set { if isHidden != newValue { isHidden = newValue } } } "The bug is that hiding and showing views in a stack view is cumulative. Weird Apple bug." Source: https://stackoverflow.com/a/45599835/9413528 — Tomasz Kamiński, Jun 07 '18 at 11:17
I don’t think that bug is relevant. It just says that you’re have to set `isHidden` multiple times to have an affect. — ABeard89, Jun 07 '18 at 11:21
My guess would be that since your pager is getting data about the table view, it might be triggering a table view reload somehow. If that table reload is triggered indirectly by the pager, then it’s changes might get caught by the animation block. — ABeard89, Jun 07 '18 at 11:24
@ABeard89 I'm updating the pager after table view gets more data from background thread. So pager do nothing with table view at all. — Tomasz Kamiński, Jun 07 '18 at 11:26
can you share the code below these lines `UIView.animate(withDuration: 0.3) { self.stateIndicator.isHiddenInStackView = true self.loaderIndicator.isHiddenInStackView = false }` — sanjaykmwt, Jun 07 '18 at 11:35
@ABeard89 you were 100% right! I had to move pager initialization code to viewDidAppear (from viewWillAppear) and it worked without wrapping things into UIView.performWithoutAnimation {}. Animation block was the issue here, somehow. Thanks! — Tomasz Kamiński, Jun 07 '18 at 11:52
Great! I’m glad the timing fixed the issue! (`performWithoutAnimation` seems like a hack to me.) — ABeard89, Jun 07 '18 at 11:56

score 2 · Accepted Answer · answered Jun 07 '18 at 11:20

2

Write the things which you don't want to animate in the block

  UIView.performWithoutAnimation {
     //Write your code here
  }

answered Jun 07 '18 at 11:20

sanjaykmwt

586
3
19

1

It worked, but I still dont understand why it happens? Now I have to use performWithoutAnimation in many places.. – Tomasz Kamiński Jun 07 '18 at 11:27
sometimes happen, suppose you are animating something and before committing that animation another UI operation is started that will be automatically animated due to that animation block – sanjaykmwt Jun 07 '18 at 11:31
1

Thank you for help, I will stay with it. – Tomasz Kamiński Jun 07 '18 at 11:40

score 0 · Answer 2 · answered Dec 18 '20 at 15:17

0

I make my animation in main queue and it worked. For example

DispatchQueue.main.async {
     //Write animation code here
}

answered Dec 18 '20 at 15:17

Birju

1,132
11
32

When animating view with UIView.animate other views are also needlessly animated

2 Answers2