Weird animation when hiding and unhiding button in UIStackView

Question

I'm trying to animate in and out a button in a stack view, when one is pressed. When hiding the camera button, the animation looks fine, but when unhiding it slides in from the left which looks odd.

Link to GIF since StackOverflow won't let me embed

Code below:

@IBAction func scanButtonTapped(_ sender: Any) {
    
    
    UIView.animate(withDuration: 0.3) { [self] in
        if cameraButton.alpha == 0{
            cameraButton.alpha = 1
        }else{
            cameraButton.alpha = 0
        }
    }
    
    UIView.animate(withDuration: 0.3) { [self] in
        cameraButton.isHidden.toggle()
        
    }
    
}

I've tried to fix it by using constraints instead of a stack but to no avail. If anyone could help it would be much appreciated. (Please ignore how awful the if/else statement is)

Also if you're just animating the alpha to 0, no need to set `isHidden`. The button is automatically made so that it can't be pressed — aheze, Oct 27 '20 at 17:56
Can you try to call stackView.layoutIfNeeded() after isHidden.toggle() — ibrahimyilmaz, Oct 27 '20 at 17:59
@aheze they are not using images, the UIButtons are using a linear gradient, but I think that is unrelated since it happens without the gradients. Removing isHidden from it means that the button no longer animates movement at all — cheesegrater, Oct 27 '20 at 18:01
Here's more context for @ibrahimyilmaz: https://stackoverflow.com/questions/46326302/uistackview-hide-view-animation?rq=1 — aheze, Oct 27 '20 at 18:01
Also, it's better to put both codes inside the same animate block. — ibrahimyilmaz, Oct 27 '20 at 18:06
@ibrahimyilmaz thanks so much... it fixed my issue.. I feel so stupid — cheesegrater, Oct 27 '20 at 18:09
It's normal because it's an unexpected behavior. I had this idea because I faced the same before. Happy for you. :) — ibrahimyilmaz, Oct 27 '20 at 18:11

cheesegrater · Answer 1 · 2020-11-18T13:51:01.847

2

Cheers to @Ibrahimyilmaz. The solution involved just adding stackView.layoutIfNeeded() after isHidden.toggle()

Some more infomation on this courtesy of @aheze

edited Nov 18 '20 at 13:51

answered Oct 27 '20 at 18:12

cheesegrater

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Weird animation when hiding and unhiding button in UIStackView

1 Answers1