如何在collectionView或tableView单元格中重复动画？

Question

The simplified version of my problem is I am trying to loop/repeat an animation on a button within collectionView cells, but the animation only is executed once. This is my animation block located within my collectionViewCell:

func animateGlowingCircle() {
    UIView.animate(withDuration: 1.0, delay: 0, options: [.autoreverse, .repeat], animations: {
        self.glowCircle.transform = CGAffineTransform(scaleX: 1.2, y: 1.2)
    }, completion: nil)
}

I have tried calling the animateGlowingCircle() from several different places: within the collectionViewController's viewDidLoad or cellForRowAt, as well as from the collectionView's draw. The closest I can get is the animation only executes once but it doesn't loop. I've found tons of info online regarding single-executed animations, but nothing for looped. Any assistance will be greatly appreciated!

Answer 1

Figured it out: the looping cell animation needs to be called from the collectionViewController's willDisplayCell method. So something like this:

// In collectionViewController    
func collectionView(_ collectionView: UICollectionView, willDisplay cell: UICollectionViewCell, forItemAt indexPath: IndexPath) {
    let timerCell = cell as! TimerCollectionViewCell
    timerCell.animateGlowingCircle()  
}


// In collectionViewCell (this is the same code posted with the question)
func animateGlowingCircle() {
    UIView.animate(withDuration: 1.0, delay: 0, options: [.autoreverse, .repeat], animations: {
        self.glowCircle.transform = CGAffineTransform(scaleX: 1.2, y: 1.2)
    }, completion: nil)
}