UICollectionViewCell - contents do not animate alongside cell's contentView

Question

Problem looks like this: http://i.imgur.com/5iaAiGQ.mp4 (red is a color of cell.contentView)

Here is the code: https://github.com/nezhyborets/UICollectionViewContentsAni

Answer 1

The solution is very easy. First, in ViewController.collectionView(_,didSelectItemAt:), write only this:

collectionView.performBatchUpdates({
        self.selectedIndex = indexPath.row
    }, completion: nil)

And then, in the class ProblematicCollectionViewCell add this func:

override func apply(_ layoutAttributes: UICollectionViewLayoutAttributes) {
    super.apply(layoutAttributes)

    self.layoutIfNeeded()
}

Enjoy!