UICollectionView Cell Scroll to centre

Question

I am using UICollectionView in my UIViewController.

My collectionview properties are set as below.

Answer 1

After setting proper itemSize, left and right insets I prefer doing this rather than subclassing layout

//Setting decelerationRate to fast gives a nice experience
collectionView.decelerationRate = .fast

//Add this to your view anywhere
func centerCell () {
    let centerPoint = CGPoint(x: collectionView.contentOffset.x + collectionView.frame.midX, y: 100)
    if let path = collectionView.indexPathForItem(at: centerPoint) {
        collectionView.scrollToItem(at: path, at: .centeredHorizontally, animated: true)
    }
}

//Set collectionView.delegate = self then add below funcs
func scrollViewDidEndDecelerating(_ scrollView: UIScrollView) {
   centerCell()
}
func scrollViewDidEndScrollingAnimation(_ scrollView: UIScrollView) {
    centerCell()
}
func scrollViewDidEndDragging(_ scrollView: UIScrollView, willDecelerate decelerate: Bool) {
    if !decelerate {
        centerCell()
    }
}