How to zoom a UICollectionViewCell on selection Swift 3.0?

Question

Here i am trying highlight the UICollectionViewCell on selection as shown in the image.I tried adding the border to the selected cell and the border comes inside the cell content view. Here is my try:

func collectionView(_ collectionView: UICollectionView, didSelectItemAt indexPath: IndexPath) {
    let cell = priorityCollectionView.cellForItem(at: indexPath)  as? BCPriorityListCollectionViewCell
    let borderWidth: CGFloat = 6
    cell?.contentView.frame = (cell?.labelBackground.frame.insetBy(dx: +borderWidth, dy: +borderWidth))!
    cell?.contentView.layer.borderColor = cell?.backgroundColor?.cgColor
    cell?.contentView.layer.borderWidth = borderWidth
}

func collectionView(_ collectionView: UICollectionView, didDeselectItemAt indexPath: IndexPath) {
    let cell = priorityCollectionView.cellForItem(at: indexPath)  as? BCPriorityListCollectionViewCell
    let borderWidth: CGFloat = 0
    cell?.contentView.frame = (cell?.labelBackground.frame.insetBy(dx: +borderWidth, dy: +borderWidth))!
    cell?.contentView.layer.borderColor = UIColor.clear.cgColor
    cell?.contentView.layer.borderWidth = borderWidth

}

How to do this?

Answer 1

Instead of adding the border width for the selected cell, just use transformation scale for zooming the selected cell. Write this code in didSelect:

func collectionView(_ collectionView: UICollectionView, didSelectItemAt indexPath: IndexPath) {
    let selectedCell = priorityCollectionView.cellForItem(at: indexPath)  as? BCPriorityListCollectionViewCell
    priorityCollectionView.bringSubview(toFront: selectedCell!)

    UIView.animate(withDuration: 0.2, delay: 0, usingSpringWithDamping: 5, initialSpringVelocity: 0, options: [], animations: { 
        selectedCell?.transform = CGAffineTransform(scaleX: 1.2, y: 2)
        })  
}

And in didDeselect:

func collectionView(_ collectionView: UICollectionView, didDeselectItemAt indexPath: IndexPath) {
    let unselectedCell = priorityCollectionView.cellForItem(at: indexPath)  as? BCPriorityListCollectionViewCell
    UIView.animate(withDuration: 0.2, delay: 0, usingSpringWithDamping: 5, initialSpringVelocity: 0, options: [], animations: {
        unselectedCell?.transform = .identity
    })
}

Result: