MaherKSantina

import UIKit
import MSPeekCollectionViewDelegateImplementation

class ViewController: UIViewController {
    
    @IBOutlet weak var collectionView: UICollectionView!
    let delegate = MSPeekCollectionViewDelegateImplementation()

    override func viewDidLoad() {
        super.viewDidLoad()

MaherKSantina

public func collectionView(_ collectionView: UICollectionView, layout collectionViewLayout: UICollectionViewLayout, insetForSectionAt section: Int) -> UIEdgeInsets {
   let leftAndRightInsets = cellSpacing + cellPeekWidth
   return UIEdgeInsets(top: 0, left: leftAndRightInsets, bottom: 0, right: leftAndRightInsets)
}

MaherKSantina

public func collectionView(_ collectionView: UICollectionView, layout collectionViewLayout: UICollectionViewLayout, sizeForItemAt indexPath: IndexPath) -> CGSize {
    let itemWidth = max(0, collectionView.frame.size.width - 2 * (cellSpacing + cellPeekWidth))
    return CGSize(width: itemWidth, height: collectionView.frame.size.height)
}

MaherKSantina

public func collectionView(_ collectionView: UICollectionView, layout collectionViewLayout: UICollectionViewLayout, minimumInteritemSpacingForSectionAt section: Int) -> CGFloat {
    return 0
}

MaherKSantina

public func scrollViewWillBeginDragging(_ scrollView: UIScrollView) {
    currentScrollOffset = scrollView.contentOffset
}

MaherKSantina

public func scrollViewWillEndDragging(_ scrollView: UIScrollView, withVelocity velocity: CGPoint, targetContentOffset: UnsafeMutablePointer<CGPoint>) {
    let target = targetContentOffset.pointee
    //Current scroll distance is the distance between where the user tapped and the destination for the scrolling (If the velocity is high, this might be of big magnitude)
    let currentScrollDistance = target.x - currentScrollOffset.x
    //Make the value an integer between -1 and 1 (Because we don't want to scroll more than one item at a time)
    let coefficent = Int(max(-1, min(currentScrollDistance/scrollThreshold, 1)))
    let currentIndex = Int(round(currentScrollOffset.x/itemWidth))
    let adjacentItemIndex = currentIndex + coefficent
    let adjacentItemIndexFloat = CGFloat(adjacentItemIndex)
    let adjacentItemOffsetX = adjacentItemIndexFloat * (itemWidth(scrollView) + cellSpacing)

MaherKSantina

public func collectionView(_ collectionView: UICollectionView, layout collectionViewLayout: UICollectionViewLayout, minimumLineSpacingForSectionAt section: Int) -> CGFloat {
    return cellSpacing
}

MaherKSantina

import UIKit
import MSAutoView

class ListingView: MSAutoView { }

MaherKSantina

class ListingView: UIView {
    
    override init(frame: CGRect) {
        super.init(frame: frame)
        initView()
    }

    required init?(coder aDecoder: NSCoder) {
        super.init(coder: aDecoder)
        initView()

MaherKSantina

// Step 1
guard let xibItems = Bundle.main.loadNibNamed("ListingView", owner: self, options: nil), let firstXibView = xibItems[0] as? UIView else {
    fatalError("Xib is empty or first view is not a UIView")
}
// Step 2
firstXibView.translatesAutoresizingMaskIntoConstraints = false

// Step 3
let viewConstraints = [NSLayoutAttribute.top, NSLayoutAttribute.left, NSLayoutAttribute.bottom, NSLayoutAttribute.right].map { (attribute) -> NSLayoutConstraint in
    return NSLayoutConstraint(item: firstXibView, attribute: attribute, relatedBy: .equal, toItem: self, attribute: attribute, multiplier: 1, constant: 0)