MSPCVDI Snippet 5

snippet.swift

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)
    targetContentOffset.pointee = CGPoint(x: adjacentItemOffsetX, y: target.y)
}