One way paging in scrollview - ios

Question

Is there a way to allow paging in a UIScrollView but restrict the paging to one direction.
For example: Allowing the user to page background (to the left) but not forward. Use case being for some type of onboarding. I know I can add buttons that move forward, have them enabled or disabled, and remove swiping but I rather not.

Answer 1

I don't know if I have well understand what you want but what about using a UICollectionView:
lazy var onBoardingCollectionView: UICollectionView = {
let layout = UICollectionViewFlowLayout()
layout.scrollDirection = .horizontal
layout.minimumLineSpacing = 0
layout.minimumInteritemSpacing = 0
let cv = UICollectionView(frame: self.view.frame, collectionViewLayout: layout)
cv.showsHorizontalScrollIndicator = false
cv.showsVerticalScrollIndicator = false
cv.isPagingEnabled = true
return cv
}()
You add you custom cell with the size of the screen as well by the method in UICollectionViewDelegateFlowLayout:
func collectionView(_ collectionView: UICollectionView, layout collectionViewLayout: UICollectionViewLayout, sizeForItemAt indexPath: IndexPath) -> CGSize {
return CGSize(width: SCREENW, height: SCREENH)
}
if you don't want to go in a specific direction you can try get the current cell displaying and removing the previous one of the dataSource and collection with this method.
func scrollViewDidEndDecelerating(_ scrollView: UIScrollView) {
let currentPage = Int(scrollView.contentOffset.x / scrollView.frame.width)
print("current cell: ", currentPage)
}