Add custom page size to UIScrollview

UIScrollViewDelegate.swift

    func scrollViewWillEndDragging(_ scrollView: UIScrollView, withVelocity velocity: CGPoint, targetContentOffset: UnsafeMutablePointer<CGPoint>) {
        
        // Page width used for estimating and calculating paging.
        let pageWidth = (self.frame.width) - interIntemMargin
        
        // Make an estimation of the current page position.
        let approximatePage = scrollView.contentOffset.x/pageWidth
        
        // Determine the current page based on velocity.
        let currentPage = (velocity.x < 0.0) ? floor(approximatePage) : ceil(approximatePage)
        
        // Create custom flickVelocity.
        let flickVelocity = velocity.x * 0.3
        
        // Check how many pages the user flicked, if <= 1 then flickedPages should return 0.
        let flickedPages = (abs(round(flickVelocity)) <= 1) ? 0 : round(flickVelocity)
        
        // Calculate newHorizontalOffset.
        let newHorizontalOffset = ((currentPage + flickedPages ) * pageWidth) - scrollView.contentInset.left
        
        targetContentOffset.pointee.x =  newHorizontalOffset
    }