How to update ScrollView Width after device rotation? - swift

Question

I am following a tutorial to create a swift app that adds a number of views to a scroll view and then allows me to scroll between them. I have the app working and understand it for the most part. When I change the orientation of the device the views width don't get updated so I have parts of more than one view controller on the screen? Does anybody know how to fix this? From my understanding I need to call something in the viewsDidTransition method to redraw the views. Any help would be greatly appreciated. Thanks!
Here is what I have so far:
import UIKit
class ViewController: UIViewController {
private let scrollView = UIScrollView()
private let pageControl: UIPageControl = {
let pageControl = UIPageControl()
pageControl.numberOfPages = 5
pageControl.backgroundColor = .systemBlue
return pageControl
}()
override func viewDidLoad() {
super.viewDidLoad()
scrollView.delegate = self
pageControl.addTarget(self,
action: #selector(pageControlDidChange(_:)),
for: .valueChanged)
scrollView.backgroundColor = .red
view.addSubview(scrollView)
view.addSubview(pageControl)
}
#objc private func pageControlDidChange(_ sender: UIPageControl){
let current = sender.currentPage
scrollView.setContentOffset(CGPoint(x: CGFloat(current) * view.frame.size.width,
y: 0), animated: true)
}
override func viewDidLayoutSubviews() {
super.viewDidLayoutSubviews()
pageControl.frame = CGRect(x: 10, y: view.frame.size.height - 100, width: view.frame.size.width - 20, height: 70)
scrollView.frame = CGRect(x: 0, y: 0, width: view.frame.size.width, height: view.frame.size.height - 100)
if scrollView.subviews.count == 2 {
configureScrollView()
}
}
private func configureScrollView(){
scrollView.contentSize = CGSize(width: view.frame.size.width*5, height: scrollView.frame.size.height)
scrollView.isPagingEnabled = true
let colors: [UIColor] = [.systemRed, .systemGray, .systemGreen, .systemOrange, .systemPurple]
for x in 0..<5{
let page = UIView(frame: CGRect(x: CGFloat(x) * view.frame.size.width, y: 0, width: view.frame.size.width, height: scrollView.frame.size.height))
page.backgroundColor = colors[x]
scrollView.addSubview(page)
}
}
override func viewWillTransition(to size: CGSize, with coordinator: UIViewControllerTransitionCoordinator) {
print("hello world")
}
}
extension ViewController: UIScrollViewDelegate {
func scrollViewDidScroll(_ scrollView: UIScrollView) {
pageControl.currentPage = Int(floorf(Float(scrollView.contentOffset.x) / Float(scrollView.frame.size.width)))
}
}