PageViewController.swift


  1. import SwiftUI
  2. import UIKit
  4. struct PageViewController<Page: View>: UIViewControllerRepresentable {
  5. var pages: [Page]
  7. func makeCoordinator() -> Coordinator {
  8. Coordinator(self)
  9. }
  11. func makeUIViewController(context: Context) -> UIPageViewController {
  12. let pageViewController = UIPageViewController(
  13. transitionStyle: .scroll,
  14. navigationOrientation: .horizontal)
  15. pageViewController.dataSource = context.coordinator
  17. return pageViewController
  18. }
  20. func updateUIViewController(_ pageViewController: UIPageViewController, context: Context) {
  21. pageViewController.setViewControllers(
  22. [context.coordinator.controllers[0]], direction: .forward, animated: true)
  23. }
  25. class Coordinator: NSObject, UIPageViewControllerDataSource {
  26. var parent: PageViewController
  27. var controllers = [UIViewController]()
  29. init(_ pageViewController: PageViewController) {
  30. parent = pageViewController
  31. controllers = parent.pages.map { UIHostingController(rootView: $0) }
  32. }
  34. func pageViewController(
  35. _ pageViewController: UIPageViewController,
  36. viewControllerBefore viewController: UIViewController) -> UIViewController?
  37. {
  38. guard let index = controllers.firstIndex(of: viewController) else {
  39. return nil
  40. }
  41. if index == 0 {
  42. return controllers.last
  43. }
  44. return controllers[index - 1]
  45. }
  47. func pageViewController(
  48. _ pageViewController: UIPageViewController,
  49. viewControllerAfter viewController: UIViewController) -> UIViewController?
  50. {
  51. guard let index = controllers.firstIndex(of: viewController) else {
  52. return nil
  53. }
  54. if index + 1 == controllers.count {
  55. return controllers.first
  56. }
  57. return controllers[index + 1]
  58. }
  59. }
  60. }