iOSアプリでカルーセルを作ってみた 1

PagingScrollView.swift

import SwiftUI

public struct PagingScrollView<Content: View>: UIViewRepresentable {
  let content: () -> Content
  let disScroll: (CGPoint) -> Void
  let disScrollEnd: () -> Void

  public init(
    @ViewBuilder _ content: @escaping () -> Content,
    disScroll: @escaping (CGPoint) -> Void,
    disScrollEnd: @escaping () -> Void
  ) {
    self.content = content
    self.disScroll = disScroll
    self.disScrollEnd = disScrollEnd
  }

  public func makeUIView(context: UIViewRepresentableContext<PagingScrollView>) -> UIScrollView {
    let view = UIScrollView()
    view.delegate = context.coordinator

    let hostingController = UIHostingController(rootView: content())
    hostingController.view.sizeToFit()
    view.addSubview(hostingController.view)
    view.contentSize = hostingController.view.bounds.size
    view.isPagingEnabled = true
    view.clipsToBounds = false
    view.showsHorizontalScrollIndicator = false
    view.addSubview(hostingController.view)
    view.bounces = false;

    NSLayoutConstraint.activate([
      hostingController.view.leadingAnchor.constraint(equalTo: view.leadingAnchor),
      hostingController.view.trailingAnchor.constraint(equalTo: view.trailingAnchor),
      hostingController.view.topAnchor.constraint(equalTo: view.topAnchor),
      hostingController.view.bottomAnchor.constraint(equalTo: view.bottomAnchor),
      hostingController.view.widthAnchor.constraint(equalTo: view.widthAnchor),
    ])

    context.coordinator.hostingController = hostingController
    return view
  }

  public func updateUIView(_ uiView: UIScrollView, context: UIViewRepresentableContext<PagingScrollView>) {}

  public func makeCoordinator() -> Coordinator {
    Coordinator(disScroll: disScroll, disScrollEnd: disScrollEnd)
  }

  public class Coordinator: NSObject, UIScrollViewDelegate {
    var hostingController: UIHostingController<Content>?
    let disScroll: (CGPoint) -> Void
    let disScrollEnd: () -> Void

    init(
      disScroll: @escaping (CGPoint) -> Void,
      disScrollEnd: @escaping () -> Void
    ) {
      self.disScroll = disScroll
      self.disScrollEnd = disScrollEnd
    }

    public func scrollViewDidScroll(_ scrollView: UIScrollView) {
      disScroll(scrollView.contentOffset)
    }

    public func scrollViewDidEndDecelerating(_ scrollView: UIScrollView) {
      disScrollEnd()
    }
  }
}