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@dlgchg
Forked from masamichiueta/PageView.swift
Created June 18, 2020 09:48
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SwiftUI PageView
import SwiftUI
import UIKit
struct PageViewController: UIViewControllerRepresentable {
var controllers: [UIViewController]
@Binding var currentPage: Int
func makeCoordinator() -> Coordinator {
Coordinator(self)
}
func makeUIViewController(context: Context) -> UIPageViewController {
let pageViewController = UIPageViewController(
transitionStyle: .scroll,
navigationOrientation: .horizontal)
pageViewController.dataSource = context.coordinator
pageViewController.delegate = context.coordinator
return pageViewController
}
func updateUIViewController(_ pageViewController: UIPageViewController, context: Context) {
pageViewController.setViewControllers(
[controllers[currentPage]], direction: .forward, animated: true)
}
class Coordinator: NSObject, UIPageViewControllerDataSource, UIPageViewControllerDelegate {
var parent: PageViewController
init(_ pageViewController: PageViewController) {
self.parent = pageViewController
}
func pageViewController(
_ pageViewController: UIPageViewController,
viewControllerBefore viewController: UIViewController) -> UIViewController?
{
guard let index = parent.controllers.firstIndex(of: viewController) else {
return nil
}
if index == 0 {
return nil
}
return parent.controllers[index - 1]
}
func pageViewController(
_ pageViewController: UIPageViewController,
viewControllerAfter viewController: UIViewController) -> UIViewController?
{
guard let index = parent.controllers.firstIndex(of: viewController) else {
return nil
}
if index + 1 == parent.controllers.count {
return nil
}
return parent.controllers[index + 1]
}
func pageViewController(_ pageViewController: UIPageViewController, didFinishAnimating finished: Bool, previousViewControllers: [UIViewController], transitionCompleted completed: Bool) {
if completed,
let visibleViewController = pageViewController.viewControllers?.first,
let index = parent.controllers.firstIndex(of: visibleViewController)
{
parent.currentPage = index
}
}
}
}
#if DEBUG
struct PageViewController_Previews: PreviewProvider {
@State static var currentPage = 0
static var previews: some View {
PageViewController(controllers: [], currentPage: $currentPage)
}
}
#endif
struct PageView<Page: View>: View {
var viewControllers: [UIHostingController<Page>]
@Binding var currentPage: Int
init(_ views: [Page], currentPage: Binding<Int>) {
self._currentPage = currentPage
self.viewControllers = views.map { UIHostingController(rootView: $0) }
}
var body: some View {
PageViewController(controllers: viewControllers, currentPage: $currentPage)
}
}
#if DEBUG
struct PageView_Previews: PreviewProvider {
@State static var page = 0
static var previews: some View {
PageView([Text("Hello")], currentPage: $page)
}
}
#endif
struct ContentView: View {
@State private var page = 0
var body: some View {
VStack {
Picker("Page", selection: $page) {
Text("Page 1").tag(0)
Text("Page 2").tag(1)
}
.pickerStyle(SegmentedPickerStyle())
.padding(EdgeInsets(top: 0, leading: 12, bottom: 0, trailing: 12))
PageView([
Text("Page1"),
Text("Page2")
], currentPage: $page)
}
}
}
struct ContentView_Previews: PreviewProvider {
static var previews: some View {
ContentView()
}
}
@dlgchg
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dlgchg commented Jun 18, 2020

1

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