How can I implement PageView in SwiftUI?

Question

I am new to SwiftUI. I have three views and I want them in a PageView. I want to move each Views by swipe like a pageview and I want the little dots to indicate in which view I'm in.

Answer 1

iOS 15+

In iOS 15 a new TabViewStyle was introduced: CarouselTabViewStyle (watchOS only).

Also, we can now set styles more easily:

.tabViewStyle(.page)

iOS 14+

There is now a native equivalent of UIPageViewController in SwiftUI 2 / iOS 14.

To create a paged view, add the .tabViewStyle modifier to TabView and pass PageTabViewStyle.

@main
struct TestApp: App {
    var body: some Scene {
        WindowGroup {
            TabView {
                FirstView()
                SecondView()
                ThirdView()
            }
            .tabViewStyle(PageTabViewStyle())
        }
    }
}

You can also control how the paging dots are displayed:

// hide paging dots
.tabViewStyle(PageTabViewStyle(indexDisplayMode: .never))

You can find a more detailed explanation in this link:

• How to create scrolling pages of content using tabViewStyle()

---

Vertical variant

TabView {
    Group {
        FirstView()
        SecondView()
        ThirdView()
    }
    .rotationEffect(Angle(degrees: -90))
}
.tabViewStyle(PageTabViewStyle(indexDisplayMode: .never))
.rotationEffect(Angle(degrees: 90))

---

Custom component

If you're tired of passing tabViewStyle every time you can create your own PageView:

Note: TabView selection in iOS 14.0 worked differently and that's why I used two Binding properties: selectionInternal and selectionExternal. As of iOS 14.3 it seems to be working with just one Binding. However, you can still access the original code from the revision history.

struct PageView<SelectionValue, Content>: View where SelectionValue: Hashable, Content: View {
    @Binding private var selection: SelectionValue
    private let indexDisplayMode: PageTabViewStyle.IndexDisplayMode
    private let indexBackgroundDisplayMode: PageIndexViewStyle.BackgroundDisplayMode
    private let content: () -> Content

    init(
        selection: Binding<SelectionValue>,
        indexDisplayMode: PageTabViewStyle.IndexDisplayMode = .automatic,
        indexBackgroundDisplayMode: PageIndexViewStyle.BackgroundDisplayMode = .automatic,
        @ViewBuilder content: @escaping () -> Content
    ) {
        self._selection = selection
        self.indexDisplayMode = indexDisplayMode
        self.indexBackgroundDisplayMode = indexBackgroundDisplayMode
        self.content = content
    }

    var body: some View {
        TabView(selection: $selection) {
            content()
        }
        .tabViewStyle(PageTabViewStyle(indexDisplayMode: indexDisplayMode))
        .indexViewStyle(PageIndexViewStyle(backgroundDisplayMode: indexBackgroundDisplayMode))
    }
}

extension PageView where SelectionValue == Int {
    init(
        indexDisplayMode: PageTabViewStyle.IndexDisplayMode = .automatic,
        indexBackgroundDisplayMode: PageIndexViewStyle.BackgroundDisplayMode = .automatic,
        @ViewBuilder content: @escaping () -> Content
    ) {
        self._selection = .constant(0)
        self.indexDisplayMode = indexDisplayMode
        self.indexBackgroundDisplayMode = indexBackgroundDisplayMode
        self.content = content
    }
}

Now you have a default PageView:

PageView {
    FirstView()
    SecondView()
    ThirdView()
}

which can be customised:

PageView(indexDisplayMode: .always, indexBackgroundDisplayMode: .always) { ... }

or provided with a selection:

struct ContentView: View {
    @State var selection = 1

    var body: some View {
        VStack {
            Text("Selection: \(selection)")
            PageView(selection: $selection, indexBackgroundDisplayMode: .always) {
                ForEach(0 ..< 3, id: \.self) {
                    Text("Page \($0)")
                        .tag($0)
                }
            }
        }
    }
}

Answer 2

Page Control

struct PageControl: UIViewRepresentable {
    var numberOfPages: Int
    @Binding var currentPage: Int
    func makeCoordinator() -> Coordinator {
        Coordinator(self)
    }

    func makeUIView(context: Context) -> UIPageControl {
        let control = UIPageControl()
        control.numberOfPages = numberOfPages
        control.pageIndicatorTintColor = UIColor.lightGray
        control.currentPageIndicatorTintColor = UIColor.darkGray
        control.addTarget(
            context.coordinator,
            action: #selector(Coordinator.updateCurrentPage(sender:)),
            for: .valueChanged)

        return control
    }

    func updateUIView(_ uiView: UIPageControl, context: Context) {
        uiView.currentPage = currentPage
    }

    class Coordinator: NSObject {
        var control: PageControl

        init(_ control: PageControl) {
            self.control = control
        }
        @objc
        func updateCurrentPage(sender: UIPageControl) {
            control.currentPage = sender.currentPage
        }
    }
}

Your page View

struct PageView<Page: View>: View {
    var viewControllers: [UIHostingController<Page>]
    @State var currentPage = 0
    init(_ views: [Page]) {
        self.viewControllers = views.map { UIHostingController(rootView: $0) }
    }

    var body: some View {
        ZStack(alignment: .bottom) {
            PageViewController(controllers: viewControllers, currentPage: $currentPage)
            PageControl(numberOfPages: viewControllers.count, currentPage: $currentPage)
        }
    }
}

Your page View Controller

struct PageViewController: UIViewControllerRepresentable {
    var controllers: [UIViewController]
    @Binding var currentPage: Int
    @State private var previousPage = 0

    init(controllers: [UIViewController],
         currentPage: Binding<Int>)
    {
        self.controllers = controllers
        self._currentPage = currentPage
        self.previousPage = currentPage.wrappedValue
    }

    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) {
        guard !controllers.isEmpty else {
            return
        }
        let direction: UIPageViewController.NavigationDirection = previousPage < currentPage ? .forward : .reverse
        context.coordinator.parent = self
        pageViewController.setViewControllers(
            [controllers[currentPage]], direction: direction, animated: true) { _ in {
            previousPage = currentPage
        }
    }

    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 parent.controllers.last
            }
            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 parent.controllers.first
            }
            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
            }
        }
    }
}

Let's say you have a view like

struct CardView: View {
    var album: Album
    var body: some View {
        URLImage(URL(string: album.albumArtWork)!)
            .resizable()
            .aspectRatio(3 / 2, contentMode: .fit)
    }
}

You can use this component in your main SwiftUI view like this.

PageView(vM.Albums.map { CardView(album: $0) }).frame(height: 250)

Answer 3

For apps that target iOS 14 and later, the answer suggested by @pawello2222 should be considered the correct one. I have tried it in two apps now and it works great, with very little code.

I have wrapped the proposed concept in a struct that can be provided with both views as well as with an item list and a view builder. It can be found here. The code looks like this:

@available(iOS 14.0, *)
public struct MultiPageView: View {
    
    public init<PageType: View>(
        pages: [PageType],
        indexDisplayMode: PageTabViewStyle.IndexDisplayMode = .automatic,
        currentPageIndex: Binding<Int>) {
        self.pages = pages.map { AnyView($0) }
        self.indexDisplayMode = indexDisplayMode
        self.currentPageIndex = currentPageIndex
    }
    
    public init<Model, ViewType: View>(
        items: [Model],
        indexDisplayMode: PageTabViewStyle.IndexDisplayMode = .automatic,
        currentPageIndex: Binding<Int>,
        pageBuilder: (Model) -> ViewType) {
        self.pages = items.map { AnyView(pageBuilder($0)) }
        self.indexDisplayMode = indexDisplayMode
        self.currentPageIndex = currentPageIndex
    }
    
    private let pages: [AnyView]
    private let indexDisplayMode: PageTabViewStyle.IndexDisplayMode
    private var currentPageIndex: Binding<Int>
    
    public var body: some View {
        TabView(selection: currentPageIndex) {
            ForEach(Array(pages.enumerated()), id: \.offset) {
                $0.element.tag($0.offset)
            }
        }
        .tabViewStyle(PageTabViewStyle(indexDisplayMode: indexDisplayMode))
    }
}