SwiftUI 新功能

1:26 - Hello World

@main
struct HelloWorld: App {
    var body: some Scene {
        WindowGroup {
            Text("Hello, world!").padding()
        }
    }
}

1:56 - Book Club app

@main
struct BookClubApp: App {
    @StateObject private var store = ReadingListStore()

    var body: some Scene {
        WindowGroup {
            ReadingListViewer(store: store)
        }
    }
}

struct ReadingListViewer: View {
    @ObservedObject var store: ReadingListStore

    var body: some View {
        NavigationView {
            List(store.books) { book in
                Text(book.title)
            }
            .navigationTitle("Currently Reading")
        }
    }
}

class ReadingListStore: ObservableObject {
    init() {}

    var books = [
        Book(title: "Book #1", author: "Author #1"),
        Book(title: "Book #2", author: "Author #2"),
        Book(title: "Book #3", author: "Author #3")
    ]
}

struct Book: Identifiable {
    let id = UUID()
    let title: String
    let author: String
}

4:46 - Settings

@main
struct BookClubApp: App {
    @StateObject private var store = ReadingListStore()

    @SceneBuilder var body: some Scene {
        WindowGroup {
            ReadingListViewer(store: store)
        }
        
    #if os(macOS)
        Settings {
            BookClubSettingsView()
        }
    #endif
    }
}

struct BookClubSettingsView: View {
    var body: some View {
        Text("Add your settings UI here.")
            .padding()
    }
}

struct ReadingListViewer: View {
    @ObservedObject var store: ReadingListStore

    var body: some View {
        NavigationView {
            List(store.books) { book in
                Text(book.title)
            }
            .navigationTitle("Currently Reading")
        }
    }
}

class ReadingListStore: ObservableObject {
    init() {}

    var books = [
        Book(title: "Book #1", author: "Author #1"),
        Book(title: "Book #2", author: "Author #2"),
        Book(title: "Book #3", author: "Author #3")
    ]
}

struct Book: Identifiable {
    let id = UUID()
    let title: String
    let author: String
}

5:10 - Document groups

import SwiftUI
import UniformTypeIdentifiers

@main
struct ShapeEditApp: App {
    var body: some Scene {
        DocumentGroup(newDocument: ShapeDocument()) { file in
            DocumentView(document: file.$document)
        }
    }
}

struct DocumentView: View {
    @Binding var document: ShapeDocument
    
    var body: some View {
        Text(document.title)
            .frame(width: 300, height: 200)
    }
}

struct ShapeDocument: Codable {
    var title: String = "Untitled"
}

extension UTType {
    static let shapeEditDocument =
        UTType(exportedAs: "com.example.ShapeEdit.shapes")
}

extension ShapeDocument: FileDocument {
    static var readableContentTypes: [UTType] { [.shapeEditDocument] }
    
    init(fileWrapper: FileWrapper, contentType: UTType) throws {
        let data = fileWrapper.regularFileContents!
        self = try JSONDecoder().decode(Self.self, from: data)
    }

    func write(to fileWrapper: inout FileWrapper, contentType: UTType) throws {
        let data = try JSONEncoder().encode(self)
        fileWrapper = FileWrapper(regularFileWithContents: data)
    }
}

5:49 - Custom Commands

import SwiftUI
import UniformTypeIdentifiers

@main
struct ShapeEditApp: App {
    var body: some Scene {
        DocumentGroup(newDocument: ShapeDocument()) { file in
            DocumentView(document: file.$document)
        }
        .commands {
            CommandMenu("Shapes") {
                Button("Add Shape...", action: addShape)
                    .keyboardShortcut("N")
                Button("Add Text", action: addText)
                    .keyboardShortcut("T")
            }
        }
    }
    
    func addShape() {}
    func addText() {}
}

struct DocumentView: View {
    @Binding var document: ShapeDocument
    
    var body: some View {
        Text(document.title)
            .frame(width: 300, height: 200)
    }
}

struct ShapeDocument: Codable {
    var title: String = "Untitled"
}

extension UTType {
    static let shapeEditDocument =
        UTType(exportedAs: "com.example.ShapeEdit.shapes")
}

extension ShapeDocument: FileDocument {
    static var readableContentTypes: [UTType] { [.shapeEditDocument] }
    
    init(fileWrapper: FileWrapper, contentType: UTType) throws {
        let data = fileWrapper.regularFileContents!
        self = try JSONDecoder().decode(Self.self, from: data)
    }

    func write(to fileWrapper: inout FileWrapper, contentType: UTType) throws {
        let data = try JSONEncoder().encode(self)
        fileWrapper = FileWrapper(regularFileWithContents: data)
    }
}

7:55 - Widgets

import SwiftUI
import WidgetKit

@main
struct RecommendedAlbum: Widget {
    var body: some WidgetConfiguration {
        StaticConfiguration(
            kind: "RecommendedAlbum",
            provider: Provider(),
            placeholder: PlaceholderView()
        ) { entry in
            AlbumWidgetView(album: entry.album)
        }
        .configurationDisplayName("Recommended Album")
        .description("Your recommendation for the day.")
    }
}

struct AlbumWidgetView: View {
    var album: Album

    var body: some View {
        Text(album.title)
    }
}

struct PlaceholderView: View {
    var body: some View {
        Text("Placeholder View")
    }
}

struct Album {
    var title: String
}

struct Provider: TimelineProvider {
    struct Entry: TimelineEntry {
        var album: Album
        var date: Date
    }

    public func snapshot(with context: Context, completion: @escaping (Entry) -> ()) {
        let entry = Entry(album: Album(title: "Untitled"), date: Date())
        completion(entry)
    }

    public func timeline(with context: Context, completion: @escaping (Timeline<Entry>) -> ()) {
        var entries: [Entry] = []

        // Generate a timeline consisting of five entries an hour apart, starting from the current date.
        let currentDate = Date()
        for hourOffset in 0 ..< 5 {
            let entryDate = Calendar.current.date(byAdding: .hour, value: hourOffset, to: currentDate)!
            let entry = Entry(album: Album(title: "Untitled #\(hourOffset)"), date: entryDate)
            entries.append(entry)
        }

        let timeline = Timeline(entries: entries, policy: .atEnd)
        completion(timeline)
    }
}

8:31 - Complications using SwiftUI

struct CoffeeHistoryChart: View {
    var body: some View {
        VStack {
            ComplicationHistoryLabel {
                Text("Weekly Coffee")
                    .complicationForeground()
            }
            HistoryChart()
        }
        .complicationChartFont()
    }
}

struct ComplicationHistoryLabel: View { ... }
struct HistoryChart: View { ... }

extension View {
    func complicationChartFont() -> some View { ... }
}

9:22 - Outlines

struct OutlineContentView: View {
    var graphics: [Graphic]
    
    var body: some View {
        List(graphics, children: \.children) { graphic in
            GraphicRow(graphic)
        }
        .listStyle(SidebarListStyle())
    }
}

struct Graphic: Identifiable {
    var id: String
    var name: String
    var icon: Image
    var children: [Graphic]?
}

struct GraphicRow: View {
    var graphic: Graphic
    
    init(_ graphic: Graphic) {
        self.graphic = graphic
    }
    
    var body: some View {
        Label {
            Text(graphic.name)
        } icon: {
            graphic.icon
        }
    }
}

10:09 - Adaptive grids

struct ContentView: View {
    var items: [Item]

    var body: some View {
        ScrollView {
            LazyVGrid(columns: [GridItem(.adaptive(minimum: 176))]) {
                ForEach(items) { item in
                    ItemView(item: item)
                }
            }
            .padding()
        }
    }
}

struct Item: Identifiable {
    var name: String
    var id = UUID()
    
    var icon: Image {
        Image(systemName: name)
    }
    var color: Color {
        colors[colorIndex % (colors.count - 1)]
    }

    private static var nextColorIndex: Int = 0
    private var colorIndex: Int

    init(name: String) {
        self.name = name

        colorIndex = Self.nextColorIndex
        Self.nextColorIndex += 1
    }
}

struct ItemView: View {
    var item: Item

    var body: some View {
        ZStack {
            RoundedRectangle(cornerRadius: 8, style: .continuous)
                .fill()
                .layoutPriority(1)
                .foregroundColor(item.color)
            item.icon
                .resizable()
                .aspectRatio(contentMode: .fit)
                .padding(.all, 16)
                .foregroundColor(.white)
        }
        .frame(width: 176, height: 110)
    }
}

10:28 - Fixed-column grids

struct ContentView: View {
    var items: [Item]

    var body: some View {
        ScrollView {
            LazyVGrid(columns: Array(repeating: GridItem(), count: 4)]) {
                ForEach(items) { item in
                    ItemView(item: item)
                }
            }
            .padding()
        }
    }
}

struct Item: Identifiable {
    var name: String
    var id = UUID()
    
    var icon: Image {
        Image(systemName: name)
    }
    var color: Color {
        colors[colorIndex % (colors.count - 1)]
    }

    private static var nextColorIndex: Int = 0
    private var colorIndex: Int

    init(name: String) {
        self.name = name

        colorIndex = Self.nextColorIndex
        Self.nextColorIndex += 1
    }
}

struct ItemView: View {
    var item: Item

    var body: some View {
        ZStack {
            RoundedRectangle(cornerRadius: 8, style: .continuous)
                .fill()
                .layoutPriority(1)
                .foregroundColor(item.color)
            item.icon
                .resizable()
                .aspectRatio(contentMode: .fit)
                .padding(.all, 16)
                .foregroundColor(.white)
        }
        .frame(width: 176, height: 110)
    }
}

10:38 - Horizontal grids

struct ContentView: View {
    var items: [Item]

    var body: some View {
        ScrollView(.horizontal) {
            LazyHGrid(rows: [GridItem(.adaptive(minimum: 110))]) {
                ForEach(items) { item in
                    ItemView(item: item)
                }
            }
            .padding()
        }
    }
}

struct Item: Identifiable {
    var name: String
    var id = UUID()
    
    var icon: Image {
        Image(systemName: name)
    }
    var color: Color {
        colors[colorIndex % (colors.count - 1)]
    }

    private static var nextColorIndex: Int = 0
    private var colorIndex: Int

    init(name: String) {
        self.name = name
        colorIndex = Self.nextColorIndex
        Self.nextColorIndex += 1
    }
}

struct ItemView: View {
    var item: Item

    var body: some View {
        ZStack {
            RoundedRectangle(cornerRadius: 8, style: .continuous)
                .fill()
                .layoutPriority(1)
                .foregroundColor(item.color)
            item.icon
                .resizable()
                .aspectRatio(contentMode: .fit)
                .padding(.all, 16)
                .foregroundColor(.white)
        }
        .frame(width: 176, height: 110)
    }
}

10:58 - Lazy stacks

struct WildlifeList: View {
    var rows: [ImageRow]

    var body: some View {
        ScrollView {
            LazyVStack(spacing: 2) {
                ForEach(rows) { row in
                    switch row.content {
                    case let .singleImage(image):
                        SingleImageLayout(image: image)
                    case let .imageGroup(images):
                        ImageGroupLayout(images: images)
                    case let .imageRow(images):
                        ImageRowLayout(images: images)
                    }
                }
            }
        }
    }
}

12:24 - Toolbar modifier

struct ContentView: View {
    var body: some View {
        List {
            Text("Book List")
        }
        .toolbar {
            Button(action: recordProgress) {
                Label("Record Progress", systemImage: "book.circle")
            }
        }
    }

    private func recordProgress() {}
}

12:40 - ToolbarItem

struct ContentView: View {
    var body: some View {
        List {
            Text("Book List")
        }
        .toolbar {
            ToolbarItem(placement: .primaryAction) {
                Button(action: recordProgress) {
                    Label("Record Progress", systemImage: "book.circle")
                }
            }
        }
    }

    private func recordProgress() {}
}

12:47 - Confirmation and cancellation toolbar placements

struct ContentView: View {
    var body: some View {
        Form {
            Slider(value: .constant(0.39))
        }
        .toolbar {
            ToolbarItem(placement: .confirmationAction) {
                Button("Save", action: saveProgress)
            }
            ToolbarItem(placement: .cancellationAction) {
                Button("Cancel", action: dismissSheet)
            }
        }
    }

    private func saveProgress() {}
    private func dismissSheet() {}
}

13:00 - Principal toolbar placement

struct ContentView: View {
    enum ViewMode {
        case details
        case notes
    }

    @State private var viewMode: ViewMode = .details

    var body: some View {
        List {
            Text("Book Detail")
        }
        .toolbar {
            ToolbarItem(placement: .principal) {
                Picker("View", selection: $viewMode) {
                    Text("Details").tag(ViewMode.details)
                    Text("Notes").tag(ViewMode.notes)
                }
            }
        }
    }
}

13:17 - Bottom bar toolbar placement

struct ContentView: View {
    var body: some View {
        List {
            Text("Book Detail")
        }
        .toolbar {
            ToolbarItem {
                Button(action: recordProgress) {
                    Label("Progress", systemImage: "book.circle")
                }
            }
            ToolbarItem(placement: .bottomBar) {
                Button(action: shareBook) {
                    Label("Share", systemImage: "square.and.arrow.up")
                }
            }
        }
    }

    private func recordProgress() {}
    private func shareBook() {}
}

13:38 - Label

Label("Progress", systemImage: "book.circle")

14:06 - Label expanded form

Label {
    Text("Progress")
} icon: {
    Image(systemName: "book.circle")
}

14:24 - Bottom bar toolbar placement

struct ContentView: View {
    var body: some View {
        List {
            Text("Book Detail")
        }
        .toolbar {
            ToolbarItem {
                Button(action: recordProgress) {
                    Label("Progress", systemImage: "book.circle")
                }
            }
            ToolbarItem(placement: .bottomBar) {
                Button(action: shareBook) {
                    Label("Share", systemImage: "square.and.arrow.up")
                }
            }
        }
    }

    private func recordProgress() {}
    private func shareBook() {}
}

14:36 - Context menu Labels

struct ContentView: View {
    var body: some View {
        List {
            Text("Book List Row")
            .contextMenu {
                Button(action: recordProgress) {
                    Label("Progress", systemImage: "book.circle")
                }
                Button(action: addToFavorites) {
                    Label("Add to Favorites", systemImage: "heart")
                }
                Button(action: shareBook) {
                    Label("Share", systemImage: "square.and.arrow.up")
                }
            }
        }
    }

    private func recordProgress() {}
    private func addToFavorites() {}
    private func shareBook() {}
}

14:39 - List Labels

struct ContentView: View {
    var body: some View {
        List {
            Group {
                Label("Introducing SwiftUI", systemImage: "hand.wave")
                Label("SwiftUI Essentials", systemImage: "studentdesk")
                Label("Data Essentials in SwiftUI", systemImage: "flowchart")
                Label("App Essentials in SwiftUI", systemImage: "macwindow.on.rectangle")
            }
            Group {
                Label("Build Document-based apps in SwiftUI", systemImage: "doc")
                Label("Stacks, Grids, and Outlines", systemImage: "list.bullet.rectangle")
                Label("Building Custom Views in SwiftUI", systemImage: "sparkles")
                Label("Build SwiftUI Apps for tvOS", systemImage: "tv")
                Label("Build SwiftUI Views for Widgets", systemImage: "square.grid.2x2.fill")
                Label("Create Complications for Apple Watch", systemImage: "gauge")
                Label("SwiftUI on All Devices", systemImage: "laptopcomputer.and.iphone")
                Label("Integrating SwiftUI", systemImage: "rectangle.connected.to.line.below")
            }
        }
    }
}

15:28 - Help modifier

struct ContentView: View {
    var body: some View {
        Button(action: recordProgress) {
            Label("Progress", systemImage: "book.circle")
        }
        .help("Record new progress entry")
    }

    private func recordProgress() {}
}

16:12 - Keyboard shortcut modifier

@main
struct BookClubApp: App {
    var body: some Scene {
        WindowGroup {
            List {
                Text("Reading List Viewer")
            }
        }
        .commands {
            Button("Previous Book", action: selectPrevious)
                .keyboardShortcut("[")
            Button("Next Book", action: selectNext)
                .keyboardShortcut("]")
        }
    }

    private func selectPreviousBook() {}
    private func selectNextBook() {}
}

16:28 - Cancel and default action keyboard shortcuts

struct ContentView: View {
    var body: some View {
        HStack {
            Button("Cancel", action: dismissSheet)
                .keyboardShortcut(.cancelAction)

            Button("Save", action: saveProgress)
                .keyboardShortcut(.defaultAction)
        }
    }

    private func dismissSheet() {}
    private func saveProgress() {}
}

17:08 - ProgressView

struct ContentView: View {
    var percentComplete: Double

    var body: some View {
        ProgressView("Downloading Photo", value: percentComplete)
    }
}

17:19 - Circular ProgressView

struct ContentView: View {
    var percentComplete: Double

    var body: some View {
        ProgressView("Downloading Photo", value: percentComplete)
            .progressViewStyle(CircularProgressViewStyle())
    }
}

17:25 - Activity indicator ProgressView

struct ContentView: View {
    var body: some View {
        ProgressView()
    }
}

17:32 - Gauge

struct ContentView: View {
    var acidity: Double

    var body: some View {
        Gauge(value: acidity, in: 3...10) {
            Label("Soil Acidity", systemImage: "drop.fill")
                .foregroundColor(.green)
        }
    }
}

17:52 - Gauge with current value label

struct ContentView: View {
    var acidity: Double

    var body: some View {
        Gauge(value: acidity, in: 3...10) {
            Label("Soil Acidity", systemImage: "drop.fill")
                .foregroundColor(.green)
        } currentValueLabel: {
            Text("\(acidity, specifier: "%.1f")")
        }
    }
}

18:00 - Gauge with minimum and maximum value labels

struct ContentView: View {
    var acidity: Double

    var body: some View {
        Gauge(value: acidity, in: 3...10) {
            Label("Soil Acidity", systemImage: "drop.fill")
                .foregroundColor(.green)
        } currentValueLabel: {
            Text("\(acidity, specifier: "%.1f")")
        } minimumValueLabel: {
            Text("3")
        } maximumValueLabel: {
            Text("10")
        }
    }
}

18:57 - Initial Album Picker

struct ContentView: View {
    @State private var selectedAlbumIDs: Set<Album.ID> = []

    var body: some View {
        VStack(spacing: 0) {
            ScrollView {
                albumGrid.padding(.horizontal)
            }

            Divider().zIndex(-1)

            selectedAlbumRow
                .frame(height: AlbumCell.albumSize)
                .padding(.top, 8)
        }
        .buttonStyle(PlainButtonStyle())
    }

    private var albumGrid: some View {
        LazyVGrid(columns: [GridItem(.adaptive(minimum: AlbumCell.albumSize))], spacing: 8) {
           ForEach(unselectedAlbums) { album in
              Button(action: { select(album) }) {
                 AlbumCell(album)
              }
           }
        }
    }

    private var selectedAlbumRow: some View {
        HStack {
            ForEach(selectedAlbums) { album in
                AlbumCell(album)
            }
        }
    }

    private var unselectedAlbums: [Album] {
        Album.allAlbums.filter { !selectedAlbumIDs.contains($0.id) }
    }
    private var selectedAlbums: [Album] {
        Album.allAlbums.filter { selectedAlbumIDs.contains($0.id) }
    }

    private func select(_ album: Album) {
        withAnimation(.spring(response: 0.5)) {
            _ = selectedAlbumIDs.insert(album.id)
        }
    }
}

struct AlbumCell: View {
    static let albumSize: CGFloat = 100

    var album: Album

    init(_ album: Album) {
        self.album = album
    }

    var body: some View {
        album.image
            .frame(width: AlbumCell.albumSize, height: AlbumCell.albumSize)
            .background(Color.pink)
            .cornerRadius(6.0)
    }
}

struct Album: Identifiable {
    static let allAlbums: [Album] = [
        .init(name: "Sample", image: Image(systemName: "music.note")),
        .init(name: "Sample 2", image: Image(systemName: "music.note.list")),
        .init(name: "Sample 3", image: Image(systemName: "music.quarternote.3")),
        .init(name: "Sample 4", image: Image(systemName: "music.mic")),
        .init(name: "Sample 5", image: Image(systemName: "music.note.house")),
        .init(name: "Sample 6", image: Image(systemName: "tv.music.note"))
    ]

    var name: String
    var image: Image

    var id: String { name }
}

19:17 - Matched geometry effect Album Picker

struct ContentView: View {
    @Namespace private var namespace
    @State private var selectedAlbumIDs: Set<Album.ID> = []

    var body: some View {
        VStack(spacing: 0) {
            ScrollView {
                albumGrid.padding(.horizontal)
            }

            Divider().zIndex(-1)

            selectedAlbumRow
                .frame(height: AlbumCell.albumSize)
                .padding(.top, 8)
        }
        .buttonStyle(PlainButtonStyle())
    }

    private var albumGrid: some View {
        LazyVGrid(columns: [GridItem(.adaptive(minimum: AlbumCell.albumSize))], spacing: 8) {
           ForEach(unselectedAlbums) { album in
              Button(action: { select(album) }) {
                 AlbumCell(album)
              }
              .matchedGeometryEffect(id: album.id, in: namespace)
           }
        }
    }

    private var selectedAlbumRow: some View {
        HStack {
            ForEach(selectedAlbums) { album in
                AlbumCell(album)
                .matchedGeometryEffect(id: album.id, in: namespace)
            }
        }
    }

    private var unselectedAlbums: [Album] {
        Album.allAlbums.filter { !selectedAlbumIDs.contains($0.id) }
    }
    private var selectedAlbums: [Album] {
        Album.allAlbums.filter { selectedAlbumIDs.contains($0.id) }
    }

    private func select(_ album: Album) {
        withAnimation(.spring(response: 0.5)) {
            _ = selectedAlbumIDs.insert(album.id)
        }
    }
}

struct AlbumCell: View {
    static let albumSize: CGFloat = 100

    var album: Album

    init(_ album: Album) {
        self.album = album
    }

    var body: some View {
        album.image
            .frame(width: AlbumCell.albumSize, height: AlbumCell.albumSize)
            .background(Color.pink)
            .cornerRadius(6.0)
    }
}

struct Album: Identifiable {
    static let allAlbums: [Album] = [
        .init(name: "Sample", image: Image(systemName: "music.note")),
        .init(name: "Sample 2", image: Image(systemName: "music.note.list")),
        .init(name: "Sample 3", image: Image(systemName: "music.quarternote.3")),
        .init(name: "Sample 4", image: Image(systemName: "music.mic")),
        .init(name: "Sample 5", image: Image(systemName: "music.note.house")),
        .init(name: "Sample 6", image: Image(systemName: "tv.music.note"))
    ]

    var name: String
    var image: Image

    var id: String { name }
}

19:53 - Container Relative Shape

struct AlbumWidgetView: View {
    var album: Album

    var body: some View {
        album.image
            .clipShape(ContainerRelativeShape())
            .padding()
    }
}

struct Album {
    var name: String
    var artist: String
    var image: Image
}

20:34 - Dynamic Type scaling

struct ContentView: View {
    var album: Album
    @ScaledMetric private var padding: CGFloat = 10

    var body: some View {
        VStack {
            Text(album.name)
                .font(.custom("AvenirNext-Bold", size: 30))

            Text("\(Image(systemName: "music.mic")) \(album.artist)")
                .font(.custom("AvenirNext-Bold", size: 17))

        }
        .padding(padding)
        .background(RoundedRectangle(cornerRadius: 16, style: .continuous).fill(Color.purple))
    }
}

struct Album {
    var name: String
    var artist: String
    var image: Image
}

22:08 - Initial Sidebar List

struct ContentView: View {
    var body: some View {
        NavigationView {
            List {
                Label("Menu", systemImage: "list.bullet")

                Label("Favorites", systemImage: "heart")

                Label("Rewards", systemImage: "seal")

                Section(header: Text("Recipes")) {
                    ForEach(1..<4) {
                        Label("Recipes \($0)", systemImage: "book.closed")
                    }
                }
            }
            .listStyle(SidebarListStyle())
        }
    }
}

22:17 - List Item Tint in Sidebars

struct ContentView: View {
    var body: some View {
        NavigationView {
            List {
                Label("Menu", systemImage: "list.bullet")

                Label("Favorites", systemImage: "heart")
                    .listItemTint(.red)

                Label("Rewards", systemImage: "seal")
                    .listItemTint(.purple)

                Section(header: Text("Recipes")) {
                    ForEach(1..<4) {
                        Label("Recipes \($0)", systemImage: "book.closed")
                    }
                }
                .listItemTint(.monochrome)
            }
            .listStyle(SidebarListStyle())
        }
    }
}

22:33 - List Item Tint on watchOS

struct ContentView: View {
    var body: some View {
        NavigationView {
            List {
                Label("Menu", systemImage: "list.bullet")

                Label("Favorites", systemImage: "heart")
                    .listItemTint(.red)

                Label("Rewards", systemImage: "seal")
                    .listItemTint(.purple)

                Section(header: Text("Recipes")) {
                    ForEach(1..<4) {
                        Label("Recipes \($0)", systemImage: "book.closed")
                    }
                }
                .listItemTint(.monochrome)
            }
        }
    }
}

22:46 - SwitchToggleStyle tint

struct ContentView: View {
    @State var order = Order()

    var body: some View {
        Toggle("Send notification when ready", isOn: $order.notifyWhenReady)
            .toggleStyle(SwitchToggleStyle(tint: .accentColor))
    }
}

struct Order {
    var notifyWhenReady = true
}

23:15 - Link

let appleURL = URL(string: "https://developer.apple.com/tutorials/swiftui/")!
let wwdcAnnouncementURL = URL(string: "https://apple.news/AjriX1CWUT-OfjXu_R4QsnA")!

struct ContentView: View {
    var body: some View {
        Form {
            Section {
                Link(destination: apple) {
                    Label("SwiftUI Tutorials", systemImage: "swift")
                }
                Link(destination: wwdcAnnouncementURL) {
                    Label("WWDC 2020 Announcement", systemImage: "chevron.left.slash.chevron.right")
                }
            }
        }
    }
}

23:56 - OpenURL Environment Action

let customPublisher = NotificationCenter.default.publisher(for: .init("CustomURLRequestNotification"))
let apple = URL(string: "https://developer.apple.com/tutorials/swiftui/")!

struct ContentView: View {
    @Environment(\.openURL) private var openURL

    var body: some View {
        Text("OpenURL Environment Action")
            .onReceive(customPublisher) { output in
                if output.userInfo!["shouldOpenURL"] as! Bool {
                    openURL(apple)
                }
            }
    }
}

24:44 - Uniform Type Identifiers

import UniformTypeIdentifiers

extension UTType {
    static let myFileFormat = UTType(exportedAs: "com.example.myfileformat")
}

func introspecContentType(_ fileURL: URL) throws {
    // Get this file's content type.
    let resourceValues = try fileURL.resourceValues(forKeys: [.contentTypeKey])
    if let type = resourceValues.contentType {
        // Get the human presentable description of the type.
        let description = type.localizedDescription

        if type.conforms(to: .myFileFormat) {
            // The file is our app’s format.
        } else if type.conforms(to: .image) {
            // The file is an image.
        }
    }
}

25:16 - Sign in with Apple Button

import AuthenticationServices
import SwiftUI

struct ContentView: View {
    var body: some View {
        SignInWithAppleButton(
            .signUp,
            onRequest: handleRequest,
            onCompletion: handleCompletion
        )
        .signInWithAppleButtonStyle(.black)
    }

    private func handleRequest(request: ASAuthorizationAppleIDRequest) {}
    private func handleCompletion(result: Result<ASAuthorization, Error>) {}
}