Accessibility Linked Text Groups for Reading Apps

import SwiftUI
import Accessibility

struct ParagraphPageView: View {
    @Namespace private var readingNamespace
    @State private var savedText: String = ""
    @State private var showSavedBanner: Bool = false

    let morningText = "We started our morning in Lincoln Park, strolling through the trails and admiring the views of the Chicago skyline. Before we left the park, we made sure to stop at the free zoo."
    let middayText = "At lunchtime, we walked along the Chicago river. The river-front path gave us great views of the city's magnificent architecture. Our favourite view was from the middle of the DuSable Bridge."

    var body: some View {
        ScrollView {
            VStack(alignment: .leading, spacing: 24) {
                Text("Morning")
                    .font(.title2.bold())

                // First paragraph — linked into the reading group
                Text(morningText)
                    .textSelection(.enabled)
                    .accessibilityLinkedGroup(id: "page1", in: readingNamespace)

                Text("Midday")
                    .font(.title2.bold())

                // Second paragraph — same group id and namespace
                // VoiceOver line/word/character rotor moves across both
                Text(middayText)
                    .textSelection(.enabled)
                    .accessibilityLinkedGroup(id: "page1", in: readingNamespace)
                    // causesPageTurn tells Speak Screen to advance the page
                    // when it reaches the end of this element
                    .accessibilityAddTraits(.causesPageTurn)

                if showSavedBanner {
                    Text("Selection saved: \(savedText)")
                        .font(.footnote)
                        .foregroundStyle(.secondary)
                        .padding(8)
                        .background(.quaternary, in: RoundedRectangle(cornerRadius: 8))
                        .transition(.opacity)
                }
            }
            .padding()
        }
        .navigationTitle("Chicago Guide")
        .toolbar {
            ToolbarItem(placement: .primaryAction) {
                Button("Save Selection") {
                    savedText = "(selection)"
                    withAnimation { showSavedBanner = true }
                }
                // Surface this action in the VoiceOver Edit rotor
                .accessibilityCustomActions(category: .edit) {
                    AccessibilityCustomAction(name: "Save recommendation") {
                        savedText = "(selection)"
                        withAnimation { showSavedBanner = true }
                        return true
                    }
                }
            }
        }
    }
}

#Preview {
    NavigationStack {
        ParagraphPageView()
    }
}