Add SwiftUI Sidebar next to PDF View on iOS

1
//
2
//  Copyright © 2019-2025 PSPDFKit GmbH. All rights reserved.
3
//
4
//  The Nutrient sample applications are licensed with a modified BSD license.
5
//  Please see License for details. This notice may not be removed from this file.
6
//
7

8
import Combine
9
import PSPDFKit
10
import PSPDFKitUI
11
import SwiftUI
12

13
private extension NSNotification.Name {
14
    static let DismissHostingController = NSNotification.Name("DismissHostingControllerNotification")
15
}
16

17
class SwiftUISidebarExample: Example {
18

19
    override init() {
20
        super.init()
21

22
        title = "SwiftUI Sidebar Example"
23
        contentDescription = "Shows how to show a PDFView in SwiftUI with sidebar."
24
        category = .swiftUI
25
        priority = 10
26
        // We present this modal, as SwiftUI controls the navigation controller here.
27
        wantsModalPresentation = true
28
        embedModalInNavigationController = false
29
    }
30

31
    private var dismissSink: AnyCancellable?
32

33
    override func invoke(with delegate: ExampleRunnerDelegate) -> UIViewController? {
34
        let document = AssetLoader.document(for: .welcome)
35
        let swiftUIView = SwiftUISidebarExampleView(document: document)
36

37
        let hostingController = DismissableHostingViewController(rootView: swiftUIView)
38
        hostingController.modalPresentationStyle = .fullScreen
39

40
        dismissSink = NotificationCenter.default.publisher(for: .DismissHostingController)
41
            .sink { _ in hostingController.dismiss(animated: true, completion: nil) }
42

43
        return hostingController
44
    }
45
}
46

47
final private class DismissableHostingViewController: UIHostingController<SwiftUISidebarExampleView> {
48
    override init(rootView: SwiftUISidebarExampleView) {
49
        super.init(rootView: rootView)
50
        self.rootView.dismiss = dismiss
51
    }
52

53
    @objc required dynamic init?(coder aDecoder: NSCoder) {
54
        fatalError("init(coder:) has not been implemented")
55
    }
56

57
    private func dismiss() {
58
        dismiss(animated: true, completion: nil)
59
    }
60
}
61

62
private struct SwiftUISidebarExampleView: View {
63
    @ObservedObject var document: Document
64

65
    // Logic is connected from the hosting view controller.
66
    var dismiss: (() -> Void)?
67

68
    @State private var sidebarActionHandler = SidebarActionHandler(didSelectAnnotation: { _ in }, didSelectBookmark: { _ in }, didSelectOutline: { _ in })
69

70
    var body: some View {
71
        NavigationView {
72
            Sidebar(dismiss: dismiss!)
73
            CombinedSidebar(document: document, actionHandler: sidebarActionHandler) // aka "PrimaryView"
74
            DetailView(document: document, sidebarActionHandler: $sidebarActionHandler)
75
                .navigationBarTitleDisplayMode(.inline)
76
        }
77
    }
78
}
79

80
private struct Sidebar: View {
81
    let dismiss: (() -> Void)
82

83
    var body: some View {
84
        Button("Exit Example", action: dismiss)
85
    }
86
}
87

88
private struct DetailView: View {
89
    let document: Document
90
    @Binding var sidebarActionHandler: SidebarActionHandler
91
    private let actionEventPublisher = PassthroughSubject<PDFView.ActionEvent, Never>()
92
    @State private var selectedAnnotations: [Annotation] = []
93

94
    var body: some View {
95
        PDFView(document: document, selectedAnnotations: $selectedAnnotations, actionEventPublisher: actionEventPublisher) {
96
            $0.pageTransition = .scrollContinuous
97
            $0.scrollDirection = .vertical
98
            $0.pageMode = .single
99
            $0.spreadFitting = .adaptive
100
        }
101
        .onAppear {
102
            // connect the sidebar handler with the event publisher
103
            sidebarActionHandler = SidebarActionHandler { annotation in
104
                selectedAnnotations = [annotation]
105
            } didSelectBookmark: { bookmark in
106
                actionEventPublisher.send(.setPageIndex(index: bookmark.pageIndex))
107
            } didSelectOutline: { outlineElement in
108
                actionEventPublisher.send(.setPageIndex(index: outlineElement.pageIndex))
109
            }
110
        }
111
    }
112
}
113

114
// MARK: Previews
115

116
struct SwiftUISidebarExamplePreviews: PreviewProvider {
117
    static var previews: some View {
118
        let document = AssetLoader.document(for: .welcome)
119
        SwiftUISidebarExampleView(document: document)
120
    }
121
}