Customize the annotations list in Swift for iOS

1
//
2
//  Copyright © 2021-2026 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 PSPDFKit
9
import PSPDFKitUI
10

11
class AnnotationListExample: Example {
12
    override init() {
13
        super.init()
14
        title = "Customizing the Annotation List"
15
        contentDescription = "Customize the annotation cell in AnnotationTableViewController."
16
        category = .viewCustomization
17
        priority = 70
18
    }
19

20
    override func invoke(with delegate: ExampleRunnerDelegate) -> UIViewController? {
21
        let guide = AssetLoader.document(for: .welcome)
22
        let controller = PDFViewController(document: guide) { builder in
23
            builder.overrideClass(AnnotationCell.self, with: CustomAnnotationCell.self)
24
            builder.overrideClass(AnnotationTableViewController.self, with: AnnotationListController.self)
25
        }
26
        controller.documentInfoCoordinator.availableControllerOptions = [.annotations]
27

28
        // Simulate tapping on the outline button.
29
        DispatchQueue.main.asyncAfter(deadline: .now() + .seconds(1)) {
30
            controller.documentInfoCoordinator.present(
31
                to: controller,
32
                options: nil,
33
                sender: controller.outlineButtonItem,
34
                animated: true,
35
                completion: nil
36
            )
37
        }
38

39
        return controller
40
    }
41
}
42

43
private class CustomAnnotationCell: AnnotationCell {
44
    var isShared: Bool {
45
        didSet {
46
            sharingStateLabel.text = isShared ? "Shared" : "Not Shared"
47
            // Ensure the size and placement are up to date
48
            sharingStateLabel.sizeToFit()
49
            setNeedsLayout()
50
        }
51
    }
52

53
    // Note: This isn’t the greatest UI. A smaller sharing indicator would be nicer.
54
    private var sharingStateLabel: UILabel
55

56
    override init(style: UITableViewCell.CellStyle, reuseIdentifier: String?) {
57
        isShared = false
58
        sharingStateLabel = UILabel()
59
        sharingStateLabel.textColor = .psc_secondaryLabel
60

61
        super.init(style: style, reuseIdentifier: reuseIdentifier)
62
        accessoryView = sharingStateLabel
63
    }
64

65
    required init?(coder: NSCoder) {
66
        fatalError("init(coder:) has not been implemented and isn’t needed")
67
    }
68
}
69

70
private class AnnotationListController: AnnotationTableViewController {
71
    override func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
72
        let anyCell = super.tableView(tableView, cellForRowAt: indexPath)
73
        guard let cell = anyCell as? CustomAnnotationCell else {
74
            return anyCell
75
        }
76

77
        // Our superclass sets the annotation on the cell, so we know we may force unwrap.
78
        let annotation = cell.annotation!
79
        cell.isShared = sharedState(for: annotation)
80

81
        return cell
82
    }
83

84
    private var sharedStateByAnnotationID: [String: Bool] = [:]
85
    private func sharedState(for annotation: Annotation) -> Bool {
86
        sharedStateByAnnotationID[annotation.id] ?? false
87
    }
88

89
    private func toggleSharedState(for annotation: Annotation) -> Bool {
90
        let desiredState = !sharedState(for: annotation)
91
        sharedStateByAnnotationID[annotation.id] = desiredState
92

93
        return desiredState
94
    }
95

96
    override func tableView(_ tableView: UITableView, trailingSwipeActionsConfigurationForRowAt indexPath: IndexPath) -> UISwipeActionsConfiguration? {
97
        guard let cell = tableView.cellForRow(at: indexPath) as? CustomAnnotationCell else {
98
            return super.tableView(tableView, trailingSwipeActionsConfigurationForRowAt: indexPath)
99
        }
100

101
        let action = UIContextualAction(
102
            style: .normal,
103
            title: cell.isShared ? "Unshare" : "Share"
104
        ) { [weak cell, weak self] _, _, completion in
105
            guard let cell, let self else {
106
                return completion(false)
107
            }
108
            cell.isShared = self.sharedState(for: cell.annotation!)
109

110
            completion(true)
111
        }
112

113
        return UISwipeActionsConfiguration(actions: [action])
114
    }
115
}