Persist View Settings using Swift for 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 PSPDFKit
9
import PSPDFKitUI
10

11
class PersistViewSettingsExample: Example, PDFViewControllerDelegate {
12
    let pageTransition = "pageTransition"
13
    let pageMode = "pageMode"
14
    let scrollDirection = "scrollDirection"
15
    let spreadFitting = "spreadFitting"
16

17
    override init() {
18
        super.init()
19

20
        title = "Persist View Settings"
21
        contentDescription = "Shows how to persist PDFSettingsViewController options using UserDefaults."
22
        category = .controllerCustomization
23
    }
24

25
    override func invoke(with delegate: ExampleRunnerDelegate) -> UIViewController {
26
        let document = AssetLoader.writableDocument(for: .welcome, overrideIfExists: false)
27
        let controller = PDFViewController(document: document, delegate: self) {
28
            // Configure the `PDFSettingsViewController`'s options.
29
            $0.settingsOptions = [.pageTransition, .pageMode, .scrollDirection, .spreadFitting]
30

31
            // Restore the settings from the user defaults.
32
            let defaults = UserDefaults.standard
33
            $0.pageTransition = PageTransition(rawValue: UInt(defaults.integer(forKey: self.pageTransition)))!
34
            $0.pageMode = PageMode(rawValue: UInt(defaults.integer(forKey: self.pageMode)))!
35
            $0.scrollDirection = ScrollDirection(rawValue: UInt(defaults.integer(forKey: self.scrollDirection)))!
36
            $0.spreadFitting = PDFConfiguration.SpreadFitting(rawValue: defaults.integer(forKey: self.spreadFitting))!
37
        }
38

39
        // Configure the left bar button items.
40
        controller.navigationItem.setLeftBarButtonItems([controller.settingsButtonItem], animated: false)
41
        controller.navigationItem.leftItemsSupplementBackButton = true
42
        return controller
43
    }
44

45
    // MARK: - PDFViewControllerDelegate
46
    func pdfViewControllerDidDismiss(_ pdfController: PDFViewController) {
47
        // Persist the settings options in the user defaults.
48
        let defaults = UserDefaults.standard
49
        defaults.set(pdfController.configuration.pageTransition.rawValue, forKey: pageTransition)
50
        defaults.set(pdfController.configuration.pageMode.rawValue, forKey: pageMode)
51
        defaults.set(pdfController.configuration.scrollDirection.rawValue, forKey: scrollDirection)
52
        defaults.set(pdfController.configuration.spreadFitting.rawValue, forKey: spreadFitting)
53
    }
54
}