State Customization

PDFViewController can be in five different states:

  • Default (showing a PDF document)
  • Loading
  • Empty
  • Locked (password-protected PDF document)
  • Error

Take a look at ControllerState for more information.

You can change the state’s strings and images or you can set PDFViewController.overlayViewController to take care of state handling yourself.

To create an overlay view controller, you have to implement the ControllerStateHandling protocol in a UIViewController subclass.

Implementing all of the states, with the exception of locked, is pretty straightforward, because they don’t feature any interaction. To unlock documents, you need to add a text field and handle the keyboard accordingly. Use Document.unlock(withPassword:) to unlock the document. After that, you need to reload the PDFViewController with reloadData().

The following code snippets should help you create your own overlay view controller correctly:

Swift
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class OverlayViewController: UIViewController, ControllerStateHandling {

    // MARK: Properties

    weak var pdfController: PDFViewController!

    private let label: UILabel = {
        let label = UILabel()
        label.translatesAutoresizingMaskIntoConstraints = false
        label.numberOfLines = 0
        label.textColor = .gray
        label.textAlignment = .center
        return label
    }()

    private let textField: UITextField = {
        let textField = UITextField()
        textField.translatesAutoresizingMaskIntoConstraints = false
        textField.isSecureTextEntry = true
        textField.autocorrectionType = .no
        textField.autocapitalizationType = .none
        textField.borderStyle = .roundedRect
        return textField
    }()

    private let button: UIButton = {
        let button = UIButton(type: .system)
        button.translatesAutoresizingMaskIntoConstraints = false
        button.setTitle("Unlock", for: .normal)
        button.setTitleColor(.blue, for: .normal)
        button.sizeToFit()
        return button
    }()

    // MARK: UIViewController

    override func viewDidLoad() {
        super.viewDidLoad()
        button.addTarget(self, action: #selector(unlock), for: .touchUpInside)

        let stackView = UIStackView(arrangedSubviews: [label, textField, button])
        stackView.translatesAutoresizingMaskIntoConstraints = false
        stackView.axis = .vertical
        stackView.distribution = .fillEqually
        stackView.spacing = 20
        view.addSubview(stackView)

        NSLayoutConstraint.activate([
            stackView.widthAnchor.constraint(equalToConstant: 300),
            stackView.heightAnchor.constraint(equalToConstant: 150),
            stackView.centerXAnchor.constraint(equalTo: view.centerXAnchor),
            stackView.centerYAnchor.constraint(equalTo: view.centerYAnchor)
        ])
    }

    // MARK: Button Actions

    @objc
    private func unlock(sender: UIButton) {
        guard let document = document, let password = textField.text else { return }
        document.unlock(withPassword: password)
        pdfController.reloadData()
    }

    // MARK: ControllerStateHandling

    var document: Document?

    public func setControllerState(_ state: ControllerState, error: Error?, animated: Bool) {
        var text = ""
        var backgroundColor: UIColor? = .white

        switch state {
        case .default:
            backgroundColor = nil
        case .empty:
            text = "No document set"
        case .loading:
            text = "Loading..."
        case .locked:
            text = "Password:"
        case .error:
            text = "Unable to display document:\n\(error!.localizedDescription)"
        }

        label.text = text
        view.backgroundColor = backgroundColor
        view.isUserInteractionEnabled = state != .default

        if state == .locked {
            textField.isHidden = false
            button.isHidden = false
            textField.becomeFirstResponder()
        } else {
            textField.isHidden = true
            button.isHidden = true
            textField.resignFirstResponder()
        }
    }
}
Objective-C
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@interface OverlayViewController : UIViewController <PSPDFControllerStateHandling>

@property (nonatomic, weak) PSPDFViewController *pdfController;

@end

@interface OverlayViewController ()

@property (nonatomic) UILabel *label;
@property (nonatomic) UITextField *textField;
@property (nonatomic) UIButton *button;

@end

@implementation OverlayViewController

#pragma mark - UIViewController

-(void)viewDidLoad {
    [super viewDidLoad];

    self.label = [UILabel new];
    self.label.translatesAutoresizingMaskIntoConstraints = NO;
    self.label.numberOfLines = 0;
    self.label.textColor = [UIColor grayColor];
    self.label.textAlignment = NSTextAlignmentCenter;

    self.textField = [UITextField new];
    self.textField.translatesAutoresizingMaskIntoConstraints = NO;
    self.textField.secureTextEntry = YES;
    self.textField.autocorrectionType = UITextAutocorrectionTypeNo;
    self.textField.autocapitalizationType = UITextAutocapitalizationTypeNone;
    self.textField.borderStyle = UITextBorderStyleRoundedRect;

    self.button = [UIButton buttonWithType:UIButtonTypeSystem];
    self.button.translatesAutoresizingMaskIntoConstraints = NO;
    [self.button setTitle:@"Unlock" forState:UIControlStateNormal];
    [self.button setTitleColor:[UIColor blueColor] forState:UIControlStateNormal];
    [self.button sizeToFit];
    [self.button addTarget:self action:@selector(unlock:) forControlEvents:UIControlEventTouchUpInside];

    UIStackView *stackView = [[UIStackView alloc] initWithArrangedSubviews:@[self.label, self.textField, self.button]];
    stackView.translatesAutoresizingMaskIntoConstraints = NO;
    stackView.axis = UILayoutConstraintAxisVertical;
    stackView.distribution = UIStackViewDistributionFillEqually;
    stackView.spacing = 20;
    [self.view addSubview:stackView];

    [NSLayoutConstraint activateConstraints:@[
        [stackView.widthAnchor constraintEqualToConstant:300],
        [stackView.heightAnchor constraintEqualToConstant:150],
        [stackView.centerXAnchor constraintEqualToAnchor:self.view.centerXAnchor],
        [stackView.centerYAnchor constraintEqualToAnchor:self.view.centerYAnchor]
    ]];
}

#pragma mark - Button Actions

- (void)unlock:(id)sender {
    NSString *password = self.textField.text;
    [self.document unlockWithPassword:password];
    [self.pdfController reloadData];
}

#pragma mark - PSPDFControllerStateHandling

@synthesize document;

-(void)setControllerState:(PSPDFControllerState)state error:(NSError *)error animated:(BOOL)animated {
    NSString *text = @"";
    UIColor *backgroundColor = [UIColor whiteColor];

    switch (state) {
        case PSPDFControllerStateDefault:
            backgroundColor = nil;
            break;

        case PSPDFControllerStateEmpty:
            text = @"No document set";
            break;

        case PSPDFControllerStateLoading:
            text = @"Loading...";
            break;

        case PSPDFControllerStateLocked:
            text = @"Password:";
            break;

        case PSPDFControllerStateError:
            text = [NSString stringWithFormat:@"Unable to display document:\n%@", error.localizedDescription];
            break;

        default:
            break;
    }

    self.label.text = text;
    self.view.backgroundColor = backgroundColor;
    self.view.userInteractionEnabled = state != PSPDFControllerStateDefault;

    if (state == PSPDFControllerStateLocked) {
        self.textField.hidden = NO;
        self.button.hidden = NO;
        [self.textField becomeFirstResponder];
    } else {
        self.textField.hidden = YES;
        self.button.hidden = YES;
        [self.textField resignFirstResponder];
    }
}

@end
Swift
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let pdfController = PDFViewController(document: document)
let overlayViewController = OverlayViewController()
overlayViewController.pdfController = pdfController
pdfController.overlayViewController = overlayViewController
Objective-C
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PSPDFViewController *pdfController = [[PSPDFViewController alloc] initWithDocument:document];
OverlayViewController *overlayViewController = [OverlayViewController new];
overlayViewController.pdfController = pdfController;
pdfController.overlayViewController = overlayViewController;

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The PSPDFKit SDK is a framework that allows you to view, annotate, sign, and fill PDF forms on iOS, Android, Windows, macOS, and Web. PSPDFKit Instant adds real-time collaboration features to seamlessly share, edit, and annotate PDF documents.