Barcode AR Overlays

/// A UIView that serves as the overlay to barcodes.
open class ALBarcodeOverlayView {

    /// Initializes an ALBarcodeOverlayView.
    public init!()

    /// Causes the view to be marked for deletion, allowing you to define
    /// a different view in the next update cycle.
    public init!(config: ALOverlayConfig!)

    /// Causes the view to be marked for deletion, allowing you to define
    /// a different view in the next update cycle.
    func invalidate()
}

/// A UIView that serves as the overlay to barcodes.
@interface ALBarcodeOverlayView : UIView

/// Initializes an ALBarcodeOverlayView.
- (instancetype)init;

/// Initializes an ALBarcodeOverlayView with a configuration.
- (instancetype)initWithConfig:(ALOverlayConfig *)config;

/// Causes the view to be marked for deletion, allowing you to define
/// a different view in the next update cycle.
- (void)invalidate;

@end

// inside a ALBarcodeOverlayCreateBlock

let overlayConfig = ALOverlayConfig(anchor: .topCenter())

let overlayView = ALBarcodeOverlayView(config: overlayConfig)

let imageVw = UIImageView(image: detectedBarcode.barcodeImage())
imageVw.contentMode = .scaleAspectFit
overlayView.addSubview(imageVw)
imageVw.translatesAutoresizingMaskIntoConstraints = false

let label = UILabel()
label.backgroundColor = .white
label.textAlignment = .center
label.numberOfLines = 0
label.font = UIFont.boldSystemFont(ofSize: 14)
label.translatesAutoresizingMaskIntoConstraints = false
label.text = "\(detectedBarcode.barcode.value)"

overlayView.addSubview(label)

// specify the Autolayout constraints of the label and image view within
// ALBarcodeOverlayView
// NOTE: setting frames for the subviews manually is also still possible

NSLayoutConstraint.activate([
    imageVw.centerXAnchor.constraint(equalTo: overlayView.centerXAnchor),
    imageVw.topAnchor.constraint(equalTo: overlayView.topAnchor),
    imageVw.leadingAnchor.constraint(equalTo: overlayView.leadingAnchor),
    imageVw.heightAnchor.constraint(lessThanOrEqualToConstant: 150),

    label.topAnchor.constraint(equalTo: imageVw.bottomAnchor),
    label.bottomAnchor.constraint(equalTo: overlayView.bottomAnchor),
    label.leadingAnchor.constraint(equalTo: overlayView.leadingAnchor),
    label.trailingAnchor.constraint(equalTo: overlayView.trailingAnchor),
    label.heightAnchor.constraint(lessThanOrEqualToConstant: 30)
])

return [ overlayView ]

// Inside a ALBarcodeOverlayCreateBlock

ALOverlayConfig *overlayConfig = [[ALOverlayConfig alloc] initWithAnchor:ALOverlayAnchorConfig.topCenter];

ALBarcodeOverlayView *overlayView = [[ALBarcodeOverlayView alloc] initWithConfig:overlayConfig];

UIImageView *imageVw = [[UIImageView alloc] initWithImage:[detectedBarcode barcodeImage]];
imageVw.contentMode = UIViewContentModeScaleAspectFit;
[overlayView addSubview:imageVw];
imageVw.translatesAutoresizingMaskIntoConstraints = NO;

UILabel *label = [[UILabel alloc] init];
label.backgroundColor = [UIColor whiteColor];
label.textAlignment = NSTextAlignmentCenter;
label.numberOfLines = 0;
label.font = [UIFont boldSystemFontOfSize:14];
label.translatesAutoresizingMaskIntoConstraints = NO;
label.text = [NSString stringWithFormat:@"%@", detectedBarcode.barcode.value];

[overlayView addSubview:label];

// Specify the Autolayout constraints of the label and image view within
// ALBarcodeOverlayView
// NOTE: setting frames for the subviews manually is also still possible

[NSLayoutConstraint activateConstraints:@[
    [imageVw.centerXAnchor constraintEqualToAnchor:overlayView.centerXAnchor],
    [imageVw.topAnchor constraintEqualToAnchor:overlayView.topAnchor],
    [imageVw.leadingAnchor constraintEqualToAnchor:overlayView.leadingAnchor],
    [imageVw.heightAnchor constraintLessThanOrEqualToConstant:150],

    [label.topAnchor constraintEqualToAnchor:imageVw.bottomAnchor],
    [label.bottomAnchor constraintEqualToAnchor:overlayView.bottomAnchor],
    [label.leadingAnchor constraintEqualToAnchor:overlayView.leadingAnchor],
    [label.trailingAnchor constraintEqualToAnchor:overlayView.trailingAnchor],
    [label.heightAnchor constraintLessThanOrEqualToConstant:30]
]];

return @[overlayView];

/// A barcode object scanned by the plugin.
open class ALDetectedBarcode : NSObject {

    /// The object corresponding to the barcode detected.
    var barcode: ALBarcode { get }

    /// The CGRect of the scanned barcode within the frame at the time
    /// of its detection.
    var enclosingCGRect: CGRect { get }

    /// Creates and returns a cropped image containing the barcode.
    func barcodeImage() -> Any!
}

/// A barcode object scanned by the plugin.
@interface ALDetectedBarcode : NSObject

/// The object corresponding to the barcode detected.
@property (nonatomic, strong, readonly) ALBarcode *barcode;

/// The CGRect of the scanned barcode within the frame at the time
/// of its detection.
@property (nonatomic, assign, readonly) CGRect enclosingCGRect;

/// Creates and returns a cropped image containing the barcode.
- (id)barcodeImage;

@end

let overlayConfig = ALOverlayConfig(anchor: .topCenter(),
                                    offsetX: nil,
                                    offsetY: .init(scaleType: .fixedPx(), scaleValue: 15),
                                    sizeX: .init(scaleType: .overlay(), scaleValue: 1.5),
                                    sizeY: .init(scaleType: .keepRatio(), scaleValue: 0.75))

let overlayView = ALBarcodeOverlayView(config: overlayConfig)
// ...

ALOverlayConfig *overlayConfig = [[ALOverlayConfig alloc] initWithAnchor:ALOverlayAnchorConfig.topCenter
                                                                 offsetX:nil
                                                                 offsetY:[[ALScaleValue alloc] initWithScaleType:ALScaleTypeConfig.fixedPx scaleValue:15]
                                                                 sizeX:[[ALScaleValue alloc] initWithScaleType:ALScaleTypeConfig.overlay scaleValue:1.5]
                                                                 sizeY:[[ALScaleValue alloc] initWithScaleType:ALScaleTypeConfig.keepRatio scaleValue:0.75]];

ALBarcodeOverlayView *overlayView = [[ALBarcodeOverlayView alloc] initWithConfig:overlayConfig];
// ...