QRCode

A simple and quick macOS/iOS/tvOS/watchOS QR Code generator/detector library for SwiftUI, Swift and Objective-C.

Why?

• It's nice to have a simple, quick drop-in component for displaying a QR code when you need it!
• It's nice to have your app look great!

Features

• Supports Swift and Objective-C.
• Supports Swift Package Manager and CocoaPods
• Generate a QR code without access to a UI.
• Supports all error correction levels.
• Configurable quiet zone
• Load/Save support
• Drop-in live display support for SwiftUI, NSView (macOS) and UIView (iOS/tvOS).
• Generate images, scalable PDFs, scalable SVGs and CGPath paths.
• Configurable designs.
• Add a logo to a QR code.
• Configurable fill styles (solid, linear gradient, radial gradient) for image generation.
• Configurable corner radius
• Command line tool for generating qr codes from the command line (macOS 10.13+).
• Basic qr code video detection (via importing QRCodeDetector).

Installing

Swift Package Manager

To use in your project, add the following dependency to your Package.swift:

.package(url: "https://github.com/dagronf/qrcode.git", from: "16.1.1")

Cocoapods

To install it, simply add the following line to your Podfile

pod 'DSF_QRCode', '~> 16.1.1'

Usage

The core functionality for generating a nice QR code is found in the QRCode library.

If you want to use the qr code video detection, you'll need to import the QRCodeDetector library. The reason for separating these out into two different libraries is because video detection requires your app to have a NSCameraUsageDescription defined in your including app (along with adding an AVFoundation dependency) if you're putting it on the app store - something that you may not want if your app doesn't need it!

• For QR code generation, link against QRCode
• For QR code video detection, link against QRCodeDetector

In your source

Swift: import QRCode

Objective-C: @import QRCode;

Generating a QR Code

The QRCode.Document class is the core class you will interact with. It is not tied to any presentation medium and is cross-platform across Apple OSes.

You can use this class to generate a QR Code and present the result as a CGPath or a CGImage. And if you're using Swift you can retrieve the raw qr code data as a 2D array of Bool to use however you need.

You can create a basic black-and-white QR code image very easily.

let doc = QRCode.Document(utf8String: "Hi there!", errorCorrection: .high)
let generated = doc.cgImage(CGSize(width: 800, height: 800))

Generates

You can further style the qr code (see below)

let doc = QRCode.Document()
doc.utf8String = "This is a test"
doc.errorCorrection = .high

// Set the background color to clear
doc.design.backgroundColor(CGColor.clear)

// Set the foreground color to blue
doc.design.foregroundColor(CGColor.blue)

// Generate a CGPath object containing the QR code
let path = doc.path(CGSize(width: 400, height: 400))

// Generate an image using the default styling (square, black foreground, white background) with 3x resolution
let image = doc.uiImage(CGSize(width: 400, height: 400), dpi: 216)

// Generate pdf data containing the qr code
let pdfdata = doc.pdfData(CGSize(width: 400, height: 400))

// Save a JSON representation of the qrcode document
let jsonData = try doc.jsonData()

// Load a qr code from json
let loadedDoc = try QRCode.Document(jsonData: jsonData)

There are also some extensions on CGImage to help making qr codes even easier

let qrCodeImage = CGImage.qrCode("Hi there!", dimension: 800)

Settings

Set the data content

/// Set raw data
@objc public var data: Data

/// Set a string
public func setString(
   _ string: String, 
   encoding: String.Encoding = .utf8, 
   allowLossyConversion: Bool = false) -> Bool

/// Set raw data using a qrcode message formatter
@objc func setMessage(_ message: QRCodeMessageFormatter)

Set the error correction

@objc public var errorCorrection: QRCode.ErrorCorrection = .quantize

The QRCode.Document has 4 different encoding levels

The higher the error correction level, the larger the QR code will be.

Design

QRCode supports a number of ways of 'designing' your qr code. By default, the qr code will be generated in its traditional form - square, black foreground and white background. By tweaking the design settings of the qr code you can make it a touch fancier.

Note You can fancify your QR code so much that it can no longer be read by readers.

1. Always check that your QR code can be read at the size that it will be presented to users. (hint: use your phone!)
2. Have good contrast between the QR Code and its background
3. If you use 'off' pixels (see below) make sure they are very high contrast to the 'on' pixels.
4. Don't have high contrast between the 'on' pixels and the eye.

The design comprises two components :-

You can individually specify the shape and fill style for each of the components of the QR code.

QR code components

The QRCode is made up of four distinct components

• The 'on' data pixels (onPixels)
• The eye, which is made up of an eye (the outer part of the eye) and a pupil (the inner part).
• The 'off' data pixels (offPixels)

Eye shape

You can provide an EyeShape object to style just the eyes of the generated qr code. There are built-in generators for square, circle, rounded rectangle, and more.

Preview	Name	Class	Description
	"square"	QRCode.EyeShape.Square	Simple square (default)
	"circle"	QRCode.EyeShape.Circle	Simple circle
	"roundedRect"	QRCode.EyeShape.RoundedRect	Simple rounded rect
	"roundedOuter"	QRCode.EyeShape.RoundedOuter	Square with the outer corner rounded
	"roundedPointingIn"	QRCode.EyeShape.RoundedPointingIn	A rounded rect with the 'inner' corner as a point
	"leaf"	QRCode.EyeShape.Leaf	An eye that look like a leaf
	"squircle"	QRCode.EyeShape.Squircle	A superellipse shape (somewhere between a square and a circle)
	"barsHorizontal"	QRCode.EyeShape.BarsHorizontal	Simple rounded rect with three horizontal bars as the pupil
	"barsVertical"	QRCode.EyeShape.BarsVertical	Simple rounded rect with three vertical bars as the pupil
	"pixels"	QRCode.EyeShape.Pixels	A simple collection of pixels with configurable corner radius for each pixel
	"corneredPixels"	QRCode.EyeShape.CorneredPixels	A simple collection of pixels with configurable corner radius for the entire shape
	"edges"	QRCode.EyeShape.Edges	Simple bordered bars with a configurable corner radius
	"shield"	QRCode.EyeShape.Shield	A shield with configurable corners

Custom Pupil shape (optional)

You can provide an override to the default EyeShape pupil shape to change just the shape of the pupil. There are built-in generators for square, circle, rounded rectangle, and more.

If you don't override the pupil shape, it defaults to the eye shape's pupil shape.

Preview	Name	Class	Description
	"square"	QRCode.PupilShape.Square	Simple square (default)
	"circle"	QRCode.PupilShape.Circle	Simple circle
	"roundedRect"	QRCode.PupilShape.RoundedRect	Simple rounded rect
	"roundedOuter"	QRCode.PupilShape.RoundedOuter	Square with the outer corner rounded
	"roundedPointingIn"	QRCode.PupilShape.RoundedPointingIn	A rounded rect with the inner corner as a point
	"roundedPointingOut"	QRCode.PupilShape.RoundedPointingOut	A rounded rect with the outer corner as a point
	"leaf"	QRCode.PupilShape.Leaf	An eye that look like a leaf
	"squircle"	QRCode.PupilShape.Squircle	A superellipse shape (somewhere between a square and a circle)
	"barsHorizontal"	QRCode.PupilShape.BarsHorizontal	Simple rounded rect with three horizontal bars as the pupil
	"barsVertical"	QRCode.PupilShape.BarsVertical	Simple rounded rect with three vertical bars as the pupil
	"pixels"	QRCode.PupilShape.Pixel	A simple collection of pixels with configurable corner radius for each pixel
	"corneredPixels"	QRCode.PupilShape.CorneredPixels	A simple collection of pixels with configurable corner radius for the entire shape
	"shield"	QRCode.PupilShape.Shield	A shield with configurable corners

Example

let doc = QRCode.Document(utf8String: "Custom pupil")
doc.design.style.background = QRCode.FillStyle.Solid(CGColor.white)
doc.design.shape.eye = QRCode.EyeShape.Squircle()
doc.design.style.eye = QRCode.FillStyle.Solid(0.149, 0.137, 0.208)
doc.design.shape.pupil = QRCode.PupilShape.BarsHorizontal()
doc.design.style.pupil = QRCode.FillStyle.Solid(0.314, 0.235, 0.322)
doc.design.style.onPixels = QRCode.FillStyle.Solid(0.624, 0.424, 0.400)

'OnPixels' shape

The data shape represents how the 'pixels' within the QR code are displayed. By default, this is a simple square, however you can supply a PixelShape object to custom-draw the data. There are built-in generators for a variety of styles.

Preview	Name	Class	Description
	"square"	QRCode.PixelShape.Square	A basic square pixel (default)
	"circle"	QRCode.PixelShape.Circle	A basic circle pixel
	"curvePixel"	QRCode.PixelShape.CurvePixel	A pixel that curves to follow paths
	"roundedRect"	QRCode.PixelShape.RoundedRect	A basic rounded rectangle pixel with configurable radius
	"horizontal"	QRCode.PixelShape.Horizontal	The pixels are horizonally joined to make continuous horizontal bars
	"vertical"	QRCode.PixelShape.Vertical	The pixels are vertically joined to make continuous vertical bars
	"roundedPath"	QRCode.PixelShape.RoundedPath	A smooth rounded-edge path
	"roundedEndIndent"	QRCode.PixelShape.RoundedEndIndent	Rounded path with circular indented ends
	"squircle"	QRCode.PixelShape.Squircle	A superellipse shape (somewhere between a square and a circle)
	"pointy"	QRCode.PixelShape.Pointy	A 'pointy' style
	"sharp"	QRCode.PixelShape.Sharp	A 'sharp' style
	"star"	QRCode.PixelShape.Star	A 'star' style
	"flower"	QRCode.PixelShape.Flower	A 'flower' style
	"shiny"	QRCode.PixelShape.Shiny	A pixel style that appears 'shiny'

'offPixels' shape (optional)

You can specify a shape to be drawn when a data 'pixel' is off. This can be used to make your qr code prettier. Just remember that the more embellishment you add to a QR code the more difficult it will be to read.

It's really important to make sure that there is a high color contrast between the 'offPixels' shape and the 'onPixels' shape to aid readers.

let doc1 = QRCode.Document(utf8String: "Hi there noodle")
doc1.design.backgroundColor(NSColor.white.cgColor)
doc1.design.shape.eye = QRCode.EyeShape.RoundedOuter()
doc1.design.shape.onPixels = QRCode.PixelShape.Circle()
doc1.design.style.onPixels = QRCode.FillStyle.Solid(NSColor.systemGreen.cgColor)
doc1.design.shape.offPixels = QRCode.PixelShape.Horizontal(insetFraction: 0.4, cornerRadiusFraction: 1)
doc1.design.style.offPixels = QRCode.FillStyle.Solid(NSColor.systemGreen.withAlphaComponent(0.4).cgColor)

// Set a custom pupil shape. If this isn't set, the default pixel shape for the eye is used
doc1.design.shape.pupil = QRCode.PupilShape.BarsHorizontal()

// Generate a image for the QRCode
let cgImage = doc1.cgImage(CGSize(width: 300, height: 300))

Fill styles

You can provide a custom fill for any of the individual components of the qr code.

• The 'onPixels'
• The eye (outer)
• The pupil (inner)
• The 'offPixels'

let doc2 = QRCode.Document(utf8String: "Github example for colors")
doc2.design.backgroundColor(NSColor.white.cgColor)
doc2.design.shape.eye = QRCode.EyeShape.RoundedOuter()
doc2.design.shape.onPixels = QRCode.PixelShape.RoundedPath()

// Eye color
doc2.design.style.eye = QRCode.FillStyle.Solid(NSColor.systemGreen.cgColor)
// Pupil color
doc2.design.style.pupil = QRCode.FillStyle.Solid(NSColor.systemBlue.cgColor)
// Data color
doc2.design.style.onPixels = QRCode.FillStyle.Solid(NSColor.systemBrown.cgColor)

// Generate a image for the QRCode
let cgImage = doc2.cgImage(CGSize(width: 300, height: 300))

This library supports the current fill types.

• solid fill (QRCode.FillStyle.Solid)
• linear gradient (QRCode.FillStyle.LinearGradient)
• radial gradient (QRCode.FillStyle.RadialGradient)
• image (QRCode.FillStyle.Image)

Style examples

A simple QRCode with a red radial fill.

let doc3 = QRCode.Document(utf8String: "Github example for colors")
doc3.design.style.background = QRCode.FillStyle.Solid(CGColor.white)

// Set the fill color for the data to radial gradient
let radial = QRCode.FillStyle.RadialGradient(
   DSFGradient(pins: [
      DSFGradient.Pin(CGColor(red: 0.8, green: 0, blue: 0, alpha: 1), 0),
      DSFGradient.Pin(CGColor(red: 0.1, green: 0, blue: 0, alpha: 1), 1)
   ])!,
   centerPoint: CGPoint(x: 0.5, y: 0.5)
)
doc3.design.style.onPixels = radial

// Generate a image for the QRCode
let cgImage = doc3.cgImage(CGSize(width: 300, height: 300))

Adding a logo to a QR code

The QRCode.LogoTemplate class is used to define a logo on the QR code. The document has a logoTemplate member where this can be set (see the examples below)

WARNING

Adding a logo can heavily adversely affect the ability to recognise the content of the QR code. If you add a logo it's highly recommended to set the errorCorrection levels to .high. Logos that cover more than 25% of the data tend to cause more failures than successes when reading.

After adding an image its important to verify that the qr code can be read (Most phone cameras can read qr codes). If the logo ends up covering more that 25% of the data, it is highly likely your QR code will have trouble being read by some readers. Before reporting a bug about the qr code failing to be read, remove the image and retry. If the code can be read without the image it means your logo is too big.

Method 1: Logo Masking

The simplest method is to provide a logo and an optional transparent image mask. If the mask is not supplied, the library will use the transparency information from the logo image to generate a mask for you.

The image and mask image should be the same size and square for the best results. Both the logo and the mask will be scaled to the final size of the QR code before application.

logo	mask		result
		➜

Sample image and mask examples

Logo and mask

let doc = QRCode.Document(utf8String: "Adding a logo to a QR code using an image and a mask image", errorCorrection: .high)
let logoImage = ... some logo image ...
let logoMaskImage = ... some mask image ...
doc.logoTemplate = QRCode.LogoTemplate(logoImage: logoImage, maskImage: logoMaskImage)

logo	mask	result

Logo only

let doc = QRCode.Document(utf8String: "Adding a logo to a QR code using an image's transparency", errorCorrection: .high)
let logoImage = ... some logo image ...
doc.logoTemplate = QRCode.LogoTemplate(logoImage: logoImage)

logo	result

Method 2: Logo templates

The logo template defines an image and a relative path in the QRCode in which to draw the image.

The relative path represents the section in the QR code 'data' where the image is drawn. It represents a relative path (ie. x=0.0, y=0.0, width=1.0, height=1.0) within the bounds of the QR code.

x=0.0, y=0.0 represents the top left of the qr code.

For example, if you wanted to put a circle logo in the center of your qr code where the circle is exactly 1/3 of the size of the QR code, then the path is defined as :-

let path = CGPath(ellipseIn: CGRect(x: 0.35, y: 0.30, width: 0.3, height: 0.3), transform: nil)

(note that a 1/3 mask will most likely render the qr code unreadable :-).

A 1/4 size rectangular logo in the lower right of the qr code would be :-

let path = CGPath(rect: CGRect(x: 0.75, y: 0.75, width: 0.25, height: 0.25), transform: nil)

The mask path only affects the onPixels and offPixels within the QR code. Defining a logo that falls within the eye boundaries will be clipped.

There are a number of pre-built LogoTemplate creators for the 'standard' logo positions.

• circle center (QRCode.LogoTemplate.CircleCenter)
• circle bottom right (QRCode.LogoTemplate.CircleBottomRight)
• square center (QRCode.LogoTemplate.SquareCenter)
• square bottom right (QRCode.LogoTemplate.SquareBottomRight)

// Define a rectangle mask within the bounds of the QR code. A centered square, 30% of the qr code size.
let doc = QRCode.Document(...)

doc.logoTemplate = QRCode.LogoTemplate(
   path: CGPath(rect: CGRect(x: 0.35, y: 0.35, width: 0.30, height: 0.30), transform: nil), 
   inset: 3,
   image: UIImage(named: "square-logo")?.cgImage
)

let qrCodeWithLogo = doc.nsImage(dimension: 300)

let doc = QRCode.Document(...)
doc.logoTemplate = QRCode.LogoTemplate(
   path: CGPath(ellipseIn: CGRect(x: 0.7, y: 0.7, width: 0.30, height: 0.30), transform: nil),
   inset: 8
)
let image = NSImage(named: "instagram-icon")!
let qrCodeWithLogo = doc.uiImage(dimension: 300, image: image)

Quiet zone

You can add a quiet zone around the outside of the QR code by setting additionalQuietZonePixels on the design object. This represents the number of pixels spacing are added around the outside of the actual QR Code.

Note that a background color/image/fill is not affected by the quiet zone (will always extend to the boundaries of the generated image)

By default, the quiet zone is set to 0 pixels.

0 pixels	5 pixels	10 pixels	15 pixels	Background Image with 6 pixels

let doc = QRCode.Document(utf8String: "https://www.swift.org/about/")
doc.design.style.background = QRCode.FillStyle.Solid(0.410, 1.000, 0.375)
doc.design.additionalQuietZonePixels = 4
let qrcodeImage = doc.cgImage(CGSize(width: 300, height: 300))

Background Corner Radius

You can specify a corner radius for your background fill on the style object, which is in fractional qr code data-pixel values.

By default, the corner radius is set to 0.

0 pixels	2 pixels	4 pixels	6 pixels

let doc = QRCode.Document(utf8String: "Corner radius checking")
doc.design.style.background = QRCode.FillStyle.Solid(1, 0, 0)
doc.design.foregroundStyle(QRCode.FillStyle.Solid(1, 1, 1))
doc.design.additionalQuietZonePixels = 2
doc.design.style.backgroundFractionalCornerRadius = 3.0
let qrcodeImage = doc.cgImage(CGSize(width: 300, height: 300))

Message Formatters

There are a number of QRCode data formats that are somewhat common with QR code readers, such as QR codes containing phone numbers or contact details.

There are a number of built-in formatters for generating some common QR Code types. These can be found in the messages subfolder.

• URLs (Link)
• Generate an email (Mail)
• A phone number (Phone)
• Contact Details (Contact)
• A UTF-8 formatted string (Text)

Generating output

Generate a path

@objc func path(_ size: CGSize, components: Components, design: QRCode.Design) -> CGPath

Produces a CGPath representation of the QRCode

• The size in pixels of the generated path
• The components of the qr code to include in the path (defaults to the standard QR components)
  • The eye 'outer' ring
  • The eye pupil
  • The pixels that are 'on' within the QR Code
  • The pixels that are 'off' within the QR Code
• The shape of the qr components

The components allow the caller to generate individual paths for the QR code components which can then be individually styled and recombined later on.

There are also extensions on CGPath to make it even easier to generate a CGPath from a qr code.

let qrcodePath = CGPath.qrCode("This is a test!!!", dimension: 800)

Generating a styled image

@objc func cgImage(_ size: CGSize, dpi: CGFloat = 72.0) -> CGImage?

Generate an CGImage from the QR Code, using an (optional) design object for styling the QR code

@objc func nsImage(_ size: CGSize, dpi: CGFloat = 72.0) -> NSImage?

(macOS only) Generate an NSImage from the QR Code, using an (optional) design object for styling the QR code

@objc func uiImage(_ size: CGSize, dpi: CGFloat = 72.0) -> UIImage?

(iOS/tvOS/watchOS/macCatalyst only) Generate an UIImage from the QR Code, using an (optional) design object for styling the QR code

Generate a styled, scalable PDF representation of the QR Code

@objc func pdfData(_ size: CGSize, pdfResolution: CGFloat) -> Data?

Generate a scalable PDF from the QRCode using an (optional) design object for styling the QR code and resolution

Generate a SVG representation of the QR Code

@objc func svg(dimension: Int) -> String

Generate an SVG representation of the QR code.

Add a QR Code to the pasteboard (macOS/iOS)

Adds multiple representations of the QRCode to the specified pasteboard

@objc func addToPasteboard(pasteboard: NSPasteboard = NSPasteboard.general, _ size: CGSize, dpi: CGFloat = 72.0)
@objc func addToPasteboard(pasteboard: UIPasteboard = UIPasteboard.general, _ size: CGSize, dpi: CGFloat = 72.0)

Generate a text representation of the QR Code

@objc func asciiRepresentation() -> String

Return an ASCII representation of the QR code using the extended ASCII code set

Only makes sense if presented using a fixed-width font.

@objc func smallAsciiRepresentation() -> String

Returns an small ASCII representation of the QR code (about 1/2 the regular size) using the extended ASCII code set

Only makes sense if presented using a fixed-width font.

Presentation

This library provides drop-in components for presenting a styled QR code.

NSView/UIView

QRCodeDocumentView

QRCodeDocumentView is a view implementation to display a QRCode.Document object.

QRCodeView

QRCodeView is a view implementation for displaying a QR Code. This view supports :-

• @IBDesignable via Interface Builder so you can design and style your QR code completely within Interface Builder without having a QRCode.Document object.
• (Optional) drag support for dragging a QR code out of the view.

SwiftUI

QRCodeViewUI

The simplest way to add a stylish QR code to your SwiftUI app. QRCodeViewUI is a SwiftUI view for displaying a qrcode with just the basic styling elements.

QRCodeViewUI(
   content: "This is a test",
   foregroundColor: CGColor(srgbRed: 1, green: 0.8, blue: 0.6, alpha: 1.0),
   backgroundColor: CGColor(srgbRed: 0.2, green: 0.2, blue: 0.8, alpha: 1.0),
   pixelStyle: QRCode.PixelShape.RoundedPath(cornerRadiusFraction: 0.7, hasInnerCorners: true),
   eyeStyle: QRCode.EyeShape.RoundedRect()
)

QRCodeDocumentViewUI

If you need more control over the styling and content of your QR code, QRCodeDocumentViewUI is a SwiftUI view that displays a QRCode.Document object.

   var body: some View {
         VStack {
            QRCodeDocumentUIView(document: doc)
         }
         .padding()
   }

QRCodeShape

QRCodeShape is a SwiftUI Shape object generating paths from different components of a QR code.

So anything you can do with any SwiftUI shape object (eg. a rectangle) you can now do with a styled QRCode shape outline.

For example, you can use .fill to set the color content (eg. a linear gradient, solid color etc), add a drop shadow, add a transform etc...

let qrContent = QRCodeShape(myData)
...
ZStack {
   qrContent
      .components(.eyeOuter)
      .fill(.green)
   qrContent
      .components(.eyePupil)
      .fill(.teal)
   qrContent
      .components(.onPixels)
      .fill(.black)
}

Modifiers

func errorCorrection(_ errorCorrection: QRCode.ErrorCorrection) -> QRCodeShape {

Set the error correction level

func components(_ components: QRCode.Components) -> QRCodeShape

Set which components of the QR code to be added to the path

func shape(_ shape: QRCode.Shape) -> QRCodeShape

Set the shape (onPixels, offPixels, eye, pupil)

func eyeShape(_ eyeShape: QRCodeEyeShape) -> QRCodeShape

Set the shape of the eye (eye and pupil)

func pupilShape(_ pupilShape: QRCodePupilShape) -> QRCodeShape

Set the shape of the pupil

func onPixelShape(_ pixelShape: QRCodePixelShape) -> QRCodeShape

Set the shape of the 'on' pixels in the QR code

func offPixelShape(_ pixelShape: QRCodePixelShape) -> QRCodeShape

Set the shape of the 'off' pixels in the QR code

func relativeMaskPath(_ maskPath: CGPath) -> QRCodeShape

Set the masking path

struct ContentView: View {

   @State var content: String = "This is a test of the QR code control"
   @State var correction: QRCodeView.ErrorCorrection = .low

   var body: some View {
      Text("Here is my QR code")
      QRCodeShape(
         text: content,
         errorCorrection: correction
      )
      .fill(LinearGradient(gradient: gradient, startPoint: .topLeading, endPoint: .bottomTrailing))
      .shadow(color: .black, radius: 1, x: 1, y: 1)
      .frame(width: 250, height: 250, alignment: .center)
   }
}

Objective-C

The QRCode library fully supports Objective-C.

QRCode* code = [[QRCode alloc] init];
[code updateWithText: @"This message"
     errorCorrection: QRCodeErrorCorrectionMax];

QRCodeStyle* style = [[QRCodeStyle alloc] init];

// Set the foreground color to a solid red
style.onPixels = [[QRCodeFillStyleSolid alloc] init: CGColorCreateGenericRGB(1, 0, 0, 1)];

// Use the leaf style
style.shape.eyeShape = [[QRCodeEyeStyleLeaf alloc] init];

// Generate the image
CGImageRef image = [code image: CGSizeMake(400, 400) scale: 1.0 style: style];
NSImage* nsImage = [[NSImage alloc] initWithCGImage:image size: CGSizeZero];

Load/Save

The QRCode.Document class has methods for loading/saving QRCode definitions to a JSON format

let qrCode = QRCode.Document()
qrCode.data = "this is a test".data(using: .utf8)!
qrCode.design.shape.onPixels = QRCode.PixelShape.Circle()
qrCode.design.shape.eye = QRCode.EyeShape.Leaf()

let jsonData = try qrCode.jsonData()

...

let loadedQRCode = try QRCode.Document.Create(jsonData: jsonData)

Detecting QR Codes

From an image

The library provides a mechanism for detecting QR codes in an image

// CGImage/NSImage/UIImage detection
if let detected = QRCode.DetectQRCodes(in: /*some image*/),
   detected.count > 0 {
   // Do something with the detected qr codes
   let qrCodeBounds = detected[0].bounds
   let qrCodeMessage = detected[0].messageString
   ...
}

Even easier, there is an extension on CGImage to detect the strings encoded within the image if you only want the string content for each match.

let image = CGImage(...)
let messages = image.qrCodedMessages()

From a video stream

In order to allow QRCode to be used in App Store or Test Flight targets without having to allow Camera usage, the video detector component has been extracted out into its own target, QRCodeDetector.

There is a video detector class QRCodeDetector.VideoDetector which is a very basic qr code detector for video streams.

There are two basic demos demonstrating the qr code detection in a video stream.

• macOS QRCode Detector: Video qr code detector for macOS targets
• iOS QRCode Detector: Video qr code detector for iOS targets (requires a real device)

Demo

There are a number of demo apps which you can find in the Demo subfolder. There are simple demo applications for

• SwiftUI (macOS, iOS, macCatalyst, watchOS)
• iOS (Swift, including macCatalyst)
• macOS (Swift and Objective-C)

Command line tool

You can build the command line tool by opening a terminal window, cd into the QRCode folder and build using

swift build -c release --product qrcodegen

The qrcodegen tool can be found in the .build/release folder.

% .build/debug/qrcodegen -h
OVERVIEW: Create a qr code

Examples:
   qrcodegen -t "This is a QR code" --output-file "fish.png" 512
   qrcodegen -t "QRCode on the clipboard" --output-format clipboard 1024
   qrcodegen --style-template-file qrtemplate.json -t "QRCode on the clipboard" --output-format clipboard 1024

* If you don't specify either -t or --input-file, the qrcode content will be read from STDIN
* If you don't specify an output file, the generated qr code will be written to a temporary file
  and opened in the default application.

USAGE: qr-code-gen [<options>] <dimension>

ARGUMENTS:
  <dimension>             The QR code dimension. 

OPTIONS:
  --input-file <input-file>
                          The file containing the content for the QR code 
  --output-file <output-file>
                          The output file 
  --output-format <output-format>
                          The output format (png [default],pdf,svg,ascii,smallascii,clipboard) 
  --output-compression <output-compression>
                          The output format compression factor (if the output format supports it, png,jpg) 
  --style-template-file <style-template-file>
                          The QR code file to use as a style template 
  -t, --text <text>       The text to be stored in the QR code 
  -s, --silence           Silence any output 
  -c, --error-correction <error-correction>
                          The level of error correction. Available levels are "L" (low), "M" (medium), "Q" (quantize),
                          "H" (high) 
  -p, --pupil-shape <pupil-shape>
                          The pupil shape to use. Available shapes are barsHorizontal, barsVertical, circle,
                          corneredPixels, leaf, pixels, roundedOuter, roundedPointingIn, roundedPointingOut,
                          roundedRect, square, squircle. 
  -e, --eye-shape <eye-shape>
                          The eye shape to use. Available shapes are barsHorizontal, barsVertical, circle,
                          corneredPixels, leaf, pixels, roundedOuter, roundedPointingIn, roundedPointingOut,
                          roundedRect, square, squircle. 
  -d, --on-pixel-shape <on-pixel-shape>
                          The onPixels shape to use. Available shapes are circle, curvePixel, horizontal, pointy,
                          roundedPath, roundedRect, sharp, square, squircle, vertical. 
  -n, --inset-fraction <inset-fraction>
                          The spacing around each individual pixel in the onPixels section 
  -r, --on-pixel-shape-corner-radius <on-pixel-shape-corner-radius>
                          The onPixels shape corner radius fractional value (0.0 -> 1.0) 
  --bg-color <bg-color>   The background color to use (format r,g,b,a - 1.0,0.5,0.5,1.0) 
  --data-color <data-color>
                          The onPixels color to use (format r,g,b,a - 1.0,0.5,0.5,1.0) 
  --eye-color <eye-color> The eye color to use (format r,g,b,a - 1.0,0.5,0.5,1.0) 
  --pupil-color <pupil-color>
                          The pupil color to use (format r,g,b,a - 1.0,0.5,0.5,1.0) 
  -h, --help              Show help information.

Example

# Generate a qr code 800x800, png format, using roundedPath for the data, leaf for the eye and a transparent background
.build/release/qrcodegen -c H -d roundedPath -e leaf --bg-color 1.0,1.0,1.0,0.0 -t "qrcode generated by command line" --output-file "output.png" 800

Thanks

Denso Wave

Denso Wave

QR Code is a registered trademark of DENSO WAVE.

swift-qrcode-generator

Since watchOS doesn't support Core Image filters, I defer to using an (optional) 3rd party for generating QR Codes for watchOS. It is based on Nayuki's QR Code generator code.

swift-qrcode-generator

License

QRCode

MIT License

Copyright (c) 2023 Darren Ford

Permission is hereby granted, free of charge, to any person obtaining a copy
of this software and associated documentation files (the "Software"), to deal
in the Software without restriction, including without limitation the rights
to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
copies of the Software, and to permit persons to whom the Software is
furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all
copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
SOFTWARE.

swift-qrcode-generator

MIT License

Copyright (c) Project Nayuki. (MIT License)
Copyright (c) 2020 fwcd

Permission is hereby granted, free of charge, to any person obtaining a copy
of this software and associated documentation files (the "Software"), to deal
in the Software without restriction, including without limitation the rights
to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
copies of the Software, and to permit persons to whom the Software is
furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all
copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
SOFTWARE.