QRCode

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

Why?

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

Features

Supports Swift, SwiftUI and Objective-C.
Supports Swift Package Manager
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

Methods

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: "20.0.0")

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;

Advanced (Tuist)

Using `Tuist` or similar

QRCode supports Objective-C at its core, allowing usage in both Swift and Objective-C.

While using QRCode directly in Xcode automatically supports this, it's important to make sure that you link against the Objective-C library. If not, you _WILL_ receive crashes during runtime.

You need to make sure your linker flags OTHER_LDFLAGS contains -ObjC to

For example, using Tuist you will need to add the following …

settings: Settings(
   base: [
      "OTHER_LDFLAGS": "-ObjC"
   ],
   ...
)

Creating a QR Code

You create a QR Code by creating an instance of QRCode.Document

Using Swift

let doc = try QRCode.Document(utf8String: "This is the content")
// Create a CGImage 
let cgImage = try doc.cgImage(dimension: 400)
// Create a PNG image
let pngData = try doc.pngData(dimension: 400)
// Create a PDF (scalable content!)
let pdfData = try doc.pdfData(dimension: 400)
// Create an SVG (scalable content!)
let svgData = try doc.svgData(dimension: 400)
// Create a CGPath
let path = try doc.path(dimension: 400)

Objective-C

Using Objective-C

``objective-c NSError* error = NULL; QRCodeDocument* code = [[QRCodeDocument alloc] initWithUtf8String:@"This is the content" errorCorrection:QRCodeErrorCorrectionHigh engine:NULL error:&error]; CGImageRef cgr = [doc cgImageWithDimension:400 error:&error];

</details>
|  Bitmap  |  Vector  |
|----------|----------|
|<a href='./Art/images/basic-doco-md-coreimage.png'><img src="./Art/images/basic-doco-md-coreimage.png" width="80"/></a>|<a href='./Art/images/basic-doco-md-coreimage.pdf'><img src="./Art/images/basic-doco-md-coreimage.png" width="80"/></a>|
Setting the error correction

swift
@objc public var errorCorrection: QRCode.ErrorCorrection = .quantize
The QRCode.Document has 4 different encoding levels
| Error correction | Description                                          |
|------------------|:-----------------------------------------------------|
| low              | Lowest error correction (L - Recovers 7% of data)    |
| medium           | Medium error correction (M - Recovers 15% of data)   |
| quantize         | Quantize error correction (Q - Recovers 25% of data) |
| high             | High error correction (H - Recovers 30% of data)     |
Generating your QR Code
QRCode.Document has many methods and styles for generating a QR Code.

Exportable types
|              |              |
|:-------------|:-------------|
| Bitmap types | PNG, TIFF, JPEG |
| Vector types | PDF, SVG |
| Path types   | CGPath | 
| Image Types  | CGImage, NSImage, UIImage |
| Text types   | json |

Settings
Set the QR code's encoded contentswift
let doc = QRCode.Document("This is a test")
// Setting raw data
doc.data = Data(...)
// Setting text
doc.utf8String = "This is my text"
doc.setText("This is my text")
// Setting a message
doc.setMessage(...)
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.

WARNING
You can style 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 :-
|        | Description                                                               |
|--------|:--------------------------------------------------------------------------|
| shape  | The shape of each of the individual components within the QR code         |
| style  | The fill styles for each of the individual components within the QR code  |
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)

Styling your QR Code
Once you have your QRCode.Document, there are many way you can style it to give your design more personality

<details>
<summary>tl;dr Simple Example</summary>swift
let doc = try QRCode.Document("This is a test")
// 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 = try doc.uiImage(CGSize(width: 400, height: 400), dpi: 216)
// Generate pdf data containing the qr code
let pdfdata = try 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)
</details>
QRCode builder
QRCode.Builder is a lightweight Swift-only convenience shim for the QRCode Document.swift
let image = try QRCode.build
   .text("https://www.worldwildlife.org/about")
   .quietZonePixelCount(3)
   .foregroundColor(CGColor(srgbRed: 1, green: 0, blue: 0.6, alpha: 1))
   .backgroundColor(CGColor(srgbRed: 0, green: 0, blue: 0.2, alpha: 1))
   .background.cornerRadius(3)
   .onPixels.shape(QRCode.PixelShape.CurvePixel())
   .eye.shape(QRCode.EyeShape.Teardrop())
   .generate.image(dimension: 600, representation: .png())
<a href="./Art/images/builder-shim.png"><img src="./Art/images/builder-shim.png" width="150"/></a>
Shape
The 'shape' represents the way that each of the components are drawn
'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.

<img src="./Art/images/data_abstract.png" width="60" title="Abstract" /> <img src="./Art/images/data_arrow.png" width="60" title="Arrow" /> <img src="./Art/images/data_blob.png" width="60" title="Blob" /> <img src="./Art/images/data_circle.png" width="60" title="Circle" /> <img src="./Art/images/data_circuit.png" width="60" title="Circuit" /> <img src="./Art/images/data_crosshatch.png" width="60" title="Crosshatch" /> <img src="./Art/images/data_crt.png" width="60" title="CRT" /> <img src="./Art/images/data_curvePixel.png" width="60" title="Curve pixel" /> <img src="./Art/images/data_diagonal.png" width="60" title="Diagonal" /> <img src="./Art/images/data_diagonalStripes.png" width="60" title="DiagonalStripes" /> <img src="./Art/images/data_diamond.png" width="60" title="Diamond" /> <img src="./Art/images/data_donut.png" width="60" title="Donut" /> <img src="./Art/images/data_dripHorizontal.png" width="60" title="Drip Horizontal" /> <img src="./Art/images/data_dripVertical.png" width="60" title="Drip Vertical" /> <img src="./Art/images/data_flame.png" width="60" title="Flame" /> <img src="./Art/images/data_flower.png" width="60" title="Flower" /> <img src="./Art/images/data_gear.png" width="60" title="Gear" /> <img src="./Art/images/data_grid2x2.png" width="60" title="2x2 Square Grid" /> <img src="./Art/images/data_grid3x3.png" width="60" title="3x3 Square Grid" /> <img src="./Art/images/data_grid4x4.png" width="60" title="4x4 Square Grid" /> <img src="./Art/images/data_heart.png" width="60" title="Heart" /> <img src="./Art/images/data_hexa.png" width="60" title="Hexa" /> <img src="./Art/images/data_hexagon.png" width="60" title="Hexagon" /> <img src="./Art/images/data_horizontal.png" width="60" title="Horizontal bars" /> <img src="./Art/images/data_koala.png" width="60" title="Koala" /> <img src="./Art/images/data_leaf.png" width="60" title="Leaf" /> <img src="./Art/images/data_pointy.png" width="60" title="Pointy" /> <img src="./Art/images/data_razor.png" width="60" title="Razor" /> <img src="./Art/images/data_roundedEndIndent.png" width="60" title="Rounded end indent" /> <img src="./Art/images/data_roundedPath.png" width="60" title="Rounded path" /> <img src="./Art/images/data_roundedRect.png" width="60" title="Rounded rectangle" /> <img src="./Art/images/data_roundedTriangle.png" width="60" title="RoundedTriangle" /> <img src="./Art/images/data_sharp.png" width="60" title="Sharp" /> <img src="./Art/images/data_shiny.png" width="60" title="Shiny" /> <img src="./Art/images/data_spikyCircle.png" width="60" title="Spiky Circle" /> <img src="./Art/images/data_square.png" width="60" title="Square" /> <img src="./Art/images/data_squircle.png" width="60" title="Squircle" /> <img src="./Art/images/data_star.png" width="60" title="Star" /> <img src="./Art/images/data_stitch.png" width="60" title="Stitch" /> <img src="./Art/images/data_vertical.png" width="60" title="Vertical bars" /> <img src="./Art/images/data_vortex.png" width="60" title="Vortex" /> <img src="./Art/images/data_wave.png" width="60" title="Wave" /> <img src="./Art/images/data_wex.png" width="60" title="Wex" />
Pixel style configuration options
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.

<img src="./Art/images/eye_arc.png" width="60" title="Arc" /> <img src="./Art/images/eye_barsHorizontal.png" width="60" title="Horizontal bars" /> <img src="./Art/images/eye_barsVertical.png" width="60" title="Vertical bars" /> <img src="./Art/images/eye_circle.png" width="60" title="Circle" /> <img src="./Art/images/eye_cloud.png" width="60" title="Cloud" /> <img src="./Art/images/eye_cloudCircle.png" width="60" title="Cloud Circle" /> <img src="./Art/images/eye_corneredPixels.png" width="60" title="Cornered pixels" /> <img src="./Art/images/eye_crt.png" width="60" title="CRT" /> <img src="./Art/images/eye_diagonalStripes.png" width="60" title="Diagonal Stripes" /> <img src="./Art/images/eye_dotDragHorizontal.png" width="60" title="Dot Drag Horizontal" /> <img src="./Art/images/eye_dotDragVertical.png" width="60" title="Dot Drag Vertical" /> <img src="./Art/images/eye_edges.png" width="60" title="Edges" /> <img src="./Art/images/eye_explode.png" width="60" title="Explode" /> <img src="./Art/images/eye_eye.png" width="60" title="Eye" /> <img src="./Art/images/eye_fabricScissors.png" width="60" title="Fabric Scissors" /> <img src="./Art/images/eye_fireball.png" width="60" title="Fireball" /> <img src="./Art/images/eye_flame.png" width="60" title="Flame" /> <img src="./Art/images/eye_headlight.png" width="60" title="Headlight" /> <img src="./Art/images/eye_holePunch.png" width="60" title="Hole Punch" /> <img src="./Art/images/eye_leaf.png" width="60" title="Leaf" /> <img src="./Art/images/eye_peacock.png" width="60" title="Peacock" /> <img src="./Art/images/eye_pinch.png" width="60" title="Pinch" /> <img src="./Art/images/eye_pixels.png" width="60" title="Pixels" /> <img src="./Art/images/eye_roundedOuter.png" width="60" title="Rounded outer" /> <img src="./Art/images/eye_roundedPointingIn.png" width="60" title="Rounded Pointing In" /> <img src="./Art/images/eye_roundedPointingOut.png" width="60" title="Rounded pointing out" /> <img src="./Art/images/eye_roundedRect.png" width="60" title="Rounded rectangle" /> <img src="./Art/images/eye_shield.png" width="60" title="Shield" /> <img src="./Art/images/eye_spikyCircle.png" width="60" title="Spiky Circle" /> <img src="./Art/images/eye_square.png" width="60" title="Square" /> <img src="./Art/images/eye_squarePeg.png" width="60" title="Square Peg" /> <img src="./Art/images/eye_squircle.png" width="60" title="Squircle" /> <img src="./Art/images/eye_surroundingBars.png" width="60" title="Surrounding bars" /> <img src="./Art/images/eye_teardrop.png" width="60" title="Teardrop" /> <img src="./Art/images/eye_ufo.png" width="60" title="UFO" /> <img src="./Art/images/eye_ufoRounded.png" width="60" title="UFO Rounded" /> <img src="./Art/images/eye_usePixelShape.png" width="60" title="Use Pixel Shape" />
Eye style configuration options
Pupil shape
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.
<img src="./Art/images/pupil_arc.png" width="30" title="Arc" /> <img src="./Art/images/pupil_arrow.png" width="30" title="Arrow" /> <img src="./Art/images/pupil_barsHorizontal.png" width="30" title="Horizontal bars" /> <img src="./Art/images/pupil_barsHorizontalSquare.png" width="30" title="Square horizontal bars" /> <img src="./Art/images/pupil_barsVertical.png" width="30" title="Vertical bars" /> <img src="./Art/images/pupil_barsVerticalSquare.png" width="30" title="Square vertical bars" /> <img src="./Art/images/pupil_blade.png" width="30" title="Blade" /> <img src="./Art/images/pupil_blobby.png" width="30" title="Blobby" /> <img src="./Art/images/pupil_circle.png" width="30" title="Circle" /> <img src="./Art/images/pupil_cloud.png" width="30" title="Cloud" /> <img src="./Art/images/pupil_cloudCircle.png" width="30" title="Cloud Circle" /> <img src="./Art/images/pupil_corneredPixels.png" width="30" title="Cornered pixels" /> <img src="./Art/images/pupil_cross.png" width="30" title="Cross" /> <img src="./Art/images/pupil_crossCurved.png" width="30" title="CrossCurved" /> <img src="./Art/images/pupil_crt.png" width="30" title="CRT" /> <img src="./Art/images/pupil_diagonalStripes.png" width="30" title="Diagonal Stripes" /> <img src="./Art/images/pupil_dotDragHorizontal.png" width="30" title="Dot Drag Horizontal" /> <img src="./Art/images/pupil_dotDragVertical.png" width="30" title="Dot Drag Vertical" /> <img src="./Art/images/pupil_edges.png" width="30" title="Edges" /> <img src="./Art/images/pupil_explode.png" width="30" title="Explode" /> <img src="./Art/images/pupil_fabricScissors.png" width="30" title="Fabric Scissors" /> <img src="./Art/images/pupil_flame.png" width="30" title="Flame" /> <img src="./Art/images/pupil_forest.png" width="30" title="Forest" /> <img src="./Art/images/pupil_gear.png" width="30" title="Gear" /> <img src="./Art/images/pupil_heart.png" width="30" title="Heart" /> <img src="./Art/images/pupil_hexagonLeaf.png" width="30" title="Hexagon Leaf" /> <img src="./Art/images/pupil_koala.png" width="30" title="Koala" /> <img src="./Art/images/pupil_leaf.png" width="30" title="Leaf" /> <img src="./Art/images/pupil_orbits.png" width="30" title="Orbits" /> <img src="./Art/images/pupil_pinch.png" width="30" title="Pinch" /> <img src="./Art/images/pupil_pixels.png" width="30" title="Pixels" /> <img src="./Art/images/pupil_roundedOuter.png" width="30" title="Rounded outer" /> <img src="./Art/images/pupil_roundedPointingIn.png" width="30" title="Rounded Pointing In" /> <img src="./Art/images/pupil_roundedPointingOut.png" width="30" title="Rounded pointing out" /> <img src="./Art/images/pupil_roundedRect.png" width="30" title="Rounded rectangle" /> <img src="./Art/images/pupil_seal.png" width="30" title="Seal" /> <img src="./Art/images/pupil_shield.png" width="30" title="Shield" /> <img src="./Art/images/pupil_spikyCircle.png" width="30" title="Spiky Circle" /> <img src="./Art/images/pupil_square.png" width="30" title="Square" /> <img src="./Art/images/pupil_squircle.png" width="30" title="Squircle" /> <img src="./Art/images/pupil_teardrop.png" width="30" title="Teardrop" /> <img src="./Art/images/pupil_ufo.png" width="30" title="UFO" /> <img src="./Art/images/pupil_ufoRounded.png" width="30" title="UFO Rounded" /> <img src="./Art/images/pupil_usePixelShape.png" width="30" title="Use Pixel Shape" />
Pupil style configuration options
<details>
<summary>Example</summary>swift
let doc = try 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)
<img src="./Art/images/custompupil.png" width="150"/>
</details>
'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.
<img src="./Art/images/dataInverted.png" width="150"/>
<details>
<summary>QRCode source</summary>swift
let doc1 = try 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 = try doc1.cgImage(CGSize(width: 300, height: 300))
</details>
Style
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'
<img src="./Art/images/eye_colorstyles.png" width="150"/>
<details>
<summary>QRCode source</summary>swift
let doc2 = try 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 = try doc2.cgImage(CGSize(width: 300, height: 300))
</details>
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.
<img src="./Art/images/fillstyles.png" width="150"/>
<details>
<summary>QRCode source</summary>swift
let doc3 = try 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 = try doc3.cgImage(CGSize(width: 300, height: 300))
</details>
Adding shadows
The QRCode.Shadow class is used to apply shadows to a QR Code. The shadow is applied to the style component
of the QRCode.Document

WARNING
Adding heavy shadows can heavily adversely affect the ability to recognise the content of the QR code.
Usage
The shadow is applied equally to the primary components of the QRCode, namely :-
.onPixels

.eye

.pupil

By default, no shadows are applied.
| Parameter  | Description |
|------------|-------------|
| dx       | The fraction of a module width to offset along the horizontal axis (1.0 == 1 module width) |
| dy       | The fraction of a module height to offset along the vertical axis (1.0 == 1 module height) | 
| blur     | The blur radius of the shadow | 
| color    | The color of the shadow |

A module represents a single square within the QRCode output. For example, in the image below, the dx and dy values are equal to 0.5.

<img src="./Art/images/shadow-module-offset.png" />
Shadow styles
Drop shadow
##### Swiftswift
let shadow = QRCode.Shadow(.dropShadow, dx: 0.2, dy: -0.2, blur: 3, color: CGColor.sRGBA(1, 0, 1))
document.design.style.shadow = shadow
##### Objective-Cobjc
NSColor* color = [NSColor colorWithRed: 1.0 green: 0.0 blue: 0.0 alpha: 1.0];
struct CGColor* shadowColor = [color CGColor];
QRCodeShadow* shadow = [[QRCodeShadow alloc] init:QRCodeShadowTypeDropShadow
                                               dx: 0.2
                                               dy: -0.2
                                             blur: 3
                                            color: shadowColor];
document.design.style.shadow = shadow;
<details>
<summary>Drop shadow example</summary>swift
let doc = try QRCode.Document(utf8String: "Drop shadow sample")
let shadow = QRCode.Shadow(
   .dropShadow,
   dx: 0.2,
   dy: -0.2,
   blur: 8,
   color: CGColor.sRGBA(0, 1, 0, 1)
)
doc.design.style.shadow = shadow
let pngData = try doc.pngData(dimension: 600, dpi: 144)
<a href="./Art/images/qrcode-drop-shadow.png"><img src="./Art/images/qrcode-drop-shadow.png" width="150"/></a>
</details>
Inner shadowswift
let shadow = QRCode.Shadow(.innerShadow, dx: 0.2, dy: -0.2, blur: 3, color: CGColor.sRGBA(1, 0, 1))
document.design.style.shadow = shadow
<details>
<summary>Inner shadow example</summary>swift
let doc = try QRCode.Document(utf8String: "Inner shadow sample")
let shadow = QRCode.Shadow(
   .innerShadow,
   dx: 0.2,
   dy: -0.2,
   blur: 8,
   color: CGColor.sRGBA(0, 1, 0, 1)
)
doc.design.style.shadow = shadow
let pngData = try doc.pngData(dimension: 600, dpi: 144)
<a href="./Art/images/qrcode-inner-shadow.png"><img src="./Art/images/qrcode-inner-shadow.png" width="150"/></a>
</details>
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 |
|:------:|:------:|:--:|:------:|
<img src="./Tests/QRCodeTests/Resources/logo.png" width="100"/> | <img src="./Tests/QRCodeTests/Resources/logo-mask.png" width="100"/> | ➜ | <img src="./Art/images/design-logo-masking.png" width="100"/> |
<details>
<summary>Sample image and mask examples </summary>
Logo and maskswift
let doc = try 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 |
|:------:|:------:|:------:|
<img src="./Tests/QRCodeTests/Resources/logo.png" width="150"/> | <img src="./Tests/QRCodeTests/Resources/logo-mask.png" width="150"/> | <img src="./Art/images/design-logo-masking.png" width="150"/> |
Logo onlyswift
let doc = try 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 |
|:------:|:------:|
<img src="./Tests/QRCodeTests/Resources/logo.png" width="150"/> | <img src="./Art/images/design-logo-masking-using-transparency.png" width="150"/> |
</details>
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 :-
<a href="./Art/logo-template-path-center.png">
  <img src="./Art/logo-template-path-center.png" width="200"/>
</a>swift
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 :-
<a href="./Art/logo-template-path-lower-right.png">
  <img src="./Art/logo-template-path-lower-right.png" width="200"/>
</a>swift
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)

<details>
<summary>Logo Template Examples</summary>
Example 1swift
// Define a rectangle mask within the bounds of the QR code. A centered square, 30% of the qr code size.
let doc = try 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 = try doc.nsImage(dimension: 300)
generates
<a href="./Art/images/qrcode-with-logo-example.png"><img src="./Art/images/qrcode-with-logo-example.png" width="100"/></a>
Example 2
A round logo in the lower right of the qr codeswift
let doc = try 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 = try doc.uiImage(dimension: 300, image: image)
generates
<a href="./Art/images/qrcode-with-logo-example-bottom-right.png"><img src="./Art/images/qrcode-with-logo-example-bottom-right.png" width="100"/></a>
</details>
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<br/> with 6 pixels |
|:----:|:----:|:----:|:----:|:----:|
| <a href="./Art/images/quiet-space-0.png"><img src="./Art/images/quiet-space-0.png" width="150"/></a> | <a href="./Art/images/quiet-space-5.png"><img src="./Art/images/quiet-space-5.png" width="150"/></a> | <a href="./Art/images/quiet-space-10.png"><img src="./Art/images/quiet-space-10.png" width="150"/></a> | <a href="./Art/images/quiet-space-15.png"><img src="./Art/images/quiet-space-15.png" width="150"/></a> | <a href="./Art/images/quiet-space-background-image.png"><img src="./Art/images/quiet-space-background-image.png" width="150"/></a> |swift
let doc = try QRCode.Document("https://www.swift.org/about/")
doc.design.style.background = QRCode.FillStyle.Solid(0.410, 1.000, 0.375)
doc.design.additionalQuietZonePixels = 4
let qrcodeImage = try 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 |
|:--------:|:--------:|:--------:|:--------:|
| <a href="./Art/images/quiet-space-0.png"><img src="./Art/images/corner-radius-0.png" width="150"/></a> | <a href="./Art/images/quiet-space-0.png"><img src="./Art/images/corner-radius-2.png" width="150"/></a> | <a href="./Art/images/quiet-space-0.png"><img src="./Art/images/corner-radius-4.png" width="150"/></a> | <a href="./Art/images/quiet-space-0.png"><img src="./Art/images/corner-radius-6.png" width="150"/></a> |
<details>
<summary>Background corner radius example</summary>swift
let doc = try QRCode.Document("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 = try doc.cgImage(CGSize(width: 300, height: 300))
<a href="./Art/images/corner-radius-example.png"><img src="./Art/images/corner-radius-example.png" width="150"/></a>
</details>
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 pathswift
@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.swift
let qrcodePath = CGPath.qrCode("This is a test!!!", dimension: 800)
### Generating a styled imageswift
@objc func cgImage(_ size: CGSize, dpi: CGFloat = 72.0) throws -> CGImage
Generate an CGImage from the QR Code, using an (optional) design object for styling the QR codeswift
@objc func nsImage(_ size: CGSize, dpi: CGFloat = 72.0) throws -> NSImage
(macOS only) Generate an NSImage from the QR Code, using an (optional) design object for styling the QR codeswift
@objc func uiImage(_ size: CGSize, dpi: CGFloat = 72.0) throws -> 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 Codeswift
@objc func pdfData(_ size: CGSize, pdfResolution: CGFloat) throws -> 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 Codeswift
@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
| Platform | Added Types        |
|:---------|:-------------------|
| macOS    | PDF/PNG/TIFF | 
| iOS      | PDF/PNG        |swift
@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 Codeswift
@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.swift
@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.swift
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),
   onPixelShape: QRCode.PixelShape.RoundedPath(cornerRadiusFraction: 0.7, hasInnerCorners: true),
   eyeShape: 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.swift
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...

<details>
<summary>Example</summary>swift
let qrContent = try QRCodeShape(myData)
...
ZStack {
   qrContent
      .components(.eyeOuter)
      .fill(.green)
   qrContent
      .components(.eyePupil)
      .fill(.teal)
   qrContent
      .components(.onPixels)
      .fill(.black)
}
</details>
Modifiersswift
func errorCorrection(_ errorCorrection: QRCode.ErrorCorrection) -> QRCodeShape {
Set the error correction levelswift
func components(_ components: QRCode.Components) -> QRCodeShape
Set which components of the QR code to be added to the pathswift
func shape(_ shape: QRCode.Shape) -> QRCodeShape
Set the shape (onPixels, offPixels, eye, pupil)swift
func eyeShape(_ eyeShape: QRCodeEyeShape) -> QRCodeShape
Set the shape of the eye (eye and pupil)swift
func pupilShape(_ pupilShape: QRCodePupilShape) -> QRCodeShape
Set the shape of the pupilswift
func onPixelShape(_ pixelShape: QRCodePixelShape) -> QRCodeShape
Set the shape of the 'on' pixels in the QR codeswift
func offPixelShape(_ pixelShape: QRCodePixelShape) -> QRCodeShape
Set the shape of the 'off' pixels in the QR codeswift
func relativeMaskPath(_ maskPath: CGPath) -> QRCodeShape
Set the masking path
<details>
<summary>Example</summary>swift
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)
   }
}
</details>
Objective-C
The QRCode library fully supports Objective-C.

<details>
<summary>Example</summary>
Using QRCode.Documentobjc
QRCodeDocument* doc = [QRCodeDocument new];
doc.utf8String = @"This is an objective-c qr code";
doc.design.shape.onPixels = [QRCodePixelShapeRazor new];
NSError* error = NULL;
CGImageRef image = [doc cgImageWithDimension:600 error:&error];
assert(error == nil);
### Using QRCode directlyobjc
QRCode* code = [[QRCode alloc] init];
[code updateWithText:@"This message"
     errorCorrection:QRCodeErrorCorrectionHigh
               error:nil];
// Create a new design
QRCodeDesign* design = [QRCodeDesign new];
// Set the foreground color to a solid red
design.style.onPixels = [[QRCodeFillStyleSolid alloc] init: CGColorCreateGenericRGB(1, 0, 0, 1)];
// Use the leaf style
design.shape.eye = [[QRCodeEyeShapeLeaf alloc] init];
// Generate the image
CGImageRef image = [code cgImage:CGSizeMake(400, 400)
                          design:design
                    logoTemplate:nil
                           error:nil];
</details>
Load/Save
The QRCode.Document class has methods for loading/saving QRCode definitions to a JSON formatswift
let qrCode = try 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 imageswift
// 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.swift
let image = CGImage(...)
let messages = image.detectQRCodeStrings()

### 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.

zsh % .build/release/qrcodegen --help 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.

You can generate a style template file by exporting to json format.

USAGE: qr-code-gen []

ARGUMENTS: The QR code dimension.

OPTIONS: --input-file The file containing the content for the QR code --output-file The output file --output-format The output format (png [default],pdf,svg,ascii,smallascii,clipboard,json) --output-compression The output format compression factor (if the output format supports it, png,jpg) --style-template-file The QR code file to use as a style template --logo-image-file The image file to use as a logo if the style template file defines a logo template -t, --text The text to be stored in the QR code -s, --silence Silence any output -c, --error-correction The level of error correction. Available levels are "L" (low), "M" (medium), "Q" (quantize), "H" (high) --all-pixel-shapes Print all the available pixel shapes. -d, --on-pixel-shape The onPixels shape to use. Available shapes are grid2x2, grid3x3, grid4x4, abstract, arrow, blob, crt, circle, circuit, curvePixel, donut, flower, heart, horizontal, pointy, razor, roundedEndIndent, roundedPath, roundedRect, sharp, shiny, spikyCircle, square, squircle, star, vertical, vortex, wave. -n, --on-pixel-inset-fraction The spacing around each individual pixel in the onPixels section -r, --on-pixel-shape-corner-radius The onPixels shape corner radius fractional value (0.0 -> 1.0) -a, --on-pixel-shape-has-inner-corners The onPixels 'has inner corners' value (true/false) --all-eye-shapes Print all the available eye shapes. -e, --eye-shape The eye shape to use. Available shapes are crt, circle, corneredPixels, dotDragHorizontal, dotDragVertical, edges, explode, eye, fireball, headlight, barsHor

... (README truncated for length)

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

QRCode

Why?

Features

Installing

Methods

In your source

Using Tuist or similar

Creating a QR Code

Using Swift

Using Objective-C

Setting the error correction

Generating your QR Code

Exportable types

Settings

Set the QR code's encoded content

Design

WARNING

QR code components

Styling your QR Code

QRCode builder

Shape

'OnPixels' shape

Eye shape

Pupil shape

'offPixels' shape (optional)

Style

Fill styles

Style examples

Adding shadows

WARNING

Usage

Shadow styles

Drop shadow

Inner shadow

Adding a logo to a QR code

WARNING

Method 1: Logo Masking

Logo and mask

Logo only

Method 2: Logo templates

Example 1

Example 2

Quiet zone

Message Formatters

Generating output

Generate a path

Generate a styled, scalable PDF representation of the QR Code

Generate a SVG representation of the QR Code

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

Presentation

NSView/UIView

QRCodeDocumentView

QRCodeView

SwiftUI

QRCodeViewUI

Modifiers

Objective-C

Using QRCode.Document

Load/Save

From an image

Demo

Command line tool

Reading Mode

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Related Stories

Using `Tuist` or similar

`Setting the error correction`

`Set the QR code's encoded content`

`Inner shadow`

`Logo and mask`

`Logo only`

`Example 1`

`Generate a path`

`Generate a styled, scalable PDF representation of the QR Code`

`Generate a SVG representation of the QR Code`

`Modifiers`

`Using QRCode.Document`