Cheat Sheet

1. Import EFQRCode

Import EFQRCode module where you want to use it:

import EFQRCode

2. Recognition

Get QR Codes from CGImage, maybe there are several codes in a image, so it will return an array:

if let testImage = UIImage(named: "test.png")?.toCGImage() {
    if let tryCodes = EFQRCode.recognize(image: testImage) {
        if tryCodes.count > 0 {
            print("There are \(tryCodes.count) codes in testImage.")
            for (index, code) in tryCodes.enumerated() {
                print("The content of \(index) QR Code is: \(code).")
            }
        } else {
            print("There is no QR Codes in testImage.")
        }
    } else {
        print("Recognize failed, check your input image!")
    }
}

3. Generation

Create QR Code image, quick usage:

// Common parameters:
//                         content: Content of QR Code
// inputCorrectionLevel (Optional): error-tolerant rate
//                                  L 7%
//                                  M 15%
//                                  Q 25%
//                                  H 30%(Default)
//                 size (Optional): Width and height of image
//        magnification (Optional): Magnification of QRCode compare with the minimum size
//                                  (Parameter size will be ignored if magnification is not nil)
//      backgroundColor (Optional): Background color of QRCode
//      foregroundColor (Optional): Foreground color of QRCode
//                 icon (Optional): Icon in the middle of QR Code Image and it's setting
//            watermark (Optional): Watermark background image and it's setting
//                extra (Optional): Extra parameters

if let tryImage = EFQRCode.generate(
    content: "https://github.com/EyreFree/EFQRCode",
    magnification: EFIntSize(width: 9, height: 9),
    watermark: EFWatermark(image: UIImage(named: "WWF")?.toCGImage(), mode: .scaleAspectFill, isColorful: false)
) {
    print("Create QRCode image success: \(tryImage)")
} else {
    print("Create QRCode image failed!")
}

Result:

User Guide

1. Recognition

EFQRCode.recognize(image: CGImage)

Or

EFQRCodeRecognizer(image: CGImage).contents

Two way before is exactly the same, because of the possibility of more than one two-dimensional code in the same iamge, so the return value is `[String]? ', if the return is nil means that the input data is incorrect or null. If the return array is empty, it means we can not recognize any two-dimensional code at the image.

2. Generation

EFQRCode.generate(
    content: String,
    inputCorrectionLevel: EFInputCorrectionLevel,
    size: EFIntSize,
    magnification: EFIntSize?,
    backgroundColor: CIColor,
    foregroundColor: CIColor,
    icon: EFIcon?,
    watermark: EFWatermark?,
    extra: EFExtra?
)

Or

let generator = EFQRCodeGenerator(
    content: String,
    inputCorrectionLevel: EFInputCorrectionLevel,
    size: EFIntSize,
    magnification: EFIntSize?,
    backgroundColor: CIColor,
    foregroundColor: CIColor
)
if let tryIcon = icon {
    generator.setIcon(icon: EFIcon?)
}
if let tryWatermark = watermark {
    generator.setWatermark(watermark: EFWatermark?)
}
if let tryExtra = extra {
    generator.setExtra(extra: EFExtra?)
}

// Final two-dimensional code image we get
generator.image

Two way before is exactly the same, the return value is CGImage?, if the return is nil means that there is some wrong during the generation.

Parameters Explaination

• content: String?

Content, compulsive, capacity is limited, 1273 character most, the density of the two-dimensional lattice increases with the increase of the content. Comparison of different capacity is as follows:

10 characters	250 characters

• inputCorrectionLevel: EFInputCorrectionLevel

Error-tolerant rate, optional, 4 different level, L: 7% / M 15% / Q 25% / H 30%, default is H, the definition of EFInputCorrectionLevel:

// EFInputCorrectionLevel
public enum EFInputCorrectionLevel: Int {
    case l = 0;     // L 7%
    case m = 1;     // M 15%
    case q = 2;     // Q 25%
    case h = 3;     // H 30%
}

Comparison of different inputCorrectionLevel:

L	M	Q	H

• size: EFIntSize

Two-dimensional code length, optional, default is 256 (PS: if magnification is not nil, size will be ignored), the definition of EFIntSize:

public class EFIntSize {
    public private(set) var width: Int = 0
    public private(set) var height: Int = 0

    public init(width: Int, height: Int) {
        self.width = width
        self.height = height
    }

    public func toCGSize() -> CGSize {
        return CGSize(width: self.width, height: self.height)
    }

    public func widthCGFloat() -> CGFloat {
        return CGFloat(width)
    }

    public func heightCGFloat() -> CGFloat {
        return CGFloat(height)
    }
}

234*234	312*234

• magnification: EFIntSize?

Magnification, optional, default is nil.

Because by the existence of size scaling two-dimensional code clarity is not high, if you want to get a more clear two-dimensional code, you can use magnification to set the size of the final generation of two-dimensional code. Here is the smallest ratio relative to the two-dimensional code matrix is concerned, if there is a wanted size but I hope to have a clear and size and have size approximation of the two-dimensional code by using magnification, through maxMagnificationLessThanOrEqualTo (size: CGFloat), and minMagnificationGreaterThanOrEqualTo (size: CGFloat), want to get magnification these two functions the specific value, the use of specific methods are as follows:

let generator = EFQRCodeGenerator(
    content: String,
    inputCorrectionLevel: EFInputCorrectionLevel,
    size: EFIntSize,
    magnification: EFIntSize?,
    backgroundColor: CIColor,
    foregroundColor: CIColor
)

// Want to get max magnification when size is less than or equalTo 600
if let magnification = generator.maxMagnificationLessThanOrEqualTo(size: 600) {
    generator.magnification = EFIntSize(width: magnification, height: magnification)
}

// Or

// Want to get min magnification when width is greater than or equalTo 600 and height is greater than or equalTo 800
// if let magnificationWidth = generator.minMagnificationGreaterThanOrEqualTo(size: 600),
//     let magnificationHeight = generator.minMagnificationGreaterThanOrEqualTo(size: 600) {
//     generator.magnification = EFIntSize(width: magnificationWidth, height: magnificationHeight)
// }

// Final two-dimensional code image
generator.image

size 300	magnification 9

• backgroundColor: CIColor

BackgroundColor, optional, default is white.

• foregroundColor: CIColor

ForegroundColor, optional, color of code point, default is black.

ForegroundColor set to red	BackgroundColor set to gray

• icon: CGImage?

Icon image in the center of code image, optional, default is nil.

• iconSize: CGFloat?

Size of icon image, optional, default is 20% of size:

Default 20% size	Set to 64

• isIconColorful: Bool

Is icon colorful, optional, default is true.

• watermark: CGImage?

Watermark image, optional, default is nil, for example:

1	2

• watermarkMode: EFWatermarkMode

The watermark placed in two-dimensional code position, optional, default is scaleAspectFill, refer to UIViewContentMode, you can treat the two-dimensional code as UIImageView, the definition of UIViewContentMode:

// Like UIViewContentMode
public enum EFWatermarkMode: Int {
    case scaleToFill        = 0;
    case scaleAspectFit     = 1;
    case scaleAspectFill    = 2;
    case center             = 3;
    case top                = 4;
    case bottom             = 5;
    case left               = 6;
    case right              = 7;
    case topLeft            = 8;
    case topRight           = 9;
    case bottomLeft         = 10;
    case bottomRight        = 11;
}

• isWatermarkColorful: Bool

Is watermark colorful, optional, default is true.

• foregroundPointOffset: CGFloat

Foreground point offset, optional, default is 0, is not recommended to use, may make the two-dimensional code broken:

0	0.5

• allowTransparent: Bool

Allow watermark image transparent, optional, default is true:

true	false

• Other

EFIcon is consist of icon, iconSize and isIconColorful, the definition is:

public struct EFIcon {
    public var image: CGImage?
    public var size: EFIntSize?
    public var isColorful: Bool = true

    public init(image: CGImage?, size: EFIntSize?, isColorful: Bool = true) {
        self.image = image
        self.size = size
        self.isColorful = isColorful
    }
}

EFWatermark is consist of watermark, watermarkMode and isWatermarkColorful, the definition is:

public struct EFWatermark {
    public var image: CGImage?
    public var mode: EFWatermarkMode = .scaleToFill
    public var isColorful: Bool = true

    public init(image: CGImage?, mode: EFWatermarkMode = .scaleToFill, isColorful: Bool = true) {
        self.image = image
        self.mode = mode
        self.isColorful = isColorful
    }
}

EFExtra is consist of foregroundPointOffset and allowTransparent, the definition is:

public struct EFExtra {
    public var foregroundPointOffset: CGFloat = 0
    public var allowTransparent: Bool = true

    public init(foregroundPointOffset: CGFloat = 0, allowTransparent: Bool = true) {
        self.foregroundPointOffset = foregroundPointOffset
        self.allowTransparent = allowTransparent
    }
}