qrcode

package module
v1.5.10 Latest Latest
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 Go to latest Published: Nov 6, 2021 License: MIT Imports: 16 Imported by: 33

README

go-qrcode

Go Report Card go.dev reference Go

QR code (abbreviated from Quick Response Code) is the trademark for a type of matrix barcode (or two-dimensional barcode) first designed in 1994 for the automotive industry in Japan. A barcode is a machine-readable optical label that contains information about the item to which it is attached. A QR code uses four standardized encoding modes (numeric, alphanumeric, byte/binary, and kanji) to store data efficiently; extensions may also be used
Features
  • Normally generate QR code across version 1 to version 40.
  • Automatically analyze QR version by source text.
  • Specifying cell shape allowably with WithCustomShape, WithCircleShape (default is rectangle)
  • Specifying output file's format with WithBuiltinImageEncoder, WithCustomImageEncoder (default is JPEG)
  • Not only shape of cell, but also color of QR Code background and foreground color.
  • WithLogoImage, WithLogoImageFilePNG, WithLogoImageFileJPEG help you add an icon at the central of QR Code.
  • WithBorderWidth allows to specify any width of 4 sides around the qrcode.
Install
go get -u github.com/yeqown/go-qrcode
Usage

link to CODE

package main

import (
	"fmt"

	qrcode "github.com/yeqown/go-qrcode"
)

func main() {
	qrc, err := qrcode.New("https://github.com/yeqown/go-qrcode")
	if err != nil {
		fmt.Printf("could not generate QRCode: %v", err)
	}

	// save file
	if err := qrc.Save("../testdata/repo-qrcode.jpeg"); err != nil {
		fmt.Printf("could not save image: %v", err)
	}
}
Options

now go-qrcode provides some options to customize output QRCode.

// WithBgColor background color
func WithBgColor(c color.Color) ImageOption {}

// WithBgColorRGBHex background color
func WithBgColorRGBHex(hex string) ImageOption {}

// WithFgColor QR color
func WithFgColor(c color.Color) ImageOption {}

// WithFgColorRGBHex Hex string to set QR Color
func WithFgColorRGBHex(hex string) ImageOption {}

// WithLogoImage .
func WithLogoImage(img image.Image) ImageOption {}

// WithLogoImageFilePNG load image from file, PNG is required
func WithLogoImageFilePNG(f string) ImageOption {}

// WithLogoImageFileJPEG load image from file, JPEG is required
func WithLogoImageFileJPEG(f string) ImageOption {}

// WithQRWidth specify width of each qr block
func WithQRWidth(width uint8) ImageOption {}

// WithCircleShape use circle shape as rectangle(default)
func WithCircleShape() ImageOption {}

// WithCustomShape use custom shape as rectangle(default)
func WithCustomShape(shape IShape) ImageOption {}

// WithBuiltinImageEncoder option includes: JPEG_FORMAT as default, PNG_FORMAT.
// This works like WithBuiltinImageEncoder, the different between them is
// formatTyp is enumerated in (JPEG_FORMAT, PNG_FORMAT)
func WithBuiltinImageEncoder(format formatTyp) ImageOption

// WithCustomImageEncoder to use custom image encoder to encode image.Image into
// io.Writer
func WithCustomImageEncoder(encoder ImageEncoder) ImageOption

// WithBorderWidth specify the both 4 sides' border width. Notice that
// WithBorderWidth(a) means all border width use this variable `a`,
// WithBorderWidth(a, b) mean top/bottom equal to `a`, left/right equal to `b`.
// WithBorderWidth(a, b, c, d) mean top, right, bottom, left.
func WithBorderWidth(widths ...int) ImageOption

use options in New and NewWithConfig.

NOTICE: NewWithSpecV is deprecated

import (
	qrcode "github.com/yeqown/go-qrcode"
)

// generating QR Code with source text and output image options.
qrc, _ := qrcode.New("text", WithQRWidth(x)) // x is uint8 (0 - 255)

// OR generating QR Code with specified ErrorCorrection Level and Encode Mode,
// output image options are also available.
qrc, _ := qrcode.NewWithConfig("text", config, WithQRWidth(x))

qrc.Save("path/to/qrcode.png")

following are some shots:


Documention

Jump to go.dev/github/yeqown/go-qrcode

Documentation

Overview

Package qrcode ... encoder.go working for data encoding

Index

Constants

View Source 
const (
	// a value of EncModeAuto will trigger a detection of the letter set from the input data,
	EncModeAuto = 0
	// EncModeNone mode ...
	EncModeNone encMode = 1 << iota
	// EncModeNumeric mode ...
	EncModeNumeric
	// EncModeAlphanumeric mode ...
	EncModeAlphanumeric
	// EncModeByte mode ...
	EncModeByte
	// EncModeJP mode ...
	EncModeJP
)
View Source 
const (
	// JPEG_FORMAT as default output file format.
	JPEG_FORMAT formatTyp = iota
	// PNG_FORMAT .
	PNG_FORMAT
)
View Source 
const (
	// ErrorCorrectionLow :Level L: 7% error recovery.
	ErrorCorrectionLow ecLevel = iota + 1

	// ErrorCorrectionMedium :Level M: 15% error recovery. Good default choice.
	ErrorCorrectionMedium

	// ErrorCorrectionQuart :Level Q: 25% error recovery.
	ErrorCorrectionQuart

	// ErrorCorrectionHighest :Level H: 30% error recovery.
	ErrorCorrectionHighest
)

Variables

View Source 
var (
	ErrInvalidStateOfQRCode = fmt.Errorf("invalid state of qrcode")
)

Functions

func SetDebugMode added in v1.3.0 

func SetDebugMode()

SetDebugMode open debug mode

Types

type Attribute added in v1.5.9 

type Attribute struct {
	// width and height of image
	W, H int
	// in the order of "top, right, bottom, left"
	Borders [4]int
	// the length of  block edges
	BlockWidth int
}

Attribute contains basic information of generated image.

type Config added in v1.5.7 

type Config = outputEncodingOption

Config alias of outputEncodingOption.

func DefaultConfig added in v1.5.7 

func DefaultConfig() *Config

DefaultConfig with EncMode = EncModeAuto, EcLevel = ErrorCorrectionQuart

type DrawContext added in v1.4.0 

type DrawContext struct {
	*gg.Context
	// contains filtered or unexported fields
}

DrawContext is a rectangle area

func (*DrawContext) Color added in v1.5.3 

func (dc *DrawContext) Color() color.Color

Color returns the color which should be fill into the shape. Note that if you're not using this color but your coded color.Color, some ImageOption functions those set foreground color would take no effect.

func (*DrawContext) Edge added in v1.5.3 

func (dc *DrawContext) Edge() (width, height int)

Edge returns width and height of each shape could take at most.

func (*DrawContext) UpperLeft added in v1.5.3 

func (dc *DrawContext) UpperLeft() image.Point

UpperLeft returns the point which indicates the upper left position.

type IShape added in v1.4.0 

type IShape interface {
	// Draw to fill the IShape of qrcode.
	Draw(ctx *DrawContext)

	// DrawFinder to fill the finder pattern of QRCode, what's finder? google it for more information.
	DrawFinder(ctx *DrawContext)
}

type ImageEncoder added in v1.5.0 

type ImageEncoder interface {
	// Encode specify which format to encode image into w io.Writer.
	Encode(w io.Writer, img image.Image) error
}

ImageEncoder is an interface which describes the rule how to encode image.Image into io.Writer

type ImageOption added in v1.3.0 

type ImageOption interface {
	// contains filtered or unexported methods
}

func WithBgColor added in v1.3.0 

func WithBgColor(c color.Color) ImageOption

WithBgColor background color

func WithBgColorRGBHex added in v1.3.0 

func WithBgColorRGBHex(hex string) ImageOption

WithBgColorRGBHex background color

func WithBorderWidth added in v1.5.8 

func WithBorderWidth(widths ...int) ImageOption

WithBorderWidth specify the both 4 sides' border width. Notice that WithBorderWidth(a) means all border width use this variable `a`, WithBorderWidth(a, b) mean top/bottom equal to `a`, left/right equal to `b`. WithBorderWidth(a, b, c, d) mean top, right, bottom, left.

func WithBuiltinImageEncoder added in v1.5.0 

func WithBuiltinImageEncoder(format formatTyp) ImageOption

WithBuiltinImageEncoder option includes: JPEG_FORMAT as default, PNG_FORMAT. This works like WithBuiltinImageEncoder, the different between them is formatTyp is enumerated in (JPEG_FORMAT, PNG_FORMAT)

func WithCircleShape added in v1.4.0 

func WithCircleShape() ImageOption

WithCircleShape use circle shape as rectangle(default)

func WithCustomImageEncoder added in v1.5.0 

func WithCustomImageEncoder(encoder ImageEncoder) ImageOption

WithCustomImageEncoder to use custom image encoder to encode image.Image into io.Writer

func WithCustomShape added in v1.4.0 

func WithCustomShape(shape IShape) ImageOption

WithCustomShape use custom shape as rectangle(default)

func WithFgColor added in v1.3.0 

func WithFgColor(c color.Color) ImageOption

WithFgColor QR color

func WithFgColorRGBHex added in v1.3.0 

func WithFgColorRGBHex(hex string) ImageOption

WithFgColorRGBHex Hex string to set QR Color

func WithLogoImage added in v1.3.0 

func WithLogoImage(img image.Image) ImageOption

WithLogoImage image should only has 1/5 width of QRCode at most

func WithLogoImageFileJPEG added in v1.3.0 

func WithLogoImageFileJPEG(f string) ImageOption

WithLogoImageFileJPEG load image from file, jpeg is required. image should only has 1/5 width of QRCode at most

func WithLogoImageFilePNG added in v1.3.0 

func WithLogoImageFilePNG(f string) ImageOption

WithLogoImageFilePNG load image from file, PNG is required. image should only has 1/5 width of QRCode at most

func WithQRWidth added in v1.3.0 

func WithQRWidth(width uint8) ImageOption

WithQRWidth specify width of each qr block

type QRCode 

type QRCode struct {
	// contains filtered or unexported fields
}

QRCode contains fields to generate QRCode matrix, outputImageOptions to Draw image, etc.

func New 

func New(text string, opts ...ImageOption) (*QRCode, error)

New generate a QRCode struct to create

func NewWithConfig added in v1.5.7 

func NewWithConfig(text string, encOpts *Config, opts ...ImageOption) (*QRCode, error)

NewWithConfig generate a QRCode struct with specified `ver`(QR version) and `ecLv`(Error Correction level)

func NewWithSpecV 

func NewWithSpecV(text string, ver int, ecLv ecLevel, opts ...ImageOption) (*QRCode, error)

NewWithSpecV generate a QRCode struct with specified `ver`(QR version) and `ecLv`(Error Correction level) Deprecated

func (*QRCode) Attribute added in v1.5.9 

func (q *QRCode) Attribute() (*Attribute, error)

Attribute pre-calculate attribute of QR Code image, before actually draw it into image. avoid raising an error, you should use New and likely functions to initialize *QRCode.

func (*QRCode) Save 

func (q *QRCode) Save(saveToPath string) (err error)

Save QRCode image into saveToPath DONE(@yeqown): use SaveTo rather than drawAndSaveToFile

func (*QRCode) SaveTo 

func (q *QRCode) SaveTo(w io.Writer) error

SaveTo QRCode image into `w`(io.Writer)

Source Files

View all Source files

Directories

Path Synopsis
cmd
qrcode Module
simple
with-custom-shape
writer
compressed Module
file Module
standard Module
terminal Module

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