qr

Documentation

Overview

Package qr can be used to create QR barcodes.

Index

• Variables
• func Encode(content string, level ErrorCorrectionLevel, mode Encoding) (barcode.Barcode, error)
• type BackgroundOption
• type Canvas
  • func NewCanvas(option CanvasOption, code barcode.Barcode) *Canvas
  • func (c *Canvas) Clear()
  • func (c *Canvas) Draw() (image.Image, error)
• type CanvasOption
  • func (o CanvasOption) Merge(other CanvasOption)
• type Code
  • func (qr *Code) At(x, y int) color.Color
  • func (qr *Code) Bounds() image.Rectangle
  • func (qr *Code) ColorModel() color.Model
  • func (qr *Code) Content() string
  • func (qr *Code) Dimension() int
  • func (qr *Code) Get(x, y int) bool
  • func (qr *Code) Metadata() barcode.Metadata
  • func (qr *Code) Set(x, y int, val bool)
• type Encoding
  • func (e Encoding) String() string
• type ErrorCorrectionLevel
  • func (ecl ErrorCorrectionLevel) String() string
• type Filter
• type HalftoneOption
• type ImageOption
• type Option
  • func WithBackgroundOption(backgroundOption BackgroundOption) Option
  • func WithCornerDotOption(cornerDotOption feature.CornerDotOption) Option
  • func WithCornerSquareOption(cornerSquareOption feature.CornerSquareOption) Option
  • func WithDotOption(dotOption feature.DotOption) Option
  • func WithHalftoneOption(halftoneOption HalftoneOption) Option
  • func WithImageOption(imageOption ImageOption) Option

Examples

• Encode

Variables

var (
	ErrValidGradient  = errors.New("invalid gradient")
	ErrInvalidBarcode = errors.New("invalid barcode")
)

var DotMask = [][]int{
	{0, 0, 0, 0, 0, 0, 0},
	{0, 0, 0, 0, 0, 0, 0},
	{0, 0, 1, 1, 1, 0, 0},
	{0, 0, 1, 1, 1, 0, 0},
	{0, 0, 1, 1, 1, 0, 0},
	{0, 0, 0, 0, 0, 0, 0},
	{0, 0, 0, 0, 0, 0, 0},
}

var ErrorCorrectionPercents = map[ErrorCorrectionLevel]float64{
	L: 0.07,
	M: 0.15,
	Q: 0.25,
	H: 0.3,
}

var QrTypes = []int{0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20,
	21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40}

var SquareMask = [][]int{
	{1, 1, 1, 1, 1, 1, 1},
	{1, 0, 0, 0, 0, 0, 1},
	{1, 0, 0, 0, 0, 0, 1},
	{1, 0, 0, 0, 0, 0, 1},
	{1, 0, 0, 0, 0, 0, 1},
	{1, 0, 0, 0, 0, 0, 1},
	{1, 1, 1, 1, 1, 1, 1},
}

Functions

func Encode

func Encode(content string, level ErrorCorrectionLevel, mode Encoding) (barcode.Barcode, error)

Encode returns a QR barcode with the given content, error correction level and uses the given encoding

Example

f, _ := os.Create("QRCode.png")
defer f.Close()

qrcode, err := Encode("hello world", L, Auto)
if err != nil {
	fmt.Println(err)
} else {
	code, err := barcode.Scale(qrcode, 100, 100)
	if err != nil {
		fmt.Println(err)
	} else {
		png.Encode(f, code)
	}
}

Types

type BackgroundOption

type BackgroundOption common.Color

type Canvas

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

func NewCanvas

func NewCanvas(option CanvasOption, code barcode.Barcode) *Canvas

func (*Canvas) Clear

func (c *Canvas) Clear()

func (*Canvas) Draw

func (c *Canvas) Draw() (image.Image, error)

Draw 必须要记住的一点是 canvas 库的左下角为坐标原点，而二维码则是左上角为坐标原点

type CanvasOption

type CanvasOption struct {
	Width  int
	Height int
	Margin int

	TypeNumber           int
	Encoding             Encoding
	ErrorCorrectionLevel ErrorCorrectionLevel

	DotOption          feature.DotOption
	CornerSquareOption feature.CornerSquareOption
	CornerDotOption    feature.CornerDotOption
	BackgroundOption   BackgroundOption
	Image              string
	ImageOption        ImageOption

	HalftoneOption HalftoneOption
}

func (CanvasOption) Merge

func (o CanvasOption) Merge(other CanvasOption)

type Code

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

func (*Code) At

func (qr *Code) At(x, y int) color.Color

func (*Code) Bounds

func (qr *Code) Bounds() image.Rectangle

func (*Code) ColorModel

func (qr *Code) ColorModel() color.Model

func (*Code) Content

func (qr *Code) Content() string

func (*Code) Dimension

func (qr *Code) Dimension() int

func (*Code) Get

func (qr *Code) Get(x, y int) bool

func (*Code) Metadata

func (qr *Code) Metadata() barcode.Metadata

func (*Code) Set

func (qr *Code) Set(x, y int, val bool)

type Encoding

type Encoding byte

Encoding mode for QR Codes.

const (
	// Auto will choose ths best matching encoding
	Auto Encoding = iota
	// Numeric encoding only encodes numbers [0-9]
	Numeric
	// AlphaNumeric encoding only encodes uppercase letters, numbers and  [Space], $, %, *, +, -, ., /, :
	AlphaNumeric
	// Unicode encoding encodes the string as utf-8
	Unicode
)

func (Encoding) String

func (e Encoding) String() string

type ErrorCorrectionLevel

type ErrorCorrectionLevel byte

ErrorCorrectionLevel indicates the amount of "backup data" stored in the QR code

const (
	// L recovers 7% of data
	L ErrorCorrectionLevel = iota
	// M recovers 15% of data
	M
	// Q recovers 25% of data
	Q
	// H recovers 30% of data
	H
)

func (ErrorCorrectionLevel) String

func (ecl ErrorCorrectionLevel) String() string

type Filter

type Filter func(i, j int) bool

type HalftoneOption

type HalftoneOption struct {
	HalftoneImage image.Image
}

type ImageOption

type ImageOption struct {
	HideBackgroundDot bool
	ImageSize         float64
	Margin            float64
}

type Option

type Option func(o *CanvasOption)

func WithBackgroundOption

func WithBackgroundOption(backgroundOption BackgroundOption) Option

func WithCornerDotOption

func WithCornerDotOption(cornerDotOption feature.CornerDotOption) Option

func WithCornerSquareOption

func WithCornerSquareOption(cornerSquareOption feature.CornerSquareOption) Option

func WithDotOption

func WithDotOption(dotOption feature.DotOption) Option

func WithHalftoneOption

func WithHalftoneOption(halftoneOption HalftoneOption) Option

func WithImageOption

func WithImageOption(imageOption ImageOption) Option