Golang : Generate Code128 barcode

Generating Code 128 barcode in Golang can be done easily with this package ( https://github.com/boombuler/barcode ). We will just adapt the code from the previous tutorial on how to generate Codabar to generating code 128 barcode.

Here you go:

 package main

 import (
 "fmt"
 "github.com/boombuler/barcode"
 "github.com/boombuler/barcode/code128"
 "github.com/disintegration/imaging"
 "github.com/llgcode/draw2d"
 "image"
 "image/color"
 "image/draw"
 "os"
 )

 func main() {

 code := "socketloop.com"

 fmt.Println("Generating code128 barcode for : ", code)

 bcode, err := code128.Encode(code)

 if err != nil {
 fmt.Printf("String %s cannot be encoded", code)
 os.Exit(1)
 }

 // scale to 250x20
 bcode, err = barcode.Scale(bcode, 250, 20)

 if err != nil {
 fmt.Println("Code128 scaling error!")
 os.Exit(1)
 }

 // now we want to append the code at the bottom
 // of the Codabar

 // Create an new image with text data
 // From https://github.com/llgcode/draw2d.samples/tree/master/helloworld
 // Set the global folder for searching fonts
 draw2d.SetFontFolder(".")

 // Initialize the graphic context on an RGBA image
 img := image.NewRGBA(image.Rect(0, 0, 250, 50))

 // set background to white
 white := color.RGBA{255, 255, 255, 255}
 draw.Draw(img, img.Bounds(), &image.Uniform{white}, image.ZP, draw.Src)

 gc := draw2d.NewGraphicContext(img)

 gc.FillStroke()

 // Set the font Montereymbi.ttf
 gc.SetFontData(draw2d.FontData{"Monterey", draw2d.FontFamilyMono, draw2d.FontStyleBold | draw2d.FontStyleItalic})
 // Set the fill text color to black
 gc.SetFillColor(image.Black)

 gc.SetFontSize(14)
 gc.FillStringAt(code, 50, 20)

 // create a new blank image with white background
 newImg := imaging.New(300, 300, color.NRGBA{255, 255, 255, 255})

 //paste the codabar to new blank image
 newImg = imaging.Paste(newImg, bcode, image.Pt(50, 50))

 //paste the text to the new blank image
 newImg = imaging.Paste(newImg, img, image.Pt(50, 90))

 err = draw2d.SaveToPngFile("./code128.png", newImg)

 if err != nil {
 fmt.Println(err)
 os.Exit(1)
 }

 // everything ok
 fmt.Println("Code128 code generated and saved to code128.png")

 }

Sample output :

NOTE : For some odd reason, the luximbi.ttf font from https://github.com/llgcode/draw2d.samples/tree/master/helloworld cannot be used. Therefore, I've replaced it with the Monterey font.

You can get the Monterey font from http://www.1001freefonts.com/monterey.font , unzip the zip file and rename the MontereyFLF.ttf to Montereymbi.ttf with this command and execute the code above in the same directory as the 'Montereymbi.ttf' file.

cp MontereyFLF.ttf Montereymbi.ttf

References :

http://en.wikipedia.org/wiki/Code_128

https://github.com/boombuler/barcode/tree/master/code128