decode.go

/*
 * Copyright (c) 2018 LI Zhennan
 *
 * Use of this work is governed by an MIT License.
 * You may find a license copy in project root.
 */

package qrcode

import (
	"errors"
	"fmt"
	"image"

	"github.com/PeterCxy/gozbar"
)

// DecodeQRCode decodes QR Code content from image
//
// content contains multiple string if there are more than one QR Code
// got decoded.
// content and err are both nil when no QR Code found.
func DecodeQRCode(img image.Image) (content []string, err error) {
	defer func() {
		if fatal := recover(); fatal != nil {
			if err == nil {
				err = fmt.Errorf("fatal error: %v", fatal)
			} else {
				err = fmt.Errorf("fatal error : %v: %v", fatal, err)
			}
		}
	}()

	input := zbar.FromImage(img)

	s := zbar.NewScanner()
	s.SetConfig(zbar.QRCODE, zbar.CFG_ENABLE, 1)
	result := s.Scan(input)

	if result < 0 {
		err = errors.New("error occurred when scanning")
		return
	}

	if result == 0 {
		// no result
		return
	}

	input.First().Each(func(item string) {
		content = append(content, item)
	})

	return
}