summaryrefslogtreecommitdiff
path: root/contrib/barcode/barcode.go
blob: b2ba2c2007cec3734faf58176be051fd45f99e14 (plain)
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
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
// Copyright (c) 2015 Jelmer Snoeck (Gmail: jelmer.snoeck)
//
// Permission to use, copy, modify, and distribute this software for any purpose
// with or without fee is hereby granted, provided that the above copyright notice
// and this permission notice appear in all copies.
//
// THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES WITH
// REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND
// FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY SPECIAL, DIRECT,
// INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM
// LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR
// OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
// PERFORMANCE OF THIS SOFTWARE.

// Package barcode provides helper methods for adding barcodes of different
// types to your pdf document. It relies on the github.com/boombuler/barcode
// package for the barcode creation.
package barcode

import (
	"bytes"
	"errors"
	"image/jpeg"
	"io"
	"strconv"

	"github.com/boombuler/barcode"
	"github.com/boombuler/barcode/codabar"
	"github.com/boombuler/barcode/code128"
	"github.com/boombuler/barcode/code39"
	"github.com/boombuler/barcode/datamatrix"
	"github.com/boombuler/barcode/ean"
	"github.com/boombuler/barcode/qr"
	"github.com/boombuler/barcode/twooffive"
	"github.com/jung-kurt/gofpdf"
	"github.com/ruudk/golang-pdf417"
)

// barcodes represents the barcodes that have been registered through this
// package. They will later be used to be scaled and put on the page.
var barcodes map[string]barcode.Barcode

// barcodePdf is a partial PDF implementation that only implements a subset of
// functions that are required to add the barcode to the PDF.
type barcodePdf interface {
	GetConversionRatio() float64
	GetImageInfo(imageStr string) *gofpdf.ImageInfoType
	Image(imageNameStr string, x, y, w, h float64, flow bool, tp string, link int, linkStr string)
	RegisterImageReader(imgName, tp string, r io.Reader) *gofpdf.ImageInfoType
	SetError(err error)
}

// Barcode puts a registered barcode in the current page.
//
// The size should be specified in the units used to create the PDF document.
//
// Positioning with x, y and flow is inherited from Fpdf.Image().
func Barcode(pdf barcodePdf, code string, x, y, w, h float64, flow bool) {
	unscaled, ok := barcodes[code]

	if !ok {
		err := errors.New("Barcode not found")
		pdf.SetError(err)
		return
	}

	bname := uniqueBarcodeName(code, x, y)
	info := pdf.GetImageInfo(bname)

	if info == nil {
		bcode, err := barcode.Scale(
			unscaled,
			int(convertTo96Dpi(pdf, w)),
			int(convertTo96Dpi(pdf, h)),
		)

		if err != nil {
			pdf.SetError(err)
			return
		}

		err = registerScaledBarcode(pdf, bname, bcode)
		if err != nil {
			pdf.SetError(err)
			return
		}
	}

	pdf.Image(bname, x, y, 0, 0, flow, "jpg", 0, "")
}

// Register registers a barcode but does not put it on the page. Use Barcode()
// with the same code to put the barcode on the PDF page.
func Register(bcode barcode.Barcode) string {
	if len(barcodes) == 0 {
		barcodes = make(map[string]barcode.Barcode)
	}

	key := barcodeKey(bcode)
	barcodes[key] = bcode
	return key
}

// RegisterCodabar registers a barcode of type Codabar to the PDF, but not to
// the page. Use Barcode() with the return value to put the barcode on the page.
func RegisterCodabar(pdf barcodePdf, code string) string {
	bcode, err := codabar.Encode(code)
	return registerBarcode(pdf, bcode, err)
}

// RegisterCode128 registers a barcode of type Code128 to the PDF, but not to
// the page. Use Barcode() with the return value to put the barcode on the page.
func RegisterCode128(pdf barcodePdf, code string) string {
	bcode, err := code128.Encode(code)
	return registerBarcode(pdf, bcode, err)
}

// RegisterCode39 registers a barcode of type Code39 to the PDF, but not to
// the page. Use Barcode() with the return value to put the barcode on the page.
//
// includeChecksum and fullASCIIMode are inherited from code39.Encode().
func RegisterCode39(pdf barcodePdf, code string, includeChecksum, fullASCIIMode bool) string {
	bcode, err := code39.Encode(code, includeChecksum, fullASCIIMode)
	return registerBarcode(pdf, bcode, err)
}

// RegisterDataMatrix registers a barcode of type DataMatrix to the PDF, but not
// to the page. Use Barcode() with the return value to put the barcode on the
// page.
func RegisterDataMatrix(pdf barcodePdf, code string) string {
	bcode, err := datamatrix.Encode(code)
	return registerBarcode(pdf, bcode, err)
}

// RegisterPdf417 registers a barcode of type Pdf417 to the PDF, but not to the
// page. code is the string to be encoded. columns specifies the number of
// barcode columns; this should be a value between 1 and 30 inclusive.
// securityLevel specifies an error correction level between zero and 8
// inclusive. Barcodes for use with FedEx must set columns to 10 and
// securityLevel to 5. Use Barcode() with the return value to put the barcode
// on the page.
func RegisterPdf417(pdf barcodePdf, code string, columns int, securityLevel int) string {
	bcode := pdf417.Encode(code, columns, securityLevel)
	return registerBarcode(pdf, bcode, nil)
}

// RegisterEAN registers a barcode of type EAN to the PDF, but not to the page.
// It will automatically detect if the barcode is EAN8 or EAN13. Use Barcode()
// with the return value to put the barcode on the page.
func RegisterEAN(pdf barcodePdf, code string) string {
	bcode, err := ean.Encode(code)
	return registerBarcode(pdf, bcode, err)
}

// RegisterQR registers a barcode of type QR to the PDF, but not to the page.
// Use Barcode() with the return value to put the barcode on the page.
//
// The ErrorCorrectionLevel and Encoding mode are inherited from qr.Encode().
func RegisterQR(pdf barcodePdf, code string, ecl qr.ErrorCorrectionLevel, mode qr.Encoding) string {
	bcode, err := qr.Encode(code, ecl, mode)
	return registerBarcode(pdf, bcode, err)
}

// RegisterTwoOfFive registers a barcode of type TwoOfFive to the PDF, but not
// to the page. Use Barcode() with the return value to put the barcode on the
// page.
//
// The interleaved bool is inherited from twooffive.Encode().
func RegisterTwoOfFive(pdf barcodePdf, code string, interleaved bool) string {
	bcode, err := twooffive.Encode(code, interleaved)
	return registerBarcode(pdf, bcode, err)
}

// registerBarcode registers a barcode internally using the Register() function.
// In case of an error generating the barcode it will not be registered and will
// set an error on the PDF. It will return a unique key for the barcode type and
// content that can be used to put the barcode on the page.
func registerBarcode(pdf barcodePdf, bcode barcode.Barcode, err error) string {
	if err != nil {
		pdf.SetError(err)
	}

	return Register(bcode)
}

// uniqueBarcodeName makes sure every barcode has a unique name for its
// dimensions. Scaling a barcode image results in quality loss, which could be
// a problem for barcode readers.
func uniqueBarcodeName(code string, x, y float64) string {
	xStr := strconv.FormatFloat(x, 'E', -1, 64)
	yStr := strconv.FormatFloat(y, 'E', -1, 64)

	return "barcode-" + code + "-" + xStr + yStr
}

// barcodeKey combines the code type and code value into a unique identifier for
// a barcode type. This is so that we can store several barcodes with the same
// code but different type in the barcodes map.
func barcodeKey(bcode barcode.Barcode) string {
	return bcode.Metadata().CodeKind + bcode.Content()
}

// registerScaledBarcode registers a barcode with its exact dimensions to the
// PDF but does not put it on the page. Use Fpdf.Image() with the same code to
// add the barcode to the page.
func registerScaledBarcode(pdf barcodePdf, code string, bcode barcode.Barcode) error {
	buf := new(bytes.Buffer)
	err := jpeg.Encode(buf, bcode, nil)

	if err != nil {
		return err
	}

	reader := bytes.NewReader(buf.Bytes())
	pdf.RegisterImageReader(code, "jpg", reader)

	return nil
}

// convertTo96DPI converts the given value, which is based on a 72 DPI value
// like the rest of the PDF document, to a 96 DPI value that is required for
// an Image.
//
// Doing this through the Fpdf.Image() function would mean that it uses a 72 DPI
// value and stretches it to a 96 DPI value. This results in quality loss which
// could be problematic for barcode scanners.
func convertTo96Dpi(pdf barcodePdf, value float64) float64 {
	return value * pdf.GetConversionRatio() / 72 * 96
}