Documentation
¶
Overview ¶
Package pdf implements a minimal PDF 1.7 writer, just functional enough to create a PDF file containing multiple CCITT fax-encoded DIN A4 sized pages.
It follows the standard “PDF 32000-1:2008 PDF 1.7”: https://www.adobe.com/content/dam/Adobe/en/devnet/acrobat/pdfs/PDF32000_2008.pdf
Example ¶
package main
import (
"bytes"
"fmt"
"image"
"log"
"os"
"time"
"github.com/stapelberg/scan2drive/internal/pdf"
)
func main() {
doc := &pdf.Catalog{
Common: pdf.Common{ObjectName: "catalog"},
Pages: &pdf.Pages{
Common: pdf.Common{ObjectName: "pages"},
Kids: []pdf.Object{
&pdf.Page{
Common: pdf.Common{ObjectName: "page0"},
Resources: []pdf.Object{
&pdf.Image{
Common: pdf.Common{
ObjectName: "scan0",
Stream: []byte("ß"),
},
Bounds: image.Rect(0, 0, 4960, 7016),
},
},
Parent: "pages",
Contents: []pdf.Object{
&pdf.Common{
ObjectName: "content0",
Stream: []byte(fmt.Sprintf("q 595.28 0 0 841.89 0.00 0.00 cm /%s Do Q\n", "scan0")),
},
},
},
},
},
}
info := &pdf.DocumentInfo{
Common: pdf.Common{ObjectName: "info"},
CreationDate: time.Unix(1493650928, 0).UTC(),
Producer: "https://github.com/stapelberg/scan2drive",
}
var buf bytes.Buffer
if err := pdf.NewEncoder(&buf).Encode(doc, info); err != nil {
log.Fatal(err)
}
// Convert the binary data at the beginning of a PDF to a
// printable sequence of bytes for the Go example test
// infrastructure.
printable := bytes.Replace(buf.Bytes(), []byte{0xe2, 0xe3, 0xcf, 0xd3}, []byte("<0xE2E3CFD3>"), 1)
// Remove trailing whitespace from xref table for more convenient
// editing of example_test.go.
printable = bytes.Replace(printable, []byte("00000 n "), []byte("00000 n"), -1)
printable = bytes.Replace(printable, []byte("65535 f "), []byte("65535 f"), -1)
os.Stdout.Write(printable)
}
Output: %PDF-1.0 %<0xE2E3CFD3> 1 0 obj << /Type /Catalog /Pages 2 0 R >> endobj 2 0 obj << /Kids [3 0 R] /Type /Pages /Count 1 >> endobj 3 0 obj << /Resources << /XObject << /scan0 4 0 R >> >> /Contents [5 0 R] /Parent 2 0 R /Type /Page /MediaBox [ 0 0 595.28 841.89 ] >> endobj 4 0 obj << /Subtype /Image /DecodeParms << /K 0 /EndOfBlock false /EndOfLine true /BlackIs1 false /Rows 7016 /Columns 4960 >> /Type /XObject /Width 4960 /Filter /CCITTFaxDecode /Height 7016 /Length 2 /BitsPerComponent 1 /ColorSpace /DeviceGray >> stream ß endstream endobj 5 0 obj << /Length 45 >> stream q 595.28 0 0 841.89 0.00 0.00 cm /scan0 Do Q endstream endobj 6 0 obj << /CreationDate (D:20170501150208+00'00') /Producer (https://github.com/stapelberg/scan2drive) >> endobj xref 0 7 0000000000 65535 f 0000000015 00000 n 0000000068 00000 n 0000000131 00000 n 0000000293 00000 n 0000000613 00000 n 0000000710 00000 n trailer << /Root 1 0 R /Size 7 /Info 6 0 R >> startxref 827 %%EOF
Index ¶
Examples ¶
Constants ¶
This section is empty.
Variables ¶
This section is empty.
Functions ¶
This section is empty.
Types ¶
type Catalog ¶
Catalog represents a PDF catalog object.
type DocumentInfo ¶
DocumentInfo represents a PDF document information object.
type Encoder ¶
type Encoder struct {
// contains filtered or unexported fields
}
Encoder is a PDF writer.
func NewEncoder ¶
NewEncoder returns a ready-to-use Encoder writing to w.
type Image ¶
Image represents a PDF image object containing a DIN A4-sized page scanned with 600dpi (i.e. into 4960x7016 pixels).
type Object ¶
type Object interface {
// Objects returns all Objects which should be encoded into the
// PDF file.
Objects() []Object
// Encode encodes the object into the PDF file w.
Encode(w io.Writer, ids map[string]ObjectID) error
// SetID updates the object id.
SetID(id ObjectID)
// Name returns the human-readable object name.
Name() string
fmt.Stringer
}
Object is implemented by all PDF objects.
type Page ¶
type Page struct {
Common
Resources []Object // Image
Contents []Object // Common (streams)
// Parent contains the human-readable name of the parent object,
// which will be translated into an object ID when encoding.
Parent string
}
Page represents a PDF page object with size DIN A4
Source Files
Click to show internal directories.
Click to hide internal directories.