gopdf/contrib/tiff/tiff.go

84 lines
2.8 KiB
Go

/*
* Copyright (c) 2016 Kurt Jung (Gmail: kurt.w.jung)
*
* 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 tiff allows standard (LZW-compressed) TIFF images to be used in
// documents generated with gofpdf.
package tiff
import (
"bytes"
"fmt"
"image"
"image/png"
"io"
"os"
"github.com/jung-kurt/gofpdf"
"golang.org/x/image/tiff"
)
// RegisterReader registers a TIFF image, adding it to the PDF file but not
// adding it to the page. imgName specifies the name that will be used in the
// call to Image() that actually places the image in the document. options
// specifies various image properties; in this case, the ImageType property
// should be set to "tiff". The TIFF image is a reader from the reader
// specified by r.
func RegisterReader(fpdf *gofpdf.Fpdf, imgName string, options gofpdf.ImageOptions, r io.Reader) (info *gofpdf.ImageInfoType) {
var err error
var img image.Image
var buf bytes.Buffer
if fpdf.Ok() {
if options.ImageType == "tiff" || options.ImageType == "tif" {
img, err = tiff.Decode(r)
if err == nil {
err = png.Encode(&buf, img)
if err == nil {
options.ImageType = "png"
info = fpdf.RegisterImageOptionsReader(imgName, options, &buf)
}
}
} else {
err = fmt.Errorf("expecting \"tiff\" or \"tif\" as image type, got \"%s\"", options.ImageType)
}
if err != nil {
fpdf.SetError(err)
}
}
return
}
// RegisterFile registers a TIFF image, adding it to the PDF file but not
// adding it to the page. imgName specifies the name that will be used in the
// call to Image() that actually places the image in the document. options
// specifies various image properties; in this case, the ImageType property
// should be set to "tiff". The TIFF image is read from the file specified by
// tiffFileStr.
func RegisterFile(fpdf *gofpdf.Fpdf, imgName string, options gofpdf.ImageOptions, tiffFileStr string) (info *gofpdf.ImageInfoType) {
var f *os.File
var err error
if fpdf.Ok() {
f, err = os.Open(tiffFileStr)
if err == nil {
info = RegisterReader(fpdf, imgName, options, f)
f.Close()
} else {
fpdf.SetError(err)
}
}
return
}