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qpdf/examples/pdf-double-page-size.cc
m-holger 78aa3b6c2b Tidy example pdf-double-page-size
Also fix typo in pdf-attach-file example.
2022-03-03 06:54:30 -05:00

119 lines
3.2 KiB
C++

#include <iostream>
#include <string.h>
#include <stdlib.h>
#include <qpdf/QPDF.hh>
#include <qpdf/QPDFPageDocumentHelper.hh>
#include <qpdf/QPDFPageObjectHelper.hh>
#include <qpdf/QUtil.hh>
#include <qpdf/Buffer.hh>
#include <qpdf/QPDFWriter.hh>
static char const* whoami = 0;
void usage()
{
std::cerr << "Usage: " << whoami << " infile.pdf outfile.pdf [in-password]"
<< std::endl
<< "Double size of all pages in infile.pdf;"
<< " write output to outfile.pdf" << std::endl;
exit(2);
}
// If there is a box of name box_name, replace it with a new box whose
// elements are double the values of the original box.
static void doubleBoxSize(QPDFPageObjectHelper& page, char const* box_name)
{
// We need to use getAttribute rather than getKey as some boxes could
// be inherited.
auto box = page.getAttribute(box_name, true);
if (box.isNull())
{
return;
}
if (! box.isRectangle())
{
throw std::runtime_error(std::string("box ") + box_name +
" is not an array of four elements");
}
std::vector<QPDFObjectHandle> doubled;
for (auto& item : box.aitems())
{
doubled.push_back(
QPDFObjectHandle::newReal(item.getNumericValue() * 2.0, 2));
}
page.getObjectHandle()
.replaceKey(box_name, QPDFObjectHandle::newArray(doubled));
}
int main(int argc, char* argv[])
{
whoami = QUtil::getWhoami(argv[0]);
// For libtool's sake....
if (strncmp(whoami, "lt-", 3) == 0)
{
whoami += 3;
}
// For test suite
bool static_id = false;
if ((argc > 1) && (strcmp(argv[1], " --static-id") == 0))
{
static_id = true;
--argc;
++argv;
}
if (! ((argc == 3) || (argc == 4)))
{
usage();
}
char const* infilename = argv[1];
char const* outfilename = argv[2];
char const* password = (argc == 4) ? argv[3] : "";
// Text to prepend to each page's contents
std::string content = "2 0 0 2 0 0 cm\n";
try
{
QPDF qpdf;
qpdf.processFile(infilename, password);
for (auto& page : QPDFPageDocumentHelper(qpdf).getAllPages())
{
// Prepend the buffer to the page's contents
page.addPageContents(
QPDFObjectHandle::newStream(&qpdf, content), true);
// Double the size of each of the content boxes
doubleBoxSize(page, "/MediaBox");
doubleBoxSize(page, "/CropBox");
doubleBoxSize(page, "/BleedBox");
doubleBoxSize(page, "/TrimBox");
doubleBoxSize(page, "/ArtBox");
}
// Write out a new file
QPDFWriter w(qpdf, outfilename);
if (static_id)
{
// For the test suite, uncompress streams and use static IDs.
w.setStaticID(true); // for testing only
w.setStreamDataMode(qpdf_s_uncompress);
}
w.write();
std::cout << whoami << ": new file written to " << outfilename
<< std::endl;
}
catch (std::exception &e)
{
std::cerr << whoami << " processing file " << infilename << ": "
<< e.what() << std::endl;
exit(2);
}
return 0;
}