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qpdf/examples/pdf-overlay-page.cc
Jay Berkenbilt 4f24617e1e Code clean up: use range-style for loops wherever possible
Where not possible, use "auto" to get the iterator type.

Editorial note: I have avoid this change for a long time because of
not wanting to make gratuitous changes to version history, which can
obscure when certain changes were made, but with having recently
touched every single file to apply automatic code formatting and with
making several broad changes to the API, I decided it was time to take
the plunge and get rid of the older (pre-C++11) verbose iterator
syntax. The new code is just easier to read and understand, and in
many cases, it will be more effecient as fewer temporary copies are
being made.

m-holger, if you're reading, you can see that I've finally come
around. :-)
2022-04-30 13:27:18 -04:00

99 lines
3.3 KiB
C++

#include <qpdf/QPDF.hh>
#include <qpdf/QPDFPageDocumentHelper.hh>
#include <qpdf/QPDFPageObjectHelper.hh>
#include <qpdf/QPDFWriter.hh>
#include <qpdf/QUtil.hh>
#include <iostream>
#include <stdlib.h>
#include <string.h>
// This program demonstrates use of form XObjects to overlay a page
// from one file onto all pages of another file. The qpdf program's
// --overlay and --underlay options provide a more general version of
// this capability.
static char const* whoami = 0;
void
usage()
{
std::cerr << "Usage: " << whoami << " infile pagefile outfile" << std::endl
<< "Stamp page 1 of pagefile on every page of infile,"
<< " writing to outfile" << std::endl;
exit(2);
}
static void
stamp_page(char const* infile, char const* stampfile, char const* outfile)
{
QPDF inpdf;
inpdf.processFile(infile);
QPDF stamppdf;
stamppdf.processFile(stampfile);
// Get first page from other file
QPDFPageObjectHelper stamp_page_1 =
QPDFPageDocumentHelper(stamppdf).getAllPages().at(0);
// Convert page to a form XObject
QPDFObjectHandle foreign_fo = stamp_page_1.getFormXObjectForPage();
// Copy form XObject to the input file
QPDFObjectHandle stamp_fo = inpdf.copyForeignObject(foreign_fo);
// For each page...
std::vector<QPDFPageObjectHelper> pages =
QPDFPageDocumentHelper(inpdf).getAllPages();
for (auto& ph: pages) {
// Find a unique resource name for the new form XObject
QPDFObjectHandle resources = ph.getAttribute("/Resources", true);
int min_suffix = 1;
std::string name = resources.getUniqueResourceName("/Fx", min_suffix);
// Generate content to place the form XObject centered within
// destination page's trim box.
QPDFMatrix m;
std::string content = ph.placeFormXObject(
stamp_fo, name, ph.getTrimBox().getArrayAsRectangle(), m);
if (!content.empty()) {
// Append the content to the page's content. Surround the
// original content with q...Q to the new content from the
// page's original content.
resources.mergeResources("<< /XObject << >> >>"_qpdf);
resources.getKey("/XObject").replaceKey(name, stamp_fo);
ph.addPageContents(
QPDFObjectHandle::newStream(&inpdf, "q\n"), true);
ph.addPageContents(
QPDFObjectHandle::newStream(&inpdf, "\nQ\n" + content), false);
}
// Copy the annotations and form fields from the original page
// to the new page. For more efficiency when copying multiple
// pages, we can create a QPDFAcroFormDocumentHelper and pass
// it in. See comments in QPDFPageObjectHelper.hh for details.
ph.copyAnnotations(stamp_page_1, m);
}
QPDFWriter w(inpdf, outfile);
w.setStaticID(true); // for testing only
w.write();
}
int
main(int argc, char* argv[])
{
whoami = QUtil::getWhoami(argv[0]);
if (argc != 4) {
usage();
}
char const* infile = argv[1];
char const* stampfile = argv[2];
char const* outfile = argv[3];
try {
stamp_page(infile, stampfile, outfile);
} catch (std::exception& e) {
std::cerr << whoami << ": " << e.what() << std::endl;
exit(2);
}
return 0;
}