qpdf/examples/pdf-set-form-values.cc

111 lines
3.6 KiB
C++

#include <stdio.h>
#include <string.h>
#include <iostream>
#include <stdlib.h>
#include <qpdf/QPDF.hh>
#include <qpdf/QPDFPageDocumentHelper.hh>
#include <qpdf/QPDFAcroFormDocumentHelper.hh>
#include <qpdf/QPDFWriter.hh>
#include <qpdf/QUtil.hh>
static char const* whoami = 0;
void usage()
{
std::cerr << "Usage: " << whoami << " infile.pdf outfile.pdf value"
<< std::endl
<< "Set the value of all text fields to a specified value"
<< std::endl;
exit(2);
}
int main(int argc, char* argv[])
{
whoami = QUtil::getWhoami(argv[0]);
// For libtool's sake....
if (strncmp(whoami, "lt-", 3) == 0)
{
whoami += 3;
}
if (argc != 4)
{
usage();
}
char const* infilename = argv[1];
char const* outfilename = argv[2];
char const* value = argv[3];
// This is a contrived example that just goes through a file page
// by page and sets the value of any text fields it finds to a
// fixed value as given on the command line. The purpose here is
// to illustrate use of the helper classes around interactive
// forms.
try
{
QPDF qpdf;
qpdf.processFile(infilename);
// We will iterate through form fields by starting at the page
// level and looking at each field for each page. We could
// also called QPDFAcroFormDocumentHelper::getFormFields to
// iterate at the field level, but doing it as below
// illustrates how we can map from annotations to fields.
QPDFAcroFormDocumentHelper afdh(qpdf);
QPDFPageDocumentHelper pdh(qpdf);
std::vector<QPDFPageObjectHelper> pages = pdh.getAllPages();
for (std::vector<QPDFPageObjectHelper>::iterator page_iter =
pages.begin();
page_iter != pages.end(); ++page_iter)
{
// Get all widget annotations for each page. Widget
// annotations are the ones that contain the details of
// what's in a form field.
std::vector<QPDFAnnotationObjectHelper> annotations =
afdh.getWidgetAnnotationsForPage(*page_iter);
for (std::vector<QPDFAnnotationObjectHelper>::iterator annot_iter =
annotations.begin();
annot_iter != annotations.end(); ++annot_iter)
{
// For each annotation, find its associated field. If
// it's a text field, set its value. This will
// automatically update the document to indicate that
// appearance streams need to be regenerated. At the
// time of this writing, qpdf doesn't have any helper
// code to assist with appearance stream generation,
// though there's nothing that prevents it from being
// possible.
QPDFFormFieldObjectHelper ffh =
afdh.getFieldForAnnotation(*annot_iter);
if (ffh.getFieldType() == "/Tx")
{
// Set the value. This will automatically set
// /NeedAppearances to true. If you don't want to
// do that, pass false as the second argument. For
// details see comments in
// QPDFFormFieldObjectHelper.hh.
ffh.setV(value);
}
}
}
// Write out a new file
QPDFWriter w(qpdf, outfilename);
w.setStaticID(true); // for testing only
w.write();
}
catch (std::exception &e)
{
std::cerr << whoami << " processing file " << infilename << ": "
<< e.what() << std::endl;
exit(2);
}
return 0;
}