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Diffstat (limited to 'lib/pdf/writer.cc')
| -rw-r--r-- | lib/pdf/writer.cc | 236 |
1 files changed, 236 insertions, 0 deletions
diff --git a/lib/pdf/writer.cc b/lib/pdf/writer.cc new file mode 100644 index 0000000..78a9355 --- /dev/null +++ b/lib/pdf/writer.cc @@ -0,0 +1,236 @@ +// writer.cc -- putting PDF object in a file +// Copyright (C) 2008 SEIKO EPSON CORPORATION +// +// This file is part of the 'iscan' program. +// +// The 'iscan' program is free-ish software. +// You can redistribute it and/or modify it under the terms of the GNU +// General Public License as published by the Free Software Foundation; +// either version 2 of the License or at your option any later version. +// +// This program is distributed in the hope that it will be useful, but +// WITHOUT ANY WARRANTY; without even the implied warranty of FITNESS +// FOR A PARTICULAR PURPOSE or MERCHANTABILITY. +// See the GNU General Public License for more details. +// +// You should have received a verbatim copy of the GNU General Public +// License along with this program; if not, write to: +// +// Free Software Foundation, Inc. +// 59 Temple Place, Suite 330 +// Boston, MA 02111-1307 USA +// +// As a special exception, the copyright holders give permission +// to link the code of this program with the esmod library and +// distribute linked combinations including the two. You must obey +// the GNU General Public License in all respects for all of the +// code used other than esmod. + + +#ifdef HAVE_CONFIG_H +#include <config.h> +#endif + +#include "writer.hh" + +#include <sstream> +#include <stdexcept> + +namespace iscan +{ + +namespace pdf +{ + using std::runtime_error; + using std::string; + +writer::writer (FILE *file) + : _xref (xref ()), _file (file) +{ + _xref_pos = 0; + _last_xref_pos = 0; + _saved_pos = 0; + _mode = object_mode; + _stream_len_obj = NULL; +} + +writer::~writer () +{ + delete _stream_len_obj; + _stream_len_obj = NULL; +} + +void +writer::write (object& obj) +{ + if (object_mode != _mode) + { + throw runtime_error ("invalid call to pdf::writer::write (object&)"); + } + + _xref[obj.obj_num ()] = ftell (_file); + + fprintf (_file, "%zu 0 obj\n", obj.obj_num ()); + obj.print (_file); + fprintf (_file, "\n"); + fprintf (_file, "endobj\n"); +} + +void +writer::begin_stream (dictionary& dict) +{ + if (stream_mode == _mode) + { + throw runtime_error ("invalid call to pdf::writer::begin_stream ()"); + } + _mode = stream_mode; + + _stream_len_obj = new primitive (); + dict.insert ("Length", object (_stream_len_obj->obj_num ())); + + _xref[dict.obj_num ()] = ftell (_file); + + fprintf (_file, "%zu 0 obj\n", dict.obj_num ()); + dict.print (_file); + fprintf (_file, "\n"); + fprintf (_file, "stream\n"); + + _saved_pos = ftell (_file); +} + +void +writer::write (const char *buf, size_t n) +{ + if (stream_mode != _mode) + { + throw runtime_error ("invalid call to pdf::writer::write ()"); + } + size_t rv = fwrite (buf, sizeof (char), n, _file); + if (rv != n) throw std::ios_base::failure ("write error"); +} + +void +writer::write (const string& s) +{ + if (stream_mode != _mode) + { + throw runtime_error ("invalid call to pdf::writer::write ()"); + } + fprintf (_file, "%s", s.c_str ()); +} + +void +writer::end_stream () +{ + if (stream_mode != _mode) + { + throw runtime_error ("invalid call to pdf::writer::end_stream ()"); + } + _mode = object_mode; + + size_t pos = ftell (_file); + size_t length = pos - _saved_pos; + + fprintf (_file, "\n"); + fprintf (_file, "endstream"); + fprintf (_file, "\n"); + fprintf (_file, "endobj"); + fprintf (_file, "\n"); + + // FIXME: overload the '=' operator in pdf::primitive + *_stream_len_obj = primitive (length); + + write (*_stream_len_obj); + delete _stream_len_obj; + _stream_len_obj = NULL; +} + +void +writer::header () +{ + if (_mode == stream_mode) + { + throw runtime_error ("cannot write header in stream mode"); + } + fprintf (_file, "%%PDF-1.0\n"); +} + +void +writer::trailer (dictionary& trailer_dict) +{ + if (_mode == stream_mode) + { + throw runtime_error ("cannot write trailer in stream mode"); + } + write_xref (); + write_trailer (trailer_dict); +} + +// FIXME: clean up this kludge +void +writer::write_xref () +{ + xref::const_iterator it; + + _last_xref_pos = _xref_pos; + _xref_pos = ftell (_file); + + fprintf (_file, "xref\n"); + + stringstream ss; + size_t start_obj_num = 0; + size_t cur_obj_num = 0; + size_t last_obj_num = 0; + + ss << "0000000000 65535 f " << endl; + for(it = _xref.begin (); _xref.end () != it; ++it) + { + cur_obj_num = it->first; + + if (cur_obj_num != last_obj_num + 1) + { + // write out the current xref section and start a new one + fprintf (_file, "%zu %zu\n", start_obj_num, + last_obj_num + 1 - start_obj_num); + fprintf (_file, "%s", ss.str ().c_str ()); + + ss.str (""); // flush stream + start_obj_num = cur_obj_num; + } + + last_obj_num = cur_obj_num; + + ss.width (10); + ss.fill ('0'); + ss << it->second << " 00000 n " << endl; + } + + if (!ss.str ().empty ()) + { + fprintf (_file, "%zu %zu\n", start_obj_num, + last_obj_num + 1 - start_obj_num); + fprintf (_file, "%s", ss.str ().c_str ()); + } +} + +void +writer::write_trailer (dictionary& trailer_dict) +{ + trailer_dict.insert ("Size", primitive (_xref.size () + 1)); + if (_last_xref_pos != 0) + { + trailer_dict.insert ("Prev", primitive (_last_xref_pos)); + } + + fprintf (_file, "trailer\n"); + trailer_dict.print (_file); + fprintf (_file, "\n"); + fprintf (_file, "startxref\n"); + fprintf (_file, "%zu\n", _xref_pos); + fprintf (_file, "%%%%EOF\n"); + + _xref.clear (); +} + +} // namespace pdf +} // namespace iscan |