mirror of
https://github.com/JakubMelka/PDF4QT.git
synced 2024-12-28 01:00:40 +01:00
101 lines
3.5 KiB
C++
101 lines
3.5 KiB
C++
// Copyright (C) 2018 Jakub Melka
|
|
//
|
|
// This file is part of PdfForQt.
|
|
//
|
|
// PdfForQt is free software: you can redistribute it and/or modify
|
|
// it under the terms of the GNU Lesser General Public License as published by
|
|
// the Free Software Foundation, either version 3 of the License, or
|
|
// (at your option) any later version.
|
|
//
|
|
// PdfForQt is distributed in the hope that it will be useful,
|
|
// but WITHOUT ANY WARRANTY; without even the implied warranty of
|
|
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
|
|
// GNU Lesser General Public License for more details.
|
|
//
|
|
// You should have received a copy of the GNU Lesser General Public License
|
|
// along with PDFForQt. If not, see <https://www.gnu.org/licenses/>.
|
|
|
|
|
|
#ifndef PDFNUMBERTREELOADER_H
|
|
#define PDFNUMBERTREELOADER_H
|
|
|
|
#include "pdfdocument.h"
|
|
|
|
#include <vector>
|
|
|
|
namespace pdf
|
|
{
|
|
|
|
/// This class can load a number tree into the array
|
|
template<typename Type>
|
|
class PDFNumberTreeLoader
|
|
{
|
|
public:
|
|
explicit PDFNumberTreeLoader() = delete;
|
|
|
|
using Objects = std::vector<Type>;
|
|
|
|
/// Parses the number tree and loads its items into the array. Some errors are ignored,
|
|
/// e.g. when kid is null. Type must contain methods to load object array.
|
|
static Objects parse(const PDFDocument* document, const PDFObject& root)
|
|
{
|
|
Objects result;
|
|
|
|
// First, try to load items from the tree into the array
|
|
parseImpl(result, document, root);
|
|
|
|
// Array may not be sorted. Sort it using comparison operator for Type.
|
|
std::stable_sort(result.begin(), result.end());
|
|
|
|
return result;
|
|
}
|
|
|
|
private:
|
|
static void parseImpl(Objects& objects, const PDFDocument* document, const PDFObject& root)
|
|
{
|
|
const PDFObject& dereferencedRoot = document->getObject(root);
|
|
if (dereferencedRoot.isDictionary())
|
|
{
|
|
const PDFDictionary* dictionary = dereferencedRoot.getDictionary();
|
|
|
|
// First, load the objects into the array
|
|
const PDFObject& numberedItems = document->getObject(dictionary->get("Nums"));
|
|
if (numberedItems.isArray())
|
|
{
|
|
const PDFArray* numberedItemsArray = numberedItems.getArray();
|
|
const size_t count = numberedItemsArray->getCount() / 2;
|
|
objects.reserve(objects.size() + count);
|
|
for (size_t i = 0; i < count; ++i)
|
|
{
|
|
const size_t numberIndex = 2 * i;
|
|
const size_t valueIndex = 2 * i + 1;
|
|
|
|
const PDFObject& number = document->getObject(numberedItemsArray->getItem(numberIndex));
|
|
if (!number.isInt())
|
|
{
|
|
continue;
|
|
}
|
|
|
|
objects.emplace_back(Type::parse(number.getInteger(), document, numberedItemsArray->getItem(valueIndex)));
|
|
}
|
|
}
|
|
|
|
// Then, follow the kids
|
|
const PDFObject& kids = document->getObject(dictionary->get("Kids"));
|
|
if (kids.isArray())
|
|
{
|
|
const PDFArray* kidsArray = kids.getArray();
|
|
const size_t count = kidsArray->getCount();
|
|
for (size_t i = 0; i < count; ++i)
|
|
{
|
|
parseImpl(objects, document, kidsArray->getItem(i));
|
|
}
|
|
}
|
|
}
|
|
}
|
|
};
|
|
|
|
} // namespace pdf
|
|
|
|
#endif // PDFNUMBERTREELOADER_H
|