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// Copyright 2017 The PDFium Authors
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
// Original code copyright 2014 Foxit Software Inc. http://www.foxitsoftware.com
#include "core/fpdfdoc/cpdf_structtree.h"
#include <utility>
#include "core/fpdfapi/parser/cpdf_array.h"
#include "core/fpdfapi/parser/cpdf_dictionary.h"
#include "core/fpdfapi/parser/cpdf_document.h"
#include "core/fpdfapi/parser/cpdf_number.h"
#include "core/fpdfapi/parser/cpdf_reference.h"
#include "core/fpdfdoc/cpdf_numbertree.h"
#include "core/fpdfdoc/cpdf_structelement.h"
#include "core/fxcrt/stl_util.h"
namespace {
bool IsTagged(const CPDF_Document* pDoc) {
RetainPtr<const CPDF_Dictionary> pMarkInfo =
pDoc->GetRoot()->GetDictFor("MarkInfo");
return pMarkInfo && pMarkInfo->GetIntegerFor("Marked");
}
} // namespace
// static
std::unique_ptr<CPDF_StructTree> CPDF_StructTree::LoadPage(
const CPDF_Document* pDoc,
RetainPtr<const CPDF_Dictionary> pPageDict) {
if (!IsTagged(pDoc))
return nullptr;
auto pTree = std::make_unique<CPDF_StructTree>(pDoc);
pTree->LoadPageTree(std::move(pPageDict));
return pTree;
}
CPDF_StructTree::CPDF_StructTree(const CPDF_Document* pDoc)
: m_pTreeRoot(pDoc->GetRoot()->GetDictFor("StructTreeRoot")),
m_pRoleMap(m_pTreeRoot ? m_pTreeRoot->GetDictFor("RoleMap") : nullptr) {}
CPDF_StructTree::~CPDF_StructTree() = default;
ByteString CPDF_StructTree::GetRoleMapNameFor(const ByteString& type) const {
if (m_pRoleMap) {
ByteString mapped = m_pRoleMap->GetNameFor(type);
if (!mapped.IsEmpty())
return mapped;
}
return type;
}
void CPDF_StructTree::LoadPageTree(RetainPtr<const CPDF_Dictionary> pPageDict) {
m_pPage = std::move(pPageDict);
if (!m_pTreeRoot)
return;
RetainPtr<const CPDF_Object> pKids = m_pTreeRoot->GetDirectObjectFor("K");
if (!pKids)
return;
uint32_t dwKids = 0;
if (pKids->IsDictionary())
dwKids = 1;
else if (const CPDF_Array* pArray = pKids->AsArray())
dwKids = fxcrt::CollectionSize<uint32_t>(*pArray);
else
return;
m_Kids.clear();
m_Kids.resize(dwKids);
RetainPtr<const CPDF_Dictionary> pParentTree =
m_pTreeRoot->GetDictFor("ParentTree");
if (!pParentTree)
return;
CPDF_NumberTree parent_tree(std::move(pParentTree));
int parents_id = m_pPage->GetIntegerFor("StructParents", -1);
if (parents_id < 0)
return;
RetainPtr<const CPDF_Array> pParentArray =
ToArray(parent_tree.LookupValue(parents_id));
if (!pParentArray)
return;
StructElementMap element_map;
for (size_t i = 0; i < pParentArray->size(); i++) {
RetainPtr<const CPDF_Dictionary> pParent = pParentArray->GetDictAt(i);
if (pParent)
AddPageNode(std::move(pParent), &element_map, 0);
}
}
RetainPtr<CPDF_StructElement> CPDF_StructTree::AddPageNode(
RetainPtr<const CPDF_Dictionary> pDict,
StructElementMap* map,
int nLevel) {
static constexpr int kStructTreeMaxRecursion = 32;
if (nLevel > kStructTreeMaxRecursion)
return nullptr;
auto it = map->find(pDict);
if (it != map->end())
return it->second;
RetainPtr<const CPDF_Dictionary> key(pDict);
auto pElement = pdfium::MakeRetain<CPDF_StructElement>(this, pDict);
(*map)[key] = pElement;
RetainPtr<const CPDF_Dictionary> pParent = pDict->GetDictFor("P");
if (!pParent || pParent->GetNameFor("Type") == "StructTreeRoot") {
if (!AddTopLevelNode(pDict, pElement))
map->erase(key);
return pElement;
}
RetainPtr<CPDF_StructElement> pParentElement =
AddPageNode(std::move(pParent), map, nLevel + 1);
if (!pParentElement)
return pElement;
if (!pParentElement->UpdateKidIfElement(pDict, pElement.Get()))
map->erase(key);
pElement->SetParent(pParentElement.Get());
return pElement;
}
bool CPDF_StructTree::AddTopLevelNode(
const CPDF_Dictionary* pDict,
const RetainPtr<CPDF_StructElement>& pElement) {
RetainPtr<const CPDF_Object> pObj = m_pTreeRoot->GetDirectObjectFor("K");
if (!pObj)
return false;
if (pObj->IsDictionary()) {
if (pObj->GetObjNum() != pDict->GetObjNum())
return false;
m_Kids[0] = pElement;
}
const CPDF_Array* pTopKids = pObj->AsArray();
if (!pTopKids)
return true;
bool bSave = false;
for (size_t i = 0; i < pTopKids->size(); i++) {
RetainPtr<const CPDF_Reference> pKidRef =
ToReference(pTopKids->GetObjectAt(i));
if (pKidRef && pKidRef->GetRefObjNum() == pDict->GetObjNum()) {
m_Kids[i] = pElement;
bSave = true;
}
}
return bSave;
}