// Copyright 2017 PDFium Authors. All rights reserved. // 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 "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 "third_party/base/ptr_util.h" namespace { bool IsTagged(const CPDF_Document* pDoc) { const CPDF_Dictionary* pCatalog = pDoc->GetRoot(); const CPDF_Dictionary* pMarkInfo = pCatalog->GetDictFor("MarkInfo"); return pMarkInfo && pMarkInfo->GetIntegerFor("Marked"); } } // namespace // static std::unique_ptr CPDF_StructTree::LoadPage( const CPDF_Document* pDoc, const CPDF_Dictionary* pPageDict) { if (!IsTagged(pDoc)) return nullptr; auto pTree = pdfium::MakeUnique(pDoc); pTree->LoadPageTree(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; void CPDF_StructTree::LoadPageTree(const CPDF_Dictionary* pPageDict) { m_pPage = pPageDict; if (!m_pTreeRoot) return; 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 = pArray->size(); else return; m_Kids.clear(); m_Kids.resize(dwKids); const CPDF_Dictionary* pParentTree = m_pTreeRoot->GetDictFor("ParentTree"); if (!pParentTree) return; CPDF_NumberTree parent_tree(pParentTree); int parents_id = pPageDict->GetIntegerFor("StructParents", -1); if (parents_id < 0) return; 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++) { if (const CPDF_Dictionary* pParent = pParentArray->GetDictAt(i)) AddPageNode(pParent, &element_map, 0); } } RetainPtr CPDF_StructTree::AddPageNode( 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; auto pElement = pdfium::MakeRetain(this, nullptr, pDict); (*map)[pDict] = pElement; const CPDF_Dictionary* pParent = pDict->GetDictFor("P"); if (!pParent || pParent->GetStringFor("Type") == "StructTreeRoot") { if (!AddTopLevelNode(pDict, pElement)) map->erase(pDict); return pElement; } RetainPtr pParentElement = AddPageNode(pParent, map, nLevel + 1); bool bSave = false; for (CPDF_StructKid& kid : *pParentElement->GetKids()) { if (kid.m_Type == CPDF_StructKid::Element && kid.m_pDict == pDict) { kid.m_pElement = pElement; bSave = true; } } if (!bSave) map->erase(pDict); return pElement; } bool CPDF_StructTree::AddTopLevelNode( const CPDF_Dictionary* pDict, const RetainPtr& pElement) { 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++) { const CPDF_Reference* pKidRef = ToReference(pTopKids->GetObjectAt(i)); if (pKidRef && pKidRef->GetRefObjNum() == pDict->GetObjNum()) { m_Kids[i] = pElement; bSave = true; } } return bSave; }