Revert "Remove the document tagged code as it is unused."

The code that was deleted is being used by Android foxit viewer
This reverts commit dbfc3522a6ee24d17f2c50a5dcc465db52a280ee and updates the #includes

Review-Url: https://codereview.chromium.org/2281083002

5 files changed, 665 insertions, 0 deletions

diff --git a/BUILD.gn b/BUILD.gn
index c8da0dc35e..c898f4d413 100644
--- a/BUILD.gn
+++ b/BUILD.gn
@@ -272,6 +272,7 @@ static_library("fpdfdoc") {
     "core/fpdfdoc/csection.h",
     "core/fpdfdoc/ctypeset.cpp",
     "core/fpdfdoc/ctypeset.h",
+    "core/fpdfdoc/doc_tagged.cpp",
     "core/fpdfdoc/include/cpdf_aaction.h",
     "core/fpdfdoc/include/cpdf_action.h",
     "core/fpdfdoc/include/cpdf_actionfields.h",
@@ -301,9 +302,11 @@ static_library("fpdfdoc") {
     "core/fpdfdoc/include/cpvt_wordplace.h",
     "core/fpdfdoc/include/cpvt_wordprops.h",
     "core/fpdfdoc/include/cpvt_wordrange.h",
+    "core/fpdfdoc/include/fpdf_tagged.h",
     "core/fpdfdoc/include/ipdf_formnotify.h",
     "core/fpdfdoc/ipdf_formnotify.cpp",
     "core/fpdfdoc/ipvt_fontmap.h",
+    "core/fpdfdoc/tagged_int.h",
   ]
   configs += [ ":pdfium_core_config" ]
 }
diff --git a/core/fpdfdoc/doc_tagged.cpp b/core/fpdfdoc/doc_tagged.cpp
new file mode 100644
index 0000000000..80a296af60
--- /dev/null
+++ b/core/fpdfdoc/doc_tagged.cpp
@@ -0,0 +1,459 @@
+// Copyright 2014 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 <map>
+
+#include "core/fpdfapi/fpdf_parser/include/cpdf_array.h"
+#include "core/fpdfapi/fpdf_parser/include/cpdf_dictionary.h"
+#include "core/fpdfapi/fpdf_parser/include/cpdf_document.h"
+#include "core/fpdfapi/fpdf_parser/include/cpdf_reference.h"
+#include "core/fpdfapi/fpdf_parser/include/cpdf_stream.h"
+#include "core/fpdfdoc/cpdf_numbertree.h"
+#include "core/fpdfdoc/include/fpdf_tagged.h"
+#include "core/fpdfdoc/tagged_int.h"
+
+namespace {
+
+const int nMaxRecursion = 32;
+
+bool IsTagged(const CPDF_Document* pDoc) {
+  CPDF_Dictionary* pCatalog = pDoc->GetRoot();
+  CPDF_Dictionary* pMarkInfo = pCatalog->GetDictBy("MarkInfo");
+  return pMarkInfo && pMarkInfo->GetIntegerBy("Marked");
+}
+
+}  // namespace
+
+// static
+IPDF_StructTree* IPDF_StructTree::LoadPage(const CPDF_Document* pDoc,
+                                           const CPDF_Dictionary* pPageDict) {
+  if (!IsTagged(pDoc))
+    return nullptr;
+
+  CPDF_StructTreeImpl* pTree = new CPDF_StructTreeImpl(pDoc);
+  pTree->LoadPageTree(pPageDict);
+  return pTree;
+}
+
+// static.
+IPDF_StructTree* IPDF_StructTree::LoadDoc(const CPDF_Document* pDoc) {
+  if (!IsTagged(pDoc))
+    return nullptr;
+
+  CPDF_StructTreeImpl* pTree = new CPDF_StructTreeImpl(pDoc);
+  pTree->LoadDocTree();
+  return pTree;
+}
+
+CPDF_StructTreeImpl::CPDF_StructTreeImpl(const CPDF_Document* pDoc)
+    : m_pTreeRoot(pDoc->GetRoot()->GetDictBy("StructTreeRoot")),
+      m_pRoleMap(m_pTreeRoot ? m_pTreeRoot->GetDictBy("RoleMap") : nullptr),
+      m_pPage(nullptr) {}
+
+CPDF_StructTreeImpl::~CPDF_StructTreeImpl() {}
+
+int CPDF_StructTreeImpl::CountTopElements() const {
+  return pdfium::CollectionSize<int>(m_Kids);
+}
+
+IPDF_StructElement* CPDF_StructTreeImpl::GetTopElement(int i) const {
+  return m_Kids[i].Get();
+}
+
+void CPDF_StructTreeImpl::LoadDocTree() {
+  m_pPage = nullptr;
+  if (!m_pTreeRoot)
+    return;
+
+  CPDF_Object* pKids = m_pTreeRoot->GetDirectObjectBy("K");
+  if (!pKids)
+    return;
+
+  if (CPDF_Dictionary* pDict = pKids->AsDictionary()) {
+    m_Kids.push_back(CFX_RetainPtr<CPDF_StructElementImpl>(
+        new CPDF_StructElementImpl(this, nullptr, pDict)));
+    return;
+  }
+
+  CPDF_Array* pArray = pKids->AsArray();
+  if (!pArray)
+    return;
+
+  for (size_t i = 0; i < pArray->GetCount(); i++) {
+    m_Kids.push_back(CFX_RetainPtr<CPDF_StructElementImpl>(
+        new CPDF_StructElementImpl(this, nullptr, pArray->GetDictAt(i))));
+  }
+}
+
+void CPDF_StructTreeImpl::LoadPageTree(const CPDF_Dictionary* pPageDict) {
+  m_pPage = pPageDict;
+  if (!m_pTreeRoot)
+    return;
+
+  CPDF_Object* pKids = m_pTreeRoot->GetDirectObjectBy("K");
+  if (!pKids)
+    return;
+
+  uint32_t dwKids = 0;
+  if (pKids->IsDictionary())
+    dwKids = 1;
+  else if (CPDF_Array* pArray = pKids->AsArray())
+    dwKids = pArray->GetCount();
+  else
+    return;
+
+  m_Kids.clear();
+  m_Kids.resize(dwKids);
+  CPDF_Dictionary* pParentTree = m_pTreeRoot->GetDictBy("ParentTree");
+  if (!pParentTree)
+    return;
+
+  CPDF_NumberTree parent_tree(pParentTree);
+  int parents_id = pPageDict->GetIntegerBy("StructParents", -1);
+  if (parents_id < 0)
+    return;
+
+  CPDF_Array* pParentArray = ToArray(parent_tree.LookupValue(parents_id));
+  if (!pParentArray)
+    return;
+
+  std::map<CPDF_Dictionary*, CPDF_StructElementImpl*> element_map;
+  for (size_t i = 0; i < pParentArray->GetCount(); i++) {
+    if (CPDF_Dictionary* pParent = pParentArray->GetDictAt(i))
+      AddPageNode(pParent, element_map);
+  }
+}
+
+CPDF_StructElementImpl* CPDF_StructTreeImpl::AddPageNode(
+    CPDF_Dictionary* pDict,
+    std::map<CPDF_Dictionary*, CPDF_StructElementImpl*>& map,
+    int nLevel) {
+  if (nLevel > nMaxRecursion)
+    return nullptr;
+
+  auto it = map.find(pDict);
+  if (it != map.end())
+    return it->second;
+
+  CPDF_StructElementImpl* pElement =
+      new CPDF_StructElementImpl(this, nullptr, pDict);
+  map[pDict] = pElement;
+  CPDF_Dictionary* pParent = pDict->GetDictBy("P");
+  if (!pParent || pParent->GetStringBy("Type") == "StructTreeRoot") {
+    if (!AddTopLevelNode(pDict, pElement)) {
+      pElement->Release();
+      map.erase(pDict);
+    }
+  } else {
+    CPDF_StructElementImpl* pParentElement =
+        AddPageNode(pParent, map, nLevel + 1);
+    FX_BOOL bSave = FALSE;
+    for (CPDF_StructKid& kid : pParentElement->m_Kids) {
+      if (kid.m_Type != CPDF_StructKid::Element)
+        continue;
+      if (kid.m_Element.m_pDict != pDict)
+        continue;
+      kid.m_Element.m_pElement = pElement->Retain();
+      bSave = TRUE;
+    }
+    if (!bSave) {
+      pElement->Release();
+      map.erase(pDict);
+    }
+  }
+  return pElement;
+}
+FX_BOOL CPDF_StructTreeImpl::AddTopLevelNode(CPDF_Dictionary* pDict,
+                                             CPDF_StructElementImpl* pElement) {
+  CPDF_Object* pObj = m_pTreeRoot->GetDirectObjectBy("K");
+  if (!pObj)
+    return FALSE;
+
+  if (pObj->IsDictionary()) {
+    if (pObj->GetObjNum() != pDict->GetObjNum())
+      return FALSE;
+    m_Kids[0].Reset(pElement);
+  }
+  if (CPDF_Array* pTopKids = pObj->AsArray()) {
+    bool bSave = false;
+    for (size_t i = 0; i < pTopKids->GetCount(); i++) {
+      CPDF_Reference* pKidRef = ToReference(pTopKids->GetObjectAt(i));
+      if (pKidRef && pKidRef->GetRefObjNum() == pDict->GetObjNum()) {
+        m_Kids[i].Reset(pElement);
+        bSave = true;
+      }
+    }
+    if (!bSave)
+      return FALSE;
+  }
+  return TRUE;
+}
+
+CPDF_StructElementImpl::CPDF_StructElementImpl(CPDF_StructTreeImpl* pTree,
+                                               CPDF_StructElementImpl* pParent,
+                                               CPDF_Dictionary* pDict)
+    : m_RefCount(0),
+      m_pTree(pTree),
+      m_pParent(pParent),
+      m_pDict(pDict),
+      m_Type(pDict->GetStringBy("S")) {
+  if (pTree->m_pRoleMap) {
+    CFX_ByteString mapped = pTree->m_pRoleMap->GetStringBy(m_Type);
+    if (!mapped.IsEmpty())
+      m_Type = mapped;
+  }
+  LoadKids(pDict);
+}
+
+IPDF_StructTree* CPDF_StructElementImpl::GetTree() const {
+  return m_pTree;
+}
+
+const CFX_ByteString& CPDF_StructElementImpl::GetType() const {
+  return m_Type;
+}
+
+IPDF_StructElement* CPDF_StructElementImpl::GetParent() const {
+  return m_pParent;
+}
+
+CPDF_Dictionary* CPDF_StructElementImpl::GetDict() const {
+  return m_pDict;
+}
+
+int CPDF_StructElementImpl::CountKids() const {
+  return pdfium::CollectionSize<int>(m_Kids);
+}
+
+const CPDF_StructKid& CPDF_StructElementImpl::GetKid(int index) const {
+  return m_Kids[index];
+}
+
+CPDF_StructElementImpl::~CPDF_StructElementImpl() {
+  for (CPDF_StructKid& kid : m_Kids) {
+    if (kid.m_Type == CPDF_StructKid::Element && kid.m_Element.m_pElement)
+      static_cast<CPDF_StructElementImpl*>(kid.m_Element.m_pElement)->Release();
+  }
+}
+
+CPDF_StructElementImpl* CPDF_StructElementImpl::Retain() {
+  m_RefCount++;
+  return this;
+}
+void CPDF_StructElementImpl::Release() {
+  if (--m_RefCount < 1) {
+    delete this;
+  }
+}
+void CPDF_StructElementImpl::LoadKids(CPDF_Dictionary* pDict) {
+  CPDF_Object* pObj = pDict->GetObjectBy("Pg");
+  uint32_t PageObjNum = 0;
+  if (CPDF_Reference* pRef = ToReference(pObj))
+    PageObjNum = pRef->GetRefObjNum();
+
+  CPDF_Object* pKids = pDict->GetDirectObjectBy("K");
+  if (!pKids)
+    return;
+
+  m_Kids.clear();
+  if (CPDF_Array* pArray = pKids->AsArray()) {
+    m_Kids.resize(pArray->GetCount());
+    for (uint32_t i = 0; i < pArray->GetCount(); i++) {
+      CPDF_Object* pKid = pArray->GetDirectObjectAt(i);
+      LoadKid(PageObjNum, pKid, &m_Kids[i]);
+    }
+  } else {
+    m_Kids.resize(1);
+    LoadKid(PageObjNum, pKids, &m_Kids[0]);
+  }
+}
+void CPDF_StructElementImpl::LoadKid(uint32_t PageObjNum,
+                                     CPDF_Object* pKidObj,
+                                     CPDF_StructKid* pKid) {
+  pKid->m_Type = CPDF_StructKid::Invalid;
+  if (!pKidObj)
+    return;
+
+  if (pKidObj->IsNumber()) {
+    if (m_pTree->m_pPage && m_pTree->m_pPage->GetObjNum() != PageObjNum) {
+      return;
+    }
+    pKid->m_Type = CPDF_StructKid::PageContent;
+    pKid->m_PageContent.m_ContentId = pKidObj->GetInteger();
+    pKid->m_PageContent.m_PageObjNum = PageObjNum;
+    return;
+  }
+
+  CPDF_Dictionary* pKidDict = pKidObj->AsDictionary();
+  if (!pKidDict)
+    return;
+
+  if (CPDF_Reference* pRef = ToReference(pKidDict->GetObjectBy("Pg")))
+    PageObjNum = pRef->GetRefObjNum();
+
+  CFX_ByteString type = pKidDict->GetStringBy("Type");
+  if (type == "MCR") {
+    if (m_pTree->m_pPage && m_pTree->m_pPage->GetObjNum() != PageObjNum) {
+      return;
+    }
+    pKid->m_Type = CPDF_StructKid::StreamContent;
+    if (CPDF_Reference* pRef = ToReference(pKidDict->GetObjectBy("Stm"))) {
+      pKid->m_StreamContent.m_RefObjNum = pRef->GetRefObjNum();
+    } else {
+      pKid->m_StreamContent.m_RefObjNum = 0;
+    }
+    pKid->m_StreamContent.m_PageObjNum = PageObjNum;
+    pKid->m_StreamContent.m_ContentId = pKidDict->GetIntegerBy("MCID");
+  } else if (type == "OBJR") {
+    if (m_pTree->m_pPage && m_pTree->m_pPage->GetObjNum() != PageObjNum) {
+      return;
+    }
+    pKid->m_Type = CPDF_StructKid::Object;
+    if (CPDF_Reference* pObj = ToReference(pKidDict->GetObjectBy("Obj"))) {
+      pKid->m_Object.m_RefObjNum = pObj->GetRefObjNum();
+    } else {
+      pKid->m_Object.m_RefObjNum = 0;
+    }
+    pKid->m_Object.m_PageObjNum = PageObjNum;
+  } else {
+    pKid->m_Type = CPDF_StructKid::Element;
+    pKid->m_Element.m_pDict = pKidDict;
+    if (!m_pTree->m_pPage) {
+      pKid->m_Element.m_pElement =
+          new CPDF_StructElementImpl(m_pTree, this, pKidDict);
+    } else {
+      pKid->m_Element.m_pElement = nullptr;
+    }
+  }
+}
+static CPDF_Dictionary* FindAttrDict(CPDF_Object* pAttrs,
+                                     const CFX_ByteStringC& owner,
+                                     FX_FLOAT nLevel = 0.0F) {
+  if (nLevel > nMaxRecursion)
+    return nullptr;
+  if (!pAttrs)
+    return nullptr;
+
+  CPDF_Dictionary* pDict = nullptr;
+  if (pAttrs->IsDictionary()) {
+    pDict = pAttrs->AsDictionary();
+  } else if (CPDF_Stream* pStream = pAttrs->AsStream()) {
+    pDict = pStream->GetDict();
+  } else if (CPDF_Array* pArray = pAttrs->AsArray()) {
+    for (uint32_t i = 0; i < pArray->GetCount(); i++) {
+      CPDF_Object* pElement = pArray->GetDirectObjectAt(i);
+      pDict = FindAttrDict(pElement, owner, nLevel + 1);
+      if (pDict)
+        return pDict;
+    }
+  }
+  if (pDict && pDict->GetStringBy("O") == owner)
+    return pDict;
+  return nullptr;
+}
+CPDF_Object* CPDF_StructElementImpl::GetAttr(const CFX_ByteStringC& owner,
+                                             const CFX_ByteStringC& name,
+                                             FX_BOOL bInheritable,
+                                             FX_FLOAT fLevel) {
+  if (fLevel > nMaxRecursion) {
+    return nullptr;
+  }
+  if (bInheritable) {
+    CPDF_Object* pAttr = GetAttr(owner, name, FALSE);
+    if (pAttr) {
+      return pAttr;
+    }
+    if (!m_pParent) {
+      return nullptr;
+    }
+    return m_pParent->GetAttr(owner, name, TRUE, fLevel + 1);
+  }
+  CPDF_Object* pA = m_pDict->GetDirectObjectBy("A");
+  if (pA) {
+    CPDF_Dictionary* pAttrDict = FindAttrDict(pA, owner);
+    if (pAttrDict) {
+      CPDF_Object* pAttr = pAttrDict->GetDirectObjectBy(CFX_ByteString(name));
+      if (pAttr) {
+        return pAttr;
+      }
+    }
+  }
+  CPDF_Object* pC = m_pDict->GetDirectObjectBy("C");
+  if (!pC)
+    return nullptr;
+
+  CPDF_Dictionary* pClassMap = m_pTree->m_pTreeRoot->GetDictBy("ClassMap");
+  if (!pClassMap)
+    return nullptr;
+
+  if (CPDF_Array* pArray = pC->AsArray()) {
+    for (uint32_t i = 0; i < pArray->GetCount(); i++) {
+      CFX_ByteString class_name = pArray->GetStringAt(i);
+      CPDF_Dictionary* pClassDict = pClassMap->GetDictBy(class_name);
+      if (pClassDict && pClassDict->GetStringBy("O") == owner)
+        return pClassDict->GetDirectObjectBy(CFX_ByteString(name));
+    }
+    return nullptr;
+  }
+  CFX_ByteString class_name = pC->GetString();
+  CPDF_Dictionary* pClassDict = pClassMap->GetDictBy(class_name);
+  if (pClassDict && pClassDict->GetStringBy("O") == owner)
+    return pClassDict->GetDirectObjectBy(CFX_ByteString(name));
+  return nullptr;
+}
+CPDF_Object* CPDF_StructElementImpl::GetAttr(const CFX_ByteStringC& owner,
+                                             const CFX_ByteStringC& name,
+                                             FX_BOOL bInheritable,
+                                             int subindex) {
+  CPDF_Object* pAttr = GetAttr(owner, name, bInheritable);
+  CPDF_Array* pArray = ToArray(pAttr);
+  if (!pArray || subindex == -1)
+    return pAttr;
+
+  if (subindex >= static_cast<int>(pArray->GetCount()))
+    return pAttr;
+  return pArray->GetDirectObjectAt(subindex);
+}
+CFX_ByteString CPDF_StructElementImpl::GetName(
+    const CFX_ByteStringC& owner,
+    const CFX_ByteStringC& name,
+    const CFX_ByteStringC& default_value,
+    FX_BOOL bInheritable,
+    int subindex) {
+  CPDF_Object* pAttr = GetAttr(owner, name, bInheritable, subindex);
+  if (ToName(pAttr))
+    return pAttr->GetString();
+  return CFX_ByteString(default_value);
+}
+
+FX_ARGB CPDF_StructElementImpl::GetColor(const CFX_ByteStringC& owner,
+                                         const CFX_ByteStringC& name,
+                                         FX_ARGB default_value,
+                                         FX_BOOL bInheritable,
+                                         int subindex) {
+  CPDF_Array* pArray = ToArray(GetAttr(owner, name, bInheritable, subindex));
+  if (!pArray)
+    return default_value;
+  return 0xff000000 | ((int)(pArray->GetNumberAt(0) * 255) << 16) |
+         ((int)(pArray->GetNumberAt(1) * 255) << 8) |
+         (int)(pArray->GetNumberAt(2) * 255);
+}
+FX_FLOAT CPDF_StructElementImpl::GetNumber(const CFX_ByteStringC& owner,
+                                           const CFX_ByteStringC& name,
+                                           FX_FLOAT default_value,
+                                           FX_BOOL bInheritable,
+                                           int subindex) {
+  CPDF_Object* pAttr = GetAttr(owner, name, bInheritable, subindex);
+  return ToNumber(pAttr) ? pAttr->GetNumber() : default_value;
+}
+int CPDF_StructElementImpl::GetInteger(const CFX_ByteStringC& owner,
+                                       const CFX_ByteStringC& name,
+                                       int default_value,
+                                       FX_BOOL bInheritable,
+                                       int subindex) {
+  CPDF_Object* pAttr = GetAttr(owner, name, bInheritable, subindex);
+  return ToNumber(pAttr) ? pAttr->GetInteger() : default_value;
+}
diff --git a/core/fpdfdoc/include/fpdf_tagged.h b/core/fpdfdoc/include/fpdf_tagged.h
new file mode 100644
index 0000000000..43d69e8db9
--- /dev/null
+++ b/core/fpdfdoc/include/fpdf_tagged.h
@@ -0,0 +1,93 @@
+// Copyright 2014 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
+
+#ifndef CORE_FPDFDOC_INCLUDE_FPDF_TAGGED_H_
+#define CORE_FPDFDOC_INCLUDE_FPDF_TAGGED_H_
+
+#include "core/fxge/include/fx_dib.h"
+
+class CPDF_Dictionary;
+class CPDF_Document;
+class IPDF_StructElement;
+
+class IPDF_StructTree {
+ public:
+  static IPDF_StructTree* LoadDoc(const CPDF_Document* pDoc);
+  static IPDF_StructTree* LoadPage(const CPDF_Document* pDoc,
+                                   const CPDF_Dictionary* pPageDict);
+
+  virtual ~IPDF_StructTree() {}
+
+  virtual int CountTopElements() const = 0;
+  virtual IPDF_StructElement* GetTopElement(int i) const = 0;
+};
+
+struct CPDF_StructKid {
+  enum { Invalid, Element, PageContent, StreamContent, Object } m_Type;
+
+  union {
+    struct {
+      IPDF_StructElement* m_pElement;
+      CPDF_Dictionary* m_pDict;
+    } m_Element;
+    struct {
+      uint32_t m_PageObjNum;
+      uint32_t m_ContentId;
+    } m_PageContent;
+    struct {
+      uint32_t m_PageObjNum;
+      uint32_t m_ContentId;
+      uint32_t m_RefObjNum;
+    } m_StreamContent;
+    struct {
+      uint32_t m_PageObjNum;
+      uint32_t m_RefObjNum;
+    } m_Object;
+  };
+};
+
+class IPDF_StructElement {
+ public:
+  virtual ~IPDF_StructElement() {}
+
+  virtual IPDF_StructTree* GetTree() const = 0;
+  virtual const CFX_ByteString& GetType() const = 0;
+  virtual IPDF_StructElement* GetParent() const = 0;
+  virtual CPDF_Dictionary* GetDict() const = 0;
+  virtual int CountKids() const = 0;
+  virtual const CPDF_StructKid& GetKid(int index) const = 0;
+
+  virtual CPDF_Object* GetAttr(const CFX_ByteStringC& owner,
+                               const CFX_ByteStringC& name,
+                               FX_BOOL bInheritable = FALSE,
+                               FX_FLOAT fLevel = 0.0F) = 0;
+
+  virtual CFX_ByteString GetName(const CFX_ByteStringC& owner,
+                                 const CFX_ByteStringC& name,
+                                 const CFX_ByteStringC& default_value,
+                                 FX_BOOL bInheritable = FALSE,
+                                 int subindex = -1) = 0;
+
+  virtual FX_ARGB GetColor(const CFX_ByteStringC& owner,
+                           const CFX_ByteStringC& name,
+                           FX_ARGB default_value,
+                           FX_BOOL bInheritable = FALSE,
+                           int subindex = -1) = 0;
+
+  virtual FX_FLOAT GetNumber(const CFX_ByteStringC& owner,
+                             const CFX_ByteStringC& name,
+                             FX_FLOAT default_value,
+                             FX_BOOL bInheritable = FALSE,
+                             int subindex = -1) = 0;
+
+  virtual int GetInteger(const CFX_ByteStringC& owner,
+                         const CFX_ByteStringC& name,
+                         int default_value,
+                         FX_BOOL bInheritable = FALSE,
+                         int subindex = -1) = 0;
+};
+
+#endif  // CORE_FPDFDOC_INCLUDE_FPDF_TAGGED_H_
diff --git a/core/fpdfdoc/tagged_int.h b/core/fpdfdoc/tagged_int.h
new file mode 100644
index 0000000000..354a93cb76
--- /dev/null
+++ b/core/fpdfdoc/tagged_int.h
@@ -0,0 +1,107 @@
+// Copyright 2014 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
+
+#ifndef CORE_FPDFDOC_TAGGED_INT_H_
+#define CORE_FPDFDOC_TAGGED_INT_H_
+
+#include <map>
+#include <memory>
+#include <vector>
+
+#include "core/fpdfdoc/include/fpdf_tagged.h"
+#include "core/fxcrt/include/cfx_retain_ptr.h"
+#include "third_party/base/stl_util.h"
+
+class CPDF_StructElementImpl;
+
+class CPDF_StructTreeImpl final : public IPDF_StructTree {
+ public:
+  explicit CPDF_StructTreeImpl(const CPDF_Document* pDoc);
+  ~CPDF_StructTreeImpl() override;
+
+  // IPDF_StructTree:
+  int CountTopElements() const override;
+  IPDF_StructElement* GetTopElement(int i) const override;
+
+  void LoadDocTree();
+  void LoadPageTree(const CPDF_Dictionary* pPageDict);
+  CPDF_StructElementImpl* AddPageNode(
+      CPDF_Dictionary* pElement,
+      std::map<CPDF_Dictionary*, CPDF_StructElementImpl*>& map,
+      int nLevel = 0);
+  FX_BOOL AddTopLevelNode(CPDF_Dictionary* pDict,
+                          CPDF_StructElementImpl* pElement);
+
+ protected:
+  const CPDF_Dictionary* const m_pTreeRoot;
+  const CPDF_Dictionary* const m_pRoleMap;
+  const CPDF_Dictionary* m_pPage;
+  std::vector<CFX_RetainPtr<CPDF_StructElementImpl>> m_Kids;
+
+  friend class CPDF_StructElementImpl;
+};
+
+class CPDF_StructElementImpl final : public IPDF_StructElement {
+ public:
+  CPDF_StructElementImpl(CPDF_StructTreeImpl* pTree,
+                         CPDF_StructElementImpl* pParent,
+                         CPDF_Dictionary* pDict);
+
+  // IPDF_StructElement
+  IPDF_StructTree* GetTree() const override;
+  const CFX_ByteString& GetType() const override;
+  IPDF_StructElement* GetParent() const override;
+  CPDF_Dictionary* GetDict() const override;
+  int CountKids() const override;
+  const CPDF_StructKid& GetKid(int index) const override;
+  CPDF_Object* GetAttr(const CFX_ByteStringC& owner,
+                       const CFX_ByteStringC& name,
+                       FX_BOOL bInheritable = FALSE,
+                       FX_FLOAT fLevel = 0.0F) override;
+  CFX_ByteString GetName(const CFX_ByteStringC& owner,
+                         const CFX_ByteStringC& name,
+                         const CFX_ByteStringC& default_value,
+                         FX_BOOL bInheritable = FALSE,
+                         int subindex = -1) override;
+  FX_ARGB GetColor(const CFX_ByteStringC& owner,
+                   const CFX_ByteStringC& name,
+                   FX_ARGB default_value,
+                   FX_BOOL bInheritable = FALSE,
+                   int subindex = -1) override;
+  FX_FLOAT GetNumber(const CFX_ByteStringC& owner,
+                     const CFX_ByteStringC& name,
+                     FX_FLOAT default_value,
+                     FX_BOOL bInheritable = FALSE,
+                     int subindex = -1) override;
+  int GetInteger(const CFX_ByteStringC& owner,
+                 const CFX_ByteStringC& name,
+                 int default_value,
+                 FX_BOOL bInheritable = FALSE,
+                 int subindex = -1) override;
+
+  void LoadKids(CPDF_Dictionary* pDict);
+  void LoadKid(uint32_t PageObjNum, CPDF_Object* pObj, CPDF_StructKid* pKid);
+  CPDF_Object* GetAttr(const CFX_ByteStringC& owner,
+                       const CFX_ByteStringC& name,
+                       FX_BOOL bInheritable,
+                       int subindex);
+  CPDF_StructElementImpl* Retain();
+  void Release();
+
+ protected:
+  ~CPDF_StructElementImpl() override;
+
+  int m_RefCount;
+  CPDF_StructTreeImpl* const m_pTree;
+  CPDF_StructElementImpl* const m_pParent;
+  CPDF_Dictionary* const m_pDict;
+  CFX_ByteString m_Type;
+  std::vector<CPDF_StructKid> m_Kids;
+
+  friend class CPDF_StructTreeImpl;
+};
+
+#endif  // CORE_FPDFDOC_TAGGED_INT_H_
diff --git a/pdfium.gyp b/pdfium.gyp
index 87c4fc6b4a..658d2dde74 100644
--- a/pdfium.gyp
+++ b/pdfium.gyp
@@ -253,6 +253,7 @@
         'core/fpdfdoc/csection.h',
         'core/fpdfdoc/ctypeset.cpp',
         'core/fpdfdoc/ctypeset.h',
+        'core/fpdfdoc/doc_tagged.cpp',
         'core/fpdfdoc/include/cpdf_aaction.h',
         'core/fpdfdoc/include/cpdf_action.h',
         'core/fpdfdoc/include/cpdf_actionfields.h',
@@ -282,9 +283,11 @@
         'core/fpdfdoc/include/cpvt_wordplace.h',
         'core/fpdfdoc/include/cpvt_wordprops.h',
         'core/fpdfdoc/include/cpvt_wordrange.h',
+        'core/fpdfdoc/include/fpdf_tagged.h',
         'core/fpdfdoc/include/ipvt_fontmap.h',
         'core/fpdfdoc/include/ipdf_formnotify.h',
         'core/fpdfdoc/ipdf_formnotify.cpp',
+        'core/fpdfdoc/tagged_int.h',
       ],
     },
     {