Split CPDF_PageObjectHolder off from CPDF_PageObjectList

Eventually, we're going to expose an iterator over
CPDF_PageObjectList that we don't want to be inherited by
the CPDF_PageObjectHolder sub-classes: page and form.

Also, the operations that the object holder performs dealing
with inquiring about masks and such seem beyond the scope of
what a list would provide.  Hence the "Holder" name.

R=thestig@chromium.org

Review URL: https://codereview.chromium.org/1701073002 .

16 files changed, 119 insertions, 141 deletions

diff --git a/core/include/fpdfapi/fpdf_module.h b/core/include/fpdfapi/fpdf_module.h
index 6888e81000..4856184932 100644
--- a/core/include/fpdfapi/fpdf_module.h
+++ b/core/include/fpdfapi/fpdf_module.h
@@ -24,7 +24,6 @@ class CPDF_Document;
 class CPDF_FontGlobals;
 class CPDF_Image;
 class CPDF_Page;
-class CPDF_PageObjectList;
 class CPDF_PageRenderCache;
 class CPDF_RenderOptions;
 class CPDF_Stream;
diff --git a/core/include/fpdfapi/fpdf_page.h b/core/include/fpdfapi/fpdf_page.h
index 20030e7dea..fb951280a2 100644
--- a/core/include/fpdfapi/fpdf_page.h
+++ b/core/include/fpdfapi/fpdf_page.h
@@ -22,50 +22,46 @@ class CPDF_StreamFilter;
 class CPDF_AllStates;
 class CPDF_ContentParser;
 class CPDF_StreamContentParser;
+
 #define PDFTRANS_GROUP 0x0100
 #define PDFTRANS_ISOLATED 0x0200
 #define PDFTRANS_KNOCKOUT 0x0400
 
-class CPDF_PageObjectList {
+class CPDF_PageObjectList : public CFX_PtrList {
  public:
-  CPDF_PageObjectList();
-  ~CPDF_PageObjectList();
-
-  void ContinueParse(IFX_Pause* pPause);
-
-  FX_BOOL IsParsed() const { return m_ParseState == CONTENT_PARSED; }
-
-  FX_POSITION GetFirstObjectPosition() const {
-    return m_ObjectList.GetHeadPosition();
-  }
-
-  FX_POSITION GetLastObjectPosition() const {
-    return m_ObjectList.GetTailPosition();
-  }
+  explicit CPDF_PageObjectList(int nBlockSize) : CFX_PtrList(nBlockSize) {}
 
   CPDF_PageObject* GetNextObject(FX_POSITION& pos) const {
-    return (CPDF_PageObject*)m_ObjectList.GetNext(pos);
+    return static_cast<CPDF_PageObject*>(GetNext(pos));
   }
 
   CPDF_PageObject* GetPrevObject(FX_POSITION& pos) const {
-    return (CPDF_PageObject*)m_ObjectList.GetPrev(pos);
+    return static_cast<CPDF_PageObject*>(GetPrev(pos));
   }
 
   CPDF_PageObject* GetObjectAt(FX_POSITION pos) const {
-    return (CPDF_PageObject*)m_ObjectList.GetAt(pos);
+    return static_cast<CPDF_PageObject*>(GetAt(pos));
   }
 
-  void AddTail(CPDF_PageObject* obj) { m_ObjectList.AddTail(obj); }
-  FX_DWORD CountObjects() const { return m_ObjectList.GetCount(); }
-
-  int GetObjectIndex(CPDF_PageObject* pObj) const;
-
+  // Linear complexity, to be avoided except as needed by public APIs.
   CPDF_PageObject* GetObjectByIndex(int index) const;
 
   FX_POSITION InsertObject(FX_POSITION posInsertAfter,
                            CPDF_PageObject* pNewObject);
+};
 
-  void Transform(const CFX_Matrix& matrix);
+class CPDF_PageObjectHolder {
+ public:
+  CPDF_PageObjectHolder();
+  ~CPDF_PageObjectHolder();
+
+  void ContinueParse(IFX_Pause* pPause);
+  FX_BOOL IsParsed() const { return m_ParseState == CONTENT_PARSED; }
+
+  CPDF_PageObjectList* GetPageObjectList() { return &m_PageObjectList; }
+  const CPDF_PageObjectList* GetPageObjectList() const {
+    return &m_PageObjectList;
+  }
 
   FX_BOOL BackgroundAlphaNeeded() const { return m_bBackgroundAlphaNeeded; }
   void SetBackgroundAlphaNeeded(FX_BOOL needed) {
@@ -74,6 +70,8 @@ class CPDF_PageObjectList {
 
   FX_BOOL HasImageMask() const { return m_bHasImageMask; }
   void SetHasImageMask(FX_BOOL value) { m_bHasImageMask = value; }
+
+  void Transform(const CFX_Matrix& matrix);
   CFX_FloatRect CalcBoundingBox() const;
 
   CPDF_Dictionary* m_pFormDict;
@@ -93,10 +91,10 @@ class CPDF_PageObjectList {
   FX_BOOL m_bHasImageMask;
   ParseState m_ParseState;
   std::unique_ptr<CPDF_ContentParser> m_pParser;
-  CFX_PtrList m_ObjectList;
+  CPDF_PageObjectList m_PageObjectList;
 };
 
-class CPDF_Page : public CPDF_PageObjectList, public CFX_PrivateData {
+class CPDF_Page : public CPDF_PageObjectHolder, public CFX_PrivateData {
  public:
   CPDF_Page();
   ~CPDF_Page();
@@ -142,7 +140,7 @@ class CPDF_ParseOptions {
 
   FX_BOOL m_bDecodeInlineImage;
 };
-class CPDF_Form : public CPDF_PageObjectList {
+class CPDF_Form : public CPDF_PageObjectHolder {
  public:
   CPDF_Form(CPDF_Document* pDocument,
             CPDF_Dictionary* pPageResources,
diff --git a/core/include/fpdfapi/fpdf_render.h b/core/include/fpdfapi/fpdf_render.h
index ec5d151914..fc0f68afe8 100644
--- a/core/include/fpdfapi/fpdf_render.h
+++ b/core/include/fpdfapi/fpdf_render.h
@@ -74,7 +74,7 @@ class CPDF_RenderContext {
  public:
   class Layer {
    public:
-    CPDF_PageObjectList* m_pObjectList;
+    CPDF_PageObjectHolder* m_pObjectHolder;
     CFX_Matrix m_Matrix;
   };
 
@@ -82,7 +82,7 @@ class CPDF_RenderContext {
   CPDF_RenderContext(CPDF_Document* pDoc, CPDF_PageRenderCache* pPageCache);
   ~CPDF_RenderContext();
 
-  void AppendLayer(CPDF_PageObjectList* pObjectList,
+  void AppendLayer(CPDF_PageObjectHolder* pObjectHolder,
                    const CFX_Matrix* pObject2Device);
 
   void Render(CFX_RenderDevice* pDevice,
diff --git a/core/include/fpdftext/fpdf_text.h b/core/include/fpdftext/fpdf_text.h
index 140fe90bf7..498b6235c3 100644
--- a/core/include/fpdftext/fpdf_text.h
+++ b/core/include/fpdftext/fpdf_text.h
@@ -10,7 +10,6 @@
 #include "core/include/fpdfapi/fpdf_parser.h"
 
 class CPDF_Page;
-class CPDF_PageObjectList;
 class CPDF_TextObject;
 class IPDF_LinkExtract;
 class IPDF_ReflowedPage;
@@ -50,7 +49,7 @@ class IPDF_TextPage {
   static IPDF_TextPage* CreateReflowTextPage(IPDF_ReflowedPage* pRefPage);
   virtual ~IPDF_TextPage() {}
 
-  virtual FX_BOOL ParseTextPage() = 0;
+  virtual void ParseTextPage() = 0;
   virtual bool IsParsed() const = 0;
   virtual int CharIndexFromTextIndex(int TextIndex) const = 0;
   virtual int TextIndexFromCharIndex(int CharIndex) const = 0;
diff --git a/core/src/fpdfapi/fpdf_edit/fpdf_edit_content.cpp b/core/src/fpdfapi/fpdf_edit/fpdf_edit_content.cpp
index 555de449fa..82ab370564 100644
--- a/core/src/fpdfapi/fpdf_edit/fpdf_edit_content.cpp
+++ b/core/src/fpdfapi/fpdf_edit/fpdf_edit_content.cpp
@@ -20,9 +20,9 @@ CPDF_PageContentGenerator::CPDF_PageContentGenerator(CPDF_Page* pPage)
   if (m_pPage) {
     m_pDocument = m_pPage->m_pDocument;
   }
-  FX_POSITION pos = pPage->GetFirstObjectPosition();
+  FX_POSITION pos = pPage->GetPageObjectList()->GetHeadPosition();
   while (pos) {
-    InsertPageObject(pPage->GetNextObject(pos));
+    InsertPageObject(pPage->GetPageObjectList()->GetNextObject(pos));
   }
 }
 CPDF_PageContentGenerator::~CPDF_PageContentGenerator() {}
diff --git a/core/src/fpdfapi/fpdf_font/fpdf_font.cpp b/core/src/fpdfapi/fpdf_font/fpdf_font.cpp
index e3d75076d7..ec86a60d6f 100644
--- a/core/src/fpdfapi/fpdf_font/fpdf_font.cpp
+++ b/core/src/fpdfapi/fpdf_font/fpdf_font.cpp
@@ -1706,7 +1706,7 @@ CPDF_Type3Char* CPDF_Type3Font::LoadChar(FX_DWORD charcode, int level) {
   ASSERT(!pdfium::ContainsKey(m_CacheMap, charcode));
   CPDF_Type3Char* pCachedChar = pNewChar.release();
   m_CacheMap[charcode] = pCachedChar;
-  if (pCachedChar->m_pForm->CountObjects() == 0) {
+  if (pCachedChar->m_pForm->GetPageObjectList()->GetCount() == 0) {
     delete pCachedChar->m_pForm;
     pCachedChar->m_pForm = nullptr;
   }
diff --git a/core/src/fpdfapi/fpdf_page/fpdf_page.cpp b/core/src/fpdfapi/fpdf_page/fpdf_page.cpp
index c4a26e9921..1a81e1b901 100644
--- a/core/src/fpdfapi/fpdf_page/fpdf_page.cpp
+++ b/core/src/fpdfapi/fpdf_page/fpdf_page.cpp
@@ -670,7 +670,7 @@ void CPDF_FormObject::CalcBoundingBox() {
   m_Right = form_rect.right;
   m_Top = form_rect.top;
 }
-CPDF_PageObjectList::CPDF_PageObjectList()
+CPDF_PageObjectHolder::CPDF_PageObjectHolder()
     : m_pFormDict(nullptr),
       m_pFormStream(nullptr),
       m_pDocument(nullptr),
@@ -680,14 +680,15 @@ CPDF_PageObjectList::CPDF_PageObjectList()
       m_bBackgroundAlphaNeeded(FALSE),
       m_bHasImageMask(FALSE),
       m_ParseState(CONTENT_NOT_PARSED),
-      m_ObjectList(128) {}
-CPDF_PageObjectList::~CPDF_PageObjectList() {
-  FX_POSITION pos = m_ObjectList.GetHeadPosition();
+      m_PageObjectList(128) {}
+
+CPDF_PageObjectHolder::~CPDF_PageObjectHolder() {
+  FX_POSITION pos = m_PageObjectList.GetHeadPosition();
   while (pos) {
-    delete (CPDF_PageObject*)m_ObjectList.GetNext(pos);
+    delete m_PageObjectList.GetNextObject(pos);
   }
 }
-void CPDF_PageObjectList::ContinueParse(IFX_Pause* pPause) {
+void CPDF_PageObjectHolder::ContinueParse(IFX_Pause* pPause) {
   if (!m_pParser) {
     return;
   }
@@ -700,43 +701,30 @@ void CPDF_PageObjectList::ContinueParse(IFX_Pause* pPause) {
 FX_POSITION CPDF_PageObjectList::InsertObject(FX_POSITION posInsertAfter,
                                               CPDF_PageObject* pNewObject) {
   if (!posInsertAfter) {
-    return m_ObjectList.AddHead(pNewObject);
-  }
-  return m_ObjectList.InsertAfter(posInsertAfter, pNewObject);
-}
-int CPDF_PageObjectList::GetObjectIndex(CPDF_PageObject* pObj) const {
-  int index = 0;
-  FX_POSITION pos = m_ObjectList.GetHeadPosition();
-  while (pos) {
-    CPDF_PageObject* pThisObj = (CPDF_PageObject*)m_ObjectList.GetNext(pos);
-    if (pThisObj == pObj) {
-      return index;
-    }
-    index++;
+    return AddHead(pNewObject);
   }
-  return -1;
+  return InsertAfter(posInsertAfter, pNewObject);
 }
 CPDF_PageObject* CPDF_PageObjectList::GetObjectByIndex(int index) const {
-  FX_POSITION pos = m_ObjectList.FindIndex(index);
-  return pos ? static_cast<CPDF_PageObject*>(m_ObjectList.GetAt(pos)) : nullptr;
+  FX_POSITION pos = FindIndex(index);
+  return pos ? GetObjectAt(pos) : nullptr;
 }
-void CPDF_PageObjectList::Transform(const CFX_Matrix& matrix) {
-  FX_POSITION pos = m_ObjectList.GetHeadPosition();
+void CPDF_PageObjectHolder::Transform(const CFX_Matrix& matrix) {
+  FX_POSITION pos = m_PageObjectList.GetHeadPosition();
   while (pos) {
-    CPDF_PageObject* pObj = (CPDF_PageObject*)m_ObjectList.GetNext(pos);
-    pObj->Transform(matrix);
+    m_PageObjectList.GetNextObject(pos)->Transform(matrix);
   }
 }
-CFX_FloatRect CPDF_PageObjectList::CalcBoundingBox() const {
-  if (m_ObjectList.GetCount() == 0) {
+CFX_FloatRect CPDF_PageObjectHolder::CalcBoundingBox() const {
+  if (m_PageObjectList.GetCount() == 0) {
     return CFX_FloatRect(0, 0, 0, 0);
   }
   FX_FLOAT left, right, top, bottom;
   left = bottom = 1000000 * 1.0f;
   right = top = -1000000 * 1.0f;
-  FX_POSITION pos = m_ObjectList.GetHeadPosition();
+  FX_POSITION pos = m_PageObjectList.GetHeadPosition();
   while (pos) {
-    CPDF_PageObject* pObj = (CPDF_PageObject*)m_ObjectList.GetNext(pos);
+    CPDF_PageObject* pObj = (CPDF_PageObject*)m_PageObjectList.GetNext(pos);
     if (left > pObj->m_Left) {
       left = pObj->m_Left;
     }
@@ -752,7 +740,7 @@ CFX_FloatRect CPDF_PageObjectList::CalcBoundingBox() const {
   }
   return CFX_FloatRect(left, bottom, right, top);
 }
-void CPDF_PageObjectList::LoadTransInfo() {
+void CPDF_PageObjectHolder::LoadTransInfo() {
   if (!m_pFormDict) {
     return;
   }
@@ -926,10 +914,10 @@ void CPDF_Form::ParseContent(CPDF_AllStates* pGraphicStates,
 CPDF_Form* CPDF_Form::Clone() const {
   CPDF_Form* pClone =
       new CPDF_Form(m_pDocument, m_pPageResources, m_pFormStream, m_pResources);
-  FX_POSITION pos = m_ObjectList.GetHeadPosition();
+  FX_POSITION pos = m_PageObjectList.GetHeadPosition();
   while (pos) {
-    CPDF_PageObject* pObj = (CPDF_PageObject*)m_ObjectList.GetNext(pos);
-    pClone->m_ObjectList.AddTail(pObj->Clone());
+    CPDF_PageObject* pObj = (CPDF_PageObject*)m_PageObjectList.GetNext(pos);
+    pClone->m_PageObjectList.AddTail(pObj->Clone());
   }
   return pClone;
 }
diff --git a/core/src/fpdfapi/fpdf_page/fpdf_page_graph_state.cpp b/core/src/fpdfapi/fpdf_page/fpdf_page_graph_state.cpp
index 20345138b4..a003d2047f 100644
--- a/core/src/fpdfapi/fpdf_page/fpdf_page_graph_state.cpp
+++ b/core/src/fpdfapi/fpdf_page/fpdf_page_graph_state.cpp
@@ -520,7 +520,7 @@ void CPDF_AllStates::ProcessExtGS(CPDF_Dictionary* pGS,
 
         pGeneralState->SetBlendMode(mode);
         if (pGeneralState->m_BlendType > FXDIB_BLEND_MULTIPLY) {
-          pParser->GetObjectList()->SetBackgroundAlphaNeeded(TRUE);
+          pParser->GetPageObjectHolder()->SetBackgroundAlphaNeeded(TRUE);
         }
         break;
       }
diff --git a/core/src/fpdfapi/fpdf_page/fpdf_page_parser.cpp b/core/src/fpdfapi/fpdf_page/fpdf_page_parser.cpp
index 7f242fdb0e..6e02cb11b4 100644
--- a/core/src/fpdfapi/fpdf_page/fpdf_page_parser.cpp
+++ b/core/src/fpdfapi/fpdf_page/fpdf_page_parser.cpp
@@ -114,7 +114,7 @@ CPDF_StreamContentParser::CPDF_StreamContentParser(
     CPDF_Dictionary* pPageResources,
     CPDF_Dictionary* pParentResources,
     CFX_Matrix* pmtContentToUser,
-    CPDF_PageObjectList* pObjList,
+    CPDF_PageObjectHolder* pObjHolder,
     CPDF_Dictionary* pResources,
     CPDF_Rect* pBBox,
     CPDF_ParseOptions* pOptions,
@@ -124,7 +124,7 @@ CPDF_StreamContentParser::CPDF_StreamContentParser(
       m_pPageResources(pPageResources),
       m_pParentResources(pParentResources),
       m_pResources(pResources),
-      m_pObjectList(pObjList),
+      m_pObjectHolder(pObjHolder),
       m_Level(level),
       m_ParamStartPos(0),
       m_ParamCount(0),
@@ -738,8 +738,8 @@ void CPDF_StreamContentParser::Handle_ExecuteXObject() {
     CPDF_ImageObject* pObj = AddImage(pXObject, NULL, FALSE);
     m_LastImageName = name;
     m_pLastImage = pObj->m_pImage;
-    if (!m_pObjectList->HasImageMask())
-      m_pObjectList->SetHasImageMask(m_pLastImage->IsMask());
+    if (!m_pObjectHolder->HasImageMask())
+      m_pObjectHolder->SetHasImageMask(m_pLastImage->IsMask());
   } else if (type == "Form") {
     AddForm(pXObject);
   } else {
@@ -764,7 +764,7 @@ void CPDF_StreamContentParser::AddForm(CPDF_Stream* pStream) {
       form_bbox.Transform(&form_matrix);
     }
     CPDF_StreamContentParser parser(m_pDocument, m_pPageResources, m_pResources,
-                                    &m_mtContentToUser, m_pObjectList,
+                                    &m_mtContentToUser, m_pObjectHolder,
                                     pResources, &form_bbox, &m_Options,
                                     m_pCurStates.get(), m_Level + 1);
     parser.m_pCurStates->m_CTM = form_matrix;
@@ -791,13 +791,13 @@ void CPDF_StreamContentParser::AddForm(CPDF_Stream* pStream) {
   status.m_ColorState = m_pCurStates->m_ColorState;
   status.m_TextState = m_pCurStates->m_TextState;
   pFormObj->m_pForm->ParseContent(&status, NULL, NULL, &m_Options, m_Level + 1);
-  if (!m_pObjectList->BackgroundAlphaNeeded() &&
+  if (!m_pObjectHolder->BackgroundAlphaNeeded() &&
       pFormObj->m_pForm->BackgroundAlphaNeeded()) {
-    m_pObjectList->SetBackgroundAlphaNeeded(TRUE);
+    m_pObjectHolder->SetBackgroundAlphaNeeded(TRUE);
   }
   pFormObj->CalcBoundingBox();
   SetGraphicStates(pFormObj, TRUE, TRUE, TRUE);
-  m_pObjectList->AddTail(pFormObj);
+  m_pObjectHolder->GetPageObjectList()->AddTail(pFormObj);
 }
 
 CPDF_ImageObject* CPDF_StreamContentParser::AddImage(CPDF_Stream* pStream,
@@ -822,7 +822,7 @@ CPDF_ImageObject* CPDF_StreamContentParser::AddImage(CPDF_Stream* pStream,
   SetGraphicStates(pImageObj, pImageObj->m_pImage->IsMask(), FALSE, FALSE);
   pImageObj->m_Matrix = ImageMatrix;
   pImageObj->CalcBoundingBox();
-  m_pObjectList->AddTail(pImageObj);
+  m_pObjectHolder->GetPageObjectList()->AddTail(pImageObj);
   return pImageObj;
 }
 
@@ -1211,7 +1211,7 @@ void CPDF_StreamContentParser::Handle_ShadeFill() {
   pObj->m_Right = bbox.right;
   pObj->m_Top = bbox.top;
   pObj->m_Bottom = bbox.bottom;
-  m_pObjectList->AddTail(pObj);
+  m_pObjectHolder->GetPageObjectList()->AddTail(pObj);
 }
 
 void CPDF_StreamContentParser::Handle_SetCharSpace() {
@@ -1389,7 +1389,7 @@ void CPDF_StreamContentParser::AddTextObject(CFX_ByteString* pStrs,
     pCopy->Copy(pText);
     m_ClipTextList.Add(pCopy);
   }
-  m_pObjectList->AddTail(pText);
+  m_pObjectHolder->GetPageObjectList()->AddTail(pText);
   if (pKerning && pKerning[nsegs - 1] != 0) {
     if (!pFont->IsVertWriting()) {
       m_pCurStates->m_TextX -=
@@ -1624,7 +1624,7 @@ void CPDF_StreamContentParser::AddPathObject(int FillType, FX_BOOL bStroke) {
     pPathObj->m_Matrix = matrix;
     SetGraphicStates(pPathObj, TRUE, FALSE, TRUE);
     pPathObj->CalcBoundingBox();
-    m_pObjectList->AddTail(pPathObj);
+    m_pObjectHolder->GetPageObjectList()->AddTail(pPathObj);
   }
   if (PathClipType) {
     if (!matrix.IsIdentity()) {
@@ -1641,12 +1641,13 @@ FX_DWORD CPDF_StreamContentParser::Parse(const uint8_t* pData,
   if (m_Level > _FPDF_MAX_FORM_LEVEL_) {
     return dwSize;
   }
-  FX_DWORD InitObjCount = m_pObjectList->CountObjects();
+  FX_DWORD InitObjCount = m_pObjectHolder->GetPageObjectList()->GetCount();
   CPDF_StreamParser syntax(pData, dwSize);
   CPDF_StreamParserAutoClearer auto_clearer(&m_pSyntax, &syntax);
   m_CompatCount = 0;
   while (1) {
-    FX_DWORD cost = m_pObjectList->CountObjects() - InitObjCount;
+    FX_DWORD cost =
+        m_pObjectHolder->GetPageObjectList()->GetCount() - InitObjCount;
     if (max_cost && cost >= max_cost) {
       break;
     }
diff --git a/core/src/fpdfapi/fpdf_page/fpdf_page_parser_old.cpp b/core/src/fpdfapi/fpdf_page/fpdf_page_parser_old.cpp
index 022c170bf0..7fa3286e11 100644
--- a/core/src/fpdfapi/fpdf_page/fpdf_page_parser_old.cpp
+++ b/core/src/fpdfapi/fpdf_page/fpdf_page_parser_old.cpp
@@ -841,10 +841,10 @@ void CPDF_ContentParser::Continue(IFX_Pause* pPause) {
         m_pType3Char->m_BBox.top =
             FXSYS_round(m_pParser->GetType3Data()[5] * 1000);
       }
-      FX_POSITION pos = m_pObjects->GetFirstObjectPosition();
+      FX_POSITION pos = m_pObjects->GetPageObjectList()->GetHeadPosition();
       while (pos) {
         CPDF_PageObject* pObj =
-            (CPDF_PageObject*)m_pObjects->GetNextObject(pos);
+            m_pObjects->GetPageObjectList()->GetNextObject(pos);
         if (pObj->m_ClipPath.IsNull()) {
           continue;
         }
diff --git a/core/src/fpdfapi/fpdf_page/pageint.h b/core/src/fpdfapi/fpdf_page/pageint.h
index 9c8946b721..4df8d6aa9f 100644
--- a/core/src/fpdfapi/fpdf_page/pageint.h
+++ b/core/src/fpdfapi/fpdf_page/pageint.h
@@ -94,7 +94,7 @@ class CPDF_StreamContentParser {
                            CPDF_Dictionary* pPageResources,
                            CPDF_Dictionary* pParentResources,
                            CFX_Matrix* pmtContentToUser,
-                           CPDF_PageObjectList* pObjList,
+                           CPDF_PageObjectHolder* pObjHolder,
                            CPDF_Dictionary* pResources,
                            CFX_FloatRect* pBBox,
                            CPDF_ParseOptions* pOptions,
@@ -102,7 +102,7 @@ class CPDF_StreamContentParser {
                            int level);
   ~CPDF_StreamContentParser();
 
-  CPDF_PageObjectList* GetObjectList() const { return m_pObjectList; }
+  CPDF_PageObjectHolder* GetPageObjectHolder() const { return m_pObjectHolder; }
   CPDF_AllStates* GetCurStates() const { return m_pCurStates.get(); }
   FX_BOOL IsColored() const { return m_bColored; }
   const FX_FLOAT* GetType3Data() const { return m_Type3Data; }
@@ -236,7 +236,7 @@ class CPDF_StreamContentParser {
   CPDF_Dictionary* m_pPageResources;
   CPDF_Dictionary* m_pParentResources;
   CPDF_Dictionary* m_pResources;
-  CPDF_PageObjectList* m_pObjectList;
+  CPDF_PageObjectHolder* m_pObjectHolder;
   int m_Level;
   CFX_Matrix m_mtContentToUser;
   CFX_FloatRect m_BBox;
@@ -298,7 +298,7 @@ class CPDF_ContentParser {
 
   ParseStatus m_Status;
   InternalStage m_InternalStage;
-  CPDF_PageObjectList* m_pObjects;
+  CPDF_PageObjectHolder* m_pObjects;
   FX_BOOL m_bForm;
   CPDF_ParseOptions m_Options;
   CPDF_Type3Char* m_pType3Char;
diff --git a/core/src/fpdfapi/fpdf_render/fpdf_render.cpp b/core/src/fpdfapi/fpdf_render/fpdf_render.cpp
index 0ea941a1e6..0023ee92de 100644
--- a/core/src/fpdfapi/fpdf_render/fpdf_render.cpp
+++ b/core/src/fpdfapi/fpdf_render/fpdf_render.cpp
@@ -237,17 +237,19 @@ FX_BOOL CPDF_RenderStatus::Initialize(CPDF_RenderContext* pContext,
   m_Transparency = transparency;
   return TRUE;
 }
-void CPDF_RenderStatus::RenderObjectList(const CPDF_PageObjectList* pObjs,
-                                         const CFX_Matrix* pObj2Device) {
+void CPDF_RenderStatus::RenderObjectList(
+    const CPDF_PageObjectHolder* pObjectHolder,
+    const CFX_Matrix* pObj2Device) {
   CFX_FloatRect clip_rect = m_pDevice->GetClipBox();
   CFX_Matrix device2object;
   device2object.SetReverse(*pObj2Device);
   device2object.TransformRect(clip_rect);
   int index = 0;
-  FX_POSITION pos = pObjs->GetFirstObjectPosition();
+  FX_POSITION pos = pObjectHolder->GetPageObjectList()->GetHeadPosition();
   while (pos) {
     index++;
-    CPDF_PageObject* pCurObj = pObjs->GetNextObject(pos);
+    CPDF_PageObject* pCurObj =
+        pObjectHolder->GetPageObjectList()->GetNextObject(pos);
     if (pCurObj == m_pStopObj) {
       m_bStopped = TRUE;
       return;
@@ -971,10 +973,10 @@ CPDF_RenderContext::CPDF_RenderContext(CPDF_Document* pDoc,
 
 CPDF_RenderContext::~CPDF_RenderContext() {}
 
-void CPDF_RenderContext::AppendLayer(CPDF_PageObjectList* pObjs,
+void CPDF_RenderContext::AppendLayer(CPDF_PageObjectHolder* pObjectHolder,
                                      const CFX_Matrix* pObject2Device) {
   Layer* pLayer = m_Layers.AddSpace();
-  pLayer->m_pObjectList = pObjs;
+  pLayer->m_pObjectHolder = pObjectHolder;
   if (pObject2Device) {
     pLayer->m_Matrix = *pObject2Device;
   } else {
@@ -999,9 +1001,9 @@ void CPDF_RenderContext::Render(CFX_RenderDevice* pDevice,
       FinalMatrix.Concat(*pLastMatrix);
       CPDF_RenderStatus status;
       status.Initialize(this, pDevice, pLastMatrix, pStopObj, NULL, NULL,
-                        pOptions, pLayer->m_pObjectList->m_Transparency, FALSE,
-                        NULL);
-      status.RenderObjectList(pLayer->m_pObjectList, &FinalMatrix);
+                        pOptions, pLayer->m_pObjectHolder->m_Transparency,
+                        FALSE, NULL);
+      status.RenderObjectList(pLayer->m_pObjectHolder, &FinalMatrix);
       if (status.m_Options.m_Flags & RENDER_LIMITEDIMAGECACHE) {
         m_pPageCache->CacheOptimization(status.m_Options.m_dwLimitCacheSize);
       }
@@ -1012,8 +1014,8 @@ void CPDF_RenderContext::Render(CFX_RenderDevice* pDevice,
     } else {
       CPDF_RenderStatus status;
       status.Initialize(this, pDevice, NULL, pStopObj, NULL, NULL, pOptions,
-                        pLayer->m_pObjectList->m_Transparency, FALSE, NULL);
-      status.RenderObjectList(pLayer->m_pObjectList, &pLayer->m_Matrix);
+                        pLayer->m_pObjectHolder->m_Transparency, FALSE, NULL);
+      status.RenderObjectList(pLayer->m_pObjectHolder, &pLayer->m_Matrix);
       if (status.m_Options.m_Flags & RENDER_LIMITEDIMAGECACHE) {
         m_pPageCache->CacheOptimization(status.m_Options.m_dwLimitCacheSize);
       }
@@ -1064,7 +1066,7 @@ void CPDF_ProgressiveRenderer::Continue(IFX_Pause* pPause) {
       m_pRenderStatus.reset(new CPDF_RenderStatus());
       m_pRenderStatus->Initialize(
           m_pContext, m_pDevice, NULL, NULL, NULL, NULL, m_pOptions,
-          m_pCurrentLayer->m_pObjectList->m_Transparency, FALSE, NULL);
+          m_pCurrentLayer->m_pObjectHolder->m_Transparency, FALSE, NULL);
       m_pDevice->SaveState();
       m_ClipRect = m_pDevice->GetClipBox();
       CFX_Matrix device2object;
@@ -1074,14 +1076,16 @@ void CPDF_ProgressiveRenderer::Continue(IFX_Pause* pPause) {
     FX_POSITION pos;
     if (m_LastObjectRendered) {
       pos = m_LastObjectRendered;
-      m_pCurrentLayer->m_pObjectList->GetNextObject(pos);
+      m_pCurrentLayer->m_pObjectHolder->GetPageObjectList()->GetNextObject(pos);
     } else {
-      pos = m_pCurrentLayer->m_pObjectList->GetFirstObjectPosition();
+      pos = m_pCurrentLayer->m_pObjectHolder->GetPageObjectList()
+                ->GetHeadPosition();
     }
     int nObjsToGo = kStepLimit;
     while (pos) {
       CPDF_PageObject* pCurObj =
-          m_pCurrentLayer->m_pObjectList->GetObjectAt(pos);
+          m_pCurrentLayer->m_pObjectHolder->GetPageObjectList()->GetObjectAt(
+              pos);
       if (pCurObj && pCurObj->m_Left <= m_ClipRect.right &&
           pCurObj->m_Right >= m_ClipRect.left &&
           pCurObj->m_Bottom <= m_ClipRect.top &&
@@ -1108,9 +1112,9 @@ void CPDF_ProgressiveRenderer::Continue(IFX_Pause* pPause) {
           return;
         nObjsToGo = kStepLimit;
       }
-      m_pCurrentLayer->m_pObjectList->GetNextObject(pos);
+      m_pCurrentLayer->m_pObjectHolder->GetPageObjectList()->GetNextObject(pos);
     }
-    if (m_pCurrentLayer->m_pObjectList->IsParsed()) {
+    if (m_pCurrentLayer->m_pObjectHolder->IsParsed()) {
       m_pRenderStatus.reset();
       m_pDevice->RestoreState();
       m_pCurrentLayer = nullptr;
@@ -1120,8 +1124,8 @@ void CPDF_ProgressiveRenderer::Continue(IFX_Pause* pPause) {
         return;
       }
     } else {
-      m_pCurrentLayer->m_pObjectList->ContinueParse(pPause);
-      if (!m_pCurrentLayer->m_pObjectList->IsParsed())
+      m_pCurrentLayer->m_pObjectHolder->ContinueParse(pPause);
+      if (!m_pCurrentLayer->m_pObjectHolder->IsParsed())
         return;
     }
   }
diff --git a/core/src/fpdfapi/fpdf_render/fpdf_render_text.cpp b/core/src/fpdfapi/fpdf_render/fpdf_render_text.cpp
index d0427f68fa..7e2c0bd0fd 100644
--- a/core/src/fpdfapi/fpdf_render/fpdf_render_text.cpp
+++ b/core/src/fpdfapi/fpdf_render/fpdf_render_text.cpp
@@ -316,9 +316,9 @@ FX_BOOL CPDF_Type3Char::LoadBitmap(CPDF_RenderContext* pContext) {
   if (m_pBitmap || !m_pForm) {
     return TRUE;
   }
-  if (m_pForm->CountObjects() == 1 && !m_bColored) {
-    CPDF_PageObject* pPageObj =
-        m_pForm->GetObjectAt(m_pForm->GetFirstObjectPosition());
+  if (m_pForm->GetPageObjectList()->GetCount() == 1 && !m_bColored) {
+    CPDF_PageObject* pPageObj = m_pForm->GetPageObjectList()->GetObjectAt(
+        m_pForm->GetPageObjectList()->GetHeadPosition());
     if (pPageObj->m_Type == CPDF_PageObject::IMAGE) {
       CPDF_ImageObject* pImage = (CPDF_ImageObject*)pPageObj;
       m_ImageMatrix = pImage->m_Matrix;
diff --git a/core/src/fpdfapi/fpdf_render/render_int.h b/core/src/fpdfapi/fpdf_render/render_int.h
index 165e6800fb..9a262ea6fc 100644
--- a/core/src/fpdfapi/fpdf_render/render_int.h
+++ b/core/src/fpdfapi/fpdf_render/render_int.h
@@ -124,7 +124,7 @@ class CPDF_RenderStatus {
                      FX_ARGB fill_color = 0,
                      FX_DWORD GroupFamily = 0,
                      FX_BOOL bLoadMask = FALSE);
-  void RenderObjectList(const CPDF_PageObjectList* pObjs,
+  void RenderObjectList(const CPDF_PageObjectHolder* pObjectHolder,
                         const CFX_Matrix* pObj2Device);
   void RenderSingleObject(const CPDF_PageObject* pObj,
                           const CFX_Matrix* pObj2Device);
diff --git a/core/src/fpdftext/fpdf_text_int.cpp b/core/src/fpdftext/fpdf_text_int.cpp
index a0f0c64822..b6e39de004 100644
--- a/core/src/fpdftext/fpdf_text_int.cpp
+++ b/core/src/fpdftext/fpdf_text_int.cpp
@@ -135,15 +135,13 @@ bool CPDF_TextPage::IsControlChar(const PAGECHAR_INFO& charInfo) {
   }
 }
 
-FX_BOOL CPDF_TextPage::ParseTextPage() {
+void CPDF_TextPage::ParseTextPage() {
   m_bIsParsed = false;
-  if (!m_pPage)
-    return FALSE;
-
   m_TextBuf.Clear();
   m_CharList.clear();
   m_pPreTextObj = NULL;
   ProcessObject();
+
   m_bIsParsed = true;
   m_CharIndex.clear();
   int nCount = pdfium::CollectionSize<int>(m_CharList);
@@ -185,7 +183,6 @@ FX_BOOL CPDF_TextPage::ParseTextPage() {
   if (indexSize % 2) {
     m_CharIndex.erase(m_CharIndex.begin() + indexSize - 1);
   }
-  return TRUE;
 }
 
 int CPDF_TextPage::CountChars() const {
@@ -756,11 +753,8 @@ int CPDF_TextPage::GetWordBreak(int index, int direction) const {
 }
 
 int32_t CPDF_TextPage::FindTextlineFlowDirection() {
-  if (!m_pPage) {
-    return -1;
-  }
-  const int32_t nPageWidth = (int32_t)((CPDF_Page*)m_pPage)->GetPageWidth();
-  const int32_t nPageHeight = (int32_t)((CPDF_Page*)m_pPage)->GetPageHeight();
+  const int32_t nPageWidth = static_cast<int32_t>(m_pPage->GetPageWidth());
+  const int32_t nPageHeight = static_cast<int32_t>(m_pPage->GetPageHeight());
   std::vector<uint8_t> nHorizontalMask(nPageWidth);
   std::vector<uint8_t> nVerticalMask(nPageHeight);
   uint8_t* pDataH = nHorizontalMask.data();
@@ -769,13 +763,13 @@ int32_t CPDF_TextPage::FindTextlineFlowDirection() {
   FX_FLOAT fLineHeight = 0.0f;
   CPDF_PageObject* pPageObj = NULL;
   FX_POSITION pos = NULL;
-  pos = m_pPage->GetFirstObjectPosition();
+  pos = m_pPage->GetPageObjectList()->GetHeadPosition();
   if (!pos) {
     return -1;
   }
   while (pos) {
-    pPageObj = m_pPage->GetNextObject(pos);
-    if (NULL == pPageObj) {
+    pPageObj = m_pPage->GetPageObjectList()->GetNextObject(pos);
+    if (!pPageObj) {
       continue;
     }
     if (CPDF_PageObject::TEXT != pPageObj->m_Type) {
@@ -854,19 +848,15 @@ int32_t CPDF_TextPage::FindTextlineFlowDirection() {
 }
 
 void CPDF_TextPage::ProcessObject() {
-  CPDF_PageObject* pPageObj = NULL;
-  if (!m_pPage) {
-    return;
-  }
-  FX_POSITION pos;
-  pos = m_pPage->GetFirstObjectPosition();
+  FX_POSITION pos = m_pPage->GetPageObjectList()->GetHeadPosition();
   if (!pos) {
     return;
   }
   m_TextlineDir = FindTextlineFlowDirection();
   int nCount = 0;
   while (pos) {
-    pPageObj = m_pPage->GetNextObject(pos);
+    CPDF_PageObject* pPageObj =
+        m_pPage->GetPageObjectList()->GetNextObject(pos);
     if (pPageObj) {
       if (pPageObj->m_Type == CPDF_PageObject::TEXT) {
         CFX_Matrix matrix;
@@ -877,7 +867,6 @@ void CPDF_TextPage::ProcessObject() {
         ProcessFormObject((CPDF_FormObject*)pPageObj, formMatrix);
       }
     }
-    pPageObj = NULL;
   }
   int count = m_LineObj.GetSize();
   for (int i = 0; i < count; i++) {
@@ -894,7 +883,7 @@ void CPDF_TextPage::ProcessFormObject(CPDF_FormObject* pFormObj,
   if (!pFormObj) {
     return;
   }
-  pos = pFormObj->m_pForm->GetFirstObjectPosition();
+  pos = pFormObj->m_pForm->GetPageObjectList()->GetHeadPosition();
   if (!pos) {
     return;
   }
@@ -902,7 +891,7 @@ void CPDF_TextPage::ProcessFormObject(CPDF_FormObject* pFormObj,
   curFormMatrix.Copy(pFormObj->m_FormMatrix);
   curFormMatrix.Concat(formMatrix);
   while (pos) {
-    pPageObj = pFormObj->m_pForm->GetNextObject(pos);
+    pPageObj = pFormObj->m_pForm->GetPageObjectList()->GetNextObject(pos);
     if (pPageObj) {
       if (pPageObj->m_Type == CPDF_PageObject::TEXT) {
         ProcessTextObject((CPDF_TextObject*)pPageObj, curFormMatrix, pos);
@@ -1851,11 +1840,11 @@ FX_BOOL CPDF_TextPage::IsSameAsPreTextObject(CPDF_TextObject* pTextObj,
   }
   int i = 0;
   if (!ObjPos) {
-    ObjPos = m_pPage->GetLastObjectPosition();
+    ObjPos = m_pPage->GetPageObjectList()->GetTailPosition();
   }
-  CPDF_PageObject* pObj = m_pPage->GetPrevObject(ObjPos);
+  CPDF_PageObject* pObj = m_pPage->GetPageObjectList()->GetPrevObject(ObjPos);
   while (i < 5 && ObjPos) {
-    pObj = m_pPage->GetPrevObject(ObjPos);
+    pObj = m_pPage->GetPageObjectList()->GetPrevObject(ObjPos);
     if (pObj == pTextObj) {
       continue;
     }
diff --git a/core/src/fpdftext/text_int.h b/core/src/fpdftext/text_int.h
index 9131cdb321..edde651ddb 100644
--- a/core/src/fpdftext/text_int.h
+++ b/core/src/fpdftext/text_int.h
@@ -57,7 +57,7 @@ class CPDF_TextPage : public IPDF_TextPage {
   ~CPDF_TextPage() override {}
 
   // IPDF_TextPage:
-  FX_BOOL ParseTextPage() override;
+  void ParseTextPage() override;
   bool IsParsed() const override { return m_bIsParsed; }
   int CharIndexFromTextIndex(int TextIndex) const override;
   int TextIndexFromCharIndex(int CharIndex) const override;
@@ -131,8 +131,8 @@ class CPDF_TextPage : public IPDF_TextPage {
                         const CPDF_Font* pFont,
                         int nItems) const;
 
+  const CPDF_Page* const m_pPage;
   std::vector<FX_WORD> m_CharIndex;
-  const CPDF_PageObjectList* const m_pPage;
   std::deque<PAGECHAR_INFO> m_CharList;
   std::deque<PAGECHAR_INFO> m_TempCharList;
   CFX_WideTextBuf m_TextBuf;