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      1 // Copyright 2016 PDFium Authors. All rights reserved.
      2 // Use of this source code is governed by a BSD-style license that can be
      3 // found in the LICENSE file.
      4 
      5 // Original code copyright 2014 Foxit Software Inc. http://www.foxitsoftware.com
      6 
      7 #include "core/fpdfapi/parser/cpdf_reference.h"
      8 
      9 #include "core/fpdfapi/parser/cpdf_indirect_object_holder.h"
     10 #include "core/fxcrt/fx_stream.h"
     11 #include "third_party/base/ptr_util.h"
     12 #include "third_party/base/stl_util.h"
     13 
     14 CPDF_Reference::CPDF_Reference(CPDF_IndirectObjectHolder* pDoc, uint32_t objnum)
     15     : m_pObjList(pDoc), m_RefObjNum(objnum) {}
     16 
     17 CPDF_Reference::~CPDF_Reference() {}
     18 
     19 CPDF_Object::Type CPDF_Reference::GetType() const {
     20   return REFERENCE;
     21 }
     22 
     23 ByteString CPDF_Reference::GetString() const {
     24   CPDF_Object* obj = SafeGetDirect();
     25   return obj ? obj->GetString() : ByteString();
     26 }
     27 
     28 float CPDF_Reference::GetNumber() const {
     29   CPDF_Object* obj = SafeGetDirect();
     30   return obj ? obj->GetNumber() : 0;
     31 }
     32 
     33 int CPDF_Reference::GetInteger() const {
     34   CPDF_Object* obj = SafeGetDirect();
     35   return obj ? obj->GetInteger() : 0;
     36 }
     37 
     38 CPDF_Dictionary* CPDF_Reference::GetDict() const {
     39   CPDF_Object* obj = SafeGetDirect();
     40   return obj ? obj->GetDict() : nullptr;
     41 }
     42 
     43 bool CPDF_Reference::IsReference() const {
     44   return true;
     45 }
     46 
     47 CPDF_Reference* CPDF_Reference::AsReference() {
     48   return this;
     49 }
     50 
     51 const CPDF_Reference* CPDF_Reference::AsReference() const {
     52   return this;
     53 }
     54 
     55 std::unique_ptr<CPDF_Object> CPDF_Reference::Clone() const {
     56   return CloneObjectNonCyclic(false);
     57 }
     58 
     59 std::unique_ptr<CPDF_Object> CPDF_Reference::CloneNonCyclic(
     60     bool bDirect,
     61     std::set<const CPDF_Object*>* pVisited) const {
     62   pVisited->insert(this);
     63   if (bDirect) {
     64     auto* pDirect = GetDirect();
     65     return pDirect && !pdfium::ContainsKey(*pVisited, pDirect)
     66                ? pDirect->CloneNonCyclic(true, pVisited)
     67                : nullptr;
     68   }
     69   return pdfium::MakeUnique<CPDF_Reference>(m_pObjList.Get(), m_RefObjNum);
     70 }
     71 
     72 CPDF_Object* CPDF_Reference::SafeGetDirect() const {
     73   CPDF_Object* obj = GetDirect();
     74   return (obj && !obj->IsReference()) ? obj : nullptr;
     75 }
     76 
     77 void CPDF_Reference::SetRef(CPDF_IndirectObjectHolder* pDoc, uint32_t objnum) {
     78   m_pObjList = pDoc;
     79   m_RefObjNum = objnum;
     80 }
     81 
     82 CPDF_Object* CPDF_Reference::GetDirect() const {
     83   return m_pObjList ? m_pObjList->GetOrParseIndirectObject(m_RefObjNum)
     84                     : nullptr;
     85 }
     86 
     87 bool CPDF_Reference::WriteTo(IFX_ArchiveStream* archive) const {
     88   return archive->WriteString(" ") && archive->WriteDWord(GetRefObjNum()) &&
     89          archive->WriteString(" 0 R ");
     90 }
     91