core/fpdfapi/parser/cpdf_object.h

// Copyright 2016 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_FPDFAPI_PARSER_CPDF_OBJECT_H_
#define CORE_FPDFAPI_PARSER_CPDF_OBJECT_H_

#include <memory>
#include <set>
#include <type_traits>

#include "core/fxcrt/fx_string.h"
#include "core/fxcrt/fx_system.h"
#include "core/fxcrt/retain_ptr.h"

class CPDF_Array;
class CPDF_Boolean;
class CPDF_Dictionary;
class CPDF_Encryptor;
class CPDF_IndirectObjectHolder;
class CPDF_Name;
class CPDF_Null;
class CPDF_Number;
class CPDF_Reference;
class CPDF_Stream;
class CPDF_String;
class IFX_ArchiveStream;

class CPDF_Object : public Retainable {
 public:
  static constexpr uint32_t kInvalidObjNum = static_cast<uint32_t>(-1);
  enum Type {
    kBoolean = 1,
    kNumber,
    kString,
    kName,
    kArray,
    kDictionary,
    kStream,
    kNullobj,
    kReference
  };

  virtual Type GetType() const = 0;
  uint32_t GetObjNum() const { return m_ObjNum; }
  void SetObjNum(uint32_t objnum) { m_ObjNum = objnum; }
  uint32_t GetGenNum() const { return m_GenNum; }
  void SetGenNum(uint32_t gennum) { m_GenNum = gennum; }
  bool IsInline() const { return m_ObjNum == 0; }

  // Create a deep copy of the object.
  virtual RetainPtr<CPDF_Object> Clone() const = 0;

  // Create a deep copy of the object except any reference object be
  // copied to the object it points to directly.
  virtual RetainPtr<CPDF_Object> CloneDirectObject() const;

  virtual CPDF_Object* GetDirect();
  virtual const CPDF_Object* GetDirect() const;
  virtual ByteString GetString() const;
  virtual WideString GetUnicodeText() const;
  virtual float GetNumber() const;
  virtual int GetInteger() const;
  virtual CPDF_Dictionary* GetDict();
  virtual const CPDF_Dictionary* GetDict() const;

  virtual void SetString(const ByteString& str);

  virtual bool IsArray() const;
  virtual bool IsBoolean() const;
  virtual bool IsDictionary() const;
  virtual bool IsName() const;
  virtual bool IsNumber() const;
  virtual bool IsReference() const;
  virtual bool IsStream() const;
  virtual bool IsString() const;
  virtual bool IsNull() const;

  virtual CPDF_Array* AsArray();
  virtual const CPDF_Array* AsArray() const;
  virtual CPDF_Boolean* AsBoolean();
  virtual const CPDF_Boolean* AsBoolean() const;
  virtual CPDF_Dictionary* AsDictionary();
  virtual const CPDF_Dictionary* AsDictionary() const;
  virtual CPDF_Name* AsName();
  virtual const CPDF_Name* AsName() const;
  virtual CPDF_Number* AsNumber();
  virtual const CPDF_Number* AsNumber() const;
  virtual CPDF_Reference* AsReference();
  virtual const CPDF_Reference* AsReference() const;
  virtual CPDF_Stream* AsStream();
  virtual const CPDF_Stream* AsStream() const;
  virtual CPDF_String* AsString();
  virtual const CPDF_String* AsString() const;

  virtual bool WriteTo(IFX_ArchiveStream* archive,
                       const CPDF_Encryptor* encryptor) const = 0;

  // Create a deep copy of the object with the option to either
  // copy a reference object or directly copy the object it refers to
  // when |bDirect| is true.
  // Also check cyclic reference against |pVisited|, no copy if it is found.
  // Complex objects should implement their own CloneNonCyclic()
  // function to properly check for possible loop.
  virtual RetainPtr<CPDF_Object> CloneNonCyclic(
      bool bDirect,
      std::set<const CPDF_Object*>* pVisited) const;

  // Return a reference to itself.
  // The object must be direct (!IsInlined).
  virtual RetainPtr<CPDF_Object> MakeReference(
      CPDF_IndirectObjectHolder* holder) const;

 protected:
  CPDF_Object() = default;
  CPDF_Object(const CPDF_Object& src) = delete;
  ~CPDF_Object() override;

  RetainPtr<CPDF_Object> CloneObjectNonCyclic(bool bDirect) const;

  uint32_t m_ObjNum = 0;
  uint32_t m_GenNum = 0;
};

template <typename T>
struct CanInternStrings {
  static constexpr bool value = std::is_same<T, CPDF_Array>::value ||
                                std::is_same<T, CPDF_Dictionary>::value ||
                                std::is_same<T, CPDF_Name>::value ||
                                std::is_same<T, CPDF_String>::value;
};

#endif  // CORE_FPDFAPI_PARSER_CPDF_OBJECT_H_