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// Copyright 2017 The PDFium Authors
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
#ifndef CORE_FPDFAPI_PARSER_CPDF_OBJECT_WALKER_H_
#define CORE_FPDFAPI_PARSER_CPDF_OBJECT_WALKER_H_
#include <memory>
#include <stack>
#include "core/fxcrt/bytestring.h"
#include "core/fxcrt/retain_ptr.h"
class CPDF_Object;
// Walk on all non-null sub-objects in an object in depth, include itself,
// like in flat list.
class CPDF_ObjectWalker {
public:
class SubobjectIterator {
public:
virtual ~SubobjectIterator();
virtual bool IsFinished() const = 0;
bool IsStarted() const { return is_started_; }
RetainPtr<const CPDF_Object> Increment();
const CPDF_Object* object() const { return object_.Get(); }
protected:
explicit SubobjectIterator(RetainPtr<const CPDF_Object> object);
virtual RetainPtr<const CPDF_Object> IncrementImpl() = 0;
virtual void Start() = 0;
private:
RetainPtr<const CPDF_Object> object_;
bool is_started_ = false;
};
explicit CPDF_ObjectWalker(RetainPtr<const CPDF_Object> root);
~CPDF_ObjectWalker();
RetainPtr<const CPDF_Object> GetNext();
void SkipWalkIntoCurrentObject();
size_t current_depth() const { return current_depth_; }
const CPDF_Object* GetParent() const { return parent_object_.Get(); }
const ByteString& dictionary_key() const { return dict_key_; }
private:
static std::unique_ptr<SubobjectIterator> MakeIterator(
RetainPtr<const CPDF_Object> object);
RetainPtr<const CPDF_Object> next_object_;
RetainPtr<const CPDF_Object> parent_object_;
ByteString dict_key_;
size_t current_depth_ = 0;
std::stack<std::unique_ptr<SubobjectIterator>> stack_;
};
class CPDF_NonConstObjectWalker final : public CPDF_ObjectWalker {
public:
explicit CPDF_NonConstObjectWalker(RetainPtr<CPDF_Object> root);
RetainPtr<CPDF_Object> GetNext();
};
#endif // CORE_FPDFAPI_PARSER_CPDF_OBJECT_WALKER_H_