summaryrefslogtreecommitdiff
path: root/xfa/fxfa/parser/cxfa_nodeiteratortemplate.h
blob: 10543fdbcfeea5333b21f19fff7395e0e7e89308 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
// Copyright 2017 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 XFA_FXFA_PARSER_CXFA_NODEITERATORTEMPLATE_H_
#define XFA_FXFA_PARSER_CXFA_NODEITERATORTEMPLATE_H_

#include "core/fxcrt/unowned_ptr.h"

template <class NodeType, class TraverseStrategy>
class CXFA_NodeIteratorTemplate {
 public:
  explicit CXFA_NodeIteratorTemplate(NodeType* pRoot)
      : m_pRoot(pRoot), m_pCurrent(pRoot) {}

  NodeType* GetRoot() const { return m_pRoot.Get(); }
  NodeType* GetCurrent() const { return m_pCurrent.Get(); }

  void Reset() { m_pCurrent = m_pRoot; }
  bool SetCurrent(NodeType* pNode) {
    if (!RootReachableFromNode(pNode)) {
      m_pCurrent = nullptr;
      return false;
    }
    m_pCurrent = pNode;
    return true;
  }

  NodeType* MoveToPrev() {
    if (!m_pRoot)
      return nullptr;
    if (!m_pCurrent) {
      m_pCurrent = LastDescendant(m_pRoot.Get());
      return m_pCurrent.Get();
    }
    NodeType* pSibling = PreviousSiblingWithinSubtree(m_pCurrent.Get());
    if (pSibling) {
      m_pCurrent = LastDescendant(pSibling);
      return m_pCurrent.Get();
    }
    NodeType* pParent = ParentWithinSubtree(m_pCurrent.Get());
    if (pParent) {
      m_pCurrent = pParent;
      return pParent;
    }
    return nullptr;
  }

  NodeType* MoveToNext() {
    if (!m_pRoot || !m_pCurrent)
      return nullptr;
    NodeType* pChild = TraverseStrategy::GetFirstChild(m_pCurrent.Get());
    if (pChild) {
      m_pCurrent = pChild;
      return pChild;
    }
    return SkipChildrenAndMoveToNext();
  }

  NodeType* SkipChildrenAndMoveToNext() {
    if (!m_pRoot)
      return nullptr;
    NodeType* pNode = m_pCurrent.Get();
    while (pNode) {
      NodeType* pSibling = NextSiblingWithinSubtree(pNode);
      if (pSibling) {
        m_pCurrent = pSibling;
        return pSibling;
      }
      pNode = ParentWithinSubtree(pNode);
    }
    m_pCurrent = nullptr;
    return nullptr;
  }

 private:
  bool RootReachableFromNode(NodeType* pNode) {
    if (!pNode)
      return false;
    if (pNode == m_pRoot)
      return true;
    return RootReachableFromNode(TraverseStrategy::GetParent(pNode));
  }

  NodeType* ParentWithinSubtree(NodeType* pNode) {
    if (!pNode || pNode == m_pRoot)
      return nullptr;
    return TraverseStrategy::GetParent(pNode);
  }

  NodeType* NextSiblingWithinSubtree(NodeType* pNode) {
    if (pNode == m_pRoot)
      return nullptr;
    return TraverseStrategy::GetNextSibling(pNode);
  }

  NodeType* PreviousSiblingWithinSubtree(NodeType* pNode) {
    NodeType* pParent = ParentWithinSubtree(pNode);
    if (!pParent)
      return nullptr;
    NodeType* pCurrent = TraverseStrategy::GetFirstChild(pParent);
    NodeType* pPrevious = nullptr;
    while (pCurrent != pNode) {
      pPrevious = pCurrent;
      pCurrent = TraverseStrategy::GetNextSibling(pCurrent);
    }
    return pPrevious;
  }

  NodeType* LastChild(NodeType* pNode) {
    NodeType* pPrevious = nullptr;
    NodeType* pChild = TraverseStrategy::GetFirstChild(pNode);
    while (pChild) {
      pPrevious = pChild;
      pChild = NextSiblingWithinSubtree(pChild);
    }
    return pPrevious;
  }

  NodeType* LastDescendant(NodeType* pNode) {
    NodeType* pChild = LastChild(pNode);
    return pChild ? LastDescendant(pChild) : pNode;
  }

  UnownedPtr<NodeType> m_pRoot;
  UnownedPtr<NodeType> m_pCurrent;
};

#endif  // XFA_FXFA_PARSER_CXFA_NODEITERATORTEMPLATE_H_