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34 #include "wtf/Assertions.h"
39 // TreeNode is generic, ContainerNode-like linked tree data structure.
40 // There are a few notable difference between TreeNode and Node:
42 // * Each TreeNode node is NOT ref counted. The user have to retain its lifetime somehow.
43 // FIXME: lifetime management could be parameterized so that ref counted implementations can be used.
44 // * It ASSERT()s invalid input. The callers have to ensure that given parameter is sound.
45 // * There is no branch-leaf difference. Every node can be a parent of other node.
61 NodeType* next() const { return m_next; }
62 NodeType* previous() const { return m_previous; }
63 NodeType* parent() const { return m_parent; }
64 NodeType* firstChild() const { return m_firstChild; }
65 NodeType* lastChild() const { return m_lastChild; }
66 NodeType* here() const { return static_cast<NodeType*>(const_cast<TreeNode*>(this)); }
68 bool orphan() const { return !m_parent && !m_next && !m_previous && !m_firstChild && !m_lastChild; }
69 bool hasChildren() const { return m_firstChild; }
71 void insertBefore(NodeType* newChild, NodeType* refChild)
73 ASSERT(!newChild->parent());
74 ASSERT(!newChild->next());
75 ASSERT(!newChild->previous());
77 ASSERT(!refChild || this == refChild->parent());
80 appendChild(newChild);
84 NodeType* newPrevious = refChild->previous();
85 newChild->m_parent = here();
86 newChild->m_next = refChild;
87 newChild->m_previous = newPrevious;
88 refChild->m_previous = newChild;
90 newPrevious->m_next = newChild;
92 m_firstChild = newChild;
95 void appendChild(NodeType* child)
97 ASSERT(!child->parent());
98 ASSERT(!child->next());
99 ASSERT(!child->previous());
101 child->m_parent = here();
104 ASSERT(!m_firstChild);
105 m_lastChild = m_firstChild = child;
109 ASSERT(!m_lastChild->m_next);
110 NodeType* oldLast = m_lastChild;
113 child->m_previous = oldLast;
114 oldLast->m_next = child;
117 NodeType* removeChild(NodeType* child)
119 ASSERT(child->parent() == this);
121 if (m_firstChild == child)
122 m_firstChild = child->next();
123 if (m_lastChild == child)
124 m_lastChild = child->previous();
126 NodeType* oldNext = child->next();
127 NodeType* oldPrevious = child->previous();
128 child->m_parent = child->m_next = child->m_previous = 0;
131 oldNext->m_previous = oldPrevious;
133 oldPrevious->m_next = oldNext;
138 void takeChildrenFrom(NodeType* oldParent)
140 ASSERT(oldParent != this);
141 while (oldParent->hasChildren()) {
142 NodeType* child = oldParent->firstChild();
143 oldParent->removeChild(child);
144 this->appendChild(child);
150 NodeType* m_previous;
152 NodeType* m_firstChild;
153 NodeType* m_lastChild;
157 inline typename TreeNode<T>::NodeType* traverseNext(const TreeNode<T>* current, const TreeNode<T>* stayWithin = 0)
159 if (typename TreeNode<T>::NodeType* next = current->firstChild())
161 if (current == stayWithin)
163 if (typename TreeNode<T>::NodeType* next = current->next())
165 for (typename TreeNode<T>::NodeType* parent = current->parent(); parent; parent = parent->parent()) {
166 if (parent == stayWithin)
168 if (typename TreeNode<T>::NodeType* next = parent->next())
176 inline typename TreeNode<T>::NodeType* traverseFirstPostOrder(const TreeNode<T>* current)
178 typename TreeNode<T>::NodeType* first = current->here();
179 while (first->firstChild())
180 first = first->firstChild();
185 inline typename TreeNode<T>::NodeType* traverseNextPostOrder(const TreeNode<T>* current, const TreeNode<T>* stayWithin = 0)
187 if (current == stayWithin)
190 typename TreeNode<T>::NodeType* next = current->next();
192 return current->parent();
193 while (next->firstChild())
194 next = next->firstChild();
201 using WTF::traverseNext;
202 using WTF::traverseNextPostOrder;