1 /*
2 * Copyright (C) 2012 Google Inc. All rights reserved.
3 *
4 * Redistribution and use in source and binary forms, with or without
5 * modification, are permitted provided that the following conditions are
6 * met:
7 *
8 * * Redistributions of source code must retain the above copyright
9 * notice, this list of conditions and the following disclaimer.
10 * * Neither the name of Google Inc. nor the names of its
11 * contributors may be used to endorse or promote products derived from
12 * this software without specific prior written permission.
13 *
14 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
15 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
16 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
17 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
18 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
19 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
20 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
21 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
22 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
23 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
24 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
25 */
26
27 #ifndef ComposedTreeWalker_h
28 #define ComposedTreeWalker_h
29
30 #include "core/dom/NodeRenderingTraversal.h"
31 #include "core/dom/shadow/InsertionPoint.h"
32 #include "core/dom/shadow/ShadowRoot.h"
33
34 namespace WebCore {
35
36 class Node;
37 class ShadowRoot;
38
39 // FIXME: Make some functions inline to optimise the performance.
40 // https://bugs.webkit.org/show_bug.cgi?id=82702
41 class ComposedTreeWalker {
42 STACK_ALLOCATED();
43 public:
44 typedef NodeRenderingTraversal::ParentDetails ParentTraversalDetails;
45
46 enum StartPolicy {
47 CanStartFromShadowBoundary,
48 CannotStartFromShadowBoundary
49 };
50
51 ComposedTreeWalker(const Node*, StartPolicy = CannotStartFromShadowBoundary);
52
get()53 Node* get() const { return const_cast<Node*>(m_node.get()); }
54
55 void firstChild();
56 void lastChild();
57
58 void nextSibling();
59 void previousSibling();
60
61 void parent();
62
63 void next();
64 void previous();
65
66 Node* traverseParent(const Node*, ParentTraversalDetails* = 0) const;
67
68 private:
69 ComposedTreeWalker(const Node*, ParentTraversalDetails*);
70
71 enum TraversalDirection {
72 TraversalDirectionForward,
73 TraversalDirectionBackward
74 };
75
assertPrecondition()76 void assertPrecondition() const
77 {
78 #ifndef NDEBUG
79 ASSERT(m_node);
80 ASSERT(!m_node->isShadowRoot());
81 ASSERT(!isActiveInsertionPoint(*m_node));
82 #endif
83 }
84
assertPostcondition()85 void assertPostcondition() const
86 {
87 #ifndef NDEBUG
88 if (m_node)
89 assertPrecondition();
90 #endif
91 }
92
93 static Node* traverseNode(const Node*, TraversalDirection);
94 static Node* traverseLightChildren(const Node*, TraversalDirection);
95
96 Node* traverseFirstChild(const Node*) const;
97 Node* traverseLastChild(const Node*) const;
98 Node* traverseChild(const Node*, TraversalDirection) const;
99
100 static Node* traverseNextSibling(const Node*);
101 static Node* traversePreviousSibling(const Node*);
102
103 static Node* traverseSiblingOrBackToInsertionPoint(const Node*, TraversalDirection);
104 static Node* traverseSiblingInCurrentTree(const Node*, TraversalDirection);
105
106 static Node* traverseSiblings(const Node*, TraversalDirection);
107 static Node* traverseDistributedNodes(const Node*, const InsertionPoint*, TraversalDirection);
108
109 static Node* traverseBackToYoungerShadowRoot(const Node*, TraversalDirection);
110
111 Node* traverseParentOrHost(const Node*) const;
112
113 RawPtrWillBeMember<const Node> m_node;
114 };
115
ComposedTreeWalker(const Node * node,StartPolicy startPolicy)116 inline ComposedTreeWalker::ComposedTreeWalker(const Node* node, StartPolicy startPolicy)
117 : m_node(node)
118 {
119 #ifndef NDEBUG
120 if (m_node && startPolicy == CannotStartFromShadowBoundary)
121 assertPrecondition();
122 #endif
123 }
124
parent()125 inline void ComposedTreeWalker::parent()
126 {
127 assertPrecondition();
128 m_node = traverseParent(m_node);
129 assertPostcondition();
130 }
131
nextSibling()132 inline void ComposedTreeWalker::nextSibling()
133 {
134 assertPrecondition();
135 m_node = traverseSiblingOrBackToInsertionPoint(m_node, TraversalDirectionForward);
136 assertPostcondition();
137 }
138
previousSibling()139 inline void ComposedTreeWalker::previousSibling()
140 {
141 assertPrecondition();
142 m_node = traverseSiblingOrBackToInsertionPoint(m_node, TraversalDirectionBackward);
143 assertPostcondition();
144 }
145
next()146 inline void ComposedTreeWalker::next()
147 {
148 assertPrecondition();
149 if (Node* next = traverseFirstChild(m_node)) {
150 m_node = next;
151 } else {
152 while (m_node) {
153 if (Node* sibling = traverseNextSibling(m_node)) {
154 m_node = sibling;
155 break;
156 }
157 m_node = traverseParent(m_node);
158 }
159 }
160 assertPostcondition();
161 }
162
previous()163 inline void ComposedTreeWalker::previous()
164 {
165 assertPrecondition();
166 if (Node* previous = traversePreviousSibling(m_node)) {
167 while (Node* child = traverseLastChild(previous))
168 previous = child;
169 m_node = previous;
170 } else {
171 parent();
172 }
173 assertPostcondition();
174 }
175
firstChild()176 inline void ComposedTreeWalker::firstChild()
177 {
178 assertPrecondition();
179 m_node = traverseChild(m_node, TraversalDirectionForward);
180 assertPostcondition();
181 }
182
lastChild()183 inline void ComposedTreeWalker::lastChild()
184 {
185 assertPrecondition();
186 m_node = traverseLastChild(m_node);
187 assertPostcondition();
188 }
189
traverseNextSibling(const Node * node)190 inline Node* ComposedTreeWalker::traverseNextSibling(const Node* node)
191 {
192 ASSERT(node);
193 return traverseSiblingOrBackToInsertionPoint(node, TraversalDirectionForward);
194 }
195
traversePreviousSibling(const Node * node)196 inline Node* ComposedTreeWalker::traversePreviousSibling(const Node* node)
197 {
198 ASSERT(node);
199 return traverseSiblingOrBackToInsertionPoint(node, TraversalDirectionBackward);
200 }
201
traverseFirstChild(const Node * node)202 inline Node* ComposedTreeWalker::traverseFirstChild(const Node* node) const
203 {
204 ASSERT(node);
205 return traverseChild(node, TraversalDirectionForward);
206 }
207
traverseLastChild(const Node * node)208 inline Node* ComposedTreeWalker::traverseLastChild(const Node* node) const
209 {
210 ASSERT(node);
211 return traverseChild(node, TraversalDirectionBackward);
212 }
213
214 } // namespace
215
216 #endif
217