1/*
2 * Copyright (C) 1999 Lars Knoll (knoll@kde.org)
3 *           (C) 1999 Antti Koivisto (koivisto@kde.org)
4 *           (C) 2001 Dirk Mueller (mueller@kde.org)
5 * Copyright (C) 2004, 2005, 2006, 2007, 2008, 2009, 2010, 2011, 2012 Apple Inc. All rights reserved.
6 * Copyright (C) 2008, 2009 Torch Mobile Inc. All rights reserved. (http://www.torchmobile.com/)
7 * Copyright (C) 2014 Samsung Electronics. All rights reserved.
8 *
9 * This library is free software; you can redistribute it and/or
10 * modify it under the terms of the GNU Library General Public
11 * License as published by the Free Software Foundation; either
12 * version 2 of the License, or (at your option) any later version.
13 *
14 * This library is distributed in the hope that it will be useful,
15 * but WITHOUT ANY WARRANTY; without even the implied warranty of
16 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
17 * Library General Public License for more details.
18 *
19 * You should have received a copy of the GNU Library General Public License
20 * along with this library; see the file COPYING.LIB.  If not, write to
21 * the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
22 * Boston, MA 02110-1301, USA.
23 *
24 */
25
26#ifndef NodeTraversal_h
27#define NodeTraversal_h
28
29#include "core/dom/ContainerNode.h"
30#include "core/dom/Node.h"
31
32namespace blink {
33
34class NodeTraversal {
35public:
36    // Does a pre-order traversal of the tree to find the next node after this one.
37    // This uses the same order that tags appear in the source file. If the stayWithin
38    // argument is non-null, the traversal will stop once the specified node is reached.
39    // This can be used to restrict traversal to a particular sub-tree.
40    static Node* next(const Node& current) { return traverseNextTemplate(current); }
41    static Node* next(const ContainerNode& current) { return traverseNextTemplate(current); }
42    static Node* next(const Node& current, const Node* stayWithin) { return traverseNextTemplate(current, stayWithin); }
43    static Node* next(const ContainerNode& current, const Node* stayWithin) { return traverseNextTemplate(current, stayWithin); }
44
45    // Like next, but skips children and starts with the next sibling.
46    static Node* nextSkippingChildren(const Node&);
47    static Node* nextSkippingChildren(const Node&, const Node* stayWithin);
48
49    static Node* lastWithin(const ContainerNode&);
50    static Node& lastWithinOrSelf(Node&);
51
52    // Does a reverse pre-order traversal to find the node that comes before the current one in document order
53    static Node* previous(const Node&, const Node* stayWithin = 0);
54
55    // Like previous, but skips children and starts with the next sibling.
56    static Node* previousSkippingChildren(const Node&, const Node* stayWithin = 0);
57
58    // Like next, but visits parents after their children.
59    static Node* nextPostOrder(const Node&, const Node* stayWithin = 0);
60
61    // Like previous, but visits parents before their children.
62    static Node* previousPostOrder(const Node&, const Node* stayWithin = 0);
63
64    // Pre-order traversal including the pseudo-elements.
65    static Node* previousIncludingPseudo(const Node&, const Node* stayWithin = 0);
66    static Node* nextIncludingPseudo(const Node&, const Node* stayWithin = 0);
67    static Node* nextIncludingPseudoSkippingChildren(const Node&, const Node* stayWithin = 0);
68
69    static Node* nextAncestorSibling(const Node&);
70    static Node* nextAncestorSibling(const Node&, const Node* stayWithin);
71    static Node& highestAncestorOrSelf(Node&);
72
73    // Children traversal.
74    static Node* childAt(const Node& parent, unsigned index) { return childAtTemplate(parent, index); }
75    static Node* childAt(const ContainerNode& parent, unsigned index) { return childAtTemplate(parent, index); }
76
77private:
78    template <class NodeType>
79    static Node* traverseNextTemplate(NodeType&);
80    template <class NodeType>
81    static Node* traverseNextTemplate(NodeType&, const Node* stayWithin);
82    template <class NodeType>
83    static Node* childAtTemplate(NodeType&, unsigned);
84};
85
86template <class NodeType>
87inline Node* NodeTraversal::traverseNextTemplate(NodeType& current)
88{
89    if (current.hasChildren())
90        return current.firstChild();
91    if (current.nextSibling())
92        return current.nextSibling();
93    return nextAncestorSibling(current);
94}
95
96template <class NodeType>
97inline Node* NodeTraversal::traverseNextTemplate(NodeType& current, const Node* stayWithin)
98{
99    if (current.hasChildren())
100        return current.firstChild();
101    if (current == stayWithin)
102        return 0;
103    if (current.nextSibling())
104        return current.nextSibling();
105    return nextAncestorSibling(current, stayWithin);
106}
107
108inline Node* NodeTraversal::nextSkippingChildren(const Node& current)
109{
110    if (current.nextSibling())
111        return current.nextSibling();
112    return nextAncestorSibling(current);
113}
114
115inline Node* NodeTraversal::nextSkippingChildren(const Node& current, const Node* stayWithin)
116{
117    if (current == stayWithin)
118        return 0;
119    if (current.nextSibling())
120        return current.nextSibling();
121    return nextAncestorSibling(current, stayWithin);
122}
123
124inline Node& NodeTraversal::highestAncestorOrSelf(Node& current)
125{
126    Node* highest = &current;
127    while (highest->parentNode())
128        highest = highest->parentNode();
129    return *highest;
130}
131
132template <class NodeType>
133inline Node* NodeTraversal::childAtTemplate(NodeType& parent, unsigned index)
134{
135    Node* child = parent.firstChild();
136    while (child && index--)
137        child = child->nextSibling();
138    return child;
139}
140
141} // namespace blink
142
143#endif
144