e717b4ce265d8736c5a3c61d2476d3d9d2b672df
[WebKit-https.git] / Source / WebCore / dom / ComposedTreeIterator.h
1 /*
2  * Copyright (C) 2015-2016 Apple 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
6  * are met:
7  * 1. Redistributions of source code must retain the above copyright
8  *    notice, this list of conditions and the following disclaimer.
9  * 2. Redistributions in binary form must reproduce the above copyright
10  *    notice, this list of conditions and the following disclaimer in the
11  *    documentation and/or other materials provided with the distribution.
12  *
13  * THIS SOFTWARE IS PROVIDED BY APPLE INC. ``AS IS'' AND ANY
14  * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
15  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
16  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL APPLE INC. OR
17  * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
18  * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
19  * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
20  * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
21  * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
22  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
23  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
24  */
25
26 #include "ElementAndTextDescendantIterator.h"
27 #include "ShadowRoot.h"
28
29 #ifndef ComposedTreeIterator_h
30 #define ComposedTreeIterator_h
31
32 namespace WebCore {
33
34 class HTMLSlotElement;
35
36 class ComposedTreeIterator {
37 public:
38     ComposedTreeIterator();
39     enum FirstChildTag { FirstChild };
40     ComposedTreeIterator(ContainerNode& root, FirstChildTag);
41     ComposedTreeIterator(ContainerNode& root, Node& current);
42
43     Node& operator*() { return current(); }
44     Node* operator->() { return &current(); }
45
46     bool operator==(const ComposedTreeIterator& other) const { return context().iterator == other.context().iterator; }
47     bool operator!=(const ComposedTreeIterator& other) const { return context().iterator != other.context().iterator; }
48
49     ComposedTreeIterator& operator++() { return traverseNext(); }
50
51     ComposedTreeIterator& traverseNext();
52     ComposedTreeIterator& traverseNextSkippingChildren();
53     ComposedTreeIterator& traverseNextSibling();
54     ComposedTreeIterator& traversePreviousSibling();
55
56     unsigned depth() const;
57
58     void dropAssertions();
59
60 private:
61     void initializeContextStack(ContainerNode& root, Node& current);
62     void traverseNextInShadowTree();
63     void traverseNextLeavingContext();
64     void traverseShadowRoot(ShadowRoot&);
65     bool advanceInSlot(int direction);
66     void traverseSiblingInSlot(int direction);
67
68     struct Context {
69         Context();
70         Context(ContainerNode& root, FirstChildTag);
71         Context(ContainerNode& root, Node& node);
72
73         enum SlottedTag { Slotted };
74         Context(ContainerNode& root, Node& node, SlottedTag);
75         ElementAndTextDescendantIterator iterator;
76         ElementAndTextDescendantIterator end;
77         size_t slotNodeIndex { notFound };
78     };
79     Context& context() { return m_contextStack.last(); }
80     const Context& context() const { return m_contextStack.last(); }
81     Node& current() { return *context().iterator; }
82
83     bool m_didDropAssertions { false };
84     Vector<Context, 8> m_contextStack;
85 };
86
87 inline ComposedTreeIterator::ComposedTreeIterator()
88 {
89     m_contextStack.uncheckedAppend({ });
90 }
91
92 inline ComposedTreeIterator& ComposedTreeIterator::traverseNext()
93 {
94     if (auto* shadowRoot = context().iterator->shadowRoot()) {
95         traverseShadowRoot(*shadowRoot);
96         return *this;
97     }
98
99     if (m_contextStack.size() > 1) {
100         traverseNextInShadowTree();
101         return *this;
102     }
103
104     context().iterator.traverseNext();
105     return *this;
106 }
107
108 inline ComposedTreeIterator& ComposedTreeIterator::traverseNextSkippingChildren()
109 {
110     context().iterator.traverseNextSkippingChildren();
111
112     if (context().iterator == context().end && m_contextStack.size() > 1)
113         traverseNextLeavingContext();
114     
115     return *this;
116 }
117
118 inline ComposedTreeIterator& ComposedTreeIterator::traverseNextSibling()
119 {
120     if (current().parentNode()->shadowRoot()) {
121         traverseSiblingInSlot(1);
122         return *this;
123     }
124     context().iterator.traverseNextSibling();
125     return *this;
126 }
127
128 inline ComposedTreeIterator& ComposedTreeIterator::traversePreviousSibling()
129 {
130     if (current().parentNode()->shadowRoot()) {
131         traverseSiblingInSlot(-1);
132         return *this;
133     }
134     context().iterator.traversePreviousSibling();
135     return *this;
136 }
137
138 inline unsigned ComposedTreeIterator::depth() const
139 {
140     unsigned depth = 0;
141     for (auto& context : m_contextStack)
142         depth += context.iterator.depth();
143     return depth;
144 }
145
146 class ComposedTreeDescendantAdapter {
147 public:
148     ComposedTreeDescendantAdapter(ContainerNode& parent)
149         : m_parent(parent)
150     { }
151
152     ComposedTreeIterator begin() { return ComposedTreeIterator(m_parent, ComposedTreeIterator::FirstChild); }
153     ComposedTreeIterator end() { return { }; }
154     ComposedTreeIterator at(const Node& child) { return ComposedTreeIterator(m_parent, const_cast<Node&>(child)); }
155     
156 private:
157     ContainerNode& m_parent;
158 };
159
160 class ComposedTreeChildAdapter {
161 public:
162     class Iterator : public ComposedTreeIterator {
163     public:
164         Iterator() = default;
165         explicit Iterator(ContainerNode& root)
166             : ComposedTreeIterator(root, ComposedTreeIterator::FirstChild)
167         { }
168         Iterator(ContainerNode& root, Node& current)
169             : ComposedTreeIterator(root, current)
170         { }
171
172         Iterator& operator++() { return static_cast<Iterator&>(traverseNextSibling()); }
173         Iterator& operator--() { return static_cast<Iterator&>(traversePreviousSibling()); }
174     };
175
176     ComposedTreeChildAdapter(ContainerNode& parent)
177         : m_parent(parent)
178     { }
179
180     Iterator begin() { return Iterator(m_parent); }
181     Iterator end() { return { }; }
182     Iterator at(const Node& child) { return Iterator(m_parent, const_cast<Node&>(child)); }
183
184 private:
185     ContainerNode& m_parent;
186 };
187
188 // FIXME: We should have const versions too.
189 inline ComposedTreeDescendantAdapter composedTreeDescendants(ContainerNode& parent)
190 {
191     return ComposedTreeDescendantAdapter(parent);
192 }
193
194 inline ComposedTreeChildAdapter composedTreeChildren(ContainerNode& parent)
195 {
196     return ComposedTreeChildAdapter(parent);
197 }
198
199 enum class ComposedTreeAsTextMode { Normal, WithPointers };
200 WEBCORE_EXPORT String composedTreeAsText(ContainerNode& root, ComposedTreeAsTextMode = ComposedTreeAsTextMode::Normal);
201
202 }
203
204 #endif