Implement ComposedTreeIterator in terms of ElementAndTextDescendantIterator
[WebKit-https.git] / Source / WebCore / dom / ComposedTreeIterator.h
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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     ComposedTreeIterator(ContainerNode& root);
40     ComposedTreeIterator(ContainerNode& root, Node& current);
41
42     Node& operator*() { return current(); }
43     Node* operator->() { return &current(); }
44
45     bool operator==(const ComposedTreeIterator& other) const { return context().iterator == other.context().iterator; }
46     bool operator!=(const ComposedTreeIterator& other) const { return context().iterator != other.context().iterator; }
47
48     ComposedTreeIterator& operator++() { return traverseNext(); }
49
50     ComposedTreeIterator& traverseNext();
51     ComposedTreeIterator& traverseNextSkippingChildren();
52     ComposedTreeIterator& traverseNextSibling();
53     ComposedTreeIterator& traversePreviousSibling();
54
55     unsigned depth() const;
56
57 private:
58     void initializeContextStack(ContainerNode& root, Node& current);
59     void traverseNextInShadowTree();
60     void traverseNextLeavingContext();
61     bool pushContext(ShadowRoot&);
62 #if ENABLE(SHADOW_DOM) || ENABLE(DETAILS_ELEMENT)
63     bool advanceInSlot(int direction);
64     void traverseSiblingInSlot(int direction);
65 #endif
66
67     struct Context {
68         Context() { }
69         explicit Context(ContainerNode& root)
70             : iterator(root)
71         { }
72         Context(ContainerNode& root, Node& node, size_t slotNodeIndex = notFound)
73             : iterator(root, &node)
74             , slotNodeIndex(slotNodeIndex)
75         { }
76
77         ElementAndTextDescendantIterator iterator;
78 #if ENABLE(SHADOW_DOM) || ENABLE(DETAILS_ELEMENT)
79         size_t slotNodeIndex { notFound };
80 #endif
81     };
82     Context& context() { return m_contextStack.last(); }
83     const Context& context() const { return m_contextStack.last(); }
84     Node& current() { return *context().iterator; }
85
86     Vector<Context, 4> m_contextStack;
87 };
88
89 inline ComposedTreeIterator::ComposedTreeIterator()
90     : m_contextStack({ { } })
91 {
92 }
93
94 inline ComposedTreeIterator& ComposedTreeIterator::traverseNext()
95 {
96     if (auto* shadowRoot = context().iterator->shadowRoot()) {
97         if (pushContext(*shadowRoot))
98             return *this;
99     }
100
101     if (m_contextStack.size() > 1) {
102         traverseNextInShadowTree();
103         return *this;
104     }
105
106     context().iterator.traverseNext();
107     return *this;
108 }
109
110 inline ComposedTreeIterator& ComposedTreeIterator::traverseNextSkippingChildren()
111 {
112     context().iterator.traverseNextSkippingChildren();
113
114     if (!context().iterator && m_contextStack.size() > 1)
115         traverseNextLeavingContext();
116     
117     return *this;
118 }
119
120 inline ComposedTreeIterator& ComposedTreeIterator::traverseNextSibling()
121 {
122 #if ENABLE(SHADOW_DOM) || ENABLE(DETAILS_ELEMENT)
123     if (current().parentNode()->shadowRoot()) {
124         traverseSiblingInSlot(1);
125         return *this;
126     }
127 #endif
128     context().iterator.traverseNextSibling();
129     return *this;
130 }
131
132 inline ComposedTreeIterator& ComposedTreeIterator::traversePreviousSibling()
133 {
134 #if ENABLE(SHADOW_DOM) || ENABLE(DETAILS_ELEMENT)
135     if (current().parentNode()->shadowRoot()) {
136         traverseSiblingInSlot(-1);
137         return *this;
138     }
139 #endif
140     context().iterator.traversePreviousSibling();
141     return *this;
142 }
143
144 inline unsigned ComposedTreeIterator::depth() const
145 {
146     unsigned depth = 0;
147     for (auto& context : m_contextStack)
148         depth += context.iterator.depth();
149     return depth;
150 }
151
152 class ComposedTreeDescendantAdapter {
153 public:
154     ComposedTreeDescendantAdapter(ContainerNode& parent)
155         : m_parent(parent)
156     { }
157
158     ComposedTreeIterator begin() { return ComposedTreeIterator(m_parent); }
159     ComposedTreeIterator end() { return { }; }
160     ComposedTreeIterator at(const Node& child) { return ComposedTreeIterator(m_parent, const_cast<Node&>(child)); }
161     
162 private:
163     ContainerNode& m_parent;
164 };
165
166 class ComposedTreeChildAdapter {
167 public:
168     class Iterator : public ComposedTreeIterator {
169     public:
170         Iterator() = default;
171         explicit Iterator(ContainerNode& root)
172             : ComposedTreeIterator(root)
173         { }
174         Iterator(ContainerNode& root, Node& current)
175             : ComposedTreeIterator(root, current)
176         { }
177
178         Iterator& operator++() { return static_cast<Iterator&>(traverseNextSibling()); }
179         Iterator& operator--() { return static_cast<Iterator&>(traversePreviousSibling()); }
180     };
181
182     ComposedTreeChildAdapter(ContainerNode& parent)
183         : m_parent(parent)
184     { }
185
186     Iterator begin() { return Iterator(m_parent); }
187     Iterator end() { return { }; }
188     Iterator at(const Node& child) { return Iterator(m_parent, const_cast<Node&>(child)); }
189
190 private:
191     ContainerNode& m_parent;
192 };
193
194 // FIXME: We should have const versions too.
195 inline ComposedTreeDescendantAdapter composedTreeDescendants(ContainerNode& parent)
196 {
197     return ComposedTreeDescendantAdapter(parent);
198 }
199
200 inline ComposedTreeChildAdapter composedTreeChildren(ContainerNode& parent)
201 {
202     return ComposedTreeChildAdapter(parent);
203 }
204
205 }
206
207 #endif