1/*
2 * Copyright (C) 2011 Google Inc. All Rights Reserved.
3 * Copyright (C) 2012 Apple Inc. All Rights Reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 * 1. Redistributions of source code must retain the above copyright
9 *    notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 *    notice, this list of conditions and the following disclaimer in the
12 *    documentation and/or other materials provided with the distribution.
13 *
14 * THIS SOFTWARE IS PROVIDED BY APPLE INC. ``AS IS'' AND ANY
15 * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
16 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
17 * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL APPLE INC. OR
18 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
19 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
20 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
21 * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
22 * 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 TreeScope_h
28#define TreeScope_h
29
30#include "core/dom/DocumentOrderedMap.h"
31#include "platform/heap/Handle.h"
32#include "wtf/text/AtomicString.h"
33
34namespace blink {
35
36class ContainerNode;
37class DOMSelection;
38class Document;
39class Element;
40class HTMLLabelElement;
41class HTMLMapElement;
42class HitTestResult;
43class IdTargetObserverRegistry;
44class ScopedStyleResolver;
45class Node;
46
47// A class which inherits both Node and TreeScope must call clearRareData() in its destructor
48// so that the Node destructor no longer does problematic NodeList cache manipulation in
49// the destructor.
50class TreeScope : public WillBeGarbageCollectedMixin {
51public:
52    TreeScope* parentTreeScope() const { return m_parentTreeScope; }
53
54    TreeScope* olderShadowRootOrParentTreeScope() const;
55    bool isInclusiveOlderSiblingShadowRootOrAncestorTreeScopeOf(const TreeScope&) const;
56
57    Element* adjustedFocusedElement() const;
58    Element* getElementById(const AtomicString&) const;
59    const WillBeHeapVector<RawPtrWillBeMember<Element> >& getAllElementsById(const AtomicString&) const;
60    bool hasElementWithId(const AtomicString& id) const;
61    bool containsMultipleElementsWithId(const AtomicString& id) const;
62    void addElementById(const AtomicString& elementId, Element*);
63    void removeElementById(const AtomicString& elementId, Element*);
64
65    Document& document() const
66    {
67        ASSERT(m_document);
68        return *m_document;
69    }
70
71    Node* ancestorInThisScope(Node*) const;
72
73    void addImageMap(HTMLMapElement*);
74    void removeImageMap(HTMLMapElement*);
75    HTMLMapElement* getImageMap(const String& url) const;
76
77    Element* elementFromPoint(int x, int y) const;
78
79    // For accessibility.
80    bool shouldCacheLabelsByForAttribute() const { return m_labelsByForAttribute; }
81    void addLabel(const AtomicString& forAttributeValue, HTMLLabelElement*);
82    void removeLabel(const AtomicString& forAttributeValue, HTMLLabelElement*);
83    HTMLLabelElement* labelElementForId(const AtomicString& forAttributeValue);
84
85    DOMSelection* getSelection() const;
86
87    // Find first anchor with the given name.
88    // First searches for an element with the given ID, but if that fails, then looks
89    // for an anchor with the given name. ID matching is always case sensitive, but
90    // Anchor name matching is case sensitive in strict mode and not case sensitive in
91    // quirks mode for historical compatibility reasons.
92    Element* findAnchor(const String& name);
93
94    // Used by the basic DOM mutation methods (e.g., appendChild()).
95    void adoptIfNeeded(Node&);
96
97    ContainerNode& rootNode() const { return *m_rootNode; }
98
99    IdTargetObserverRegistry& idTargetObserverRegistry() const { return *m_idTargetObserverRegistry.get(); }
100
101
102#if !ENABLE(OILPAN)
103    // Nodes belonging to this scope hold guard references -
104    // these are enough to keep the scope from being destroyed, but
105    // not enough to keep it from removing its children. This allows a
106    // node that outlives its scope to still have a valid document
107    // pointer without introducing reference cycles.
108    void guardRef()
109    {
110        ASSERT(!deletionHasBegun());
111        ++m_guardRefCount;
112    }
113
114    void guardDeref()
115    {
116        ASSERT(m_guardRefCount > 0);
117        ASSERT(!deletionHasBegun());
118        --m_guardRefCount;
119        if (!m_guardRefCount && !refCount() && !rootNodeHasTreeSharedParent()) {
120            beginDeletion();
121            delete this;
122        }
123    }
124#endif
125
126    void removedLastRefToScope();
127
128    bool isInclusiveAncestorOf(const TreeScope&) const;
129    unsigned short comparePosition(const TreeScope&) const;
130
131    const TreeScope* commonAncestorTreeScope(const TreeScope& other) const;
132    TreeScope* commonAncestorTreeScope(TreeScope& other);
133
134    Element* getElementByAccessKey(const String& key) const;
135
136    virtual void trace(Visitor*);
137
138    ScopedStyleResolver* scopedStyleResolver() const { return m_scopedStyleResolver.get(); }
139    ScopedStyleResolver& ensureScopedStyleResolver();
140    void clearScopedStyleResolver();
141
142protected:
143    TreeScope(ContainerNode&, Document&);
144    TreeScope(Document&);
145    virtual ~TreeScope();
146
147#if !ENABLE(OILPAN)
148    void destroyTreeScopeData();
149#endif
150
151    void setDocument(Document& document) { m_document = &document; }
152    void setParentTreeScope(TreeScope&);
153
154#if !ENABLE(OILPAN)
155    bool hasGuardRefCount() const { return m_guardRefCount; }
156#endif
157
158    void setNeedsStyleRecalcForViewportUnits();
159
160private:
161    virtual void dispose() { }
162
163#if !ENABLE(OILPAN)
164    int refCount() const;
165
166#if ENABLE(SECURITY_ASSERT)
167    bool deletionHasBegun();
168    void beginDeletion();
169#else
170    bool deletionHasBegun() { return false; }
171    void beginDeletion() { }
172#endif
173#endif
174
175    bool rootNodeHasTreeSharedParent() const;
176
177    RawPtrWillBeMember<ContainerNode> m_rootNode;
178    RawPtrWillBeMember<Document> m_document;
179    RawPtrWillBeMember<TreeScope> m_parentTreeScope;
180
181#if !ENABLE(OILPAN)
182    int m_guardRefCount;
183#endif
184
185    OwnPtrWillBeMember<DocumentOrderedMap> m_elementsById;
186    OwnPtrWillBeMember<DocumentOrderedMap> m_imageMapsByName;
187    OwnPtrWillBeMember<DocumentOrderedMap> m_labelsByForAttribute;
188
189    OwnPtrWillBeMember<IdTargetObserverRegistry> m_idTargetObserverRegistry;
190
191    OwnPtrWillBeMember<ScopedStyleResolver> m_scopedStyleResolver;
192
193    mutable RefPtrWillBeMember<DOMSelection> m_selection;
194};
195
196inline bool TreeScope::hasElementWithId(const AtomicString& id) const
197{
198    ASSERT(!id.isNull());
199    return m_elementsById && m_elementsById->contains(id);
200}
201
202inline bool TreeScope::containsMultipleElementsWithId(const AtomicString& id) const
203{
204    return m_elementsById && m_elementsById->containsMultiple(id);
205}
206
207DEFINE_COMPARISON_OPERATORS_WITH_REFERENCES(TreeScope)
208
209HitTestResult hitTestInDocument(const Document*, int x, int y);
210TreeScope* commonTreeScope(Node*, Node*);
211
212} // namespace blink
213
214#endif // TreeScope_h
215