1/*
2 * Copyright (C) 2010 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
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 GOOGLE 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 GOOGLE 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#pragma once
27
28#include "HTMLStackItem.h"
29#include <wtf/Forward.h>
30#include <wtf/RefPtr.h>
31#include <wtf/Vector.h>
32
33namespace WebCore {
34
35class Element;
36
37// This may end up merged into HTMLElementStack.
38class HTMLFormattingElementList {
39 WTF_MAKE_NONCOPYABLE(HTMLFormattingElementList);
40public:
41 HTMLFormattingElementList();
42 ~HTMLFormattingElementList();
43
44 // Ideally Entry would be private, but HTMLTreeBuilder has to coordinate
45 // between the HTMLFormattingElementList and HTMLElementStack and needs
46 // access to Entry::isMarker() and Entry::replaceElement() to do so.
47 class Entry {
48 public:
49 // Inline because they're hot and Vector<T> uses them.
50 explicit Entry(Ref<HTMLStackItem>&& item)
51 : m_item(WTFMove(item))
52 {
53 }
54 enum MarkerEntryType { MarkerEntry };
55 Entry(MarkerEntryType)
56 {
57 }
58
59 bool isMarker() const { return !m_item; }
60
61 HTMLStackItem* stackItem() const { return m_item.get(); }
62 Element& element() const
63 {
64 // The fact that !m_item == isMarker() is an implementation detail
65 // callers should check isMarker() before calling element().
66 ASSERT(m_item);
67 return m_item->element();
68 }
69 void replaceElement(Ref<HTMLStackItem>&& item) { m_item = WTFMove(item); }
70
71 // Needed for use with Vector. These are super-hot and must be inline.
72 bool operator==(Element* element) const { return !m_item ? !element : &m_item->element() == element; }
73 bool operator!=(Element* element) const { return !m_item ? !!element : &m_item->element() != element; }
74
75 private:
76 RefPtr<HTMLStackItem> m_item;
77 };
78
79 class Bookmark {
80 public:
81 explicit Bookmark(Entry& entry)
82 : m_hasBeenMoved(false)
83 , m_mark(&entry)
84 {
85 }
86
87 void moveToAfter(Entry& before)
88 {
89 m_hasBeenMoved = true;
90 m_mark = &before;
91 }
92
93 bool hasBeenMoved() const { return m_hasBeenMoved; }
94 Entry& mark() const { ASSERT(m_mark); return *m_mark; }
95
96 private:
97 bool m_hasBeenMoved;
98 Entry* m_mark;
99 };
100
101 bool isEmpty() const { return !size(); }
102 size_t size() const { return m_entries.size(); }
103
104 Element* closestElementInScopeWithName(const AtomicString&);
105
106 Entry* find(Element&);
107 bool contains(Element&);
108 void append(Ref<HTMLStackItem>&&);
109 void remove(Element&);
110
111 Bookmark bookmarkFor(Element&);
112 void swapTo(Element& oldElement, Ref<HTMLStackItem>&& newItem, const Bookmark&);
113
114 void appendMarker();
115 // clearToLastMarker also clears the marker (per the HTML5 spec).
116 void clearToLastMarker();
117
118 const Entry& at(size_t i) const { return m_entries[i]; }
119 Entry& at(size_t i) { return m_entries[i]; }
120
121#if ENABLE(TREE_DEBUGGING)
122 void show();
123#endif
124
125private:
126 Entry& first() { return at(0); }
127
128 // http://www.whatwg.org/specs/web-apps/current-work/multipage/parsing.html#list-of-active-formatting-elements
129 // These functions enforce the "Noah's Ark" condition, which removes redundant mis-nested elements.
130 void tryToEnsureNoahsArkConditionQuickly(HTMLStackItem&, Vector<HTMLStackItem*>& remainingCandidates);
131 void ensureNoahsArkCondition(HTMLStackItem&);
132
133 Vector<Entry> m_entries;
134};
135
136} // namespace WebCore
137