1/*
2 * Copyright (C) 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#pragma once
27
28#include <wtf/HashMap.h>
29
30namespace WebCore {
31
32class Document;
33class DocumentRuleSets;
34class Element;
35class Node;
36class RenderStyle;
37class RuleSet;
38class SelectorFilter;
39class SpaceSplitString;
40class StyledElement;
41
42namespace Style {
43
44class Update;
45
46class SharingResolver {
47public:
48 SharingResolver(const Document&, const DocumentRuleSets&, const SelectorFilter&);
49
50 std::unique_ptr<RenderStyle> resolve(const Element&, const Update&);
51
52private:
53 struct Context;
54
55 StyledElement* findSibling(const Context&, Node*, unsigned& count) const;
56 Node* locateCousinList(const Element* parent) const;
57 bool canShareStyleWithElement(const Context&, const StyledElement& candidateElement) const;
58 bool styleSharingCandidateMatchesRuleSet(const StyledElement&, const RuleSet*) const;
59 bool sharingCandidateHasIdenticalStyleAffectingAttributes(const Context&, const StyledElement& sharingCandidate) const;
60 bool classNamesAffectedByRules(const SpaceSplitString& classNames) const;
61
62 const Document& m_document;
63 const DocumentRuleSets& m_ruleSets;
64 const SelectorFilter& m_selectorFilter;
65
66 HashMap<const Element*, const Element*> m_elementsSharingStyle;
67};
68
69}
70}
71