1/* 2 * Copyright (C) 2013 Google, Inc. 3 * Copyright (C) 1999 Lars Knoll (knoll@kde.org) 4 * Copyright (C) 2003, 2004, 2005, 2006, 2007, 2008, 2009, 2010, 2011 Apple Inc. All rights reserved. 5 * 6 * This library is free software; you can redistribute it and/or 7 * modify it under the terms of the GNU Library General Public 8 * License as published by the Free Software Foundation; either 9 * version 2 of the License, or (at your option) any later version. 10 * 11 * This library is distributed in the hope that it will be useful, 12 * but WITHOUT ANY WARRANTY; without even the implied warranty of 13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 14 * Library General Public License for more details. 15 * 16 * You should have received a copy of the GNU Library General Public License 17 * along with this library; see the file COPYING.LIB. If not, write to 18 * the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, 19 * Boston, MA 02110-1301, USA. 20 */ 21 22#ifndef SharedStyleFinder_h 23#define SharedStyleFinder_h 24 25#include "core/css/resolver/ElementResolveContext.h" 26#include "core/dom/Element.h" 27 28namespace blink { 29 30class Element; 31class RenderStyle; 32class RuleFeatureSet; 33class RuleSet; 34class SpaceSplitString; 35class StyleResolver; 36 37class SharedStyleFinder { 38 STACK_ALLOCATED(); 39public: 40 // RuleSets are passed non-const as the act of matching against them can cause them 41 // to be compacted. :( 42 SharedStyleFinder(const ElementResolveContext& context, 43 const RuleFeatureSet& features, RuleSet* siblingRuleSet, 44 RuleSet* uncommonAttributeRuleSet, StyleResolver& styleResolver) 45 : m_elementAffectedByClassRules(false) 46 , m_features(features) 47 , m_siblingRuleSet(siblingRuleSet) 48 , m_uncommonAttributeRuleSet(uncommonAttributeRuleSet) 49 , m_styleResolver(styleResolver) 50 , m_context(context) 51 { } 52 53 RenderStyle* findSharedStyle(); 54 55private: 56 Element* findElementForStyleSharing() const; 57 58 // Only used when we're collecting stats on styles. 59 bool documentContainsValidCandidate() const; 60 61 bool classNamesAffectedByRules(const SpaceSplitString&) const; 62 63 bool canShareStyleWithElement(Element& candidate) const; 64 bool canShareStyleWithControl(Element& candidate) const; 65 bool sharingCandidateHasIdenticalStyleAffectingAttributes(Element& candidate) const; 66 bool sharingCandidateCanShareHostStyles(Element& candidate) const; 67 bool sharingCandidateDistributedToSameInsertionPoint(Element& candidate) const; 68 bool matchesRuleSet(RuleSet*); 69 70 Element& element() const { return *m_context.element(); } 71 Document& document() const { return element().document(); } 72 73 bool m_elementAffectedByClassRules; 74 const RuleFeatureSet& m_features; 75 RawPtrWillBeMember<RuleSet> m_siblingRuleSet; 76 RawPtrWillBeMember<RuleSet> m_uncommonAttributeRuleSet; 77 StyleResolver& m_styleResolver; 78 const ElementResolveContext& m_context; 79}; 80 81} // namespace blink 82 83#endif // SharedStyleFinder_h 84