Source/core/css/ElementRuleCollector.h

/*
 * Copyright (C) 1999 Lars Knoll (knoll@kde.org)
 * Copyright (C) 2003, 2004, 2005, 2006, 2007, 2008, 2009, 2010, 2011 Apple Inc. All rights reserved.
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Library General Public
 * License as published by the Free Software Foundation; either
 * version 2 of the License, or (at your option) any later version.
 *
 * This library is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Library General Public License for more details.
 *
 * You should have received a copy of the GNU Library General Public License
 * along with this library; see the file COPYING.LIB.  If not, write to
 * the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
 * Boston, MA 02110-1301, USA.
 *
 */

#ifndef ElementRuleCollector_h
#define ElementRuleCollector_h

#include "core/css/PseudoStyleRequest.h"
#include "core/css/SelectorChecker.h"
#include "core/css/resolver/ElementResolveContext.h"
#include "core/css/resolver/MatchRequest.h"
#include "core/css/resolver/MatchResult.h"
#include "wtf/RefPtr.h"
#include "wtf/Vector.h"

namespace WebCore {

class CSSStyleSheet;
class CSSRuleList;
class RenderRegion;
class RuleData;
class RuleSet;
class ScopedStyleResolver;
class SelectorFilter;
class StaticCSSRuleList;

typedef unsigned CascadeScope;
typedef unsigned CascadeOrder;

const CascadeScope ignoreCascadeScope = 0;
const CascadeOrder ignoreCascadeOrder = 0;

class MatchedRule {
    WTF_MAKE_FAST_ALLOCATED;
public:
    explicit MatchedRule(const RuleData* ruleData, unsigned specificity, CascadeScope cascadeScope, CascadeOrder cascadeOrder, unsigned styleSheetIndex, const CSSStyleSheet* parentStyleSheet)
        : m_ruleData(ruleData)
        , m_specificity(specificity)
        , m_cascadeScope(cascadeScope)
        , m_parentStyleSheet(parentStyleSheet)
    {
        ASSERT(m_ruleData);
        static const unsigned BitsForPositionInRuleData = 18;
        static const unsigned BitsForStyleSheetIndex = 32;
        m_position = ((uint64_t)cascadeOrder << (BitsForStyleSheetIndex + BitsForPositionInRuleData)) + ((uint64_t)styleSheetIndex << BitsForPositionInRuleData)+ m_ruleData->position();
    }

    const RuleData* ruleData() const { return m_ruleData; }
    uint32_t cascadeScope() const { return m_cascadeScope; }
    uint64_t position() const { return m_position; }
    unsigned specificity() const { return ruleData()->specificity() + m_specificity; }
    const CSSStyleSheet* parentStyleSheet() const { return m_parentStyleSheet; }

private:
    const RuleData* m_ruleData;
    unsigned m_specificity;
    CascadeScope m_cascadeScope;
    uint64_t m_position;
    const CSSStyleSheet* m_parentStyleSheet;
};

class StyleRuleList : public RefCounted<StyleRuleList> {
public:
    static PassRefPtr<StyleRuleList> create() { return adoptRef(new StyleRuleList()); }
    Vector<StyleRule*> m_list;
};

// ElementRuleCollector is designed to be used as a stack object.
// Create one, ask what rules the ElementResolveContext matches
// and then let it go out of scope.
// FIXME: Currently it modifies the RenderStyle but should not!
class ElementRuleCollector {
    WTF_MAKE_NONCOPYABLE(ElementRuleCollector);
public:
    ElementRuleCollector(const ElementResolveContext&, const SelectorFilter&, RenderStyle* = 0);
    ~ElementRuleCollector();

    void setMode(SelectorChecker::Mode mode) { m_mode = mode; }
    void setPseudoStyleRequest(const PseudoStyleRequest& request) { m_pseudoStyleRequest = request; }
    void setSameOriginOnly(bool f) { m_sameOriginOnly = f; }
    void setRegionForStyling(const RenderRegion* regionForStyling) { m_regionForStyling = regionForStyling; }

    void setMatchingUARules(bool matchingUARules) { m_matchingUARules = matchingUARules; }
    bool hasAnyMatchingRules(RuleSet*);

    MatchResult& matchedResult();
    PassRefPtr<StyleRuleList> matchedStyleRuleList();
    PassRefPtr<CSSRuleList> matchedCSSRuleList();

    void collectMatchingRules(const MatchRequest&, RuleRange&, SelectorChecker::BehaviorAtBoundary = SelectorChecker::DoesNotCrossBoundary, CascadeScope = ignoreCascadeScope, CascadeOrder = ignoreCascadeOrder);
    void collectMatchingRulesForRegion(const MatchRequest&, RuleRange&, SelectorChecker::BehaviorAtBoundary = SelectorChecker::DoesNotCrossBoundary, CascadeScope = ignoreCascadeScope, CascadeOrder = ignoreCascadeOrder);
    void sortAndTransferMatchedRules();
    void clearMatchedRules();
    void addElementStyleProperties(const StylePropertySet*, bool isCacheable = true);

    unsigned lastMatchedRulesPosition() const { return m_matchedRules ? m_matchedRules->size() : 0; }
    void sortMatchedRulesFrom(unsigned position);
    void sortAndTransferMatchedRulesWithOnlySortBySpecificity();

private:
    void collectRuleIfMatches(const RuleData&, SelectorChecker::BehaviorAtBoundary, CascadeScope, CascadeOrder, const MatchRequest&, RuleRange&);
    void collectMatchingRulesForList(const Vector<RuleData>*, SelectorChecker::BehaviorAtBoundary, CascadeScope, CascadeOrder, const MatchRequest&, RuleRange&);
    void collectMatchingRulesForList(const RuleData*, SelectorChecker::BehaviorAtBoundary, CascadeScope, CascadeOrder, const MatchRequest&, RuleRange&);
    bool ruleMatches(const RuleData&, const ContainerNode* scope, SelectorChecker::BehaviorAtBoundary, SelectorChecker::MatchResult*);

    CSSRuleList* nestedRuleList(CSSRule*);
    template<class CSSRuleCollection>
    CSSRule* findStyleRule(CSSRuleCollection*, StyleRule*);
    void appendCSSOMWrapperForRule(CSSStyleSheet*, StyleRule*);

    void sortMatchedRules();
    void addMatchedRule(const RuleData*, unsigned specificity, CascadeScope, CascadeOrder, unsigned styleSheetIndex, const CSSStyleSheet* parentStyleSheet);

    StaticCSSRuleList* ensureRuleList();
    StyleRuleList* ensureStyleRuleList();

private:
    const ElementResolveContext& m_context;
    const SelectorFilter& m_selectorFilter;
    RefPtr<RenderStyle> m_style; // FIXME: This can be mutated during matching!

    const RenderRegion* m_regionForStyling;
    PseudoStyleRequest m_pseudoStyleRequest;
    SelectorChecker::Mode m_mode;
    bool m_canUseFastReject;
    bool m_sameOriginOnly;
    bool m_matchingUARules;

    OwnPtr<Vector<MatchedRule, 32> > m_matchedRules;

    // Output.
    RefPtr<StaticCSSRuleList> m_cssRuleList;
    RefPtr<StyleRuleList> m_styleRuleList;
    MatchResult m_result;
};

} // namespace WebCore

#endif // ElementRuleCollector_h