*** DO NOT LAND *** Attempt to understand Regions complexity

Source/core/css/resolver/StyleResolver.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,
@@ skipping 43 matching lines @@
 class CSSValue;
 class ContainerNode;
 class Document;
 class DocumentTimeline;
 class Element;
 class ElementRuleCollector;
 class KeyframeList;
 class KeyframeValue;
 class MediaQueryEvaluator;
 class MediaQueryResult;
-class RenderRegion;
 class RuleData;
 class Settings;
 class StyleKeyframe;
 class StylePropertySet;
 class StyleResolverStats;
 class StyleRule;
 class StyleRuleKeyframes;
 class StyleRulePage;
 class ViewportStyleResolver;
 
@@ skipping 35 matching lines @@
     // FIXME: StyleResolver should not be keeping tree-walk state.
     // These should move to some global tree-walk state, or should be contained in a
     // TreeWalkContext or similar which is passed in to StyleResolver methods when available.
     // Using these during tree walk will allow style selector to optimize child and descendant selector lookups.
     void pushParentElement(Element&);
     void popParentElement(Element&);
     void pushParentShadowRoot(const ShadowRoot&);
     void popParentShadowRoot(const ShadowRoot&);
 
     PassRefPtr<RenderStyle> styleForElement(Element*, RenderStyle* parentStyle = 0, StyleSharingBehavior = AllowStyleSharing,
-        RuleMatchingBehavior = MatchAllRules, RenderRegion* regionForStyling = 0);
+        RuleMatchingBehavior = MatchAllRules);
 
     // FIXME: keyframeStylesForAnimation is only used in the legacy animations implementation
     // and should be removed when that is replaced by Web Animations.
     void keyframeStylesForAnimation(Element*, const RenderStyle&, KeyframeList&);
     PassRefPtr<RenderStyle> styleForKeyframe(Element*, const RenderStyle&, RenderStyle* parentStyle, const StyleKeyframe*, const AtomicString& animationName);
     static PassRefPtr<KeyframeEffectModel> createKeyframeEffectModel(Element&, const Vector<RefPtr<MutableStylePropertySet> >&, KeyframeEffectModel::KeyframeVector&);
 
     PassRefPtr<RenderStyle> pseudoStyleForElement(Element*, const PseudoStyleRequest&, RenderStyle* parentStyle);
 
     PassRefPtr<RenderStyle> styleForPage(int pageIndex);
@@ skipping 54 matching lines @@
     // |properties| is an array with |count| elements.
     void applyPropertiesToStyle(const CSSPropertyValue* properties, size_t count, RenderStyle*);
 
     ViewportStyleResolver* viewportStyleResolver() { return m_viewportStyleResolver.get(); }
 
     void addMediaQueryResults(const MediaQueryResultList&);
     MediaQueryResultList* viewportDependentMediaQueryResults() { return &m_viewportDependentMediaQueryResults; }
     bool hasViewportDependentMediaQueries() const { return !m_viewportDependentMediaQueryResults.isEmpty(); }
     bool mediaQueryAffectedByViewportChange() const;
 
-    // FIXME: Regions should not require special logic in StyleResolver.
-    bool checkRegionStyle(Element* regionElement);
-
     // FIXME: Rename to reflect the purpose, like didChangeFontSize or something.
     void invalidateMatchedPropertiesCache();
 
     void notifyResizeForViewportUnits();
 
     // Exposed for RenderStyle::isStyleAvilable().
     static RenderStyle* styleNotYetAvailable() { return s_styleNotYetAvailable; }
 
     const RuleFeatureSet& ensureRuleFeatureSet()
     {
@@ skipping 118 matching lines @@
 
     StyleSharingList m_styleSharingList;
 
     OwnPtr<StyleResolverStats> m_styleResolverStats;
     OwnPtr<StyleResolverStats> m_styleResolverStatsTotals;
     unsigned m_styleResolverStatsSequence;
 
     unsigned m_accessCount;
 };
 
-inline bool checkRegionSelector(const CSSSelector* regionSelector, Element* regionElement)
-{
-    if (!regionSelector || !regionElement)
-        return false;
-
-    SelectorChecker selectorChecker(regionElement->document(), SelectorChecker::QueryingRules);
-    for (const CSSSelector* s = regionSelector; s; s = CSSSelectorList::next(s)) {
-        SelectorChecker::SelectorCheckingContext selectorCheckingContext(s, regionElement, SelectorChecker::VisitedMatchDisabled);
-        if (selectorChecker.match(selectorCheckingContext, DOMSiblingTraversalStrategy()) == SelectorChecker::SelectorMatches)
-            return true;
-    }
-    return false;
-}
-
 } // namespace WebCore
 
 #endif // StyleResolver_h