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

Source/core/css/RuleSet.cpp

 /*
  * Copyright (C) 1999 Lars Knoll (knoll@kde.org)
  *           (C) 2004-2005 Allan Sandfeld Jensen (kde@carewolf.com)
  * Copyright (C) 2006, 2007 Nicholas Shanks (webkit@nickshanks.com)
  * Copyright (C) 2005, 2006, 2007, 2008, 2009, 2010, 2011, 2012 Apple Inc. All rights reserved.
  * Copyright (C) 2007 Alexey Proskuryakov <ap@webkit.org>
  * Copyright (C) 2007, 2008 Eric Seidel <eric@webkit.org>
  * Copyright (C) 2008, 2009 Torch Mobile Inc. All rights reserved. (http://www.torchmobile.com/)
  * Copyright (c) 2011, Code Aurora Forum. All rights reserved.
  * Copyright (C) Research In Motion Limited 2011. All rights reserved.
@@ skipping 92 matching lines @@
         if (selector->isAttributeSelector())
             return true;
         if (selectorListContainsUncommonAttributeSelector(selector))
             return true;
     }
     return false;
 }
 
 static inline PropertyWhitelistType determinePropertyWhitelistType(const AddRuleFlags addRuleFlags, const CSSSelector* selector)
 {
-    if (addRuleFlags & RuleIsInRegionRule)
-        return PropertyWhitelistRegion;
     for (const CSSSelector* component = selector; component; component = component->tagHistory()) {
         if (component->pseudoType() == CSSSelector::PseudoCue || (component->m_match == CSSSelector::PseudoElement && component->value() == TextTrackCue::cueShadowPseudoId()))
             return PropertyWhitelistCue;
     }
     return PropertyWhitelistNone;
 }
 
 namespace {
 
 // FIXME: Should we move this class to WTF?
@@ skipping 170 matching lines @@
     ensurePendingRules(); // So that m_fontFaceRules.shrinkToFit() gets called.
     m_fontFaceRules.append(rule);
 }
 
 void RuleSet::addKeyframesRule(StyleRuleKeyframes* rule)
 {
     ensurePendingRules(); // So that m_keyframesRules.shrinkToFit() gets called.
     m_keyframesRules.append(rule);
 }
 
-void RuleSet::addRegionRule(StyleRuleRegion* regionRule, bool hasDocumentSecurityOrigin)
-{
-    ensurePendingRules(); // So that m_regionSelectorsAndRuleSets.shrinkToFit() gets called.
-    OwnPtr<RuleSet> regionRuleSet = RuleSet::create();
-    // The region rule set should take into account the position inside the parent rule set.
-    // Otherwise, the rules inside region block might be incorrectly positioned before other similar rules from
-    // the stylesheet that contains the region block.
-    regionRuleSet->m_ruleCount = m_ruleCount;
-
-    // Collect the region rules into a rule set
-    // FIXME: Should this add other types of rules? (i.e. use addChildRules() directly?)
-    const Vector<RefPtr<StyleRuleBase> >& childRules = regionRule->childRules();
-    AddRuleFlags addRuleFlags = hasDocumentSecurityOrigin ? RuleHasDocumentSecurityOrigin : RuleHasNoSpecialState;
-    addRuleFlags = static_cast<AddRuleFlags>(addRuleFlags | RuleIsInRegionRule | RuleCanUseFastCheckSelector);
-    for (unsigned i = 0; i < childRules.size(); ++i) {
-        StyleRuleBase* regionStylingRule = childRules[i].get();
-        if (regionStylingRule->isStyleRule())
-            regionRuleSet->addStyleRule(toStyleRule(regionStylingRule), addRuleFlags);
-    }
-    // Update the "global" rule count so that proper order is maintained
-    m_ruleCount = regionRuleSet->m_ruleCount;
-
-    m_regionSelectorsAndRuleSets.append(RuleSetSelectorPair(regionRule->selectorList().first(), regionRuleSet.release()));
-}
-
 void RuleSet::addChildRules(const Vector<RefPtr<StyleRuleBase> >& rules, const MediaQueryEvaluator& medium, AddRuleFlags addRuleFlags)
 {
     for (unsigned i = 0; i < rules.size(); ++i) {
         StyleRuleBase* rule = rules[i].get();
 
         if (rule->isStyleRule()) {
             StyleRule* styleRule = toStyleRule(rule);
 
             const CSSSelectorList& selectorList = styleRule->selectorList();
             for (size_t selectorIndex = 0; selectorIndex != kNotFound; selectorIndex = selectorList.indexOfNextSelectorAfter(selectorIndex)) {
                 if (selectorList.hasCombinatorCrossingTreeBoundaryAt(selectorIndex)) {
                     m_treeBoundaryCrossingRules.append(MinimalRuleData(styleRule, selectorIndex, addRuleFlags));
                 } else if (selectorList.hasShadowDistributedAt(selectorIndex)) {
                     m_shadowDistributedRules.append(MinimalRuleData(styleRule, selectorIndex, addRuleFlags));
                 } else {
                     addRule(styleRule, selectorIndex, addRuleFlags);
                 }
             }
         } else if (rule->isPageRule()) {
             addPageRule(toStyleRulePage(rule));
         } else if (rule->isMediaRule()) {
             StyleRuleMedia* mediaRule = toStyleRuleMedia(rule);
             if ((!mediaRule->mediaQueries() || medium.eval(mediaRule->mediaQueries(), &m_viewportDependentMediaQueryResults)))
                 addChildRules(mediaRule->childRules(), medium, addRuleFlags);
         } else if (rule->isFontFaceRule()) {
             addFontFaceRule(toStyleRuleFontFace(rule));
         } else if (rule->isKeyframesRule()) {
             addKeyframesRule(toStyleRuleKeyframes(rule));
-        } else if (rule->isRegionRule()) {
-            addRegionRule(toStyleRuleRegion(rule), addRuleFlags & RuleHasDocumentSecurityOrigin);
         } else if (rule->isViewportRule()) {
             addViewportRule(toStyleRuleViewport(rule));
         } else if (rule->isSupportsRule() && toStyleRuleSupports(rule)->conditionIsSupported()) {
             addChildRules(toStyleRuleSupports(rule)->childRules(), medium, addRuleFlags);
         }
     }
 }
 
 void RuleSet::addRulesFromSheet(StyleSheetContents* sheet, const MediaQueryEvaluator& medium, AddRuleFlags addRuleFlags)
 {
@@ skipping 48 matching lines @@
     m_universalRules.shrinkToFit();
     m_pageRules.shrinkToFit();
     m_viewportRules.shrinkToFit();
     m_fontFaceRules.shrinkToFit();
     m_keyframesRules.shrinkToFit();
     m_treeBoundaryCrossingRules.shrinkToFit();
     m_shadowDistributedRules.shrinkToFit();
 }
 
 } // namespace WebCore