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

Source/core/css/StyleRule.h

 /*
  * (C) 1999-2003 Lars Knoll (knoll@kde.org)
  * (C) 2002-2003 Dirk Mueller (mueller@kde.org)
  * Copyright (C) 2002, 2006, 2008, 2012, 2013 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.
  *
@@ skipping 31 matching lines @@
         Style,
         Charset, // Not used. These are internally strings owned by the style sheet.
         Import,
         Media,
         FontFace,
         Page,
         Keyframes,
         Keyframe, // Not used. These are internally non-rule StyleKeyframe objects.
         Supports = 12,
         Viewport = 15,
-        Region = 16,
         Filter = 17
     };
 
     Type type() const { return static_cast<Type>(m_type); }
 
     bool isCharsetRule() const { return type() == Charset; }
     bool isFontFaceRule() const { return type() == FontFace; }
     bool isKeyframesRule() const { return type() == Keyframes; }
     bool isMediaRule() const { return type() == Media; }
     bool isPageRule() const { return type() == Page; }
     bool isStyleRule() const { return type() == Style; }
-    bool isRegionRule() const { return type() == Region; }
     bool isSupportsRule() const { return type() == Supports; }
     bool isViewportRule() const { return type() == Viewport; }
     bool isImportRule() const { return type() == Import; }
     bool isFilterRule() const { return type() == Filter; }
 
     PassRefPtr<StyleRuleBase> copy() const;
 
     void deref()
     {
         if (derefBase())
@@ skipping 134 matching lines @@
     PassRefPtr<StyleRuleSupports> copy() const { return adoptRef(new StyleRuleSupports(*this)); }
 
 private:
     StyleRuleSupports(const String& conditionText, bool conditionIsSupported, Vector<RefPtr<StyleRuleBase> >& adoptRules);
     StyleRuleSupports(const StyleRuleSupports&);
 
     String m_conditionText;
     bool m_conditionIsSupported;
 };
 
-class StyleRuleRegion : public StyleRuleGroup {
-public:
-    static PassRefPtr<StyleRuleRegion> create(Vector<OwnPtr<CSSParserSelector> >* selectors, Vector<RefPtr<StyleRuleBase> >& adoptRules)
-    {
-        return adoptRef(new StyleRuleRegion(selectors, adoptRules));
-    }
-
-    const CSSSelectorList& selectorList() const { return m_selectorList; }
-
-    PassRefPtr<StyleRuleRegion> copy() const { return adoptRef(new StyleRuleRegion(*this)); }
-
-private:
-    StyleRuleRegion(Vector<OwnPtr<CSSParserSelector> >*, Vector<RefPtr<StyleRuleBase> >& adoptRules);
-    StyleRuleRegion(const StyleRuleRegion&);
-
-    CSSSelectorList m_selectorList;
-};
-
 class StyleRuleViewport : public StyleRuleBase {
 public:
     static PassRefPtr<StyleRuleViewport> create() { return adoptRef(new StyleRuleViewport); }
 
     ~StyleRuleViewport();
 
     const StylePropertySet* properties() const { return m_properties.get(); }
     MutableStylePropertySet* mutableProperties();
 
     void setProperties(PassRefPtr<StylePropertySet>);
@@ skipping 31 matching lines @@
 };
 
 #define DEFINE_STYLE_RULE_TYPE_CASTS(Type) \
     DEFINE_TYPE_CASTS(StyleRule##Type, StyleRuleBase, rule, rule->is##Type##Rule(), rule.is##Type##Rule())
 
 DEFINE_TYPE_CASTS(StyleRule, StyleRuleBase, rule, rule->isStyleRule(), rule.isStyleRule());
 DEFINE_STYLE_RULE_TYPE_CASTS(FontFace);
 DEFINE_STYLE_RULE_TYPE_CASTS(Page);
 DEFINE_STYLE_RULE_TYPE_CASTS(Media);
 DEFINE_STYLE_RULE_TYPE_CASTS(Supports);
-DEFINE_STYLE_RULE_TYPE_CASTS(Region);
 DEFINE_STYLE_RULE_TYPE_CASTS(Viewport);
 DEFINE_STYLE_RULE_TYPE_CASTS(Filter);
 
 } // namespace WebCore
 
 #endif // StyleRule_h