Make SelectorChecker a const operation over element.

sky/engine/core/css/SelectorChecker.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, 2013 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 21 matching lines @@
 #include "sky/engine/core/dom/Document.h"
 #include "sky/engine/core/dom/shadow/ShadowRoot.h"
 #include "sky/engine/core/editing/FrameSelection.h"
 #include "sky/engine/core/frame/LocalFrame.h"
 #include "sky/engine/core/html/parser/HTMLParserIdioms.h"
 #include "sky/engine/core/page/FocusController.h"
 #include "sky/engine/core/rendering/style/RenderStyle.h"
 
 namespace blink {
 
-SelectorChecker::SelectorChecker(Document& document, Mode mode)
-    : m_mode(mode)
+SelectorChecker::SelectorChecker()
+    : m_matchedAttributeSelector(false)
+    , m_matchedFocusSelector(false)
+    , m_matchedHoverSelector(false)
+    , m_matchedActiveSelector(false)
 {
 }
 
 static bool scopeContainsLastMatchedElement(const SelectorChecker::SelectorCheckingContext& context)
 {
     if (!context.scope)
         return true;
 
     ASSERT(context.scope);
     if (context.scope->treeScope() == context.element->treeScope())
         return true;
 
     // Because Blink treats a shadow host's TreeScope as a separate one from its descendent shadow roots,
     // if the last matched element is a shadow host, the condition above isn't met, even though it
     // should be.
     return context.element == context.scope->shadowHost();
 }
 
-bool SelectorChecker::match(const SelectorCheckingContext& context) const
+bool SelectorChecker::match(const SelectorCheckingContext& context)
 {
     // FIXME(sky): Get rid of SelectorCheckingContext.
     SelectorCheckingContext matchContext(context);
 
     bool isShadowHost = isHostInItsShadowTree(*context.element, context.scope);
 
     while (true) {
         const CSSSelector& selector = *matchContext.selector;
         // Only :host and :host-context() should match the host:
         // http://drafts.csswg.org/css-scoping/#host-element
@@ skipping 80 matching lines @@
         if (value.length() != selectorValue.length() && value[selectorValue.length()] != '-')
             return false;
         break;
     default:
         break;
     }
 
     return true;
 }
 
-static bool anyAttributeMatches(Element& element, CSSSelector::Match match, const CSSSelector& selector)
+static bool anyAttributeMatches(const Element& element, CSSSelector::Match match, const CSSSelector& selector)
 {
     const QualifiedName& selectorAttr = selector.attribute();
     ASSERT(selectorAttr.localName() != starAtom); // Should not be possible from the CSS grammar.
 
     // Synchronize the attribute in case it is lazy-computed.
     element.synchronizeAttribute(selectorAttr.localName());
 
     const AtomicString& selectorValue = selector.value();
     bool caseInsensitive = selector.attributeMatchType() == CSSSelector::CaseInsensitive;
 
     AttributeCollection attributes = element.attributesWithoutUpdate();
     AttributeCollection::iterator end = attributes.end();
     for (AttributeCollection::iterator it = attributes.begin(); it != end; ++it) {
         const Attribute& attributeItem = *it;
 
         if (!attributeItem.matches(selectorAttr))
             continue;
 
         if (attributeValueMatches(attributeItem, match, selectorValue, !caseInsensitive))
             return true;
     }
 
     return false;
 }
 
-bool SelectorChecker::checkOne(const SelectorCheckingContext& context) const
+bool SelectorChecker::checkOne(const SelectorCheckingContext& context)
 {
     ASSERT(context.element);
-    Element& element = *context.element;
+    const Element& element = *context.element;
     ASSERT(context.selector);
     const CSSSelector& selector = *context.selector;
 
     switch (selector.match()) {
     case CSSSelector::Tag:
         return tagMatches(element, selector.tagQName());
     case CSSSelector::Class:
         return element.hasClass() && element.classNames().contains(selector.value());
     case CSSSelector::Id:
         return element.hasID() && element.idForStyleResolution() == selector.value();
     case CSSSelector::Exact:
     case CSSSelector::Set:
     case CSSSelector::Hyphen:
     case CSSSelector::List:
     case CSSSelector::Contain:
     case CSSSelector::Begin:
     case CSSSelector::End:
         if (anyAttributeMatches(element, selector.match(), selector)) {
-            if (m_mode == ResolvingStyle && context.elementStyle)
-                context.elementStyle->setUnique();
+            m_matchedAttributeSelector = true;
             return true;
         }
         return false;
     case CSSSelector::PseudoClass:
         return checkPseudoClass(context);
     // FIXME(sky): Remove pseudo elements completely.
     case CSSSelector::PseudoElement:
     case CSSSelector::Unknown:
         return false;
     }
     ASSERT_NOT_REACHED();
     return false;
 }
 
-bool SelectorChecker::checkPseudoClass(const SelectorCheckingContext& context) const
+bool SelectorChecker::checkPseudoClass(const SelectorCheckingContext& context)
 {
     ASSERT(context.element);
-    Element& element = *context.element;
+    const Element& element = *context.element;
     ASSERT(context.selector);
     const CSSSelector& selector = *context.selector;
     ASSERT(selector.match() == CSSSelector::PseudoClass);
 
     // Normal element pseudo class checking.
     switch (selector.pseudoType()) {
     case CSSSelector::PseudoFocus:
-        if (m_mode == ResolvingStyle) {
-            if (context.elementStyle)
-                context.elementStyle->setAffectedByFocus();
-        }
+        m_matchedFocusSelector = true;
         return matchesFocusPseudoClass(element);
 
     case CSSSelector::PseudoHover:
-        if (m_mode == ResolvingStyle) {
-            if (context.elementStyle)
-                context.elementStyle->setAffectedByHover();
-        }
+        m_matchedHoverSelector = true;
         return element.hovered();
 
     case CSSSelector::PseudoActive:
-        if (m_mode == ResolvingStyle) {
-            if (context.elementStyle)
-                context.elementStyle->setAffectedByActive();
-        }
+        m_matchedActiveSelector = true;
         return element.active();
 
     case CSSSelector::PseudoLang:
         {
             AtomicString value = element.computeInheritedLanguage();
             const AtomicString& argument = selector.argument();
             if (value.isEmpty() || !value.startsWith(argument, false))
                 break;
             if (value.length() != argument.length() && value[argument.length()] != '-')
                 break;
             return true;
         }
 
     case CSSSelector::PseudoUnresolved:
         return element.isUnresolvedCustomElement();
 
     case CSSSelector::PseudoHost:
         {
-            if (m_mode == SharingRules)

[eseidel1, 2015/01/09 02:04:17]

Do we care about removal of this early-out?

-                return true;
             // :host only matches a shadow host when :host is in a shadow tree of the shadow host.
             if (!context.scope)
                 return false;
             const ContainerNode* shadowHost = context.scope->shadowHost();
             if (!shadowHost || shadowHost != element)
                 return false;
             ASSERT(element.shadow());
 
             // For empty parameter case, i.e. just :host or :host().
             if (!selector.selectorList())
@@ skipping 27 matching lines @@
         return false;
     LocalFrame* frame = element.document().frame();
     if (!frame)
         return false;
     if (!frame->selection().isFocusedAndActive())
         return false;
     return true;
 }
 
 }