Source/WebCore/css/PropertySetCSSStyleDeclaration.cpp - WebKit - Git at Google

 /*
  * (C) 1999-2003 Lars Knoll (knoll@kde.org)
  * Copyright (C) 2004, 2005, 2006, 2007, 2008, 2009, 2010, 2012 Apple Inc. All rights reserved.
  * Copyright (C) 2011 Research In Motion Limited. 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.
  */

 #include "config.h"
 #include "PropertySetCSSStyleDeclaration.h"

 #include "CSSPropertyParser.h"
 #include "CSSRule.h"
 #include "CSSStyleSheet.h"
 #include "CustomElementReactionQueue.h"
 #include "HTMLNames.h"
 #include "InspectorInstrumentation.h"
 #include "MutationObserverInterestGroup.h"
 #include "MutationRecord.h"
 #include "StyleProperties.h"
 #include "StyleSheetContents.h"
 #include "StyledElement.h"
 #include <wtf/IsoMallocInlines.h>

 namespace WebCore {

 WTF_MAKE_ISO_ALLOCATED_IMPL(PropertySetCSSStyleDeclaration);
 WTF_MAKE_ISO_ALLOCATED_IMPL(StyleRuleCSSStyleDeclaration);
 WTF_MAKE_ISO_ALLOCATED_IMPL(InlineCSSStyleDeclaration);

 class StyleAttributeMutationScope {
     WTF_MAKE_NONCOPYABLE(StyleAttributeMutationScope);
 public:
     StyleAttributeMutationScope(PropertySetCSSStyleDeclaration* decl)
     {
         ++s_scopeCount;

         if (s_scopeCount != 1) {
             ASSERT(s_currentDecl == decl);
             return;
         }

         ASSERT(!s_currentDecl);
         s_currentDecl = decl;

         auto* element = s_currentDecl->parentElement();
         if (!element)
             return;

         bool shouldReadOldValue = false;

         m_mutationRecipients = MutationObserverInterestGroup::createForAttributesMutation(*s_currentDecl->parentElement(), HTMLNames::styleAttr);
         if (m_mutationRecipients && m_mutationRecipients->isOldValueRequested())
             shouldReadOldValue = true;

         if (UNLIKELY(element->isDefinedCustomElement())) {
             auto* reactionQueue = element->reactionQueue();
             if (reactionQueue && reactionQueue->observesStyleAttribute()) {
                 m_customElement = element;
                 shouldReadOldValue = true;
             }
         }

         if (shouldReadOldValue)
             m_oldValue = s_currentDecl->parentElement()->getAttribute(HTMLNames::styleAttr);
     }

     ~StyleAttributeMutationScope()
     {
         --s_scopeCount;
         if (s_scopeCount)
             return;

         if (s_shouldDeliver) {
             if (m_mutationRecipients) {
                 auto mutation = MutationRecord::createAttributes(*s_currentDecl->parentElement(), HTMLNames::styleAttr, m_oldValue);
                 m_mutationRecipients->enqueueMutationRecord(WTFMove(mutation));
             }
             if (m_customElement) {
                 auto& newValue = m_customElement->getAttribute(HTMLNames::styleAttr);
                 CustomElementReactionQueue::enqueueAttributeChangedCallbackIfNeeded(*m_customElement, HTMLNames::styleAttr, m_oldValue, newValue);
             }
         }

         s_shouldDeliver = false;
         if (!s_shouldNotifyInspector) {
             s_currentDecl = nullptr;
             return;
         }
         // We have to clear internal state before calling Inspector's code.
         PropertySetCSSStyleDeclaration* localCopyStyleDecl = s_currentDecl;
         s_currentDecl = nullptr;
         s_shouldNotifyInspector = false;

         if (auto* parentElement = localCopyStyleDecl->parentElement())
             InspectorInstrumentation::didInvalidateStyleAttr(*parentElement);
     }

     void enqueueMutationRecord()
     {
         s_shouldDeliver = true;
     }

     void didInvalidateStyleAttr()
     {
         s_shouldNotifyInspector = true;
     }

 private:
     static unsigned s_scopeCount;
     static PropertySetCSSStyleDeclaration* s_currentDecl;
     static bool s_shouldNotifyInspector;
     static bool s_shouldDeliver;

     std::unique_ptr<MutationObserverInterestGroup> m_mutationRecipients;
     AtomicString m_oldValue;
     RefPtr<Element> m_customElement;
 };

 unsigned StyleAttributeMutationScope::s_scopeCount = 0;
 PropertySetCSSStyleDeclaration* StyleAttributeMutationScope::s_currentDecl = nullptr;
 bool StyleAttributeMutationScope::s_shouldNotifyInspector = false;
 bool StyleAttributeMutationScope::s_shouldDeliver = false;

 void PropertySetCSSStyleDeclaration::ref()
 {
     m_propertySet->ref();
 }

 void PropertySetCSSStyleDeclaration::deref()
 {
     m_propertySet->deref();
 }

 unsigned PropertySetCSSStyleDeclaration::length() const
 {
     return m_propertySet->propertyCount();
 }

 String PropertySetCSSStyleDeclaration::item(unsigned i) const
 {
     if (i >= m_propertySet->propertyCount())
         return String();
     return m_propertySet->propertyAt(i).cssName();
 }

 String PropertySetCSSStyleDeclaration::cssText() const
 {
     return m_propertySet->asText();
 }

 ExceptionOr<void> PropertySetCSSStyleDeclaration::setCssText(const String& text)
 {
     StyleAttributeMutationScope mutationScope(this);
     if (!willMutate())
         return { };

     bool changed = m_propertySet->parseDeclaration(text, cssParserContext());

     didMutate(changed ? PropertyChanged : NoChanges);

     mutationScope.enqueueMutationRecord();
     return { };
 }

 RefPtr<DeprecatedCSSOMValue> PropertySetCSSStyleDeclaration::getPropertyCSSValue(const String& propertyName)
 {
     if (isCustomPropertyName(propertyName)) {
         RefPtr<CSSValue> value = m_propertySet->getCustomPropertyCSSValue(propertyName);
         if (!value)
             return nullptr;
         return wrapForDeprecatedCSSOM(value.get());
     }

     CSSPropertyID propertyID = cssPropertyID(propertyName);
     if (!propertyID)
         return nullptr;
     return wrapForDeprecatedCSSOM(getPropertyCSSValueInternal(propertyID).get());
 }

 String PropertySetCSSStyleDeclaration::getPropertyValue(const String& propertyName)
 {
     if (isCustomPropertyName(propertyName))
         return m_propertySet->getCustomPropertyValue(propertyName);

     CSSPropertyID propertyID = cssPropertyID(propertyName);
     if (!propertyID)
         return String();
     return getPropertyValueInternal(propertyID);
 }

 String PropertySetCSSStyleDeclaration::getPropertyPriority(const String& propertyName)
 {
     if (isCustomPropertyName(propertyName))
         return m_propertySet->customPropertyIsImportant(propertyName) ? "important"_s : emptyString();

     CSSPropertyID propertyID = cssPropertyID(propertyName);
     if (!propertyID)
         return String();
     return m_propertySet->propertyIsImportant(propertyID) ? "important"_s : emptyString();
 }

 String PropertySetCSSStyleDeclaration::getPropertyShorthand(const String& propertyName)
 {
     CSSPropertyID propertyID = cssPropertyID(propertyName);
     if (!propertyID)
         return String();
     return m_propertySet->getPropertyShorthand(propertyID);
 }

 bool PropertySetCSSStyleDeclaration::isPropertyImplicit(const String& propertyName)
 {
     CSSPropertyID propertyID = cssPropertyID(propertyName);
     if (!propertyID)
         return false;
     return m_propertySet->isPropertyImplicit(propertyID);
 }

 ExceptionOr<void> PropertySetCSSStyleDeclaration::setProperty(const String& propertyName, const String& value, const String& priority)
 {
     StyleAttributeMutationScope mutationScope(this);

     CSSPropertyID propertyID = cssPropertyID(propertyName);
     if (isCustomPropertyName(propertyName))
         propertyID = CSSPropertyCustom;
     if (!propertyID)
         return { };

     if (!willMutate())
         return { };

     bool important = equalIgnoringASCIICase(priority, "important");
     if (!important && !priority.isEmpty())
         return { };

     bool changed;
     if (UNLIKELY(propertyID == CSSPropertyCustom)) {
         Document* document = nullptr;

         if (parentElement())
             document = &parentElement()->document();
         else
             document = parentStyleSheet()->ownerDocument();

         changed = m_propertySet->setCustomProperty(document, propertyName, value, important, cssParserContext());
     } else
         changed = m_propertySet->setProperty(propertyID, value, important, cssParserContext());

     didMutate(changed ? PropertyChanged : NoChanges);

     if (changed) {
         // CSS DOM requires raising SyntaxError of parsing failed, but this is too dangerous for compatibility,
         // see <http://bugs.webkit.org/show_bug.cgi?id=7296>.
         mutationScope.enqueueMutationRecord();
     }

     return { };
 }

 ExceptionOr<String> PropertySetCSSStyleDeclaration::removeProperty(const String& propertyName)
 {
     StyleAttributeMutationScope mutationScope(this);
     CSSPropertyID propertyID = cssPropertyID(propertyName);
     if (isCustomPropertyName(propertyName))
         propertyID = CSSPropertyCustom;
     if (!propertyID)
         return String();

     if (!willMutate())
         return String();

     String result;
     bool changed = propertyID != CSSPropertyCustom ? m_propertySet->removeProperty(propertyID, &result) : m_propertySet->removeCustomProperty(propertyName, &result);

     didMutate(changed ? PropertyChanged : NoChanges);

     if (changed)
         mutationScope.enqueueMutationRecord();
     return result;
 }

 RefPtr<CSSValue> PropertySetCSSStyleDeclaration::getPropertyCSSValueInternal(CSSPropertyID propertyID)
 {
     return m_propertySet->getPropertyCSSValue(propertyID);
 }

 String PropertySetCSSStyleDeclaration::getPropertyValueInternal(CSSPropertyID propertyID)
 {
     String value = m_propertySet->getPropertyValue(propertyID);
     if (!value.isEmpty())
         return value;

     return String();
 }

 ExceptionOr<bool> PropertySetCSSStyleDeclaration::setPropertyInternal(CSSPropertyID propertyID, const String& value, bool important)
 {
     StyleAttributeMutationScope mutationScope(this);
     if (!willMutate())
         return false;

     bool changed = m_propertySet->setProperty(propertyID, value, important, cssParserContext());

     didMutate(changed ? PropertyChanged : NoChanges);

     if (changed)
         mutationScope.enqueueMutationRecord();
     return changed;
 }

 RefPtr<DeprecatedCSSOMValue> PropertySetCSSStyleDeclaration::wrapForDeprecatedCSSOM(CSSValue* internalValue)
 {
     if (!internalValue)
         return nullptr;

     // The map is here to maintain the object identity of the CSSValues over multiple invocations.
     // FIXME: It is likely that the identity is not important for web compatibility and this code should be removed.
     if (!m_cssomValueWrappers)
         m_cssomValueWrappers = std::make_unique<HashMap<CSSValue*, WeakPtr<DeprecatedCSSOMValue>>>();

     auto& clonedValue = m_cssomValueWrappers->add(internalValue, WeakPtr<DeprecatedCSSOMValue>()).iterator->value;
     if (clonedValue)
         return clonedValue.get();

     RefPtr<DeprecatedCSSOMValue> wrapper = internalValue->createDeprecatedCSSOMWrapper(*this);
     clonedValue = makeWeakPtr(wrapper.get());
     return wrapper;
 }

 StyleSheetContents* PropertySetCSSStyleDeclaration::contextStyleSheet() const
 {
     CSSStyleSheet* cssStyleSheet = parentStyleSheet();
     return cssStyleSheet ? &cssStyleSheet->contents() : nullptr;
 }

 CSSParserContext PropertySetCSSStyleDeclaration::cssParserContext() const
 {
     return CSSParserContext(m_propertySet->cssParserMode());
 }

 Ref<MutableStyleProperties> PropertySetCSSStyleDeclaration::copyProperties() const
 {
     return m_propertySet->mutableCopy();
 }

 StyleRuleCSSStyleDeclaration::StyleRuleCSSStyleDeclaration(MutableStyleProperties& propertySet, CSSRule& parentRule)
     : PropertySetCSSStyleDeclaration(propertySet)
     , m_refCount(1)
     , m_parentRule(&parentRule)
 {
     m_propertySet->ref();
 }

 StyleRuleCSSStyleDeclaration::~StyleRuleCSSStyleDeclaration()
 {
     m_propertySet->deref();
 }

 void StyleRuleCSSStyleDeclaration::ref()
 {
     ++m_refCount;
 }

 void StyleRuleCSSStyleDeclaration::deref()
 {
     ASSERT(m_refCount);
     if (!--m_refCount)
         delete this;
 }

 bool StyleRuleCSSStyleDeclaration::willMutate()
 {
     if (!m_parentRule || !m_parentRule->parentStyleSheet())
         return false;
     m_parentRule->parentStyleSheet()->willMutateRules();
     return true;
 }

 void StyleRuleCSSStyleDeclaration::didMutate(MutationType type)
 {
     ASSERT(m_parentRule);
     ASSERT(m_parentRule->parentStyleSheet());

     if (type == PropertyChanged)
         m_cssomValueWrappers = nullptr;

     // Style sheet mutation needs to be signaled even if the change failed. willMutate*/didMutate* must pair.
     m_parentRule->parentStyleSheet()->didMutateRuleFromCSSStyleDeclaration();
 }

 CSSStyleSheet* StyleRuleCSSStyleDeclaration::parentStyleSheet() const
 {
     return m_parentRule ? m_parentRule->parentStyleSheet() : nullptr;
 }

 CSSParserContext StyleRuleCSSStyleDeclaration::cssParserContext() const
 {
     auto* styleSheet = contextStyleSheet();
     if (!styleSheet)
         return PropertySetCSSStyleDeclaration::cssParserContext();

     return styleSheet->parserContext();
 }

 void StyleRuleCSSStyleDeclaration::reattach(MutableStyleProperties& propertySet)
 {
     m_propertySet->deref();
     m_propertySet = &propertySet;
     m_propertySet->ref();
 }

 bool InlineCSSStyleDeclaration::willMutate()
 {
     if (m_parentElement)
         InspectorInstrumentation::willInvalidateStyleAttr(*m_parentElement);
     return true;
 }

 void InlineCSSStyleDeclaration::didMutate(MutationType type)
 {
     if (type == NoChanges)
         return;

     m_cssomValueWrappers = nullptr;

     if (!m_parentElement)
         return;

     m_parentElement->invalidateStyleAttribute();
     StyleAttributeMutationScope(this).didInvalidateStyleAttr();
 }

 CSSStyleSheet* InlineCSSStyleDeclaration::parentStyleSheet() const
 {
     return nullptr;
 }

 CSSParserContext InlineCSSStyleDeclaration::cssParserContext() const
 {
     if (!m_parentElement)
         return PropertySetCSSStyleDeclaration::cssParserContext();

     CSSParserContext context(m_parentElement->document());
     context.mode = m_propertySet->cssParserMode();
     return context;
 }

 } // namespace WebCore
	/*
	* (C) 1999-2003 Lars Knoll (knoll@kde.org)
	* Copyright (C) 2004, 2005, 2006, 2007, 2008, 2009, 2010, 2012 Apple Inc. All rights reserved.
	* Copyright (C) 2011 Research In Motion Limited. 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.
	*/

	#include "config.h"
	#include "PropertySetCSSStyleDeclaration.h"

	#include "CSSPropertyParser.h"
	#include "CSSRule.h"
	#include "CSSStyleSheet.h"
	#include "CustomElementReactionQueue.h"
	#include "HTMLNames.h"
	#include "InspectorInstrumentation.h"
	#include "MutationObserverInterestGroup.h"
	#include "MutationRecord.h"
	#include "StyleProperties.h"
	#include "StyleSheetContents.h"
	#include "StyledElement.h"
	#include <wtf/IsoMallocInlines.h>

	namespace WebCore {

	WTF_MAKE_ISO_ALLOCATED_IMPL(PropertySetCSSStyleDeclaration);
	WTF_MAKE_ISO_ALLOCATED_IMPL(StyleRuleCSSStyleDeclaration);
	WTF_MAKE_ISO_ALLOCATED_IMPL(InlineCSSStyleDeclaration);

	class StyleAttributeMutationScope {
	WTF_MAKE_NONCOPYABLE(StyleAttributeMutationScope);
	public:
	StyleAttributeMutationScope(PropertySetCSSStyleDeclaration* decl)
	{
	++s_scopeCount;

	if (s_scopeCount != 1) {
	ASSERT(s_currentDecl == decl);
	return;
	}

	ASSERT(!s_currentDecl);
	s_currentDecl = decl;

	auto* element = s_currentDecl->parentElement();
	if (!element)
	return;

	bool shouldReadOldValue = false;

	m_mutationRecipients = MutationObserverInterestGroup::createForAttributesMutation(*s_currentDecl->parentElement(), HTMLNames::styleAttr);
	if (m_mutationRecipients && m_mutationRecipients->isOldValueRequested())
	shouldReadOldValue = true;

	if (UNLIKELY(element->isDefinedCustomElement())) {
	auto* reactionQueue = element->reactionQueue();
	if (reactionQueue && reactionQueue->observesStyleAttribute()) {
	m_customElement = element;
	shouldReadOldValue = true;
	}
	}

	if (shouldReadOldValue)
	m_oldValue = s_currentDecl->parentElement()->getAttribute(HTMLNames::styleAttr);
	}

	~StyleAttributeMutationScope()
	{
	--s_scopeCount;
	if (s_scopeCount)
	return;

	if (s_shouldDeliver) {
	if (m_mutationRecipients) {
	auto mutation = MutationRecord::createAttributes(*s_currentDecl->parentElement(), HTMLNames::styleAttr, m_oldValue);
	m_mutationRecipients->enqueueMutationRecord(WTFMove(mutation));
	}
	if (m_customElement) {
	auto& newValue = m_customElement->getAttribute(HTMLNames::styleAttr);
	CustomElementReactionQueue::enqueueAttributeChangedCallbackIfNeeded(*m_customElement, HTMLNames::styleAttr, m_oldValue, newValue);
	}
	}

	s_shouldDeliver = false;
	if (!s_shouldNotifyInspector) {
	s_currentDecl = nullptr;
	return;
	}
	// We have to clear internal state before calling Inspector's code.
	PropertySetCSSStyleDeclaration* localCopyStyleDecl = s_currentDecl;
	s_currentDecl = nullptr;
	s_shouldNotifyInspector = false;

	if (auto* parentElement = localCopyStyleDecl->parentElement())
	InspectorInstrumentation::didInvalidateStyleAttr(*parentElement);
	}

	void enqueueMutationRecord()
	{
	s_shouldDeliver = true;
	}

	void didInvalidateStyleAttr()
	{
	s_shouldNotifyInspector = true;
	}

	private:
	static unsigned s_scopeCount;
	static PropertySetCSSStyleDeclaration* s_currentDecl;
	static bool s_shouldNotifyInspector;
	static bool s_shouldDeliver;

	std::unique_ptr<MutationObserverInterestGroup> m_mutationRecipients;
	AtomicString m_oldValue;
	RefPtr<Element> m_customElement;
	};

	unsigned StyleAttributeMutationScope::s_scopeCount = 0;
	PropertySetCSSStyleDeclaration* StyleAttributeMutationScope::s_currentDecl = nullptr;
	bool StyleAttributeMutationScope::s_shouldNotifyInspector = false;
	bool StyleAttributeMutationScope::s_shouldDeliver = false;

	void PropertySetCSSStyleDeclaration::ref()
	{
	m_propertySet->ref();
	}

	void PropertySetCSSStyleDeclaration::deref()
	{
	m_propertySet->deref();
	}

	unsigned PropertySetCSSStyleDeclaration::length() const
	{
	return m_propertySet->propertyCount();
	}

	String PropertySetCSSStyleDeclaration::item(unsigned i) const
	{
	if (i >= m_propertySet->propertyCount())
	return String();
	return m_propertySet->propertyAt(i).cssName();
	}

	String PropertySetCSSStyleDeclaration::cssText() const
	{
	return m_propertySet->asText();
	}

	ExceptionOr<void> PropertySetCSSStyleDeclaration::setCssText(const String& text)
	{
	StyleAttributeMutationScope mutationScope(this);
	if (!willMutate())
	return { };

	bool changed = m_propertySet->parseDeclaration(text, cssParserContext());

	didMutate(changed ? PropertyChanged : NoChanges);

	mutationScope.enqueueMutationRecord();
	return { };
	}

	RefPtr<DeprecatedCSSOMValue> PropertySetCSSStyleDeclaration::getPropertyCSSValue(const String& propertyName)
	{
	if (isCustomPropertyName(propertyName)) {
	RefPtr<CSSValue> value = m_propertySet->getCustomPropertyCSSValue(propertyName);
	if (!value)
	return nullptr;
	return wrapForDeprecatedCSSOM(value.get());
	}

	CSSPropertyID propertyID = cssPropertyID(propertyName);
	if (!propertyID)
	return nullptr;
	return wrapForDeprecatedCSSOM(getPropertyCSSValueInternal(propertyID).get());
	}

	String PropertySetCSSStyleDeclaration::getPropertyValue(const String& propertyName)
	{
	if (isCustomPropertyName(propertyName))
	return m_propertySet->getCustomPropertyValue(propertyName);

	CSSPropertyID propertyID = cssPropertyID(propertyName);
	if (!propertyID)
	return String();
	return getPropertyValueInternal(propertyID);
	}

	String PropertySetCSSStyleDeclaration::getPropertyPriority(const String& propertyName)
	{
	if (isCustomPropertyName(propertyName))
	return m_propertySet->customPropertyIsImportant(propertyName) ? "important"_s : emptyString();

	CSSPropertyID propertyID = cssPropertyID(propertyName);
	if (!propertyID)
	return String();
	return m_propertySet->propertyIsImportant(propertyID) ? "important"_s : emptyString();
	}

	String PropertySetCSSStyleDeclaration::getPropertyShorthand(const String& propertyName)
	{
	CSSPropertyID propertyID = cssPropertyID(propertyName);
	if (!propertyID)
	return String();
	return m_propertySet->getPropertyShorthand(propertyID);
	}

	bool PropertySetCSSStyleDeclaration::isPropertyImplicit(const String& propertyName)
	{
	CSSPropertyID propertyID = cssPropertyID(propertyName);
	if (!propertyID)
	return false;
	return m_propertySet->isPropertyImplicit(propertyID);
	}

	ExceptionOr<void> PropertySetCSSStyleDeclaration::setProperty(const String& propertyName, const String& value, const String& priority)
	{
	StyleAttributeMutationScope mutationScope(this);

	CSSPropertyID propertyID = cssPropertyID(propertyName);
	if (isCustomPropertyName(propertyName))
	propertyID = CSSPropertyCustom;
	if (!propertyID)
	return { };

	if (!willMutate())
	return { };

	bool important = equalIgnoringASCIICase(priority, "important");
	if (!important && !priority.isEmpty())
	return { };

	bool changed;
	if (UNLIKELY(propertyID == CSSPropertyCustom)) {
	Document* document = nullptr;

	if (parentElement())
	document = &parentElement()->document();
	else
	document = parentStyleSheet()->ownerDocument();

	changed = m_propertySet->setCustomProperty(document, propertyName, value, important, cssParserContext());
	} else
	changed = m_propertySet->setProperty(propertyID, value, important, cssParserContext());

	didMutate(changed ? PropertyChanged : NoChanges);

	if (changed) {
	// CSS DOM requires raising SyntaxError of parsing failed, but this is too dangerous for compatibility,
	// see <http://bugs.webkit.org/show_bug.cgi?id=7296>.
	mutationScope.enqueueMutationRecord();
	}

	return { };
	}

	ExceptionOr<String> PropertySetCSSStyleDeclaration::removeProperty(const String& propertyName)
	{
	StyleAttributeMutationScope mutationScope(this);
	CSSPropertyID propertyID = cssPropertyID(propertyName);
	if (isCustomPropertyName(propertyName))
	propertyID = CSSPropertyCustom;
	if (!propertyID)
	return String();

	if (!willMutate())
	return String();

	String result;
	bool changed = propertyID != CSSPropertyCustom ? m_propertySet->removeProperty(propertyID, &result) : m_propertySet->removeCustomProperty(propertyName, &result);

	didMutate(changed ? PropertyChanged : NoChanges);

	if (changed)
	mutationScope.enqueueMutationRecord();
	return result;
	}

	RefPtr<CSSValue> PropertySetCSSStyleDeclaration::getPropertyCSSValueInternal(CSSPropertyID propertyID)
	{
	return m_propertySet->getPropertyCSSValue(propertyID);
	}

	String PropertySetCSSStyleDeclaration::getPropertyValueInternal(CSSPropertyID propertyID)
	{
	String value = m_propertySet->getPropertyValue(propertyID);
	if (!value.isEmpty())
	return value;

	return String();
	}

	ExceptionOr<bool> PropertySetCSSStyleDeclaration::setPropertyInternal(CSSPropertyID propertyID, const String& value, bool important)
	{
	StyleAttributeMutationScope mutationScope(this);
	if (!willMutate())
	return false;

	bool changed = m_propertySet->setProperty(propertyID, value, important, cssParserContext());

	didMutate(changed ? PropertyChanged : NoChanges);

	if (changed)
	mutationScope.enqueueMutationRecord();
	return changed;
	}

	RefPtr<DeprecatedCSSOMValue> PropertySetCSSStyleDeclaration::wrapForDeprecatedCSSOM(CSSValue* internalValue)
	{
	if (!internalValue)
	return nullptr;

	// The map is here to maintain the object identity of the CSSValues over multiple invocations.
	// FIXME: It is likely that the identity is not important for web compatibility and this code should be removed.
	if (!m_cssomValueWrappers)
	m_cssomValueWrappers = std::make_unique<HashMap<CSSValue*, WeakPtr<DeprecatedCSSOMValue>>>();

	auto& clonedValue = m_cssomValueWrappers->add(internalValue, WeakPtr<DeprecatedCSSOMValue>()).iterator->value;
	if (clonedValue)
	return clonedValue.get();

	RefPtr<DeprecatedCSSOMValue> wrapper = internalValue->createDeprecatedCSSOMWrapper(*this);
	clonedValue = makeWeakPtr(wrapper.get());
	return wrapper;
	}

	StyleSheetContents* PropertySetCSSStyleDeclaration::contextStyleSheet() const
	{
	CSSStyleSheet* cssStyleSheet = parentStyleSheet();
	return cssStyleSheet ? &cssStyleSheet->contents() : nullptr;
	}

	CSSParserContext PropertySetCSSStyleDeclaration::cssParserContext() const
	{
	return CSSParserContext(m_propertySet->cssParserMode());
	}

	Ref<MutableStyleProperties> PropertySetCSSStyleDeclaration::copyProperties() const
	{
	return m_propertySet->mutableCopy();
	}

	StyleRuleCSSStyleDeclaration::StyleRuleCSSStyleDeclaration(MutableStyleProperties& propertySet, CSSRule& parentRule)
	: PropertySetCSSStyleDeclaration(propertySet)
	, m_refCount(1)
	, m_parentRule(&parentRule)
	{
	m_propertySet->ref();
	}

	StyleRuleCSSStyleDeclaration::~StyleRuleCSSStyleDeclaration()
	{
	m_propertySet->deref();
	}

	void StyleRuleCSSStyleDeclaration::ref()
	{
	++m_refCount;
	}

	void StyleRuleCSSStyleDeclaration::deref()
	{
	ASSERT(m_refCount);
	if (!--m_refCount)
	delete this;
	}

	bool StyleRuleCSSStyleDeclaration::willMutate()
	{
	if (!m_parentRule \|\| !m_parentRule->parentStyleSheet())
	return false;
	m_parentRule->parentStyleSheet()->willMutateRules();
	return true;
	}

	void StyleRuleCSSStyleDeclaration::didMutate(MutationType type)
	{
	ASSERT(m_parentRule);
	ASSERT(m_parentRule->parentStyleSheet());

	if (type == PropertyChanged)
	m_cssomValueWrappers = nullptr;

	// Style sheet mutation needs to be signaled even if the change failed. willMutate/didMutate must pair.
	m_parentRule->parentStyleSheet()->didMutateRuleFromCSSStyleDeclaration();
	}

	CSSStyleSheet* StyleRuleCSSStyleDeclaration::parentStyleSheet() const
	{
	return m_parentRule ? m_parentRule->parentStyleSheet() : nullptr;
	}

	CSSParserContext StyleRuleCSSStyleDeclaration::cssParserContext() const
	{
	auto* styleSheet = contextStyleSheet();
	if (!styleSheet)
	return PropertySetCSSStyleDeclaration::cssParserContext();

	return styleSheet->parserContext();
	}

	void StyleRuleCSSStyleDeclaration::reattach(MutableStyleProperties& propertySet)
	{
	m_propertySet->deref();
	m_propertySet = &propertySet;
	m_propertySet->ref();
	}

	bool InlineCSSStyleDeclaration::willMutate()
	{
	if (m_parentElement)
	InspectorInstrumentation::willInvalidateStyleAttr(*m_parentElement);
	return true;
	}

	void InlineCSSStyleDeclaration::didMutate(MutationType type)
	{
	if (type == NoChanges)
	return;

	m_cssomValueWrappers = nullptr;

	if (!m_parentElement)
	return;

	m_parentElement->invalidateStyleAttribute();
	StyleAttributeMutationScope(this).didInvalidateStyleAttr();
	}

	CSSStyleSheet* InlineCSSStyleDeclaration::parentStyleSheet() const
	{
	return nullptr;
	}

	CSSParserContext InlineCSSStyleDeclaration::cssParserContext() const
	{
	if (!m_parentElement)
	return PropertySetCSSStyleDeclaration::cssParserContext();

	CSSParserContext context(m_parentElement->document());
	context.mode = m_propertySet->cssParserMode();
	return context;
	}

	} // namespace WebCore