Source/WebCore/style/ChildChangeInvalidation.cpp - WebKit - Git at Google

 /*
  * Copyright (C) 2021 Apple Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  * 1. Redistributions of source code must retain the above copyright
  *    notice, this list of conditions and the following disclaimer.
  * 2. Redistributions in binary form must reproduce the above copyright
  *    notice, this list of conditions and the following disclaimer in the
  *    documentation and/or other materials provided with the distribution.
  *
  * THIS SOFTWARE IS PROVIDED BY APPLE INC. AND ITS CONTRIBUTORS ``AS IS''
  * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
  * THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
  * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL APPLE INC. OR ITS CONTRIBUTORS
  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF
  * THE POSSIBILITY OF SUCH DAMAGE.
  */

 #include "config.h"
 #include "ChildChangeInvalidation.h"

 #include "ElementTraversal.h"
 #include "NodeRenderStyle.h"
 #include "ShadowRoot.h"
 #include "SlotAssignment.h"
 #include "StyleResolver.h"
 #include "StyleScopeRuleSets.h"
 #include "TypedElementDescendantIterator.h"

 namespace WebCore::Style {

 ChildChangeInvalidation::ChildChangeInvalidation(ContainerNode& container, const ContainerNode::ChildChange& childChange)
     : m_parentElement(is<Element>(container) ? downcast<Element>(&container) : nullptr)
     , m_isEnabled(m_parentElement ? m_parentElement->needsStyleInvalidation() : false)
     , m_childChange(childChange)
 {
     if (!m_isEnabled)
         return;

     traverseRemovedElements([&](auto& changedElement) {
         invalidateForChangedElement(changedElement);
     });
 }

 ChildChangeInvalidation::~ChildChangeInvalidation()
 {
     if (!m_isEnabled)
         return;

     traverseAddedElements([&](auto& changedElement) {
         invalidateForChangedElement(changedElement);
     });

     invalidateAfterChange();
 }

 void ChildChangeInvalidation::invalidateForChangedElement(Element& changedElement)
 {
     auto& ruleSets = parentElement().styleResolver().ruleSets();

     Invalidator::MatchElementRuleSets matchElementRuleSets;

     auto addHasInvalidation = [&](const Vector<InvalidationRuleSet>* invalidationRuleSets)  {
         if (!invalidationRuleSets)
             return;
         for (auto& invalidationRuleSet : *invalidationRuleSets) {
             if (isHasPseudoClassMatchElement(invalidationRuleSet.matchElement))
                 Invalidator::addToMatchElementRuleSets(matchElementRuleSets, invalidationRuleSet);
         }
     };

     auto tagName = changedElement.localName().convertToASCIILowercase();
     addHasInvalidation(ruleSets.tagInvalidationRuleSets(tagName));

     if (changedElement.hasAttributes()) {
         for (auto& attribute : changedElement.attributesIterator()) {
             auto attributeName = attribute.localName().convertToASCIILowercase();
             addHasInvalidation(ruleSets.attributeInvalidationRuleSets(attributeName));
         }
     }

     if (changedElement.hasClass()) {
         auto count = changedElement.classNames().size();
         for (size_t i = 0; i < count; ++i) {
             auto& className = changedElement.classNames()[i];
             addHasInvalidation(ruleSets.classInvalidationRuleSets(className));
         }
     }

     Invalidator::invalidateWithMatchElementRuleSets(changedElement, matchElementRuleSets);
 }

 static bool needsTraversal(const RuleFeatureSet& features, const ContainerNode::ChildChange& childChange)
 {
     if (features.usesMatchElement(MatchElement::HasChild))
         return true;
     if (features.usesMatchElement(MatchElement::HasDescendant))
         return true;
     return features.usesMatchElement(MatchElement::HasSibling) && childChange.previousSiblingElement;
 };

 static bool needsDescendantTraversal(const RuleFeatureSet& features)
 {
     return features.usesMatchElement(MatchElement::HasDescendant);
 };

 template<typename Function>
 void ChildChangeInvalidation::traverseRemovedElements(Function&& function)
 {
     if (m_childChange.isInsertion() && m_childChange.type != ContainerNode::ChildChange::Type::AllChildrenReplaced)
         return;

     auto& features = parentElement().styleResolver().ruleSets().features();
     if (!needsTraversal(features, m_childChange))
         return;

     bool needsDescendantTraversal = Style::needsDescendantTraversal(features);

     auto* toRemove = m_childChange.previousSiblingElement ? m_childChange.previousSiblingElement->nextElementSibling() : parentElement().firstElementChild();
     for (; toRemove != m_childChange.nextSiblingElement; toRemove = toRemove->nextElementSibling()) {
         function(*toRemove);

         if (!needsDescendantTraversal)
             continue;

         for (auto& descendant : descendantsOfType<Element>(*toRemove))
             function(descendant);
     }
 }

 template<typename Function>
 void ChildChangeInvalidation::traverseAddedElements(Function&& function)
 {
     if (!m_childChange.isInsertion())
         return;

     auto* newElement = [&] {
         auto* previous = m_childChange.previousSiblingElement;
         auto* candidate = previous ? ElementTraversal::nextSibling(*previous) : ElementTraversal::firstChild(parentElement());
         if (candidate == m_childChange.nextSiblingElement)
             candidate = nullptr;
         return candidate;
     }();

     if (!newElement)
         return;

     auto& features = parentElement().styleResolver().ruleSets().features();
     if (!needsTraversal(features, m_childChange))
         return;

     function(*newElement);

     if (!needsDescendantTraversal(features))
         return;

     for (auto& descendant : descendantsOfType<Element>(*newElement))
         function(descendant);
 }

 static void checkForEmptyStyleChange(Element& element)
 {
     if (!element.styleAffectedByEmpty())
         return;

     auto* style = element.renderStyle();
     if (!style || (!style->emptyState() || element.hasChildNodes()))
         element.invalidateStyleForSubtree();
 }

 static void invalidateForForwardPositionalRules(Element& parent, Element* elementAfterChange)
 {
     bool childrenAffected = parent.childrenAffectedByForwardPositionalRules();
     bool descendantsAffected = parent.descendantsAffectedByForwardPositionalRules();

     if (!childrenAffected && !descendantsAffected)
         return;

     for (auto* sibling = elementAfterChange; sibling; sibling = sibling->nextElementSibling()) {
         if (childrenAffected)
             sibling->invalidateStyleInternal();
         if (descendantsAffected) {
             for (auto* siblingChild = sibling->firstElementChild(); siblingChild; siblingChild = siblingChild->nextElementSibling())
                 siblingChild->invalidateStyleForSubtreeInternal();
         }
     }
 }

 static void invalidateForBackwardPositionalRules(Element& parent, Element* elementBeforeChange)
 {
     bool childrenAffected = parent.childrenAffectedByBackwardPositionalRules();
     bool descendantsAffected = parent.descendantsAffectedByBackwardPositionalRules();

     if (!childrenAffected && !descendantsAffected)
         return;

     for (auto* sibling = elementBeforeChange; sibling; sibling = sibling->previousElementSibling()) {
         if (childrenAffected)
             sibling->invalidateStyleInternal();
         if (descendantsAffected) {
             for (auto* siblingChild = sibling->firstElementChild(); siblingChild; siblingChild = siblingChild->nextElementSibling())
                 siblingChild->invalidateStyleForSubtreeInternal();
         }
     }
 }

 static void invalidateForFirstChildState(Element& child, bool state)
 {
     auto* style = child.renderStyle();
     if (!style || style->firstChildState() == state)
         child.invalidateStyleForSubtreeInternal();
 }

 static void invalidateForLastChildState(Element& child, bool state)
 {
     auto* style = child.renderStyle();
     if (!style || style->lastChildState() == state)
         child.invalidateStyleForSubtreeInternal();
 }

 void ChildChangeInvalidation::invalidateAfterChange()
 {
     checkForEmptyStyleChange(parentElement());

     if (m_childChange.source == ContainerNode::ChildChange::Source::Parser)
         return;

     checkForSiblingStyleChanges();
 }

 void ChildChangeInvalidation::invalidateAfterFinishedParsingChildren(Element& parent)
 {
     if (!parent.needsStyleInvalidation())
         return;

     checkForEmptyStyleChange(parent);

     auto* lastChildElement = ElementTraversal::lastChild(parent);
     if (!lastChildElement)
         return;

     if (parent.childrenAffectedByLastChildRules())
         invalidateForLastChildState(*lastChildElement, false);

     invalidateForBackwardPositionalRules(parent, lastChildElement);
 }

 void ChildChangeInvalidation::checkForSiblingStyleChanges()
 {
     auto& parent = parentElement();
     auto* elementBeforeChange = m_childChange.previousSiblingElement;
     auto* elementAfterChange = m_childChange.nextSiblingElement;

     // :first-child. In the parser callback case, we don't have to check anything, since we were right the first time.
     // In the DOM case, we only need to do something if |afterChange| is not 0.
     // |afterChange| is 0 in the parser case, so it works out that we'll skip this block.
     if (parent.childrenAffectedByFirstChildRules() && elementAfterChange) {
         // Find our new first child.
         RefPtr<Element> newFirstElement = ElementTraversal::firstChild(parent);

         // This is the insert/append case.
         if (newFirstElement != elementAfterChange)
             invalidateForFirstChildState(*elementAfterChange, true);

         // We also have to handle node removal.
         if (m_childChange.type == ContainerNode::ChildChange::Type::ElementRemoved && newFirstElement == elementAfterChange)
             invalidateForFirstChildState(*newFirstElement, false);
     }

     // :last-child. In the parser callback case, we don't have to check anything, since we were right the first time.
     // In the DOM case, we only need to do something if |afterChange| is not 0.
     if (parent.childrenAffectedByLastChildRules() && elementBeforeChange) {
         // Find our new last child.
         RefPtr<Element> newLastElement = ElementTraversal::lastChild(parent);

         if (newLastElement != elementBeforeChange)
             invalidateForLastChildState(*elementBeforeChange, true);

         // We also have to handle node removal.
         if (m_childChange.type == ContainerNode::ChildChange::Type::ElementRemoved && newLastElement == elementBeforeChange)
             invalidateForLastChildState(*newLastElement, false);
     }

     invalidateForSiblingCombinators(elementAfterChange);

     invalidateForForwardPositionalRules(parent, elementAfterChange);
     invalidateForBackwardPositionalRules(parent, elementBeforeChange);
 }

 }
	/*
	* Copyright (C) 2021 Apple Inc. All rights reserved.
	*
	* Redistribution and use in source and binary forms, with or without
	* modification, are permitted provided that the following conditions
	* are met:
	* 1. Redistributions of source code must retain the above copyright
	* notice, this list of conditions and the following disclaimer.
	* 2. Redistributions in binary form must reproduce the above copyright
	* notice, this list of conditions and the following disclaimer in the
	* documentation and/or other materials provided with the distribution.
	*
	* THIS SOFTWARE IS PROVIDED BY APPLE INC. AND ITS CONTRIBUTORS ``AS IS''
	* AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
	* THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
	* PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL APPLE INC. OR ITS CONTRIBUTORS
	* BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
	* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
	* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
	* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
	* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
	* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF
	* THE POSSIBILITY OF SUCH DAMAGE.
	*/

	#include "config.h"
	#include "ChildChangeInvalidation.h"

	#include "ElementTraversal.h"
	#include "NodeRenderStyle.h"
	#include "ShadowRoot.h"
	#include "SlotAssignment.h"
	#include "StyleResolver.h"
	#include "StyleScopeRuleSets.h"
	#include "TypedElementDescendantIterator.h"

	namespace WebCore::Style {

	ChildChangeInvalidation::ChildChangeInvalidation(ContainerNode& container, const ContainerNode::ChildChange& childChange)
	: m_parentElement(is<Element>(container) ? downcast<Element>(&container) : nullptr)
	, m_isEnabled(m_parentElement ? m_parentElement->needsStyleInvalidation() : false)
	, m_childChange(childChange)
	{
	if (!m_isEnabled)
	return;

	traverseRemovedElements([&](auto& changedElement) {
	invalidateForChangedElement(changedElement);
	});
	}

	ChildChangeInvalidation::~ChildChangeInvalidation()
	{
	if (!m_isEnabled)
	return;

	traverseAddedElements([&](auto& changedElement) {
	invalidateForChangedElement(changedElement);
	});

	invalidateAfterChange();
	}

	void ChildChangeInvalidation::invalidateForChangedElement(Element& changedElement)
	{
	auto& ruleSets = parentElement().styleResolver().ruleSets();

	Invalidator::MatchElementRuleSets matchElementRuleSets;

	auto addHasInvalidation = [&](const Vector<InvalidationRuleSet>* invalidationRuleSets) {
	if (!invalidationRuleSets)
	return;
	for (auto& invalidationRuleSet : *invalidationRuleSets) {
	if (isHasPseudoClassMatchElement(invalidationRuleSet.matchElement))
	Invalidator::addToMatchElementRuleSets(matchElementRuleSets, invalidationRuleSet);
	}
	};

	auto tagName = changedElement.localName().convertToASCIILowercase();
	addHasInvalidation(ruleSets.tagInvalidationRuleSets(tagName));

	if (changedElement.hasAttributes()) {
	for (auto& attribute : changedElement.attributesIterator()) {
	auto attributeName = attribute.localName().convertToASCIILowercase();
	addHasInvalidation(ruleSets.attributeInvalidationRuleSets(attributeName));
	}
	}

	if (changedElement.hasClass()) {
	auto count = changedElement.classNames().size();
	for (size_t i = 0; i < count; ++i) {
	auto& className = changedElement.classNames()[i];
	addHasInvalidation(ruleSets.classInvalidationRuleSets(className));
	}
	}

	Invalidator::invalidateWithMatchElementRuleSets(changedElement, matchElementRuleSets);
	}

	static bool needsTraversal(const RuleFeatureSet& features, const ContainerNode::ChildChange& childChange)
	{
	if (features.usesMatchElement(MatchElement::HasChild))
	return true;
	if (features.usesMatchElement(MatchElement::HasDescendant))
	return true;
	return features.usesMatchElement(MatchElement::HasSibling) && childChange.previousSiblingElement;
	};

	static bool needsDescendantTraversal(const RuleFeatureSet& features)
	{
	return features.usesMatchElement(MatchElement::HasDescendant);
	};

	template<typename Function>
	void ChildChangeInvalidation::traverseRemovedElements(Function&& function)
	{
	if (m_childChange.isInsertion() && m_childChange.type != ContainerNode::ChildChange::Type::AllChildrenReplaced)
	return;

	auto& features = parentElement().styleResolver().ruleSets().features();
	if (!needsTraversal(features, m_childChange))
	return;

	bool needsDescendantTraversal = Style::needsDescendantTraversal(features);

	auto* toRemove = m_childChange.previousSiblingElement ? m_childChange.previousSiblingElement->nextElementSibling() : parentElement().firstElementChild();
	for (; toRemove != m_childChange.nextSiblingElement; toRemove = toRemove->nextElementSibling()) {
	function(*toRemove);

	if (!needsDescendantTraversal)
	continue;

	for (auto& descendant : descendantsOfType<Element>(*toRemove))
	function(descendant);
	}
	}

	template<typename Function>
	void ChildChangeInvalidation::traverseAddedElements(Function&& function)
	{
	if (!m_childChange.isInsertion())
	return;

	auto* newElement = [&] {
	auto* previous = m_childChange.previousSiblingElement;
	auto* candidate = previous ? ElementTraversal::nextSibling(*previous) : ElementTraversal::firstChild(parentElement());
	if (candidate == m_childChange.nextSiblingElement)
	candidate = nullptr;
	return candidate;
	}();

	if (!newElement)
	return;

	auto& features = parentElement().styleResolver().ruleSets().features();
	if (!needsTraversal(features, m_childChange))
	return;

	function(*newElement);

	if (!needsDescendantTraversal(features))
	return;

	for (auto& descendant : descendantsOfType<Element>(*newElement))
	function(descendant);
	}

	static void checkForEmptyStyleChange(Element& element)
	{
	if (!element.styleAffectedByEmpty())
	return;

	auto* style = element.renderStyle();
	if (!style \|\| (!style->emptyState() \|\| element.hasChildNodes()))
	element.invalidateStyleForSubtree();
	}

	static void invalidateForForwardPositionalRules(Element& parent, Element* elementAfterChange)
	{
	bool childrenAffected = parent.childrenAffectedByForwardPositionalRules();
	bool descendantsAffected = parent.descendantsAffectedByForwardPositionalRules();

	if (!childrenAffected && !descendantsAffected)
	return;

	for (auto* sibling = elementAfterChange; sibling; sibling = sibling->nextElementSibling()) {
	if (childrenAffected)
	sibling->invalidateStyleInternal();
	if (descendantsAffected) {
	for (auto* siblingChild = sibling->firstElementChild(); siblingChild; siblingChild = siblingChild->nextElementSibling())
	siblingChild->invalidateStyleForSubtreeInternal();
	}
	}
	}

	static void invalidateForBackwardPositionalRules(Element& parent, Element* elementBeforeChange)
	{
	bool childrenAffected = parent.childrenAffectedByBackwardPositionalRules();
	bool descendantsAffected = parent.descendantsAffectedByBackwardPositionalRules();

	if (!childrenAffected && !descendantsAffected)
	return;

	for (auto* sibling = elementBeforeChange; sibling; sibling = sibling->previousElementSibling()) {
	if (childrenAffected)
	sibling->invalidateStyleInternal();
	if (descendantsAffected) {
	for (auto* siblingChild = sibling->firstElementChild(); siblingChild; siblingChild = siblingChild->nextElementSibling())
	siblingChild->invalidateStyleForSubtreeInternal();
	}
	}
	}

	static void invalidateForFirstChildState(Element& child, bool state)
	{
	auto* style = child.renderStyle();
	if (!style \|\| style->firstChildState() == state)
	child.invalidateStyleForSubtreeInternal();
	}

	static void invalidateForLastChildState(Element& child, bool state)
	{
	auto* style = child.renderStyle();
	if (!style \|\| style->lastChildState() == state)
	child.invalidateStyleForSubtreeInternal();
	}

	void ChildChangeInvalidation::invalidateAfterChange()
	{
	checkForEmptyStyleChange(parentElement());

	if (m_childChange.source == ContainerNode::ChildChange::Source::Parser)
	return;

	checkForSiblingStyleChanges();
	}

	void ChildChangeInvalidation::invalidateAfterFinishedParsingChildren(Element& parent)
	{
	if (!parent.needsStyleInvalidation())
	return;

	checkForEmptyStyleChange(parent);

	auto* lastChildElement = ElementTraversal::lastChild(parent);
	if (!lastChildElement)
	return;

	if (parent.childrenAffectedByLastChildRules())
	invalidateForLastChildState(*lastChildElement, false);

	invalidateForBackwardPositionalRules(parent, lastChildElement);
	}

	void ChildChangeInvalidation::checkForSiblingStyleChanges()
	{
	auto& parent = parentElement();
	auto* elementBeforeChange = m_childChange.previousSiblingElement;
	auto* elementAfterChange = m_childChange.nextSiblingElement;

	// :first-child. In the parser callback case, we don't have to check anything, since we were right the first time.
	// In the DOM case, we only need to do something if \|afterChange\| is not 0.
	// \|afterChange\| is 0 in the parser case, so it works out that we'll skip this block.
	if (parent.childrenAffectedByFirstChildRules() && elementAfterChange) {
	// Find our new first child.
	RefPtr<Element> newFirstElement = ElementTraversal::firstChild(parent);

	// This is the insert/append case.
	if (newFirstElement != elementAfterChange)
	invalidateForFirstChildState(*elementAfterChange, true);

	// We also have to handle node removal.
	if (m_childChange.type == ContainerNode::ChildChange::Type::ElementRemoved && newFirstElement == elementAfterChange)
	invalidateForFirstChildState(*newFirstElement, false);
	}

	// :last-child. In the parser callback case, we don't have to check anything, since we were right the first time.
	// In the DOM case, we only need to do something if \|afterChange\| is not 0.
	if (parent.childrenAffectedByLastChildRules() && elementBeforeChange) {
	// Find our new last child.
	RefPtr<Element> newLastElement = ElementTraversal::lastChild(parent);

	if (newLastElement != elementBeforeChange)
	invalidateForLastChildState(*elementBeforeChange, true);

	// We also have to handle node removal.
	if (m_childChange.type == ContainerNode::ChildChange::Type::ElementRemoved && newLastElement == elementBeforeChange)
	invalidateForLastChildState(*newLastElement, false);
	}

	invalidateForSiblingCombinators(elementAfterChange);

	invalidateForForwardPositionalRules(parent, elementAfterChange);
	invalidateForBackwardPositionalRules(parent, elementBeforeChange);
	}

	}