Source/WebCore/dom/ContainerNode.h - WebKit - Git at Google

 /*
  * Copyright (C) 1999 Lars Knoll (knoll@kde.org)
  *           (C) 1999 Antti Koivisto (koivisto@kde.org)
  *           (C) 2001 Dirk Mueller (mueller@kde.org)
  * Copyright (C) 2004-2018 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.
  *
  * 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.
  *
  */

 #pragma once

 #include "CollectionType.h"
 #include "Node.h"

 namespace WebCore {

 class HTMLCollection;
 class RadioNodeList;
 class RenderElement;

 const int initialNodeVectorSize = 11; // Covers 99.5%. See webkit.org/b/80706
 typedef Vector<Ref<Node>, initialNodeVectorSize> NodeVector;

 class ContainerNode : public Node {
     WTF_MAKE_ISO_ALLOCATED(ContainerNode);
 public:
     virtual ~ContainerNode();

     Node* firstChild() const { return m_firstChild; }
     static ptrdiff_t firstChildMemoryOffset() { return OBJECT_OFFSETOF(ContainerNode, m_firstChild); }
     Node* lastChild() const { return m_lastChild; }
     static ptrdiff_t lastChildMemoryOffset() { return OBJECT_OFFSETOF(ContainerNode, m_lastChild); }
     bool hasChildNodes() const { return m_firstChild; }
     bool hasOneChild() const { return m_firstChild && !m_firstChild->nextSibling(); }

     bool directChildNeedsStyleRecalc() const { return getFlag(DirectChildNeedsStyleRecalcFlag); }
     void setDirectChildNeedsStyleRecalc() { setFlag(DirectChildNeedsStyleRecalcFlag); }

     WEBCORE_EXPORT unsigned countChildNodes() const;
     WEBCORE_EXPORT Node* traverseToChildAt(unsigned) const;

     ExceptionOr<void> insertBefore(Node& newChild, Node* refChild);
     ExceptionOr<void> replaceChild(Node& newChild, Node& oldChild);
     WEBCORE_EXPORT ExceptionOr<void> removeChild(Node& child);
     WEBCORE_EXPORT ExceptionOr<void> appendChild(Node& newChild);
     void replaceAllChildren(Ref<Node>&&);
     void replaceAllChildren(std::nullptr_t);

     // These methods are only used during parsing.
     // They don't send DOM mutation events or handle reparenting.
     // However, arbitrary code may be run by beforeload handlers.
     void parserAppendChild(Node&);
     void parserRemoveChild(Node&);
     void parserInsertBefore(Node& newChild, Node& refChild);

     void removeChildren();

     void takeAllChildrenFrom(ContainerNode*);

     void cloneChildNodes(ContainerNode& clone);

     enum ChildChangeType { ElementInserted, ElementRemoved, TextInserted, TextRemoved, TextChanged, AllChildrenRemoved, NonContentsChildRemoved, NonContentsChildInserted, AllChildrenReplaced };
     enum class ChildChangeSource { Parser, API };
     struct ChildChange {
         ChildChangeType type;
         Element* previousSiblingElement;
         Element* nextSiblingElement;
         ChildChangeSource source;

         bool isInsertion() const
         {
             switch (type) {
             case ElementInserted:
             case TextInserted:
             case NonContentsChildInserted:
             case AllChildrenReplaced:
                 return true;
             case ElementRemoved:
             case TextRemoved:
             case TextChanged:
             case AllChildrenRemoved:
             case NonContentsChildRemoved:
                 return false;
             }
             ASSERT_NOT_REACHED();
             return false;
         }
     };
     virtual void childrenChanged(const ChildChange&);

     void disconnectDescendantFrames();

     RenderElement* renderer() const;

     // Return a bounding box in absolute coordinates enclosing this node and all its descendants.
     // This gives the area within which events may get handled by a hander registered on this node.
     virtual LayoutRect absoluteEventHandlerBounds(bool& /* includesFixedPositionElements */) { return LayoutRect(); }

     WEBCORE_EXPORT ExceptionOr<Element*> querySelector(const String& selectors);
     WEBCORE_EXPORT ExceptionOr<Ref<NodeList>> querySelectorAll(const String& selectors);

     WEBCORE_EXPORT Ref<HTMLCollection> getElementsByTagName(const AtomicString&);
     WEBCORE_EXPORT Ref<HTMLCollection> getElementsByTagNameNS(const AtomicString& namespaceURI, const AtomicString& localName);
     WEBCORE_EXPORT Ref<NodeList> getElementsByName(const String& elementName);
     WEBCORE_EXPORT Ref<HTMLCollection> getElementsByClassName(const AtomicString& classNames);
     Ref<RadioNodeList> radioNodeList(const AtomicString&);

     // From the ParentNode interface - https://dom.spec.whatwg.org/#interface-parentnode
     WEBCORE_EXPORT Ref<HTMLCollection> children();
     WEBCORE_EXPORT Element* firstElementChild() const;
     WEBCORE_EXPORT Element* lastElementChild() const;
     WEBCORE_EXPORT unsigned childElementCount() const;
     ExceptionOr<void> append(Vector<NodeOrString>&&);
     ExceptionOr<void> prepend(Vector<NodeOrString>&&);

     ExceptionOr<void> ensurePreInsertionValidity(Node& newChild, Node* refChild);

 protected:
     explicit ContainerNode(Document&, ConstructionType = CreateContainer);

     friend void addChildNodesToDeletionQueue(Node*& head, Node*& tail, ContainerNode&);

     void removeDetachedChildren();
     void setFirstChild(Node* child) { m_firstChild = child; }
     void setLastChild(Node* child) { m_lastChild = child; }

     HTMLCollection* cachedHTMLCollection(CollectionType);

 private:
     void executePreparedChildrenRemoval();
     enum class DeferChildrenChanged { Yes, No };
     NodeVector removeAllChildrenWithScriptAssertion(ChildChangeSource, DeferChildrenChanged = DeferChildrenChanged::No);
     bool removeNodeWithScriptAssertion(Node&, ChildChangeSource);

     void removeBetween(Node* previousChild, Node* nextChild, Node& oldChild);
     ExceptionOr<void> appendChildWithoutPreInsertionValidityCheck(Node&);
     void insertBeforeCommon(Node& nextChild, Node& oldChild);
     void appendChildCommon(Node&);

     void rebuildSVGExtensionsElementsIfNecessary();

     bool isContainerNode() const = delete;

     Node* m_firstChild { nullptr };
     Node* m_lastChild { nullptr };
 };

 inline ContainerNode::ContainerNode(Document& document, ConstructionType type)
     : Node(document, type)
 {
 }

 inline unsigned Node::countChildNodes() const
 {
     if (!is<ContainerNode>(*this))
         return 0;
     return downcast<ContainerNode>(*this).countChildNodes();
 }

 inline Node* Node::traverseToChildAt(unsigned index) const
 {
     if (!is<ContainerNode>(*this))
         return nullptr;
     return downcast<ContainerNode>(*this).traverseToChildAt(index);
 }

 inline Node* Node::firstChild() const
 {
     if (!is<ContainerNode>(*this))
         return nullptr;
     return downcast<ContainerNode>(*this).firstChild();
 }

 inline Node* Node::lastChild() const
 {
     if (!is<ContainerNode>(*this))
         return nullptr;
     return downcast<ContainerNode>(*this).lastChild();
 }

 inline bool Node::isTreeScope() const
 {
     return &treeScope().rootNode() == this;
 }

 inline Node& Node::rootNode() const
 {
     if (isInTreeScope())
         return treeScope().rootNode();
     return traverseToRootNode();
 }

 inline NodeVector collectChildNodes(Node& node)
 {
     NodeVector children;
     for (Node* child = node.firstChild(); child; child = child->nextSibling())
         children.append(*child);
     return children;
 }

 class ChildNodesLazySnapshot {
     WTF_MAKE_NONCOPYABLE(ChildNodesLazySnapshot);
     WTF_MAKE_FAST_ALLOCATED;
 public:
     explicit ChildNodesLazySnapshot(Node& parentNode)
         : m_currentNode(parentNode.firstChild())
         , m_currentIndex(0)
         , m_hasSnapshot(false)
     {
         m_nextSnapshot = latestSnapshot;
         latestSnapshot = this;
     }

     ALWAYS_INLINE ~ChildNodesLazySnapshot()
     {
         latestSnapshot = m_nextSnapshot;
     }

     // Returns 0 if there is no next Node.
     RefPtr<Node> nextNode()
     {
         if (LIKELY(!hasSnapshot())) {
             RefPtr<Node> node = WTFMove(m_currentNode);
             if (node)
                 m_currentNode = node->nextSibling();
             return node;
         }
         if (m_currentIndex >= m_snapshot.size())
             return nullptr;
         return m_snapshot[m_currentIndex++];
     }

     void takeSnapshot()
     {
         if (hasSnapshot())
             return;
         m_hasSnapshot = true;
         Node* node = m_currentNode.get();
         while (node) {
             m_snapshot.append(node);
             node = node->nextSibling();
         }
     }

     ChildNodesLazySnapshot* nextSnapshot() { return m_nextSnapshot; }
     bool hasSnapshot() { return m_hasSnapshot; }

     static void takeChildNodesLazySnapshot()
     {
         ChildNodesLazySnapshot* snapshot = latestSnapshot;
         while (snapshot && !snapshot->hasSnapshot()) {
             snapshot->takeSnapshot();
             snapshot = snapshot->nextSnapshot();
         }
     }

 private:
     static ChildNodesLazySnapshot* latestSnapshot;

     RefPtr<Node> m_currentNode;
     unsigned m_currentIndex;
     bool m_hasSnapshot;
     Vector<RefPtr<Node>> m_snapshot; // Lazily instantiated.
     ChildNodesLazySnapshot* m_nextSnapshot;
 };

 } // namespace WebCore

 SPECIALIZE_TYPE_TRAITS_BEGIN(WebCore::ContainerNode)
     static bool isType(const WebCore::Node& node) { return node.isContainerNode(); }
 SPECIALIZE_TYPE_TRAITS_END()
	/*
	* Copyright (C) 1999 Lars Knoll (knoll@kde.org)
	* (C) 1999 Antti Koivisto (koivisto@kde.org)
	* (C) 2001 Dirk Mueller (mueller@kde.org)
	* Copyright (C) 2004-2018 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.
	*
	* 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.
	*
	*/

	#pragma once

	#include "CollectionType.h"
	#include "Node.h"

	namespace WebCore {

	class HTMLCollection;
	class RadioNodeList;
	class RenderElement;

	const int initialNodeVectorSize = 11; // Covers 99.5%. See webkit.org/b/80706
	typedef Vector<Ref<Node>, initialNodeVectorSize> NodeVector;

	class ContainerNode : public Node {
	WTF_MAKE_ISO_ALLOCATED(ContainerNode);
	public:
	virtual ~ContainerNode();

	Node* firstChild() const { return m_firstChild; }
	static ptrdiff_t firstChildMemoryOffset() { return OBJECT_OFFSETOF(ContainerNode, m_firstChild); }
	Node* lastChild() const { return m_lastChild; }
	static ptrdiff_t lastChildMemoryOffset() { return OBJECT_OFFSETOF(ContainerNode, m_lastChild); }
	bool hasChildNodes() const { return m_firstChild; }
	bool hasOneChild() const { return m_firstChild && !m_firstChild->nextSibling(); }

	bool directChildNeedsStyleRecalc() const { return getFlag(DirectChildNeedsStyleRecalcFlag); }
	void setDirectChildNeedsStyleRecalc() { setFlag(DirectChildNeedsStyleRecalcFlag); }

	WEBCORE_EXPORT unsigned countChildNodes() const;
	WEBCORE_EXPORT Node* traverseToChildAt(unsigned) const;

	ExceptionOr<void> insertBefore(Node& newChild, Node* refChild);
	ExceptionOr<void> replaceChild(Node& newChild, Node& oldChild);
	WEBCORE_EXPORT ExceptionOr<void> removeChild(Node& child);
	WEBCORE_EXPORT ExceptionOr<void> appendChild(Node& newChild);
	void replaceAllChildren(Ref<Node>&&);
	void replaceAllChildren(std::nullptr_t);

	// These methods are only used during parsing.
	// They don't send DOM mutation events or handle reparenting.
	// However, arbitrary code may be run by beforeload handlers.
	void parserAppendChild(Node&);
	void parserRemoveChild(Node&);
	void parserInsertBefore(Node& newChild, Node& refChild);

	void removeChildren();

	void takeAllChildrenFrom(ContainerNode*);

	void cloneChildNodes(ContainerNode& clone);

	enum ChildChangeType { ElementInserted, ElementRemoved, TextInserted, TextRemoved, TextChanged, AllChildrenRemoved, NonContentsChildRemoved, NonContentsChildInserted, AllChildrenReplaced };
	enum class ChildChangeSource { Parser, API };
	struct ChildChange {
	ChildChangeType type;
	Element* previousSiblingElement;
	Element* nextSiblingElement;
	ChildChangeSource source;

	bool isInsertion() const
	{
	switch (type) {
	case ElementInserted:
	case TextInserted:
	case NonContentsChildInserted:
	case AllChildrenReplaced:
	return true;
	case ElementRemoved:
	case TextRemoved:
	case TextChanged:
	case AllChildrenRemoved:
	case NonContentsChildRemoved:
	return false;
	}
	ASSERT_NOT_REACHED();
	return false;
	}
	};
	virtual void childrenChanged(const ChildChange&);

	void disconnectDescendantFrames();

	RenderElement* renderer() const;

	// Return a bounding box in absolute coordinates enclosing this node and all its descendants.
	// This gives the area within which events may get handled by a hander registered on this node.
	virtual LayoutRect absoluteEventHandlerBounds(bool& /* includesFixedPositionElements */) { return LayoutRect(); }

	WEBCORE_EXPORT ExceptionOr<Element*> querySelector(const String& selectors);
	WEBCORE_EXPORT ExceptionOr<Ref<NodeList>> querySelectorAll(const String& selectors);

	WEBCORE_EXPORT Ref<HTMLCollection> getElementsByTagName(const AtomicString&);
	WEBCORE_EXPORT Ref<HTMLCollection> getElementsByTagNameNS(const AtomicString& namespaceURI, const AtomicString& localName);
	WEBCORE_EXPORT Ref<NodeList> getElementsByName(const String& elementName);
	WEBCORE_EXPORT Ref<HTMLCollection> getElementsByClassName(const AtomicString& classNames);
	Ref<RadioNodeList> radioNodeList(const AtomicString&);

	// From the ParentNode interface - https://dom.spec.whatwg.org/#interface-parentnode
	WEBCORE_EXPORT Ref<HTMLCollection> children();
	WEBCORE_EXPORT Element* firstElementChild() const;
	WEBCORE_EXPORT Element* lastElementChild() const;
	WEBCORE_EXPORT unsigned childElementCount() const;
	ExceptionOr<void> append(Vector<NodeOrString>&&);
	ExceptionOr<void> prepend(Vector<NodeOrString>&&);

	ExceptionOr<void> ensurePreInsertionValidity(Node& newChild, Node* refChild);

	protected:
	explicit ContainerNode(Document&, ConstructionType = CreateContainer);

	friend void addChildNodesToDeletionQueue(Node& head, Node& tail, ContainerNode&);

	void removeDetachedChildren();
	void setFirstChild(Node* child) { m_firstChild = child; }
	void setLastChild(Node* child) { m_lastChild = child; }

	HTMLCollection* cachedHTMLCollection(CollectionType);

	private:
	void executePreparedChildrenRemoval();
	enum class DeferChildrenChanged { Yes, No };
	NodeVector removeAllChildrenWithScriptAssertion(ChildChangeSource, DeferChildrenChanged = DeferChildrenChanged::No);
	bool removeNodeWithScriptAssertion(Node&, ChildChangeSource);

	void removeBetween(Node* previousChild, Node* nextChild, Node& oldChild);
	ExceptionOr<void> appendChildWithoutPreInsertionValidityCheck(Node&);
	void insertBeforeCommon(Node& nextChild, Node& oldChild);
	void appendChildCommon(Node&);

	void rebuildSVGExtensionsElementsIfNecessary();

	bool isContainerNode() const = delete;

	Node* m_firstChild { nullptr };
	Node* m_lastChild { nullptr };
	};

	inline ContainerNode::ContainerNode(Document& document, ConstructionType type)
	: Node(document, type)
	{
	}

	inline unsigned Node::countChildNodes() const
	{
	if (!is<ContainerNode>(*this))
	return 0;
	return downcast<ContainerNode>(*this).countChildNodes();
	}

	inline Node* Node::traverseToChildAt(unsigned index) const
	{
	if (!is<ContainerNode>(*this))
	return nullptr;
	return downcast<ContainerNode>(*this).traverseToChildAt(index);
	}

	inline Node* Node::firstChild() const
	{
	if (!is<ContainerNode>(*this))
	return nullptr;
	return downcast<ContainerNode>(*this).firstChild();
	}

	inline Node* Node::lastChild() const
	{
	if (!is<ContainerNode>(*this))
	return nullptr;
	return downcast<ContainerNode>(*this).lastChild();
	}

	inline bool Node::isTreeScope() const
	{
	return &treeScope().rootNode() == this;
	}

	inline Node& Node::rootNode() const
	{
	if (isInTreeScope())
	return treeScope().rootNode();
	return traverseToRootNode();
	}

	inline NodeVector collectChildNodes(Node& node)
	{
	NodeVector children;
	for (Node* child = node.firstChild(); child; child = child->nextSibling())
	children.append(*child);
	return children;
	}

	class ChildNodesLazySnapshot {
	WTF_MAKE_NONCOPYABLE(ChildNodesLazySnapshot);
	WTF_MAKE_FAST_ALLOCATED;
	public:
	explicit ChildNodesLazySnapshot(Node& parentNode)
	: m_currentNode(parentNode.firstChild())
	, m_currentIndex(0)
	, m_hasSnapshot(false)
	{
	m_nextSnapshot = latestSnapshot;
	latestSnapshot = this;
	}

	ALWAYS_INLINE ~ChildNodesLazySnapshot()
	{
	latestSnapshot = m_nextSnapshot;
	}

	// Returns 0 if there is no next Node.
	RefPtr<Node> nextNode()
	{
	if (LIKELY(!hasSnapshot())) {
	RefPtr<Node> node = WTFMove(m_currentNode);
	if (node)
	m_currentNode = node->nextSibling();
	return node;
	}
	if (m_currentIndex >= m_snapshot.size())
	return nullptr;
	return m_snapshot[m_currentIndex++];
	}

	void takeSnapshot()
	{
	if (hasSnapshot())
	return;
	m_hasSnapshot = true;
	Node* node = m_currentNode.get();
	while (node) {
	m_snapshot.append(node);
	node = node->nextSibling();
	}
	}

	ChildNodesLazySnapshot* nextSnapshot() { return m_nextSnapshot; }
	bool hasSnapshot() { return m_hasSnapshot; }

	static void takeChildNodesLazySnapshot()
	{
	ChildNodesLazySnapshot* snapshot = latestSnapshot;
	while (snapshot && !snapshot->hasSnapshot()) {
	snapshot->takeSnapshot();
	snapshot = snapshot->nextSnapshot();
	}
	}

	private:
	static ChildNodesLazySnapshot* latestSnapshot;

	RefPtr<Node> m_currentNode;
	unsigned m_currentIndex;
	bool m_hasSnapshot;
	Vector<RefPtr<Node>> m_snapshot; // Lazily instantiated.
	ChildNodesLazySnapshot* m_nextSnapshot;
	};

	} // namespace WebCore

	SPECIALIZE_TYPE_TRAITS_BEGIN(WebCore::ContainerNode)
	static bool isType(const WebCore::Node& node) { return node.isContainerNode(); }
	SPECIALIZE_TYPE_TRAITS_END()