node.h

linux下开源浏览器WebKit的源码,市面上的很多商用浏览器都是移植自WebKit

/*
 * Copyright (C) 1999 Lars Knoll ([e-mail])
 *           (C) 1999 Antti Koivisto ([e-mail])
 *           (C) 2001 Dirk Mueller ([e-mail])
 * Copyright (C) 2004, 2005, 2006, 2007, 2008, 2009 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.
 *
 */

#ifndef Node_h
#define Node_h

#include "DocPtr.h"
#include "EventTarget.h"
#include "KURLHash.h"
#include "PlatformString.h"
#include "TreeShared.h"
#include "FloatPoint.h"
#include <wtf/Assertions.h>
#include <wtf/ListHashSet.h>
#include <wtf/OwnPtr.h>
#include <wtf/PassRefPtr.h>

namespace WebCore {

class AtomicString;
class Attribute;
class ContainerNode;
class Document;
class DynamicNodeList;
class Element;
class Event;
class EventListener;
class Frame;
class IntRect;
class KeyboardEvent;
class NSResolver;
class NamedAttrMap;
class NodeList;
class NodeRareData;
class PlatformKeyboardEvent;
class PlatformMouseEvent;
class PlatformWheelEvent;
class QualifiedName;
class RegisteredEventListener;
class RenderArena;
class RenderBox;
class RenderBoxModelObject;
class RenderObject;
class RenderStyle;
class StringBuilder;

typedef int ExceptionCode;

typedef Vector<RefPtr<RegisteredEventListener> > RegisteredEventListenerVector;

enum StyleChangeType { NoStyleChange, InlineStyleChange, FullStyleChange, AnimationStyleChange };

const unsigned short DOCUMENT_POSITION_EQUIVALENT = 0x00;
const unsigned short DOCUMENT_POSITION_DISCONNECTED = 0x01;
const unsigned short DOCUMENT_POSITION_PRECEDING = 0x02;
const unsigned short DOCUMENT_POSITION_FOLLOWING = 0x04;
const unsigned short DOCUMENT_POSITION_CONTAINS = 0x08;
const unsigned short DOCUMENT_POSITION_CONTAINED_BY = 0x10;
const unsigned short DOCUMENT_POSITION_IMPLEMENTATION_SPECIFIC = 0x20;

// this class implements nodes, which can have a parent but no children:
class Node : public EventTarget, public TreeShared<Node> {
    friend class Document;
public:
    enum NodeType {
        ELEMENT_NODE = 1,
        ATTRIBUTE_NODE = 2,
        TEXT_NODE = 3,
        CDATA_SECTION_NODE = 4,
        ENTITY_REFERENCE_NODE = 5,
        ENTITY_NODE = 6,
        PROCESSING_INSTRUCTION_NODE = 7,
        COMMENT_NODE = 8,
        DOCUMENT_NODE = 9,
        DOCUMENT_TYPE_NODE = 10,
        DOCUMENT_FRAGMENT_NODE = 11,
        NOTATION_NODE = 12,
        XPATH_NAMESPACE_NODE = 13
    };
    
    static bool isSupported(const String& feature, const String& version);

    static void startIgnoringLeaks();
    static void stopIgnoringLeaks();

    static void dumpStatistics();

    enum StyleChange { NoChange, NoInherit, Inherit, Detach, Force };    
    static StyleChange diff(RenderStyle*, RenderStyle*);

    Node(Document*, bool isElement = false, bool isContainer = false, bool isText = false);
    virtual ~Node();

    // DOM methods & attributes for Node

    bool hasTagName(const QualifiedName&) const;
    virtual String nodeName() const = 0;
    virtual String nodeValue() const;
    virtual void setNodeValue(const String&, ExceptionCode&);
    virtual NodeType nodeType() const = 0;
    Node* parentNode() const { return parent(); }
    Element* parentElement() const;
    Node* previousSibling() const { return m_previous; }
    Node* nextSibling() const { return m_next; }
    PassRefPtr<NodeList> childNodes();
    Node* firstChild() const { return isContainerNode() ? containerFirstChild() : 0; }
    Node* lastChild() const { return isContainerNode() ? containerLastChild() : 0; }
    bool hasAttributes() const;
    NamedAttrMap* attributes() const;

    virtual KURL baseURI() const;
    
    void getSubresourceURLs(ListHashSet<KURL>&) const;

    // These should all actually return a node, but this is only important for language bindings,
    // which will already know and hold a ref on the right node to return. Returning bool allows
    // these methods to be more efficient since they don't need to return a ref
    virtual bool insertBefore(PassRefPtr<Node> newChild, Node* refChild, ExceptionCode&, bool shouldLazyAttach = false);
    virtual bool replaceChild(PassRefPtr<Node> newChild, Node* oldChild, ExceptionCode&, bool shouldLazyAttach = false);
    virtual bool removeChild(Node* child, ExceptionCode&);
    virtual bool appendChild(PassRefPtr<Node> newChild, ExceptionCode&, bool shouldLazyAttach = false);

    void remove(ExceptionCode&);
    bool hasChildNodes() const { return firstChild(); }
    virtual PassRefPtr<Node> cloneNode(bool deep) = 0;
    const AtomicString& localName() const { return virtualLocalName(); }
    const AtomicString& namespaceURI() const { return virtualNamespaceURI(); }
    const AtomicString& prefix() const { return virtualPrefix(); }
    virtual void setPrefix(const AtomicString&, ExceptionCode&);
    void normalize();

    bool isSameNode(Node* other) const { return this == other; }
    bool isEqualNode(Node*) const;
    bool isDefaultNamespace(const AtomicString& namespaceURI) const;
    String lookupPrefix(const AtomicString& namespaceURI) const;
    String lookupNamespaceURI(const String& prefix) const;
    String lookupNamespacePrefix(const AtomicString& namespaceURI, const Element* originalElement) const;
    
    String textContent(bool convertBRsToNewlines = false) const;
    void setTextContent(const String&, ExceptionCode&);
    
    Node* lastDescendant() const;
    Node* firstDescendant() const;
    
    // Other methods (not part of DOM)

    bool isElementNode() const { return m_isElement; }
    bool isContainerNode() const { return m_isContainer; }
    bool isTextNode() const { return m_isText; }

    virtual bool isHTMLElement() const { return false; }

#if ENABLE(SVG)
    virtual bool isSVGElement() const { return false; }
#else
    static bool isSVGElement() { return false; }
#endif

#if ENABLE(WML)
    virtual bool isWMLElement() const { return false; }
#else
    static bool isWMLElement() { return false; }
#endif

    virtual bool isStyledElement() const { return false; }
    virtual bool isFrameOwnerElement() const { return false; }
    virtual bool isAttributeNode() const { return false; }
    virtual bool isCommentNode() const { return false; }
    virtual bool isCharacterDataNode() const { return false; }
    bool isDocumentNode() const;
    virtual bool isShadowNode() const { return false; }
    virtual Node* shadowParentNode() { return 0; }
    Node* shadowAncestorNode();
    Node* shadowTreeRootNode();
    bool isInShadowTree();

    // The node's parent for the purpose of event capture and bubbling.
    virtual ContainerNode* eventParentNode();

    bool isBlockFlow() const;
    bool isBlockFlowOrBlockTable() const;
    
    // These low-level calls give the caller responsibility for maintaining the integrity of the tree.
    void setPreviousSibling(Node* previous) { m_previous = previous; }
    void setNextSibling(Node* next) { m_next = next; }

    // FIXME: These two functions belong in editing -- "atomic node" is an editing concept.
    Node* previousNodeConsideringAtomicNodes() const;
    Node* nextNodeConsideringAtomicNodes() const;
    
    /** (Not part of the official DOM)
     * Returns the next leaf node.
     *
     * Using this function delivers leaf nodes as if the whole DOM tree were a linear chain of its leaf nodes.
     * @return next leaf node or 0 if there are no more.
     */
    Node* nextLeafNode() const;

    /** (Not part of the official DOM)
     * Returns the previous leaf node.
     *
     * Using this function delivers leaf nodes as if the whole DOM tree were a linear chain of its leaf nodes.
     * @return previous leaf node or 0 if there are no more.
     */
    Node* previousLeafNode() const;

    bool isEditableBlock() const;
    
    // enclosingBlockFlowElement() is deprecated.  Use enclosingBlock instead.
    Element* enclosingBlockFlowElement() const;
    
    Element* enclosingInlineElement() const;
    Element* rootEditableElement() const;
    
    bool inSameContainingBlockFlowElement(Node*);
    
    // Used by the parser. Checks against the DTD, unlike DOM operations like appendChild().
    // Also does not dispatch DOM mutation events.
    // Returns the appropriate container node for future insertions as you parse, or 0 for failure.
    virtual ContainerNode* addChild(PassRefPtr<Node>);

    // Called by the parser when this element's close tag is reached,
    // signalling that all child tags have been parsed and added.
    // This is needed for <applet> and <object> elements, which can't lay themselves out
    // until they know all of their nested <param>s. [Radar 3603191, 4040848].
    // Also used for script elements and some SVG elements for similar purposes,
    // but making parsing a special case in this respect should be avoided if possible.
    virtual void finishParsingChildren() { }
    virtual void beginParsingChildren() { }

    // Called by the frame right before dispatching an unloadEvent. [Radar 4532113]
    // This is needed for HTMLInputElements to tell the frame that it is done editing 
    // (sends textFieldDidEndEditing notification)
    virtual void aboutToUnload() { }

    // For <link> and <style> elements.
    virtual bool sheetLoaded() { return true; }

    bool hasID() const { return m_hasId; }
    bool hasClass() const { return m_hasClass; }
    bool active() const { return m_active; }
    bool inActiveChain() const { return m_inActiveChain; }
    bool inDetach() const { return m_inDetach; }
    bool hovered() const { return m_hovered; }
    bool focused() const { return hasRareData() ? rareDataFocused() : false; }
    bool attached() const { return m_attached; }
    void setAttached(bool b = true) { m_attached = b; }
    bool changed() const { return m_styleChange != NoStyleChange; }
    StyleChangeType styleChangeType() const { return static_cast<StyleChangeType>(m_styleChange); }
    bool hasChangedChild() const { return m_hasChangedChild; }
    bool isLink() const { return m_isLink; }
    void setHasID(bool b = true) { m_hasId = b; }
    void setHasClass(bool b = true) { m_hasClass = b; }
    void setHasChangedChild( bool b = true ) { m_hasChangedChild = b; }
    void setInDocument(bool b = true) { m_inDocument = b; }
    void setInActiveChain(bool b = true) { m_inActiveChain = b; }
    void setChanged(StyleChangeType changeType = FullStyleChange);
    void setIsLink(bool b = true) { m_isLink = b; }

    bool inSubtreeMark() const { return m_inSubtreeMark; }
    void setInSubtreeMark(bool b = true) { m_inSubtreeMark = b; }

    void lazyAttach();
    virtual bool canLazyAttach();

    virtual void setFocus(bool b = true);
    virtual void setActive(bool b = true, bool /*pause*/ = false) { m_active = b; }
    virtual void setHovered(bool b = true) { m_hovered = b; }

    virtual short tabIndex() const;

    /**
     * Whether this node can receive the keyboard focus.
     */
    virtual bool supportsFocus() const { return isFocusable(); }
    virtual bool isFocusable() const;
    virtual bool isKeyboardFocusable(KeyboardEvent*) const;
    virtual bool isMouseFocusable() const;

    virtual bool isContentEditable() const;
    virtual bool isContentRichlyEditable() const;
    virtual bool shouldUseInputMethod() const;
    virtual IntRect getRect() const;

    virtual void recalcStyle(StyleChange = NoChange) { }

    unsigned nodeIndex() const;

    // Returns the DOM ownerDocument attribute. This method never returns NULL, except in the case 
    // of (1) a Document node or (2) a DocumentType node that is not used with any Document yet. 
    virtual Document* ownerDocument() const;

    // Returns the document associated with this node. This method never returns NULL, except in the case 
    // of a DocumentType node that is not used with any Document yet. A Document node returns itself.
    Document* document() const
    {
        ASSERT(this);
        ASSERT(m_document || nodeType() == DOCUMENT_TYPE_NODE && !inDocument());
        return m_document.get();
    }
    void setDocument(Document*);

    // Returns true if this node is associated with a document and is in its associated document's
    // node tree, false otherwise.
    bool inDocument() const 
    { 
        ASSERT(m_document || !m_inDocument);
        return m_inDocument; 
    }

    bool isReadOnlyNode() const { return nodeType() == ENTITY_REFERENCE_NODE; }
    virtual bool childTypeAllowed(NodeType) { return false; }
    unsigned childNodeCount() const { return isContainerNode() ? containerChildNodeCount() : 0; }
    Node* childNode(unsigned index) const { return isContainerNode() ? containerChildNode(index) : 0; }

    /**
     * Does a pre-order traversal of the tree to find the node next node after this one. This uses the same order that
     * the tags appear in the source file.
     *
     * @param stayWithin If not null, the traversal will stop once the specified node is reached. This can be used to
     * restrict traversal to a particular sub-tree.
     *
     * @return The next node, in document order
     *
     * see @ref traversePreviousNode()
     */
    Node* traverseNextNode(const Node* stayWithin = 0) const;
    
    // Like traverseNextNode, but skips children and starts with the next sibling.
    Node* traverseNextSibling(const Node* stayWithin = 0) const;

    /**
     * Does a reverse pre-order traversal to find the node that comes before the current one in document order
     *
     * see @ref traverseNextNode()
     */
    Node* traversePreviousNode(const Node * stayWithin = 0) const;

    // Like traverseNextNode, but visits parents after their children.
    Node* traverseNextNodePostOrder() const;

    // Like traversePreviousNode, but visits parents before their children.
    Node* traversePreviousNodePostOrder(const Node *stayWithin = 0) const;
    Node* traversePreviousSiblingPostOrder(const Node *stayWithin = 0) const;

    /**
     * Finds previous or next editable leaf node.
     */