/*

 * 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, 2005, 2006, 2007, 2008, 2009 Apple Inc. All rights reserved.

 * Copyright (C) 2008, 2009 Torch Mobile Inc. All rights reserved. (http://www.torchmobile.com/)

 *

 * 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 "EventTarget.h"

#include "KURLHash.h"

#include "RenderStyleConstants.h"

#include "ScriptWrappable.h"

#include "TreeShared.h"

#include <wtf/ListHashSet.h>

#if USE(JSC)

namespace JSC {

    class JSGlobalData;

    class MarkStack;

}

#endif

namespace WebCore {

class AtomicString;

class Attribute;

class ClassNodeList;

class ContainerNode;

class Document;

class DynamicNodeList;

class Element;

class Event;

class EventListener;

class FloatPoint;

class Frame;

class IntRect;

class KeyboardEvent;

class NSResolver;

class NamedNodeMap;

class NameNodeList;

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;

class TagNodeList;

typedef int ExceptionCode;

const int nodeStyleChangeShift = 24;

// SyntheticStyleChange means that we need to go through the entire style change logic even though

// no style property has actually changed. It is used to restructure the tree when, for instance,

// RenderLayers are created or destroyed due to animation changes.

enum StyleChangeType { 

    NoStyleChange = 0, 

    InlineStyleChange = 1 << nodeStyleChangeShift, 

    FullStyleChange = 2 << nodeStyleChangeShift, 

    SyntheticStyleChange = 3 << nodeStyleChangeShift

};

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>, public ScriptWrappable {

    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(const RenderStyle*, const RenderStyle*);

    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;

    NamedNodeMap* 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 getFlag(IsElementFlag); }

    bool isContainerNode() const { return getFlag(IsContainerFlag); }

    bool isTextNode() const { return getFlag(IsTextFlag); }

    bool isHTMLElement() const { return getFlag(IsHTMLFlag); }

    bool isSVGElement() const { return getFlag(IsSVGFlag); }

#if ENABLE(WML)

    virtual bool isWMLElement() const { return false; }

#else

    static bool isWMLElement() { return false; }

#endif

#if ENABLE(MATHML)

    virtual bool isMathMLElement() const { return false; }

#else

    static bool isMathMLElement() { return false; }

#endif

    virtual bool isMediaControlElement() const { return false; }

    bool isStyledElement() const { return getFlag(IsStyledElementFlag); }

    virtual bool isFrameOwnerElement() const { return false; }

    virtual bool isAttributeNode() const { return false; }

    bool isCommentNode() const { return getFlag(IsCommentFlag); }

    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();

    // Returns the enclosing event parent node (or self) that, when clicked, would trigger a navigation.

    Node* enclosingLinkEventParentOrSelf();

    // Node ancestors when concerned about event flow

    void eventAncestors(Vector<RefPtr<ContainerNode> > &ancestors);

    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* legacyParserAddChild(PassRefPtr<Node>);

    // addChild is tied into the logic of the LegacyHTMLTreeBuilder.  We need

    // a "clean" version to use for the HTML5 version of the HTMLTreeBuilder.

    virtual void parserAddChild(PassRefPtr<Node>);

    // Called by the parser when this element's close tag is reached,

    // signaling 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 getFlag(HasIDFlag); }

    bool hasClass() const { return getFlag(HasClassFlag); }

    bool active() const { return getFlag(IsActiveFlag); }

    bool inActiveChain() const { return getFlag(InActiveChainFlag); }

    bool inDetach() const { return getFlag(InDetachFlag); }

    bool hovered() const { return getFlag(IsHoveredFlag); }

    bool focused() const { return hasRareData() ? rareDataFocused() : false; }

    bool attached() const { return getFlag(IsAttachedFlag); }

    void setAttached() { setFlag(IsAttachedFlag); }

    bool needsStyleRecalc() const { return styleChangeType() != NoStyleChange; }

    StyleChangeType styleChangeType() const { return static_cast<StyleChangeType>(m_nodeFlags & StyleChangeMask); }

    bool childNeedsStyleRecalc() const { return getFlag(ChildNeedsStyleRecalcFlag); }

    bool isLink() const { return getFlag(IsLinkFlag); }

    void setHasID(bool f) { setFlag(f, HasIDFlag); }

    void setHasClass(bool f) { setFlag(f, HasClassFlag); }

    void setChildNeedsStyleRecalc() { setFlag(ChildNeedsStyleRecalcFlag); }

    void clearChildNeedsStyleRecalc() { clearFlag(ChildNeedsStyleRecalcFlag); }

    void setInDocument() { setFlag(InDocumentFlag); }

    void clearInDocument() { clearFlag(InDocumentFlag); }

    void setInActiveChain() { setFlag(InActiveChainFlag); }

    void clearInActiveChain() { clearFlag(InActiveChainFlag); }

    void setNeedsStyleRecalc(StyleChangeType changeType = FullStyleChange);

    void setIsLink(bool f) { setFlag(f, IsLinkFlag); }

    void setIsLink() { setFlag(IsLinkFlag); }

    void clearIsLink() { clearFlag(IsLinkFlag); }

    void lazyAttach();

    virtual bool canLazyAttach();

    virtual void setFocus(bool b = true);

    virtual void setActive(bool f = true, bool /*pause*/ = false) { setFlag(f, IsActiveFlag); }

    virtual void setHovered(bool f = true) { setFlag(f, IsHoveredFlag); }

    virtual short tabIndex() const;

    // Whether this kind of node can receive focus by default. Most nodes are

    // not focusable but some elements, such as form controls and links are.

    virtual bool supportsFocus() const;

    // Whether the node can actually be focused.

    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;

    IntRect renderRect(bool* isReplaced);

    // Returns true if the node has a non-empty bounding box in layout.

    // This does not 100% guarantee the user can see it, but is pretty close.

    // Note: This method only works properly after layout has occurred.

    bool hasNonEmptyBoundingBox() 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;

    }

    // Do not use this method to change the document of a node until after the node has been

    // removed from its previous document.

    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 || !getFlag(InDocumentFlag));

        return getFlag(InDocumentFlag);

    }

    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.

     */

    Node* previousEditable() const;

    Node* nextEditable() const;

    RenderObject* renderer() const { return m_renderer; }

    RenderObject* nextRenderer();

    RenderObject* previousRenderer();

    void setRenderer(RenderObject* renderer) { m_renderer = renderer; }

    // Use these two methods with caution.

    RenderBox* renderBox() const;

    RenderBoxModelObject* renderBoxModelObject() const;

    void checkSetPrefix(const AtomicString& prefix, ExceptionCode&);

    bool isDescendantOf(const Node*) const;

    bool contains(const Node*) const;

    // These two methods are mutually exclusive.  The former is used to do strict error-checking

    // when adding children via the public DOM API (e.g., appendChild()).  The latter is called only when parsing, 

    // to sanity-check against the DTD for error recovery.

    void checkAddChild(Node* newChild, ExceptionCode&); // Error-checking when adding via the DOM API

    virtual bool childAllowed(Node* newChild);          // Error-checking during parsing that checks the DTD

    void checkReplaceChild(Node* newChild, Node* oldChild, ExceptionCode&);

    virtual bool canReplaceChild(Node* newChild, Node* oldChild);

    // Used to determine whether range offsets use characters or node indices.

    virtual bool offsetInCharacters() const;

    // Number of DOM 16-bit units contained in node. Note that rendered text length can be different - e.g. because of

    // css-transform:capitalize breaking up precomposed characters and ligatures.

    virtual int maxCharacterOffset() const;

    // FIXME: We should try to find a better location for these methods.

    virtual bool canSelectAll() const { return false; }

    virtual void selectAll() { }

    // Whether or not a selection can be started in this object

    virtual bool canStartSelection() const;

    // Getting points into and out of screen space

    FloatPoint convertToPage(const FloatPoint& p) const;

    FloatPoint convertFromPage(const FloatPoint& p) const;

    // -----------------------------------------------------------------------------

    // Integration with rendering tree

    /**

     * Attaches this node to the rendering tree. This calculates the style to be applied to the node and creates an

     * appropriate RenderObject which will be inserted into the tree (except when the style has display: none). This

     * makes the node visible in the FrameView.

     */

    virtual void attach();

    /**

     * Detaches the node from the rendering tree, making it invisible in the rendered view. This method will remove

     * the node's rendering object from the rendering tree and delete it.

     */

    virtual void detach();

    virtual void willRemove();

    void createRendererIfNeeded();

    PassRefPtr<RenderStyle> styleForRenderer();

    virtual bool rendererIsNeeded(RenderStyle*);

#if ENABLE(SVG) || ENABLE(XHTMLMP)

    virtual bool childShouldCreateRenderer(Node*) const { return true; }

#endif

    virtual RenderObject* createRenderer(RenderArena*, RenderStyle*);

    // Wrapper for nodes that don't have a renderer, but still cache the style (like HTMLOptionElement).

    RenderStyle* renderStyle() const;

    virtual void setRenderStyle(PassRefPtr<RenderStyle>);

    RenderStyle* computedStyle(PseudoId pseudoElementSpecifier = NOPSEUDO) { return virtualComputedStyle(pseudoElementSpecifier); }

    // -----------------------------------------------------------------------------

    // Notification of document structure changes

    /**

     * Notifies the node that it has been inserted into the document. This is called during document parsing, and also

     * when a node is added through the DOM methods insertBefore(), appendChild() or replaceChild(). Note that this only

     * happens when the node becomes part of the document tree, i.e. only when the document is actually an ancestor of

     * the node. The call happens _after_ the node has been added to the tree.

     *

     * This is similar to the DOMNodeInsertedIntoDocument DOM event, but does not require the overhead of event

     * dispatching.

     */

    virtual void insertedIntoDocument();

    /**

     * Notifies the node that it is no longer part of the document tree, i.e. when the document is no longer an ancestor

     * node.

     *

     * This is similar to the DOMNodeRemovedFromDocument DOM event, but does not require the overhead of event

     * dispatching, and is called _after_ the node is removed from the tree.

     */

    virtual void removedFromDocument();

    // These functions are called whenever you are connected or disconnected from a tree.  That tree may be the main

    // document tree, or it could be another disconnected tree.  Override these functions to do any work that depends

    // on connectedness to some ancestor (e.g., an ancestor <form> for example).

    virtual void insertedIntoTree(bool /*deep*/) { }

    virtual void removedFromTree(bool /*deep*/) { }

    /**

     * Notifies the node that it's list of children have changed (either by adding or removing child nodes), or a child

     * node that is of the type CDATA_SECTION_NODE, TEXT_NODE or COMMENT_NODE has changed its value.

     */

    virtual void childrenChanged(bool /*changedByParser*/ = false, Node* /*beforeChange*/ = 0, Node* /*afterChange*/ = 0, int /*childCountDelta*/ = 0) { }

#ifndef NDEBUG

    virtual void formatForDebugger(char* buffer, unsigned length) const;

    void showNode(const char* prefix = "") const;

    void showTreeForThis() const;

    void showTreeAndMark(const Node* markedNode1, const char* markedLabel1, const Node* markedNode2 = 0, const char* markedLabel2 = 0) const;

#endif

    void registerDynamicNodeList(DynamicNodeList*);