/*
 * Copyright (C) 1999 Lars Knoll (knoll@kde.org)
 *           (C) 1999 Antti Koivisto (koivisto@kde.org)
 *           (C) 2001 Peter Kelly (pmk@post.com)
 *           (C) 2001 Dirk Mueller (mueller@kde.org)
 * Copyright (C) 2003, 2004, 2005, 2006, 2007, 2008, 2009, 2010, 2011 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 Element_h
#define Element_h

#include "Document.h"
#include "ExceptionCodePlaceholder.h"
#include "FragmentScriptingPermission.h"
#include "NamedNodeMap.h"
#include "ScrollTypes.h"

namespace WebCore {

class Attribute;
class ClientRect;
class ClientRectList;
class DOMStringMap;
class DOMTokenList;
class ElementRareData;
class IntSize;
class ShadowRoot;
class WebKitAnimationList;

enum SpellcheckAttributeState {
    SpellcheckAttributeTrue,
    SpellcheckAttributeFalse,
    SpellcheckAttributeDefault
};

class Element : public ContainerNode {
public:
    static PassRefPtr<Element> create(const QualifiedName&, Document*);
    virtual ~Element();

    DEFINE_ATTRIBUTE_EVENT_LISTENER(abort);
    DEFINE_ATTRIBUTE_EVENT_LISTENER(change);
    DEFINE_ATTRIBUTE_EVENT_LISTENER(click);
    DEFINE_ATTRIBUTE_EVENT_LISTENER(contextmenu);
    DEFINE_ATTRIBUTE_EVENT_LISTENER(dblclick);
    DEFINE_ATTRIBUTE_EVENT_LISTENER(dragenter);
    DEFINE_ATTRIBUTE_EVENT_LISTENER(dragover);
    DEFINE_ATTRIBUTE_EVENT_LISTENER(dragleave);
    DEFINE_ATTRIBUTE_EVENT_LISTENER(drop);
    DEFINE_ATTRIBUTE_EVENT_LISTENER(dragstart);
    DEFINE_ATTRIBUTE_EVENT_LISTENER(drag);
    DEFINE_ATTRIBUTE_EVENT_LISTENER(dragend);
    DEFINE_ATTRIBUTE_EVENT_LISTENER(input);
    DEFINE_ATTRIBUTE_EVENT_LISTENER(invalid);
    DEFINE_ATTRIBUTE_EVENT_LISTENER(keydown);
    DEFINE_ATTRIBUTE_EVENT_LISTENER(keypress);
    DEFINE_ATTRIBUTE_EVENT_LISTENER(keyup);
    DEFINE_ATTRIBUTE_EVENT_LISTENER(mousedown);
    DEFINE_ATTRIBUTE_EVENT_LISTENER(mousemove);
    DEFINE_ATTRIBUTE_EVENT_LISTENER(mouseout);
    DEFINE_ATTRIBUTE_EVENT_LISTENER(mouseover);
    DEFINE_ATTRIBUTE_EVENT_LISTENER(mouseup);
    DEFINE_ATTRIBUTE_EVENT_LISTENER(mousewheel);
    DEFINE_ATTRIBUTE_EVENT_LISTENER(scroll);
    DEFINE_ATTRIBUTE_EVENT_LISTENER(select);
    DEFINE_ATTRIBUTE_EVENT_LISTENER(submit);

    // These four attribute event handler attributes are overridden by HTMLBodyElement
    // and HTMLFrameSetElement to forward to the DOMWindow.
    DECLARE_VIRTUAL_ATTRIBUTE_EVENT_LISTENER(blur);
    DECLARE_VIRTUAL_ATTRIBUTE_EVENT_LISTENER(error);
    DECLARE_VIRTUAL_ATTRIBUTE_EVENT_LISTENER(focus);
    DECLARE_VIRTUAL_ATTRIBUTE_EVENT_LISTENER(load);

    // WebKit extensions
    DEFINE_ATTRIBUTE_EVENT_LISTENER(beforecut);
    DEFINE_ATTRIBUTE_EVENT_LISTENER(cut);
    DEFINE_ATTRIBUTE_EVENT_LISTENER(beforecopy);
    DEFINE_ATTRIBUTE_EVENT_LISTENER(copy);
    DEFINE_ATTRIBUTE_EVENT_LISTENER(beforepaste);
    DEFINE_ATTRIBUTE_EVENT_LISTENER(paste);
    DEFINE_ATTRIBUTE_EVENT_LISTENER(reset);
    DEFINE_ATTRIBUTE_EVENT_LISTENER(search);
    DEFINE_ATTRIBUTE_EVENT_LISTENER(selectstart);
#if ENABLE(TOUCH_EVENTS)
    DEFINE_ATTRIBUTE_EVENT_LISTENER(touchstart);
    DEFINE_ATTRIBUTE_EVENT_LISTENER(touchmove);
    DEFINE_ATTRIBUTE_EVENT_LISTENER(touchend);
    DEFINE_ATTRIBUTE_EVENT_LISTENER(touchcancel);
#endif
#if ENABLE(FULLSCREEN_API)
    DEFINE_ATTRIBUTE_EVENT_LISTENER(webkitfullscreenchange);
#endif

    bool hasAttribute(const QualifiedName&) const;
    const AtomicString& getAttribute(const QualifiedName&) const;
    void setAttribute(const QualifiedName&, const AtomicString& value, ExceptionCode&);
    void removeAttribute(const QualifiedName&, ExceptionCode&);

    // Typed getters and setters for language bindings.
    int getIntegralAttribute(const QualifiedName& attributeName) const;
    void setIntegralAttribute(const QualifiedName& attributeName, int value);
    unsigned getUnsignedIntegralAttribute(const QualifiedName& attributeName) const;
    void setUnsignedIntegralAttribute(const QualifiedName& attributeName, unsigned value);

    // Call this to get the value of an attribute that is known not to be the style
    // attribute or one of the SVG animatable attributes.
    bool fastHasAttribute(const QualifiedName&) const;
    const AtomicString& fastGetAttribute(const QualifiedName&) const;
#ifndef NDEBUG
    bool fastAttributeLookupAllowed(const QualifiedName&) const;
#endif

    bool hasAttributes() const;

    bool hasAttribute(const String& name) const;
    bool hasAttributeNS(const String& namespaceURI, const String& localName) const;

    const AtomicString& getAttribute(const String& name) const;
    const AtomicString& getAttributeNS(const String& namespaceURI, const String& localName) const;

    void setAttribute(const AtomicString& name, const AtomicString& value, ExceptionCode&);
    void setAttributeNS(const AtomicString& namespaceURI, const AtomicString& qualifiedName, const AtomicString& value, ExceptionCode&, FragmentScriptingPermission = FragmentScriptingAllowed);

    bool isIdAttributeName(const QualifiedName&) const;
    const AtomicString& getIdAttribute() const;
    void setIdAttribute(const AtomicString&);

    // Call this to get the value of the id attribute for style resolution purposes.
    // The value will already be lowercased if the document is in compatibility mode,
    // so this function is not suitable for non-style uses.
    const AtomicString& idForStyleResolution() const;

    void scrollIntoView(bool alignToTop = true);
    void scrollIntoViewIfNeeded(bool centerIfNeeded = true);

    void scrollByLines(int lines);
    void scrollByPages(int pages);

    int offsetLeft();
    int offsetTop();
    int offsetWidth();
    int offsetHeight();
    Element* offsetParent();
    int clientLeft();
    int clientTop();
    int clientWidth();
    int clientHeight();
    virtual int scrollLeft();
    virtual int scrollTop();
    virtual void setScrollLeft(int);
    virtual void setScrollTop(int);
    virtual int scrollWidth();
    virtual int scrollHeight();

    // Note that the 'window space' has a flipped coordinate system on some platforms.
    LayoutRect boundsInWindowSpace();

    PassRefPtr<ClientRectList> getClientRects();
    PassRefPtr<ClientRect> getBoundingClientRect();
    
    // Returns the absolute bounding box translated into screen coordinates:
    LayoutRect screenRect() const;

    void removeAttribute(const String& name, ExceptionCode&);
    void removeAttributeNS(const String& namespaceURI, const String& localName, ExceptionCode&);

    PassRefPtr<Attr> getAttributeNode(const String& name);
    PassRefPtr<Attr> getAttributeNodeNS(const String& namespaceURI, const String& localName);
    PassRefPtr<Attr> setAttributeNode(Attr*, ExceptionCode&);
    PassRefPtr<Attr> setAttributeNodeNS(Attr*, ExceptionCode&);
    PassRefPtr<Attr> removeAttributeNode(Attr*, ExceptionCode&);
    
    virtual CSSStyleDeclaration* style();

    const QualifiedName& tagQName() const { return m_tagName; }
    String tagName() const { return nodeName(); }
    bool hasTagName(const QualifiedName& tagName) const { return m_tagName.matches(tagName); }
    
    // A fast function for checking the local name against another atomic string.
    bool hasLocalName(const AtomicString& other) const { return m_tagName.localName() == other; }
    bool hasLocalName(const QualifiedName& other) const { return m_tagName.localName() == other.localName(); }

    const AtomicString& localName() const { return m_tagName.localName(); }
    const AtomicString& prefix() const { return m_tagName.prefix(); }
    const AtomicString& namespaceURI() const { return m_tagName.namespaceURI(); }

    virtual KURL baseURI() const;

    virtual String nodeName() const;

    PassRefPtr<Element> cloneElementWithChildren();
    PassRefPtr<Element> cloneElementWithoutChildren();

    void normalizeAttributes();
    String nodeNamePreservingCase() const;

    // convenience methods which ignore exceptions
    void setAttribute(const QualifiedName&, const AtomicString& value);
    void setBooleanAttribute(const QualifiedName& name, bool);

    NamedNodeMap* attributes(bool readonly = false) const;

    // This method is called whenever an attribute is added, changed or removed.
    virtual void attributeChanged(Attribute*, bool preserveDecls = false);

    void setAttributeMap(PassRefPtr<NamedNodeMap>, FragmentScriptingPermission = FragmentScriptingAllowed);
    NamedNodeMap* attributeMap() const { return m_attributeMap.get(); }

    virtual void copyNonAttributeProperties(const Element* source);

    virtual void attach();
    virtual void detach();
    virtual RenderObject* createRenderer(RenderArena*, RenderStyle*);
    void recalcStyle(StyleChange = NoChange);

    ShadowRoot* shadowRoot() const;
    void setShadowRoot(PassRefPtr<ShadowRoot>, ExceptionCode&);
    ShadowRoot* ensureShadowRoot();
    void removeShadowRoot();

    virtual const AtomicString& shadowPseudoId() const;
    void setShadowPseudoId(const AtomicString&, ExceptionCode& = ASSERT_NO_EXCEPTION);

    RenderStyle* computedStyle(PseudoId = NOPSEUDO);

    void setStyleAffectedByEmpty();
    bool styleAffectedByEmpty() const;

    AtomicString computeInheritedLanguage() const;

    void dispatchAttrRemovalEvent(Attribute*);
    void dispatchAttrAdditionEvent(Attribute*);

    virtual void accessKeyAction(bool /*sendToAnyEvent*/) { }

    virtual bool isURLAttribute(Attribute*) const;

    KURL getURLAttribute(const QualifiedName&) const;
    KURL getNonEmptyURLAttribute(const QualifiedName&) const;

    virtual const QualifiedName& imageSourceAttributeName() const;
    virtual String target() const { return String(); }

    virtual void focus(bool restorePreviousSelection = true);
    virtual void updateFocusAppearance(bool restorePreviousSelection);
    void blur();

    String innerText();
    String outerText();
 
    virtual String title() const;

    void updateId(const AtomicString& oldId, const AtomicString& newId);

    LayoutSize minimumSizeForResizing() const;
    void setMinimumSizeForResizing(const LayoutSize&);

    // Use Document::registerForDocumentActivationCallbacks() to subscribe to these
    virtual void documentWillBecomeInactive() { }
    virtual void documentDidBecomeActive() { }

    // Use Document::registerForMediaVolumeCallbacks() to subscribe to this
    virtual void mediaVolumeDidChange() { }

    // Use Document::registerForPrivateBrowsingStateChangedCallbacks() to subscribe to this.
    virtual void privateBrowsingStateDidChange() { }

    virtual void didBecomeFullscreenElement() { }
    virtual void willStopBeingFullscreenElement() { }

    bool isFinishedParsingChildren() const { return isParsingChildrenFinished(); }
    virtual void finishParsingChildren();
    virtual void beginParsingChildren();

    // ElementTraversal API
    Element* firstElementChild() const;
    Element* lastElementChild() const;
    Element* previousElementSibling() const;
    Element* nextElementSibling() const;
    unsigned childElementCount() const;

    bool webkitMatchesSelector(const String& selectors, ExceptionCode&);

    DOMTokenList* classList();
    DOMTokenList* optionalClassList() const;

    DOMStringMap* dataset();

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

#if ENABLE(VIDEO)
    virtual bool isMediaElement() const { return false; }
#endif

#if ENABLE(INPUT_SPEECH)
    virtual bool isInputFieldSpeechButtonElement() const { return false; }
#endif

    virtual bool isFormControlElement() const { return false; }
    virtual bool isEnabledFormControl() const { return true; }
    virtual bool isReadOnlyFormControl() const { return false; }
    virtual bool isSpinButtonElement() const { return false; }
    virtual bool isTextFormControl() const { return false; }
    virtual bool isOptionalFormControl() const { return false; }
    virtual bool isRequiredFormControl() const { return false; }
    virtual bool isDefaultButtonForForm() const { return false; }
    virtual bool willValidate() const { return false; }
    virtual bool isValidFormControlElement() { return false; }
    virtual bool hasUnacceptableValue() const { return false; }
    virtual bool isInRange() const { return false; }
    virtual bool isOutOfRange() const { return false; }
    virtual bool isFrameElementBase() const { return false; }

    virtual bool canContainRangeEndPoint() const { return true; }

    virtual const AtomicString& formControlName() const { return nullAtom; }
    virtual const AtomicString& formControlType() const { return nullAtom; }

    virtual bool shouldSaveAndRestoreFormControlState() const { return true; }
    virtual bool saveFormControlState(String&) const { return false; }
    virtual void restoreFormControlState(const String&) { }

    virtual bool wasChangedSinceLastFormControlChangeEvent() const;
    virtual void setChangedSinceLastFormControlChangeEvent(bool);
    virtual void dispatchFormControlChangeEvent() { }

#if ENABLE(SVG)
    virtual bool childShouldCreateRenderer(Node*) const; 
#endif
    
#if ENABLE(FULLSCREEN_API)
    enum {
        ALLOW_KEYBOARD_INPUT = 1
    };
    
    void webkitRequestFullScreen(unsigned short flags);
    virtual bool containsFullScreenElement() const;
    virtual void setContainsFullScreenElement(bool);
    virtual void setContainsFullScreenElementOnAncestorsCrossingFrameBoundaries(bool);
#endif

    virtual bool isSpellCheckingEnabled() const;

    PassRefPtr<WebKitAnimationList> webkitGetAnimations() const;
    
    PassRefPtr<RenderStyle> styleForRenderer();

protected:
    Element(const QualifiedName& tagName, Document* document, ConstructionType type)
        : ContainerNode(document, type)
        , m_tagName(tagName)
    {
    }

    virtual void willRemove();
    virtual void insertedIntoDocument();
    virtual void removedFromDocument();
    virtual void insertedIntoTree(bool);
    virtual void removedFromTree(bool);
    virtual void childrenChanged(bool changedByParser = false, Node* beforeChange = 0, Node* afterChange = 0, int childCountDelta = 0);
    virtual bool willRecalcStyle(StyleChange) { return true; }
    virtual void didRecalcStyle(StyleChange) { }
    virtual PassRefPtr<RenderStyle> customStyleForRenderer();

    // The implementation of Element::attributeChanged() calls the following two functions.
    // They are separated to allow a different flow of control in StyledElement::attributeChanged().
    void recalcStyleIfNeededAfterAttributeChanged(Attribute*);
    void updateAfterAttributeChanged(Attribute*);
    
    void idAttributeChanged(Attribute*);

private:
    void scrollByUnits(int units, ScrollGranularity);

    virtual void setPrefix(const AtomicString&, ExceptionCode&);
    virtual NodeType nodeType() const;
    virtual bool childTypeAllowed(NodeType) const;

    virtual PassRefPtr<Attribute> createAttribute(const QualifiedName&, const AtomicString& value);
    
#ifndef NDEBUG
    virtual void formatForDebugger(char* buffer, unsigned length) const;
#endif

    bool pseudoStyleCacheIsInvalid(const RenderStyle* currentStyle, RenderStyle* newStyle);

    void createAttributeMap() const;

    virtual void updateStyleAttribute() const { }

#if ENABLE(SVG)
    virtual void updateAnimatedSVGAttribute(const QualifiedName&) const { }
#endif

    void cancelFocusAppearanceUpdate();

    virtual const AtomicString& virtualPrefix() const { return prefix(); }
    virtual const AtomicString& virtualLocalName() const { return localName(); }
    virtual const AtomicString& virtualNamespaceURI() const { return namespaceURI(); }
    virtual RenderStyle* virtualComputedStyle(PseudoId pseudoElementSpecifier = NOPSEUDO) { return computedStyle(pseudoElementSpecifier); }
    
    // cloneNode is private so that non-virtual cloneElementWithChildren and cloneElementWithoutChildren
    // are used instead.
    virtual PassRefPtr<Node> cloneNode(bool deep);
    virtual PassRefPtr<Element> cloneElementWithoutAttributesAndChildren();

    QualifiedName m_tagName;
    virtual OwnPtr<NodeRareData> createRareData();

    ElementRareData* rareData() const;
    ElementRareData* ensureRareData();

    SpellcheckAttributeState spellcheckAttributeState() const;

private:
    mutable RefPtr<NamedNodeMap> m_attributeMap;
};
    
inline Element* toElement(Node* node)
{
    ASSERT(!node || node->isElementNode());
    return static_cast<Element*>(node);
}

inline const Element* toElement(const Node* node)
{
    ASSERT(!node || node->isElementNode());
    return static_cast<const Element*>(node);
}

// This will catch anyone doing an unnecessary cast.
void toElement(const Element*);

inline bool Node::hasTagName(const QualifiedName& name) const
{
    return isElementNode() && toElement(this)->hasTagName(name);
}
    
inline bool Node::hasLocalName(const AtomicString& name) const
{
    return isElementNode() && toElement(this)->hasLocalName(name);
}

inline bool Node::hasAttributes() const
{
    return isElementNode() && toElement(this)->hasAttributes();
}

inline NamedNodeMap* Node::attributes() const
{
    return isElementNode() ? toElement(this)->attributes() : 0;
}

inline Element* Node::parentElement() const
{
    ContainerNode* parent = parentNode();
    return parent && parent->isElementNode() ? toElement(parent) : 0;
}

inline NamedNodeMap* Element::attributes(bool readonly) const
{
    if (!isStyleAttributeValid())
        updateStyleAttribute();

#if ENABLE(SVG)
    if (!areSVGAttributesValid())
        updateAnimatedSVGAttribute(anyQName());
#endif

    if (!readonly && !m_attributeMap)
        createAttributeMap();
    return m_attributeMap.get();
}

inline void Element::updateId(const AtomicString& oldId, const AtomicString& newId)
{
    if (!inDocument())
        return;

    if (oldId == newId)
        return;

    TreeScope* scope = treeScope();
    if (!oldId.isEmpty())
        scope->removeElementById(oldId, this);
    if (!newId.isEmpty())
        scope->addElementById(newId, this);
}

inline bool Element::fastHasAttribute(const QualifiedName& name) const
{
    ASSERT(fastAttributeLookupAllowed(name));
    return m_attributeMap && m_attributeMap->getAttributeItem(name);
}

inline const AtomicString& Element::fastGetAttribute(const QualifiedName& name) const
{
    ASSERT(fastAttributeLookupAllowed(name));
    if (m_attributeMap) {
        if (Attribute* attribute = m_attributeMap->getAttributeItem(name))
            return attribute->value();
    }
    return nullAtom;
}

inline const AtomicString& Element::idForStyleResolution() const
{
    ASSERT(hasID());
    return m_attributeMap->idForStyleResolution();
}

inline bool Element::isIdAttributeName(const QualifiedName& attributeName) const
{
    // FIXME: This check is probably not correct for the case where the document has an id attribute
    // with a non-null namespace, because it will return false, a false negative, if the prefixes
    // don't match but the local name and namespace both do. However, since this has been like this
    // for a while and the code paths may be hot, we'll have to measure performance if we fix it.
    return attributeName == document()->idAttributeName();
}

inline const AtomicString& Element::getIdAttribute() const
{
    return fastGetAttribute(document()->idAttributeName());
}

inline void Element::setIdAttribute(const AtomicString& value)
{
    setAttribute(document()->idAttributeName(), value);
}

inline Element* firstElementChild(const ContainerNode* container)
{
    ASSERT_ARG(container, container);
    Node* child = container->firstChild();
    while (child && !child->isElementNode())
        child = child->nextSibling();
    return static_cast<Element*>(child);
}

} // namespace

#endif
