Source/WebCore/dom/Attribute.h

/*
 * 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, 2008 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 Attribute_h
#define Attribute_h

#include "CSSMappedAttributeDeclaration.h"
#include "QualifiedName.h"

namespace WebCore {

class Attr;
class CSSStyleDeclaration;
class Element;
class NamedNodeMap;

// This has no counterpart in DOM.
// It is an internal representation of the node value of an Attr.
// The actual Attr with its value as a Text child is allocated only if needed.
class Attribute : public RefCounted<Attribute> {
    friend class Attr;
    friend class NamedNodeMap;
public:
    static PassRefPtr<Attribute> create(const QualifiedName& name, const AtomicString& value)
    {
        return adoptRef(new Attribute(name, value, false, 0));
    }
    static PassRefPtr<Attribute> createMapped(const QualifiedName& name, const AtomicString& value)
    {
        return adoptRef(new Attribute(name, value, true, 0));
    }
    static PassRefPtr<Attribute> createMapped(const AtomicString& name, const AtomicString& value)
    {
        return adoptRef(new Attribute(name, value, true, 0));
    }

    const AtomicString& value() const { return m_value; }
    const AtomicString& prefix() const { return m_name.prefix(); }
    const AtomicString& localName() const { return m_name.localName(); }
    const AtomicString& namespaceURI() const { return m_name.namespaceURI(); }
    
    const QualifiedName& name() const { return m_name; }
    
    Attr* attr() const;
    PassRefPtr<Attr> createAttrIfNeeded(Element*);

    bool isNull() const { return m_value.isNull(); }
    bool isEmpty() const { return m_value.isEmpty(); }
    
    PassRefPtr<Attribute> clone() const;

    // An extension to get the style information for presentational attributes.
    CSSStyleDeclaration* style() const { return m_styleDecl.get(); }
    CSSMappedAttributeDeclaration* decl() const { return m_styleDecl.get(); }
    void setDecl(PassRefPtr<CSSMappedAttributeDeclaration> decl) { m_styleDecl = decl; }

    void setValue(const AtomicString& value) { m_value = value; }
    void setPrefix(const AtomicString& prefix) { m_name.setPrefix(prefix); }

    // Note: This API is only for HTMLTreeBuilder.  It is not safe to change the
    // name of an attribute once parseMappedAttribute has been called as DOM
    // elements may have placed the Attribute in a hash by name.
    void parserSetName(const QualifiedName& name) { m_name = name; }

    bool isMappedAttribute() { return m_isMappedAttribute; }

private:
    Attribute(const QualifiedName& name, const AtomicString& value, bool isMappedAttribute, CSSMappedAttributeDeclaration* styleDecl)
        : m_isMappedAttribute(isMappedAttribute)
        , m_hasAttr(false)
        , m_name(name)
        , m_value(value)
        , m_styleDecl(styleDecl)
    {
    }

    Attribute(const AtomicString& name, const AtomicString& value, bool isMappedAttribute, CSSMappedAttributeDeclaration* styleDecl)
        : m_isMappedAttribute(isMappedAttribute)
        , m_hasAttr(false)
        , m_name(nullAtom, name, nullAtom)
        , m_value(value)
        , m_styleDecl(styleDecl)
    {
    }

    void bindAttr(Attr*);
    void unbindAttr(Attr*);

    // These booleans will go into the spare 32-bits of padding from RefCounted in 64-bit.
    bool m_isMappedAttribute;
    bool m_hasAttr;
    
    QualifiedName m_name;
    AtomicString m_value;
    RefPtr<CSSMappedAttributeDeclaration> m_styleDecl;
};

} // namespace WebCore

#endif // Attribute_h