/*

 * Copyright (C) 2010 Google, Inc. All Rights Reserved.

 *

 * Redistribution and use in source and binary forms, with or without

 * modification, are permitted provided that the following conditions

 * are met:

 * 1. Redistributions of source code must retain the above copyright

 *    notice, this list of conditions and the following disclaimer.

 * 2. Redistributions in binary form must reproduce the above copyright

 *    notice, this list of conditions and the following disclaimer in the

 *    documentation and/or other materials provided with the distribution.

 *

 * THIS SOFTWARE IS PROVIDED BY GOOGLE INC. ``AS IS'' AND ANY

 * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE

 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR

 * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL GOOGLE INC. OR

 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,

 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,

 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR

 * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY

 * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT

 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE

 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 

 */

#ifndef HTMLElementStack_h

#define HTMLElementStack_h

#include <wtf/Noncopyable.h>

#include <wtf/OwnPtr.h>

#include <wtf/PassOwnPtr.h>

#include <wtf/RefPtr.h>

namespace WebCore {

class AtomicString;

class Element;

class QualifiedName;

// NOTE: The HTML5 spec uses a backwards (grows downward) stack.  We're using

// more standard (grows upwards) stack terminology here.

class HTMLElementStack : public Noncopyable {

public:

    HTMLElementStack();

    ~HTMLElementStack();

    class ElementRecord : public Noncopyable {

    public:

        ~ElementRecord(); // Public for ~PassOwnPtr()

        Element* element() const { return m_element.get(); }

        void replaceElement(PassRefPtr<Element>);

        bool isAbove(ElementRecord*) const;

        ElementRecord* next() const { return m_next.get(); }

    private:

        friend class HTMLElementStack;

        ElementRecord(PassRefPtr<Element>, PassOwnPtr<ElementRecord>);

        PassOwnPtr<ElementRecord> releaseNext() { return m_next.release(); }

        void setNext(PassOwnPtr<ElementRecord> next) { m_next = next; }

        RefPtr<Element> m_element;

        OwnPtr<ElementRecord> m_next;

    };

    Element* top() const;

    Element* oneBelowTop() const;

    ElementRecord* topRecord() const;

    Element* bottom() const;

    ElementRecord* find(Element*) const;

    ElementRecord* topmost(const AtomicString& tagName) const;

    void insertAbove(PassRefPtr<Element>, ElementRecord*);

    void push(PassRefPtr<Element>);

    void pushHTMLHtmlElement(PassRefPtr<Element>);

    void pushHTMLHeadElement(PassRefPtr<Element>);

    void pushHTMLBodyElement(PassRefPtr<Element>);

    void pop();

    void popUntil(const AtomicString& tagName);

    void popUntilElementWithNamespace(const AtomicString& namespaceURI);

    void popUntil(Element*);

    void popUntilPopped(const AtomicString& tagName);

    void popUntilPopped(Element*);

    void popUntilTableScopeMarker(); // "clear the stack back to a table context" in the spec.

    void popUntilTableBodyScopeMarker(); // "clear the stack back to a table body context" in the spec.

    void popUntilTableRowScopeMarker(); // "clear the stack back to a table row context" in the spec.

    void popHTMLHeadElement();

    void popHTMLBodyElement();

    void popAll();

    void remove(Element*);

    void removeHTMLHeadElement(Element*);

    bool contains(Element*) const;

    bool contains(const AtomicString& tagName) const;

    bool inScope(Element*) const;

    bool inScope(const AtomicString& tagName) const;

    bool inScope(const QualifiedName&) const;

    bool inListItemScope(const AtomicString& tagName) const;

    bool inListItemScope(const QualifiedName&) const;

    bool inTableScope(const AtomicString& tagName) const;

    bool inTableScope(const QualifiedName&) const;

    bool inButtonScope(const AtomicString& tagName) const;

    bool inButtonScope(const QualifiedName&) const;

    bool hasOnlyHTMLElementsInScope() const;

    Element* htmlElement() const;

    Element* headElement() const;

    Element* bodyElement() const;

#ifndef NDEBUG

    void show();

#endif

private:

    void pushCommon(PassRefPtr<Element>);

    void popCommon();

    void removeNonTopCommon(Element*);

    OwnPtr<ElementRecord> m_top;

    // We remember <html>, <head> and <body> as they are pushed.  Their

    // ElementRecords keep them alive.  <html> is never popped.

    // FIXME: We don't currently require type-specific information about

    // these elements so we haven't yet bothered to plumb the types all the

    // way down through createElement, etc.

    Element* m_htmlElement;

    Element* m_headElement;

    Element* m_bodyElement;

};

} // namespace WebCore

#endif // HTMLElementStack_h