/*

 * Copyright (C) 2004, 2006 Apple Computer, 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 APPLE COMPUTER, 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 APPLE COMPUTER, 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 Position_h

#define Position_h

#include "Node.h"

#include "TextAffinity.h"

namespace WebCore {

class CSSComputedStyleDeclaration;

class Element;

class PositionIterator;

class Range;

enum EUsingComposedCharacters { NotUsingComposedCharacters = false, UsingComposedCharacters = true };

class Position

{

public:

    Position() : m_node(0), m_offset(0) { }

    Position(Node*, int offset);

    Position(const PositionIterator&);

    void clear();

    Node *node() const { return m_node.get(); }

    Element* documentElement() const;

    int offset() const { return m_offset; }

    bool isNull() const { return m_node == 0; }

    bool isNotNull() const { return m_node != 0; }

    Element* element() const;

    PassRefPtr<CSSComputedStyleDeclaration> computedStyle() const;

    // Move up or down the DOM by one position

    Position previous(EUsingComposedCharacters usingComposedCharacters=NotUsingComposedCharacters) const;

    Position next(EUsingComposedCharacters usingComposedCharacters=NotUsingComposedCharacters) const;

    bool atStart() const;

    bool atEnd() const;

    // FIXME: Make these non-member functions and put them somewhere in the editing directory.

    // These aren't really basic "position" operations. More high level editing helper functions.

    Position leadingWhitespacePosition(EAffinity, bool considerNonCollapsibleWhitespace = false) const;

    Position trailingWhitespacePosition(EAffinity, bool considerNonCollapsibleWhitespace = false) const;

    // p.upstream() through p.downstream() is the range of positions that map to the same VisiblePosition as p.

    Position upstream() const;

    Position downstream() const;

    bool isCandidate() const;

    bool inRenderedText() const;

    bool isRenderedCharacter() const;

    bool rendersInDifferentPosition(const Position &pos) const;

    static bool hasRenderedNonAnonymousDescendantsWithHeight(RenderObject*);

    static bool nodeIsUserSelectNone(Node*);

    void debugPosition(const char* msg = "") const;

#ifndef NDEBUG

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

    void showTreeForThis() const;

#endif

private:

    int renderedOffset() const;

    Position previousCharacterPosition(EAffinity) const;

    Position nextCharacterPosition(EAffinity) const;

    RefPtr<Node> m_node;

    int m_offset;

};

inline bool operator==(const Position &a, const Position &b)

{

    return a.node() == b.node() && a.offset() == b.offset();

}

inline bool operator!=(const Position &a, const Position &b)

{

    return !(a == b);

}

Position startPosition(const Range*);

Position endPosition(const Range*);

} // namespace WebCore

#ifndef NDEBUG

// Outside the WebCore namespace for ease of invocation from gdb.

void showTree(const WebCore::Position&);

void showTree(const WebCore::Position*);

#endif

#endif // Position_h