1 /*

     2  * Copyright (C) 2007, 2008 Apple Inc. All rights reserved.

     3  *

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

     5  * modification, are permitted provided that the following conditions

     6  * are met:

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

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

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

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

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

    12  *

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

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

    15  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR

    16  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL APPLE INC. OR

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

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

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

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

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

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

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

    24  */

    25 

    26 #ifndef PositionIterator_h

    27 #define PositionIterator_h

    28 

    29 #include "Node.h"

    30 #include "Position.h"

    31 

    32 namespace WebCore {

    33 

    34 // A Position iterator with constant-time

    35 // increment, decrement, and several predicates on the Position it is at.

    36 // Conversion to/from Position is O(n) in the offset.

    37 class PositionIterator {

    38 public:

    39     PositionIterator()

    40         : m_anchorNode(0)

    41         , m_nodeAfterPositionInAnchor(0)

    42         , m_offsetInAnchor(0)

    43     {

    44     }

    45 

    46     PositionIterator(const Position& pos)

    47         : m_anchorNode(pos.anchorNode())

    48         , m_nodeAfterPositionInAnchor(m_anchorNode->childNode(pos.deprecatedEditingOffset()))

    49         , m_offsetInAnchor(m_nodeAfterPositionInAnchor ? 0 : pos.deprecatedEditingOffset())

    50     {

    51     }

    52     operator Position() const;

    53 

    54     void increment();

    55     void decrement();

    56 

    57     Node* node() const { return m_anchorNode; }

    58     int offsetInLeafNode() const { return m_offsetInAnchor; }

    59 

    60     bool atStart() const;

    61     bool atEnd() const;

    62     bool atStartOfNode() const;

    63     bool atEndOfNode() const;

    64     bool isCandidate() const;

    65 

    66 private:

    67     Node* m_anchorNode;

    68     Node* m_nodeAfterPositionInAnchor; // If this is non-null, m_nodeAfterPositionInAnchor->parentNode() == m_anchorNode;

    69     int m_offsetInAnchor;

    70 };

    71 

    72 } // namespace WebCore

    73 

    74 #endif // PositionIterator_h