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:
PositionIterator()39     PositionIterator()
40         : m_anchorNode(0)
41         , m_nodeAfterPositionInAnchor(0)
42         , m_offsetInAnchor(0)
43     {
44     }
45 
PositionIterator(const Position & pos)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 
node()57     Node* node() const { return m_anchorNode; }
offsetInLeafNode()58     int offsetInLeafNode() const { return m_offsetInAnchor; }
59     void setOffsetInLeafNode(int offset);
60 
61     bool atStart() const;
62     bool atEnd() const;
63     bool atStartOfNode() const;
64     bool atEndOfNode() const;
65     bool isCandidate() const;
66 
67 private:
68     Node* m_anchorNode;
69     Node* m_nodeAfterPositionInAnchor; // If this is non-null, m_nodeAfterPositionInAnchor->parentNode() == m_anchorNode;
70     int m_offsetInAnchor;
71 };
72 
73 } // namespace WebCore
74 
75 #endif // PositionIterator_h
76