1/*
2 * Copyright (C) 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 RangeBoundaryPoint_h
27#define RangeBoundaryPoint_h
28
29#include "Node.h"
30#include "Position.h"
31
32namespace WebCore {
33
34class RangeBoundaryPoint {
35public:
36    explicit RangeBoundaryPoint(PassRefPtr<Node> container);
37
38    const Position toPosition() const;
39
40    Node* container() const;
41    int offset() const;
42    Node* childBefore() const;
43
44    void clear();
45
46    void set(PassRefPtr<Node> container, int offset, Node* childBefore);
47    void setOffset(int offset);
48
49    void setToBeforeChild(Node*);
50    void setToStartOfNode(PassRefPtr<Node>);
51    void setToEndOfNode(PassRefPtr<Node>);
52
53    void childBeforeWillBeRemoved();
54    void invalidateOffset() const;
55    void ensureOffsetIsValid() const;
56
57private:
58    static const int invalidOffset = -1;
59
60    RefPtr<Node> m_containerNode;
61    mutable int m_offsetInContainer;
62    RefPtr<Node> m_childBeforeBoundary;
63};
64
65inline RangeBoundaryPoint::RangeBoundaryPoint(PassRefPtr<Node> container)
66    : m_containerNode(container)
67    , m_offsetInContainer(0)
68    , m_childBeforeBoundary(0)
69{
70    ASSERT(m_containerNode);
71}
72
73inline Node* RangeBoundaryPoint::container() const
74{
75    return m_containerNode.get();
76}
77
78inline Node* RangeBoundaryPoint::childBefore() const
79{
80    return m_childBeforeBoundary.get();
81}
82
83inline void RangeBoundaryPoint::ensureOffsetIsValid() const
84{
85    if (m_offsetInContainer >= 0)
86        return;
87
88    ASSERT(m_childBeforeBoundary);
89    m_offsetInContainer = m_childBeforeBoundary->nodeIndex() + 1;
90}
91
92inline const Position RangeBoundaryPoint::toPosition() const
93{
94    ensureOffsetIsValid();
95    return createLegacyEditingPosition(m_containerNode.get(), m_offsetInContainer);
96}
97
98inline int RangeBoundaryPoint::offset() const
99{
100    ensureOffsetIsValid();
101    return m_offsetInContainer;
102}
103
104inline void RangeBoundaryPoint::clear()
105{
106    m_containerNode.clear();
107    m_offsetInContainer = 0;
108    m_childBeforeBoundary = 0;
109}
110
111inline void RangeBoundaryPoint::set(PassRefPtr<Node> container, int offset, Node* childBefore)
112{
113    ASSERT(container);
114    ASSERT(offset >= 0);
115    ASSERT(childBefore == (offset ? container->childNode(offset - 1) : 0));
116    m_containerNode = container;
117    m_offsetInContainer = offset;
118    m_childBeforeBoundary = childBefore;
119}
120
121inline void RangeBoundaryPoint::setOffset(int offset)
122{
123    ASSERT(m_containerNode);
124    ASSERT(m_containerNode->offsetInCharacters());
125    ASSERT(m_offsetInContainer >= 0);
126    ASSERT(!m_childBeforeBoundary);
127    m_offsetInContainer = offset;
128}
129
130inline void RangeBoundaryPoint::setToBeforeChild(Node* child)
131{
132    ASSERT(child);
133    ASSERT(child->parentNode());
134    m_childBeforeBoundary = child->previousSibling();
135    m_containerNode = child->parentNode();
136    m_offsetInContainer = m_childBeforeBoundary ? invalidOffset : 0;
137}
138
139inline void RangeBoundaryPoint::setToStartOfNode(PassRefPtr<Node> container)
140{
141    ASSERT(container);
142    m_containerNode = container;
143    m_offsetInContainer = 0;
144    m_childBeforeBoundary = 0;
145}
146
147inline void RangeBoundaryPoint::setToEndOfNode(PassRefPtr<Node> container)
148{
149    ASSERT(container);
150    m_containerNode = container;
151    if (m_containerNode->offsetInCharacters()) {
152        m_offsetInContainer = m_containerNode->maxCharacterOffset();
153        m_childBeforeBoundary = 0;
154    } else {
155        m_childBeforeBoundary = m_containerNode->lastChild();
156        m_offsetInContainer = m_childBeforeBoundary ? invalidOffset : 0;
157    }
158}
159
160inline void RangeBoundaryPoint::childBeforeWillBeRemoved()
161{
162    ASSERT(m_offsetInContainer);
163    m_childBeforeBoundary = m_childBeforeBoundary->previousSibling();
164    if (!m_childBeforeBoundary)
165        m_offsetInContainer = 0;
166    else if (m_offsetInContainer > 0)
167        --m_offsetInContainer;
168}
169
170inline void RangeBoundaryPoint::invalidateOffset() const
171{
172    m_offsetInContainer = invalidOffset;
173}
174
175inline bool operator==(const RangeBoundaryPoint& a, const RangeBoundaryPoint& b)
176{
177    if (a.container() != b.container())
178        return false;
179    if (a.childBefore() || b.childBefore()) {
180        if (a.childBefore() != b.childBefore())
181            return false;
182    } else {
183        if (a.offset() != b.offset())
184            return false;
185    }
186    return true;
187}
188
189}
190
191#endif
192