WebCore/RangeBoundaryPoint.h

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