WebCore/dom/PositionIterator.cpp

   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 #include "config.h"
  27 #include "PositionIterator.h"
  28
  29 #include "Node.h"
  30 #include "RenderObject.h"
  31 #include "htmlediting.h"
  32
  33 namespace WebCore {
  34
  35 using namespace HTMLNames;
  36
  37 PositionIterator::operator Position() const
  38 {
  39     return Position(m_parent, m_child ? m_child->nodeIndex() : (m_parent->hasChildNodes() ? maxDeepOffset(m_parent) : m_offset));
  40 }
  41
  42 void PositionIterator::increment()
  43 {
  44     if (!m_parent)
  45         return;
  46
  47     if (m_child) {
  48         m_parent = m_child;
  49         m_child = m_parent->firstChild();
  50         m_offset = 0;
  51         return;
  52     }
  53
  54     if (!m_parent->hasChildNodes() && m_offset < maxDeepOffset(m_parent))
  55         m_offset = Position::uncheckedNextOffset(m_parent, m_offset);
  56     else {
  57         m_child = m_parent;
  58         m_parent = m_child->parentNode();
  59         m_child = m_child->nextSibling();
  60         m_offset = 0;
  61     }
  62 }
  63
  64 void PositionIterator::decrement()
  65 {
  66     if (!m_parent)
  67         return;
  68
  69     if (m_child) {
  70         m_parent = m_child->previousSibling();
  71         if (m_parent) {
  72             m_child = 0;
  73             m_offset = m_parent->hasChildNodes() ? 0 : maxDeepOffset(m_parent);
  74         } else {
  75             m_child = m_child->parentNode();
  76             m_parent = m_child->parentNode();
  77             m_offset = 0;
  78         }
  79         return;
  80     }
  81
  82     if (m_offset) {
  83         m_offset = Position::uncheckedPreviousOffset(m_parent, m_offset);
  84     } else {
  85         if (m_parent->hasChildNodes()) {
  86             m_parent = m_parent->lastChild();
  87             if (!m_parent->hasChildNodes())
  88                 m_offset = maxDeepOffset(m_parent);
  89         } else {
  90             m_child = m_parent;
  91             m_parent = m_parent->parentNode();
  92         }
  93     }
  94 }
  95
  96 bool PositionIterator::atStart() const
  97 {
  98     if (!m_parent)
  99         return true;
 100     if (m_parent->parentNode())
 101         return false;
 102     return !m_parent->hasChildNodes() && !m_offset || m_child && !m_child->previousSibling();
 103 }
 104
 105 bool PositionIterator::atEnd() const
 106 {
 107     if (!m_parent)
 108         return true;
 109     if (m_child)
 110         return false;
 111     return !m_parent->parentNode() && (m_parent->hasChildNodes() || m_offset >= maxDeepOffset(m_parent));
 112 }
 113
 114 bool PositionIterator::atStartOfNode() const
 115 {
 116     if (!m_parent)
 117         return true;
 118     if (!m_child)
 119         return !m_parent->hasChildNodes() && !m_offset;
 120     return !m_child->previousSibling();
 121 }
 122
 123 bool PositionIterator::atEndOfNode() const
 124 {
 125     if (!m_parent)
 126         return true;
 127     if (m_child)
 128         return false;
 129     return m_parent->hasChildNodes() || m_offset >= maxDeepOffset(m_parent);
 130 }
 131
 132 bool PositionIterator::isCandidate() const
 133 {
 134     if (!m_parent)
 135         return false;
 136
 137     RenderObject* renderer = m_parent->renderer();
 138     if (!renderer)
 139         return false;
 140
 141     if (renderer->style()->visibility() != VISIBLE)
 142         return false;
 143
 144     if (renderer->isBR())
 145         return !m_offset && !Position::nodeIsUserSelectNone(m_parent->parent());
 146
 147     if (renderer->isText())
 148         return Position(*this).inRenderedText() && !Position::nodeIsUserSelectNone(m_parent);
 149
 150     if (isTableElement(m_parent) || editingIgnoresContent(m_parent))
 151         return (atStartOfNode() || atEndOfNode()) && !Position::nodeIsUserSelectNone(m_parent->parent());
 152
 153     if (!m_parent->hasTagName(htmlTag) && renderer->isBlockFlow() && !Position::hasRenderedNonAnonymousDescendantsWithHeight(renderer) &&
 154        (renderer->height() || m_parent->hasTagName(bodyTag)))
 155         return atStartOfNode() && !Position::nodeIsUserSelectNone(m_parent);
 156
 157     return false;
 158 }
 159
 160 } // namespace WebCore