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      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 "core/dom/PositionIterator.h"
     28 
     29 #include "core/editing/htmlediting.h"
     30 #include "core/html/HTMLHtmlElement.h"
     31 #include "core/rendering/RenderBlock.h"
     32 
     33 namespace WebCore {
     34 
     35 using namespace HTMLNames;
     36 
     37 PositionIterator::operator Position() const
     38 {
     39     if (m_nodeAfterPositionInAnchor) {
     40         ASSERT(m_nodeAfterPositionInAnchor->parentNode() == m_anchorNode);
     41         // FIXME: This check is inadaquete because any ancestor could be ignored by editing
     42         if (editingIgnoresContent(m_nodeAfterPositionInAnchor->parentNode()))
     43             return positionBeforeNode(m_anchorNode);
     44         return positionInParentBeforeNode(*m_nodeAfterPositionInAnchor);
     45     }
     46     if (m_anchorNode->hasChildren())
     47         return lastPositionInOrAfterNode(m_anchorNode);
     48     return createLegacyEditingPosition(m_anchorNode, m_offsetInAnchor);
     49 }
     50 
     51 void PositionIterator::increment()
     52 {
     53     if (!m_anchorNode)
     54         return;
     55 
     56     if (m_nodeAfterPositionInAnchor) {
     57         m_anchorNode = m_nodeAfterPositionInAnchor;
     58         m_nodeAfterPositionInAnchor = m_anchorNode->firstChild();
     59         m_offsetInAnchor = 0;
     60         return;
     61     }
     62 
     63     if (!m_anchorNode->hasChildren() && m_offsetInAnchor < lastOffsetForEditing(m_anchorNode))
     64         m_offsetInAnchor = Position::uncheckedNextOffset(m_anchorNode, m_offsetInAnchor);
     65     else {
     66         m_nodeAfterPositionInAnchor = m_anchorNode;
     67         m_anchorNode = m_nodeAfterPositionInAnchor->parentNode();
     68         m_nodeAfterPositionInAnchor = m_nodeAfterPositionInAnchor->nextSibling();
     69         m_offsetInAnchor = 0;
     70     }
     71 }
     72 
     73 void PositionIterator::decrement()
     74 {
     75     if (!m_anchorNode)
     76         return;
     77 
     78     if (m_nodeAfterPositionInAnchor) {
     79         m_anchorNode = m_nodeAfterPositionInAnchor->previousSibling();
     80         if (m_anchorNode) {
     81             m_nodeAfterPositionInAnchor = nullptr;
     82             m_offsetInAnchor = m_anchorNode->hasChildren() ? 0 : lastOffsetForEditing(m_anchorNode);
     83         } else {
     84             m_nodeAfterPositionInAnchor = m_nodeAfterPositionInAnchor->parentNode();
     85             m_anchorNode = m_nodeAfterPositionInAnchor->parentNode();
     86             m_offsetInAnchor = 0;
     87         }
     88         return;
     89     }
     90 
     91     if (m_anchorNode->hasChildren()) {
     92         m_anchorNode = m_anchorNode->lastChild();
     93         m_offsetInAnchor = m_anchorNode->hasChildren()? 0: lastOffsetForEditing(m_anchorNode);
     94     } else {
     95         if (m_offsetInAnchor)
     96             m_offsetInAnchor = Position::uncheckedPreviousOffset(m_anchorNode, m_offsetInAnchor);
     97         else {
     98             m_nodeAfterPositionInAnchor = m_anchorNode;
     99             m_anchorNode = m_anchorNode->parentNode();
    100         }
    101     }
    102 }
    103 
    104 bool PositionIterator::atStart() const
    105 {
    106     if (!m_anchorNode)
    107         return true;
    108     if (m_anchorNode->parentNode())
    109         return false;
    110     return (!m_anchorNode->hasChildren() && !m_offsetInAnchor) || (m_nodeAfterPositionInAnchor && !m_nodeAfterPositionInAnchor->previousSibling());
    111 }
    112 
    113 bool PositionIterator::atEnd() const
    114 {
    115     if (!m_anchorNode)
    116         return true;
    117     if (m_nodeAfterPositionInAnchor)
    118         return false;
    119     return !m_anchorNode->parentNode() && (m_anchorNode->hasChildren() || m_offsetInAnchor >= lastOffsetForEditing(m_anchorNode));
    120 }
    121 
    122 bool PositionIterator::atStartOfNode() const
    123 {
    124     if (!m_anchorNode)
    125         return true;
    126     if (!m_nodeAfterPositionInAnchor)
    127         return !m_anchorNode->hasChildren() && !m_offsetInAnchor;
    128     return !m_nodeAfterPositionInAnchor->previousSibling();
    129 }
    130 
    131 bool PositionIterator::atEndOfNode() const
    132 {
    133     if (!m_anchorNode)
    134         return true;
    135     if (m_nodeAfterPositionInAnchor)
    136         return false;
    137     return m_anchorNode->hasChildren() || m_offsetInAnchor >= lastOffsetForEditing(m_anchorNode);
    138 }
    139 
    140 bool PositionIterator::isCandidate() const
    141 {
    142     if (!m_anchorNode)
    143         return false;
    144 
    145     RenderObject* renderer = m_anchorNode->renderer();
    146     if (!renderer)
    147         return false;
    148 
    149     if (renderer->style()->visibility() != VISIBLE)
    150         return false;
    151 
    152     if (renderer->isBR()) {
    153         // For br element, the condition
    154         // |(!m_anchorNode->hasChildren() || m_nodeAfterPositionInAnchor)|
    155         // corresponds to the condition
    156         // |m_anchorType != PositionIsAfterAnchor| in Position.isCandaite.
    157         // Both conditions say this position is not in tail of the element.
    158         // If conditions lose consitency, VisiblePosition::canonicalPosition
    159         // will fail on |canonicalizeCandidate(previousCandidate(position))|,
    160         // because previousCandidate returns a Position converted from
    161         // a "Candidate" PositionIterator and cannonicalizeCandidate(Position)
    162         // assumes the Position is "Candidate".
    163         return !m_offsetInAnchor && (!m_anchorNode->hasChildren() || m_nodeAfterPositionInAnchor) && !Position::nodeIsUserSelectNone(m_anchorNode->parentNode());
    164     }
    165     if (renderer->isText())
    166         return !Position::nodeIsUserSelectNone(m_anchorNode) && Position(*this).inRenderedText();
    167 
    168     if (renderer->isSVG()) {
    169         // We don't consider SVG elements are contenteditable except for
    170         // associated renderer returns isText() true, e.g. RenderSVGInlineText.
    171         return false;
    172     }
    173 
    174     if (isRenderedTableElement(m_anchorNode) || editingIgnoresContent(m_anchorNode))
    175         return (atStartOfNode() || atEndOfNode()) && !Position::nodeIsUserSelectNone(m_anchorNode->parentNode());
    176 
    177     if (!isHTMLHtmlElement(*m_anchorNode) && renderer->isRenderBlockFlow()) {
    178         if (toRenderBlock(renderer)->logicalHeight() || isHTMLBodyElement(*m_anchorNode)) {
    179             if (!Position::hasRenderedNonAnonymousDescendantsWithHeight(renderer))
    180                 return atStartOfNode() && !Position::nodeIsUserSelectNone(m_anchorNode);
    181             return m_anchorNode->rendererIsEditable() && !Position::nodeIsUserSelectNone(m_anchorNode) && Position(*this).atEditingBoundary();
    182         }
    183     }
    184 
    185     return false;
    186 }
    187 
    188 } // namespace WebCore
    189