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      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  *
      8  * 1.  Redistributions of source code must retain the above copyright
      9  *     notice, this list of conditions and the following disclaimer.
     10  * 2.  Redistributions in binary form must reproduce the above copyright
     11  *     notice, this list of conditions and the following disclaimer in the
     12  *     documentation and/or other materials provided with the distribution.
     13  * 3.  Neither the name of Apple Computer, Inc. ("Apple") nor the names of
     14  *     its contributors may be used to endorse or promote products derived
     15  *     from this software without specific prior written permission.
     16  *
     17  * THIS SOFTWARE IS PROVIDED BY APPLE AND ITS CONTRIBUTORS "AS IS" AND ANY
     18  * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
     19  * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
     20  * DISCLAIMED. IN NO EVENT SHALL APPLE OR ITS CONTRIBUTORS BE LIABLE FOR ANY
     21  * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
     22  * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
     23  * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
     24  * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
     25  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
     26  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
     27  */
     28 
     29 #include "config.h"
     30 #include "core/accessibility/AccessibilityTableCell.h"
     31 
     32 #include "core/accessibility/AXObjectCache.h"
     33 #include "core/rendering/RenderTableCell.h"
     34 
     35 using namespace std;
     36 
     37 namespace WebCore {
     38 
     39 using namespace HTMLNames;
     40 
     41 AccessibilityTableCell::AccessibilityTableCell(RenderObject* renderer)
     42     : AccessibilityRenderObject(renderer)
     43 {
     44 }
     45 
     46 AccessibilityTableCell::~AccessibilityTableCell()
     47 {
     48 }
     49 
     50 PassRefPtr<AccessibilityTableCell> AccessibilityTableCell::create(RenderObject* renderer)
     51 {
     52     return adoptRef(new AccessibilityTableCell(renderer));
     53 }
     54 
     55 bool AccessibilityTableCell::computeAccessibilityIsIgnored() const
     56 {
     57     AccessibilityObjectInclusion decision = defaultObjectInclusion();
     58     if (decision == IncludeObject)
     59         return false;
     60     if (decision == IgnoreObject)
     61         return true;
     62 
     63     if (!isTableCell())
     64         return AccessibilityRenderObject::computeAccessibilityIsIgnored();
     65 
     66     return false;
     67 }
     68 
     69 AccessibilityObject* AccessibilityTableCell::parentTable() const
     70 {
     71     if (!m_renderer || !m_renderer->isTableCell())
     72         return 0;
     73 
     74     // If the document no longer exists, we might not have an axObjectCache.
     75     if (!axObjectCache())
     76         return 0;
     77 
     78     // Do not use getOrCreate. parentTable() can be called while the render tree is being modified
     79     // by javascript, and creating a table element may try to access the render tree while in a bad state.
     80     // By using only get() implies that the AXTable must be created before AXTableCells. This should
     81     // always be the case when AT clients access a table.
     82     // https://bugs.webkit.org/show_bug.cgi?id=42652
     83     return axObjectCache()->get(toRenderTableCell(m_renderer)->table());
     84 }
     85 
     86 bool AccessibilityTableCell::isTableCell() const
     87 {
     88     AccessibilityObject* parent = parentObjectUnignored();
     89     if (!parent || !parent->isTableRow())
     90         return false;
     91 
     92     return true;
     93 }
     94 
     95 AccessibilityRole AccessibilityTableCell::determineAccessibilityRole()
     96 {
     97     if (!isTableCell())
     98         return AccessibilityRenderObject::determineAccessibilityRole();
     99 
    100     return CellRole;
    101 }
    102 
    103 void AccessibilityTableCell::rowIndexRange(pair<unsigned, unsigned>& rowRange)
    104 {
    105     if (!m_renderer || !m_renderer->isTableCell())
    106         return;
    107 
    108     RenderTableCell* renderCell = toRenderTableCell(m_renderer);
    109     rowRange.first = renderCell->rowIndex();
    110     rowRange.second = renderCell->rowSpan();
    111 
    112     // since our table might have multiple sections, we have to offset our row appropriately
    113     RenderTableSection* section = renderCell->section();
    114     RenderTable* table = renderCell->table();
    115     if (!table || !section)
    116         return;
    117 
    118     RenderTableSection* tableSection = table->topSection();
    119     unsigned rowOffset = 0;
    120     while (tableSection) {
    121         if (tableSection == section)
    122             break;
    123         rowOffset += tableSection->numRows();
    124         tableSection = table->sectionBelow(tableSection, SkipEmptySections);
    125     }
    126 
    127     rowRange.first += rowOffset;
    128 }
    129 
    130 void AccessibilityTableCell::columnIndexRange(pair<unsigned, unsigned>& columnRange)
    131 {
    132     if (!m_renderer || !m_renderer->isTableCell())
    133         return;
    134 
    135     RenderTableCell* renderCell = toRenderTableCell(m_renderer);
    136     columnRange.first = renderCell->col();
    137     columnRange.second = renderCell->colSpan();
    138 }
    139 
    140 AccessibilityObject* AccessibilityTableCell::titleUIElement() const
    141 {
    142     // Try to find if the first cell in this row is a <th>. If it is,
    143     // then it can act as the title ui element. (This is only in the
    144     // case when the table is not appearing as an AXTable.)
    145     if (isTableCell() || !m_renderer || !m_renderer->isTableCell())
    146         return 0;
    147 
    148     // Table cells that are th cannot have title ui elements, since by definition
    149     // they are title ui elements
    150     Node* node = m_renderer->node();
    151     if (node && node->hasTagName(thTag))
    152         return 0;
    153 
    154     RenderTableCell* renderCell = toRenderTableCell(m_renderer);
    155 
    156     // If this cell is in the first column, there is no need to continue.
    157     int col = renderCell->col();
    158     if (!col)
    159         return 0;
    160 
    161     int row = renderCell->rowIndex();
    162 
    163     RenderTableSection* section = renderCell->section();
    164     if (!section)
    165         return 0;
    166 
    167     RenderTableCell* headerCell = section->primaryCellAt(row, 0);
    168     if (!headerCell || headerCell == renderCell)
    169         return 0;
    170 
    171     Node* cellElement = headerCell->node();
    172     if (!cellElement || !cellElement->hasTagName(thTag))
    173         return 0;
    174 
    175     return axObjectCache()->getOrCreate(headerCell);
    176 }
    177 
    178 } // namespace WebCore
    179