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      1 /*
      2  * Copyright (C) 2009 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 "AccessibilityARIAGrid.h"
     31 
     32 #include "AXObjectCache.h"
     33 #include "AccessibilityTableCell.h"
     34 #include "AccessibilityTableColumn.h"
     35 #include "AccessibilityTableHeaderContainer.h"
     36 #include "AccessibilityTableRow.h"
     37 #include "RenderObject.h"
     38 
     39 using namespace std;
     40 
     41 namespace WebCore {
     42 
     43 AccessibilityARIAGrid::AccessibilityARIAGrid(RenderObject* renderer)
     44     : AccessibilityTable(renderer)
     45 {
     46 #if ACCESSIBILITY_TABLES
     47     m_isAccessibilityTable = true;
     48 #else
     49     m_isAccessibilityTable = false;
     50 #endif
     51 }
     52 
     53 AccessibilityARIAGrid::~AccessibilityARIAGrid()
     54 {
     55 }
     56 
     57 PassRefPtr<AccessibilityARIAGrid> AccessibilityARIAGrid::create(RenderObject* renderer)
     58 {
     59     return adoptRef(new AccessibilityARIAGrid(renderer));
     60 }
     61 
     62 void AccessibilityARIAGrid::addChild(AccessibilityObject* child, HashSet<AccessibilityObject*>& appendedRows, unsigned& columnCount)
     63 {
     64     if (!child || !child->isTableRow() || child->ariaRoleAttribute() != RowRole)
     65         return;
     66 
     67     AccessibilityTableRow* row = static_cast<AccessibilityTableRow*>(child);
     68     if (appendedRows.contains(row))
     69         return;
     70 
     71     // store the maximum number of columns
     72     unsigned rowCellCount = row->children().size();
     73     if (rowCellCount > columnCount)
     74         columnCount = rowCellCount;
     75 
     76     row->setRowIndex((int)m_rows.size());
     77     m_rows.append(row);
     78 
     79     // Try adding the row if it's not ignoring accessibility,
     80     // otherwise add its children (the cells) as the grid's children.
     81     if (!row->accessibilityIsIgnored())
     82         m_children.append(row);
     83     else
     84         m_children.append(row->children());
     85 
     86     appendedRows.add(row);
     87 }
     88 
     89 void AccessibilityARIAGrid::addChildren()
     90 {
     91     ASSERT(!m_haveChildren);
     92 
     93     if (!isAccessibilityTable()) {
     94         AccessibilityRenderObject::addChildren();
     95         return;
     96     }
     97 
     98     m_haveChildren = true;
     99     if (!m_renderer)
    100         return;
    101 
    102     AXObjectCache* axCache = m_renderer->document()->axObjectCache();
    103 
    104     // add only rows that are labeled as aria rows
    105     HashSet<AccessibilityObject*> appendedRows;
    106     unsigned columnCount = 0;
    107     for (RefPtr<AccessibilityObject> child = firstChild(); child; child = child->nextSibling()) {
    108 
    109         if (child->isTableRow() || child->ariaRoleAttribute() == RowRole)
    110             addChild(child.get(), appendedRows, columnCount);
    111         else {
    112             // in case the render tree doesn't match the expected ARIA hierarchy, look at the children
    113             if (!child->hasChildren())
    114                 child->addChildren();
    115 
    116             // Do not navigate children through the Accessibility
    117             // children vector to let addChild() check the result
    118             // of accessibilityIsIgnored() and make the proper
    119             // decision (add the objects or their children).
    120             AccessibilityObject* grandChild = 0;
    121             for (grandChild = child->firstChild(); grandChild; grandChild = grandChild->nextSibling())
    122                 addChild(grandChild, appendedRows, columnCount);
    123         }
    124     }
    125 
    126     // make the columns based on the number of columns in the first body
    127     for (unsigned i = 0; i < columnCount; ++i) {
    128         AccessibilityTableColumn* column = static_cast<AccessibilityTableColumn*>(axCache->getOrCreate(ColumnRole));
    129         column->setColumnIndex((int)i);
    130         column->setParentTable(this);
    131         m_columns.append(column);
    132         if (!column->accessibilityIsIgnored())
    133             m_children.append(column);
    134     }
    135 
    136     AccessibilityObject* headerContainerObject = headerContainer();
    137     if (headerContainerObject && !headerContainerObject->accessibilityIsIgnored())
    138         m_children.append(headerContainerObject);
    139 }
    140 
    141 AccessibilityTableCell* AccessibilityARIAGrid::cellForColumnAndRow(unsigned column, unsigned row)
    142 {
    143     if (!m_renderer)
    144         return 0;
    145 
    146     updateChildrenIfNecessary();
    147 
    148     if (column >= columnCount() || row >= rowCount())
    149         return 0;
    150 
    151     int intRow = (int)row;
    152     int intColumn = (int)column;
    153 
    154     pair<int, int> columnRange;
    155     pair<int, int> rowRange;
    156 
    157     // Iterate backwards through the rows in case the desired cell has a rowspan and exists
    158     // in a previous row.
    159     for (; intRow >= 0; --intRow) {
    160         AccessibilityObject* tableRow = m_rows[intRow].get();
    161         if (!tableRow)
    162             continue;
    163 
    164         AccessibilityChildrenVector children = tableRow->children();
    165         unsigned childrenLength = children.size();
    166 
    167         // Since some cells may have colspans, we have to check the actual range of each
    168         // cell to determine which is the right one.
    169         for (unsigned k = 0; k < childrenLength; ++k) {
    170             AccessibilityObject* child = children[k].get();
    171             if (!child->isTableCell())
    172                 continue;
    173 
    174             AccessibilityTableCell* tableCellChild = static_cast<AccessibilityTableCell*>(child);
    175             tableCellChild->columnIndexRange(columnRange);
    176             tableCellChild->rowIndexRange(rowRange);
    177 
    178             if ((intColumn >= columnRange.first && intColumn < (columnRange.first + columnRange.second))
    179                 && (intRow >= rowRange.first && intRow < (rowRange.first + rowRange.second)))
    180                 return tableCellChild;
    181         }
    182     }
    183 
    184     return 0;
    185 }
    186 
    187 } // namespace WebCore
    188