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 
AccessibilityARIAGrid(RenderObject * renderer)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 
~AccessibilityARIAGrid()53 AccessibilityARIAGrid::~AccessibilityARIAGrid()
54 {
55 }
56 
create(RenderObject * renderer)57 PassRefPtr<AccessibilityARIAGrid> AccessibilityARIAGrid::create(RenderObject* renderer)
58 {
59     return adoptRef(new AccessibilityARIAGrid(renderer));
60 }
61 
addChild(AccessibilityObject * child,HashSet<AccessibilityObject * > & appendedRows,unsigned & columnCount)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 
addChildren()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 
cellForColumnAndRow(unsigned column,unsigned row)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