--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/WebCore/accessibility/AccessibilityTable.cpp Fri Sep 17 09:02:29 2010 +0300
@@ -0,0 +1,545 @@
+/*
+ * Copyright (C) 2008 Apple Inc. All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ * notice, this list of conditions and the following disclaimer in the
+ * documentation and/or other materials provided with the distribution.
+ * 3. Neither the name of Apple Computer, Inc. ("Apple") nor the names of
+ * its contributors may be used to endorse or promote products derived
+ * from this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY APPLE AND ITS CONTRIBUTORS "AS IS" AND ANY
+ * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
+ * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+ * DISCLAIMED. IN NO EVENT SHALL APPLE OR ITS CONTRIBUTORS BE LIABLE FOR ANY
+ * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
+ * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
+ * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
+ * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
+ * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#include "config.h"
+#include "AccessibilityTable.h"
+
+#include "AXObjectCache.h"
+#include "AccessibilityTableCell.h"
+#include "AccessibilityTableColumn.h"
+#include "AccessibilityTableHeaderContainer.h"
+#include "AccessibilityTableRow.h"
+#include "HTMLNames.h"
+#include "HTMLTableCaptionElement.h"
+#include "HTMLTableCellElement.h"
+#include "HTMLTableElement.h"
+#include "RenderObject.h"
+#include "RenderTable.h"
+#include "RenderTableCell.h"
+#include "RenderTableSection.h"
+
+using namespace std;
+
+namespace WebCore {
+
+using namespace HTMLNames;
+
+AccessibilityTable::AccessibilityTable(RenderObject* renderer)
+ : AccessibilityRenderObject(renderer),
+ m_headerContainer(0)
+{
+#if ACCESSIBILITY_TABLES
+ m_isAccessibilityTable = isTableExposableThroughAccessibility();
+#else
+ m_isAccessibilityTable = false;
+#endif
+}
+
+AccessibilityTable::~AccessibilityTable()
+{
+}
+
+PassRefPtr<AccessibilityTable> AccessibilityTable::create(RenderObject* renderer)
+{
+ return adoptRef(new AccessibilityTable(renderer));
+}
+
+bool AccessibilityTable::isTableExposableThroughAccessibility()
+{
+ // the following is a heuristic used to determine if a
+ // <table> should be exposed as an AXTable. The goal
+ // is to only show "data" tables
+
+ if (!m_renderer || !m_renderer->isTable())
+ return false;
+
+ // if the developer assigned an aria role to this, then we shouldn't
+ // expose it as a table, unless, of course, the aria role is a table
+ AccessibilityRole ariaRole = ariaRoleAttribute();
+ if (ariaRole != UnknownRole)
+ return false;
+
+ RenderTable* table = toRenderTable(m_renderer);
+
+ // this employs a heuristic to determine if this table should appear.
+ // Only "data" tables should be exposed as tables.
+ // Unfortunately, there is no good way to determine the difference
+ // between a "layout" table and a "data" table
+
+ Node* tableNode = table->node();
+ if (!tableNode || !tableNode->hasTagName(tableTag))
+ return false;
+
+ // Gtk+ ATs expect all tables to be exposed as tables.
+#if PLATFORM(GTK)
+ return true;
+#endif
+
+ // if there is a caption element, summary, THEAD, or TFOOT section, it's most certainly a data table
+ HTMLTableElement* tableElement = static_cast<HTMLTableElement*>(tableNode);
+ if (!tableElement->summary().isEmpty() || tableElement->tHead() || tableElement->tFoot() || tableElement->caption())
+ return true;
+
+ // if someone used "rules" attribute than the table should appear
+ if (!tableElement->rules().isEmpty())
+ return true;
+
+ // go through the cell's and check for tell-tale signs of "data" table status
+ // cells have borders, or use attributes like headers, abbr, scope or axis
+ RenderTableSection* firstBody = table->firstBody();
+ if (!firstBody)
+ return false;
+
+ int numCols = firstBody->numColumns();
+ int numRows = firstBody->numRows();
+
+ // if there's only one cell, it's not a good AXTable candidate
+ if (numRows == 1 && numCols == 1)
+ return false;
+
+ // store the background color of the table to check against cell's background colors
+ RenderStyle* tableStyle = table->style();
+ if (!tableStyle)
+ return false;
+ Color tableBGColor = tableStyle->visitedDependentColor(CSSPropertyBackgroundColor);
+
+ // check enough of the cells to find if the table matches our criteria
+ // Criteria:
+ // 1) must have at least one valid cell (and)
+ // 2) at least half of cells have borders (or)
+ // 3) at least half of cells have different bg colors than the table, and there is cell spacing
+ unsigned validCellCount = 0;
+ unsigned borderedCellCount = 0;
+ unsigned backgroundDifferenceCellCount = 0;
+
+ Color alternatingRowColors[5];
+ int alternatingRowColorCount = 0;
+
+ int headersInFirstColumnCount = 0;
+ for (int row = 0; row < numRows; ++row) {
+
+ int headersInFirstRowCount = 0;
+ for (int col = 0; col < numCols; ++col) {
+ RenderTableCell* cell = firstBody->cellAt(row, col).cell;
+ if (!cell)
+ continue;
+ Node* cellNode = cell->node();
+ if (!cellNode)
+ continue;
+
+ if (cell->width() < 1 || cell->height() < 1)
+ continue;
+
+ validCellCount++;
+
+ HTMLTableCellElement* cellElement = static_cast<HTMLTableCellElement*>(cellNode);
+
+ bool isTHCell = cellElement->hasTagName(thTag);
+ // If the first row is comprised of all <th> tags, assume it is a data table.
+ if (!row && isTHCell)
+ headersInFirstRowCount++;
+
+ // If the first column is comprised of all <tg> tags, assume it is a data table.
+ if (!col && isTHCell)
+ headersInFirstColumnCount++;
+
+ // in this case, the developer explicitly assigned a "data" table attribute
+ if (!cellElement->headers().isEmpty() || !cellElement->abbr().isEmpty()
+ || !cellElement->axis().isEmpty() || !cellElement->scope().isEmpty())
+ return true;
+
+ RenderStyle* renderStyle = cell->style();
+ if (!renderStyle)
+ continue;
+
+ // a cell needs to have matching bordered sides, before it can be considered a bordered cell.
+ if ((cell->borderTop() > 0 && cell->borderBottom() > 0)
+ || (cell->borderLeft() > 0 && cell->borderRight() > 0))
+ borderedCellCount++;
+
+ // if the cell has a different color from the table and there is cell spacing,
+ // then it is probably a data table cell (spacing and colors take the place of borders)
+ Color cellColor = renderStyle->visitedDependentColor(CSSPropertyBackgroundColor);
+ if (table->hBorderSpacing() > 0 && table->vBorderSpacing() > 0
+ && tableBGColor != cellColor && cellColor.alpha() != 1)
+ backgroundDifferenceCellCount++;
+
+ // if we've found 10 "good" cells, we don't need to keep searching
+ if (borderedCellCount >= 10 || backgroundDifferenceCellCount >= 10)
+ return true;
+
+ // For the first 5 rows, cache the background color so we can check if this table has zebra-striped rows.
+ if (row < 5 && row == alternatingRowColorCount) {
+ RenderObject* renderRow = cell->parent();
+ if (!renderRow || !renderRow->isTableRow())
+ continue;
+ RenderStyle* rowRenderStyle = renderRow->style();
+ if (!rowRenderStyle)
+ continue;
+ Color rowColor = rowRenderStyle->visitedDependentColor(CSSPropertyBackgroundColor);
+ alternatingRowColors[alternatingRowColorCount] = rowColor;
+ alternatingRowColorCount++;
+ }
+ }
+
+ if (!row && headersInFirstRowCount == numCols && numCols > 1)
+ return true;
+ }
+
+ if (headersInFirstColumnCount == numRows && numRows > 1)
+ return true;
+
+ // if there is less than two valid cells, it's not a data table
+ if (validCellCount <= 1)
+ return false;
+
+ // half of the cells had borders, it's a data table
+ unsigned neededCellCount = validCellCount / 2;
+ if (borderedCellCount >= neededCellCount)
+ return true;
+
+ // half had different background colors, it's a data table
+ if (backgroundDifferenceCellCount >= neededCellCount)
+ return true;
+
+ // Check if there is an alternating row background color indicating a zebra striped style pattern.
+ if (alternatingRowColorCount > 2) {
+ Color firstColor = alternatingRowColors[0];
+ for (int k = 1; k < alternatingRowColorCount; k++) {
+ // If an odd row was the same color as the first row, its not alternating.
+ if (k % 2 == 1 && alternatingRowColors[k] == firstColor)
+ return false;
+ // If an even row is not the same as the first row, its not alternating.
+ if (!(k % 2) && alternatingRowColors[k] != firstColor)
+ return false;
+ }
+ return true;
+ }
+
+ return false;
+}
+
+void AccessibilityTable::clearChildren()
+{
+ AccessibilityRenderObject::clearChildren();
+ m_rows.clear();
+ m_columns.clear();
+}
+
+void AccessibilityTable::addChildren()
+{
+ if (!isDataTable()) {
+ AccessibilityRenderObject::addChildren();
+ return;
+ }
+
+ ASSERT(!m_haveChildren);
+
+ m_haveChildren = true;
+ if (!m_renderer || !m_renderer->isTable())
+ return;
+
+ RenderTable* table = toRenderTable(m_renderer);
+ AXObjectCache* axCache = m_renderer->document()->axObjectCache();
+
+ // go through all the available sections to pull out the rows
+ // and add them as children
+ RenderTableSection* tableSection = table->header();
+ if (!tableSection)
+ tableSection = table->firstBody();
+
+ if (!tableSection)
+ return;
+
+ RenderTableSection* initialTableSection = tableSection;
+
+ while (tableSection) {
+
+ HashSet<AccessibilityObject*> appendedRows;
+
+ unsigned numRows = tableSection->numRows();
+ unsigned numCols = tableSection->numColumns();
+ for (unsigned rowIndex = 0; rowIndex < numRows; ++rowIndex) {
+ for (unsigned colIndex = 0; colIndex < numCols; ++colIndex) {
+
+ RenderTableCell* cell = tableSection->cellAt(rowIndex, colIndex).cell;
+ if (!cell)
+ continue;
+
+ AccessibilityObject* rowObject = axCache->getOrCreate(cell->parent());
+ if (!rowObject->isTableRow())
+ continue;
+
+ AccessibilityTableRow* row = static_cast<AccessibilityTableRow*>(rowObject);
+ // we need to check every cell for a new row, because cell spans
+ // can cause us to mess rows if we just check the first column
+ if (appendedRows.contains(row))
+ continue;
+
+ row->setRowIndex((int)m_rows.size());
+ m_rows.append(row);
+ if (!row->accessibilityIsIgnored())
+ m_children.append(row);
+#if PLATFORM(GTK)
+ else
+ m_children.append(row->children());
+#endif
+ appendedRows.add(row);
+ }
+ }
+
+ tableSection = table->sectionBelow(tableSection, true);
+ }
+
+ // make the columns based on the number of columns in the first body
+ unsigned length = initialTableSection->numColumns();
+ for (unsigned i = 0; i < length; ++i) {
+ AccessibilityTableColumn* column = static_cast<AccessibilityTableColumn*>(axCache->getOrCreate(ColumnRole));
+ column->setColumnIndex((int)i);
+ column->setParentTable(this);
+ m_columns.append(column);
+ if (!column->accessibilityIsIgnored())
+ m_children.append(column);
+ }
+
+ AccessibilityObject* headerContainerObject = headerContainer();
+ if (headerContainerObject && !headerContainerObject->accessibilityIsIgnored())
+ m_children.append(headerContainerObject);
+}
+
+AccessibilityObject* AccessibilityTable::headerContainer()
+{
+ if (m_headerContainer)
+ return m_headerContainer;
+
+ m_headerContainer = static_cast<AccessibilityTableHeaderContainer*>(axObjectCache()->getOrCreate(TableHeaderContainerRole));
+ m_headerContainer->setParentTable(this);
+
+ return m_headerContainer;
+}
+
+AccessibilityObject::AccessibilityChildrenVector& AccessibilityTable::columns()
+{
+ updateChildrenIfNecessary();
+
+ return m_columns;
+}
+
+AccessibilityObject::AccessibilityChildrenVector& AccessibilityTable::rows()
+{
+ updateChildrenIfNecessary();
+
+ return m_rows;
+}
+
+void AccessibilityTable::rowHeaders(AccessibilityChildrenVector& headers)
+{
+ if (!m_renderer)
+ return;
+
+ updateChildrenIfNecessary();
+
+ unsigned rowCount = m_rows.size();
+ for (unsigned k = 0; k < rowCount; ++k) {
+ AccessibilityObject* header = static_cast<AccessibilityTableRow*>(m_rows[k].get())->headerObject();
+ if (!header)
+ continue;
+ headers.append(header);
+ }
+}
+
+void AccessibilityTable::columnHeaders(AccessibilityChildrenVector& headers)
+{
+ if (!m_renderer)
+ return;
+
+ updateChildrenIfNecessary();
+
+ unsigned colCount = m_columns.size();
+ for (unsigned k = 0; k < colCount; ++k) {
+ AccessibilityObject* header = static_cast<AccessibilityTableColumn*>(m_columns[k].get())->headerObject();
+ if (!header)
+ continue;
+ headers.append(header);
+ }
+}
+
+void AccessibilityTable::cells(AccessibilityObject::AccessibilityChildrenVector& cells)
+{
+ if (!m_renderer)
+ return;
+
+ updateChildrenIfNecessary();
+
+ int numRows = m_rows.size();
+ for (int row = 0; row < numRows; ++row) {
+ AccessibilityChildrenVector rowChildren = m_rows[row]->children();
+ cells.append(rowChildren);
+ }
+}
+
+unsigned AccessibilityTable::columnCount()
+{
+ updateChildrenIfNecessary();
+
+ return m_columns.size();
+}
+
+unsigned AccessibilityTable::rowCount()
+{
+ updateChildrenIfNecessary();
+
+ return m_rows.size();
+}
+
+AccessibilityTableCell* AccessibilityTable::cellForColumnAndRow(unsigned column, unsigned row)
+{
+ if (!m_renderer || !m_renderer->isTable())
+ return 0;
+
+ updateChildrenIfNecessary();
+
+ RenderTable* table = toRenderTable(m_renderer);
+ RenderTableSection* tableSection = table->header();
+ if (!tableSection)
+ tableSection = table->firstBody();
+
+ RenderTableCell* cell = 0;
+ unsigned rowCount = 0;
+ unsigned rowOffset = 0;
+ while (tableSection) {
+
+ unsigned numRows = tableSection->numRows();
+ unsigned numCols = tableSection->numColumns();
+
+ rowCount += numRows;
+
+ unsigned sectionSpecificRow = row - rowOffset;
+ if (row < rowCount && column < numCols && sectionSpecificRow < numRows) {
+ cell = tableSection->cellAt(sectionSpecificRow, column).cell;
+
+ // we didn't find the cell, which means there's spanning happening
+ // search backwards to find the spanning cell
+ if (!cell) {
+
+ // first try rows
+ for (int testRow = sectionSpecificRow-1; testRow >= 0; --testRow) {
+ cell = tableSection->cellAt(testRow, column).cell;
+ // cell overlapped. use this one
+ if (cell && ((cell->row() + (cell->rowSpan()-1)) >= (int)sectionSpecificRow))
+ break;
+ cell = 0;
+ }
+
+ if (!cell) {
+ // try cols
+ for (int testCol = column-1; testCol >= 0; --testCol) {
+ cell = tableSection->cellAt(sectionSpecificRow, testCol).cell;
+ // cell overlapped. use this one
+ if (cell && ((cell->col() + (cell->colSpan()-1)) >= (int)column))
+ break;
+ cell = 0;
+ }
+ }
+ }
+ }
+
+ if (cell)
+ break;
+
+ rowOffset += numRows;
+ // we didn't find anything between the rows we should have
+ if (row < rowCount)
+ break;
+ tableSection = table->sectionBelow(tableSection, true);
+ }
+
+ if (!cell)
+ return 0;
+
+ AccessibilityObject* cellObject = axObjectCache()->getOrCreate(cell);
+ ASSERT(cellObject->isTableCell());
+
+ return static_cast<AccessibilityTableCell*>(cellObject);
+}
+
+AccessibilityRole AccessibilityTable::roleValue() const
+{
+ if (!isDataTable())
+ return AccessibilityRenderObject::roleValue();
+
+ return TableRole;
+}
+
+bool AccessibilityTable::accessibilityIsIgnored() const
+{
+ AccessibilityObjectInclusion decision = accessibilityIsIgnoredBase();
+ if (decision == IncludeObject)
+ return false;
+ if (decision == IgnoreObject)
+ return true;
+
+ if (!isDataTable())
+ return AccessibilityRenderObject::accessibilityIsIgnored();
+
+ return false;
+}
+
+String AccessibilityTable::title() const
+{
+ if (!isDataTable())
+ return AccessibilityRenderObject::title();
+
+ String title;
+ if (!m_renderer)
+ return title;
+
+ // see if there is a caption
+ Node* tableElement = m_renderer->node();
+ if (tableElement && tableElement->hasTagName(tableTag)) {
+ HTMLTableCaptionElement* caption = static_cast<HTMLTableElement*>(tableElement)->caption();
+ if (caption)
+ title = caption->innerText();
+ }
+
+ // try the standard
+ if (title.isEmpty())
+ title = AccessibilityRenderObject::title();
+
+ return title;
+}
+
+bool AccessibilityTable::isDataTable() const
+{
+ if (!m_renderer)
+ return false;
+
+ return m_isAccessibilityTable;
+}
+
+} // namespace WebCore