HTMLTableCellElement* HTMLTableCellElement::cellAbove() const
{
LayoutObject* cellLayoutObject = layoutObject();
if (!cellLayoutObject)
return nullptr;
if (!cellLayoutObject->isTableCell())
return nullptr;
LayoutTableCell* tableCellLayoutObject = toLayoutTableCell(cellLayoutObject);
LayoutTableCell* cellAboveLayoutObject = tableCellLayoutObject->table()->cellAbove(tableCellLayoutObject);
if (!cellAboveLayoutObject)
return nullptr;
return toHTMLTableCellElement(cellAboveLayoutObject->node());
}
void AXTableColumn::headerObjectsForColumn(AXObjectVector& headers) {
if (!m_parent)
return;
LayoutObject* layoutObject = m_parent->getLayoutObject();
if (!layoutObject)
return;
if (!m_parent->isAXTable())
return;
if (toAXTable(m_parent)->isAriaTable()) {
for (const auto& cell : children()) {
if (cell->roleValue() == ColumnHeaderRole)
headers.append(cell);
}
return;
}
if (!layoutObject->isTable())
return;
LayoutTable* table = toLayoutTable(layoutObject);
LayoutTableSection* tableSection = table->topSection();
for (; tableSection;
tableSection = table->sectionBelow(tableSection, SkipEmptySections)) {
unsigned numCols = tableSection->numEffectiveColumns();
if (m_columnIndex >= numCols)
continue;
unsigned numRows = tableSection->numRows();
for (unsigned r = 0; r < numRows; r++) {
LayoutTableCell* layoutCell =
tableSection->primaryCellAt(r, m_columnIndex);
if (!layoutCell)
continue;
AXObject* cell = axObjectCache().getOrCreate(layoutCell->node());
if (!cell || !cell->isTableCell() || headers.contains(cell))
continue;
if (toAXTableCell(cell)->scanToDecideHeaderRole() == ColumnHeaderRole)
headers.append(cell);
}
}
}
bool AXTable::isDataTable() const
{
if (!m_layoutObject || !node())
return false;
// Do not consider it a data table if it has an ARIA role.
if (hasARIARole())
return false;
// When a section of the document is contentEditable, all tables should be
// treated as data tables, otherwise users may not be able to work with rich
// text editors that allow creating and editing tables.
if (node() && node()->hasEditableStyle())
return true;
// 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.
LayoutTable* table = toLayoutTable(m_layoutObject);
Node* tableNode = table->node();
if (!isHTMLTableElement(tableNode))
return false;
// Do not consider it a data table if any of its descendants have an ARIA role.
HTMLTableElement* tableElement = toHTMLTableElement(tableNode);
if (elementHasAriaRole(tableElement->tHead()))
return false;
if (elementHasAriaRole(tableElement->tFoot()))
return false;
RefPtrWillBeRawPtr<HTMLCollection> bodies = tableElement->tBodies();
for (unsigned bodyIndex = 0; bodyIndex < bodies->length(); ++bodyIndex) {
Element* bodyElement = bodies->item(bodyIndex);
if (elementHasAriaRole(bodyElement))
return false;
}
RefPtrWillBeRawPtr<HTMLTableRowsCollection> rows = tableElement->rows();
unsigned rowCount = rows->length();
for (unsigned rowIndex = 0; rowIndex < rowCount; ++rowIndex) {
HTMLTableRowElement* rowElement = rows->item(rowIndex);
if (elementHasAriaRole(rowElement))
return false;
RefPtrWillBeRawPtr<HTMLCollection> cells = rowElement->cells();
for (unsigned cellIndex = 0; cellIndex < cells->length(); ++cellIndex) {
if (elementHasAriaRole(cells->item(cellIndex)))
return false;
}
}
// If there is a caption element, summary, THEAD, or TFOOT section, it's most certainly a data table
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;
// if there's a colgroup or col element, it's probably a data table.
if (Traversal<HTMLTableColElement>::firstChild(*tableElement))
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
table->recalcSectionsIfNeeded();
LayoutTableSection* firstBody = table->firstBody();
if (!firstBody)
return false;
int numCols = firstBody->numEffectiveColumns();
int numRows = firstBody->numRows();
// If there's only one cell, it's not a good AXTable candidate.
if (numRows == 1 && numCols == 1)
return false;
// If there are at least 20 rows, we'll call it a data table.
if (numRows >= 20)
return true;
// Store the background color of the table to check against cell's background colors.
const ComputedStyle* 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;
unsigned cellsWithTopBorder = 0;
unsigned cellsWithBottomBorder = 0;
unsigned cellsWithLeftBorder = 0;
unsigned cellsWithRightBorder = 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) {
LayoutTableCell* cell = firstBody->primaryCellAt(row, col);
if (!cell)
continue;
Node* cellNode = cell->node();
if (!cellNode)
continue;
if (cell->size().width() < 1 || cell->size().height() < 1)
continue;
validCellCount++;
bool isTHCell = cellNode->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 <th> tags, assume it is a data table.
if (!col && isTHCell)
headersInFirstColumnCount++;
// in this case, the developer explicitly assigned a "data" table attribute
if (isHTMLTableCellElement(*cellNode)) {
HTMLTableCellElement& cellElement = toHTMLTableCellElement(*cellNode);
if (!cellElement.headers().isEmpty() || !cellElement.abbr().isEmpty()
|| !cellElement.axis().isEmpty() || !cellElement.scope().isEmpty())
return true;
}
const ComputedStyle* computedStyle = cell->style();
if (!computedStyle)
continue;
// If the empty-cells style is set, we'll call it a data table.
if (computedStyle->emptyCells() == HIDE)
return true;
// If a cell has matching bordered sides, call it a (fully) bordered cell.
if ((cell->borderTop() > 0 && cell->borderBottom() > 0)
|| (cell->borderLeft() > 0 && cell->borderRight() > 0))
borderedCellCount++;
// Also keep track of each individual border, so we can catch tables where most
// cells have a bottom border, for example.
if (cell->borderTop() > 0)
cellsWithTopBorder++;
if (cell->borderBottom() > 0)
cellsWithBottomBorder++;
if (cell->borderLeft() > 0)
cellsWithLeftBorder++;
if (cell->borderRight() > 0)
cellsWithRightBorder++;
// 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 = computedStyle->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) {
LayoutObject* layoutRow = cell->parent();
if (!layoutRow || !layoutRow->isBoxModelObject() || !toLayoutBoxModelObject(layoutRow)->isTableRow())
continue;
const ComputedStyle* rowComputedStyle = layoutRow->style();
if (!rowComputedStyle)
continue;
Color rowColor = rowComputedStyle->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
|| cellsWithTopBorder >= neededCellCount
|| cellsWithBottomBorder >= neededCellCount
|| cellsWithLeftBorder >= neededCellCount
|| cellsWithRightBorder >= 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;
}