C++ RenderTable::firstBody方法代码示例

void AccessibilityTableCell::rowIndexRange(pair<int, int>& rowRange)
{
    if (!m_renderer || !m_renderer->isTableCell())
        return;
    
    RenderTableCell* renderCell = toRenderTableCell(m_renderer);
    rowRange.first = renderCell->rowIndex();
    rowRange.second = renderCell->rowSpan();
    
    // since our table might have multiple sections, we have to offset our row appropriately
    RenderTableSection* section = renderCell->section();
    RenderTable* table = renderCell->table();
    if (!table || !section)
        return;

    // FIXME: This will skip a table with just a tfoot. Should fix by using RenderTable::topSection.
    RenderTableSection* tableSection = table->header();
    if (!tableSection)
        tableSection = table->firstBody();
    
    unsigned rowOffset = 0;
    while (tableSection) {
        if (tableSection == section)
            break;
        rowOffset += tableSection->numRows();
        tableSection = table->sectionBelow(tableSection, SkipEmptySections);
    }

    rowRange.first += rowOffset;
}

void AccessibilityTableCell::rowIndexRange(pair<int, int>& rowRange)
{
    if (!m_renderer)
        return;
    
    RenderTableCell* renderCell = static_cast<RenderTableCell*>(m_renderer);
    rowRange.first = renderCell->row();
    rowRange.second = renderCell->rowSpan();
    
    // since our table might have multiple sections, we have to offset our row appropriately
    RenderTableSection* section = renderCell->section();
    RenderTable* table = renderCell->table();
    if (!table || !section)
        return;
    
    RenderTableSection* tableSection = table->header();
    if (!tableSection)
        tableSection = table->firstBody();
    
    unsigned rowOffset = 0;
    while (tableSection) {
        if (tableSection == section)
            break;
        rowOffset += tableSection->numRows();
        tableSection = table->sectionBelow(tableSection, true); 
    }

    rowRange.first += rowOffset;
}

AccessibilityObject* AccessibilityTableColumn::headerObject()
{
    if (!m_parent)
        return 0;
    
    RenderObject* renderer = m_parent->renderer();
    if (!renderer)
        return 0;
    
    if (!m_parent->isAccessibilityTable())
        return 0;
    
    AccessibilityTable* parentTable = toAccessibilityTable(m_parent);
    if (parentTable->isAriaTable()) {
        AccessibilityChildrenVector rowChildren = children();
        unsigned childrenCount = rowChildren.size();
        for (unsigned i = 0; i < childrenCount; ++i) {
            AccessibilityObject* cell = rowChildren[i].get();
            if (cell->ariaRoleAttribute() == ColumnHeaderRole)
                return cell;
        }
        
        return 0;
    }

    if (!renderer->isTable())
        return 0;
    
    RenderTable* table = toRenderTable(renderer);
    
    AccessibilityObject* headerObject = 0;
    
    // try the <thead> section first. this doesn't require th tags
    headerObject = headerObjectForSection(table->header(), false);

    if (headerObject)
        return headerObject;
    
    // now try for <th> tags in the first body
    headerObject = headerObjectForSection(table->firstBody(), true);

    return headerObject;
}

HTMLTableElement* AccessibilityTable::tableElement() const
{
    if (!m_renderer->isTable())
        return nullptr;
    
    RenderTable* table = toRenderTable(m_renderer);
    if (table->element() && isHTMLTableElement(table->element()))
        return toHTMLTableElement(table->element());
    
    // If the table has a display:table-row-group, then the RenderTable does not have a pointer to it's HTMLTableElement.
    // We can instead find it by asking the firstSection for its parent.
    RenderTableSection* firstBody = table->firstBody();
    if (!firstBody || !firstBody->element())
        return nullptr;
    
    Element* actualTable = firstBody->element()->parentElement();
    if (!actualTable || !isHTMLTableElement(actualTable))
        return nullptr;
    
    return toHTMLTableElement(actualTable);
}

bool AccessibilityTable::isDataTable() const
{
    if (!m_renderer)
        return false;

    // Do not consider it a data table is 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.
    
    RenderTable* table = toRenderTable(m_renderer);
    if (!table->element() || !isHTMLTableElement(table->element()))
        return false;

    // if there is a caption element, summary, THEAD, or TFOOT section, it's most certainly a data table
    HTMLTableElement* tableElement = toHTMLTableElement(table->element());
    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.
    for (const auto& child : childrenOfType<Element>(*tableElement)) {
        if (child.hasTagName(colTag) || child.hasTagName(colgroupTag))
            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();
    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;

    // 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 RenderStyle& tableStyle = table->style();
    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) {    
            RenderTableCell* cell = firstBody->primaryCellAt(row, col);
            if (!cell)
                continue;

            Element* cellElement = cell->element();
            if (!cellElement)
                continue;
            
            if (cell->width() < 1 || cell->height() < 1)
                continue;
            
            validCellCount++;
            
            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++;

//.........这里部分代码省略.........

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 == TableRole)
        return true;
    if (ariaRole != UnknownRole)
        return false;
    
    RenderTable* table = static_cast<RenderTable*>(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->element();
    if (!tableNode || !tableNode->hasTagName(tableTag))
        return false;
    
    // 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->backgroundColor();
    
    // 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;
    
    for (int row = 0; row < numRows; ++row) {
        for (int col = 0; col < numCols; ++col) {    
            RenderTableCell* cell = firstBody->cellAt(row, col).cell;
            if (!cell)
                continue;
            Node* cellNode = cell->element();
            if (!cellNode)
                continue;
            
            if (cell->width() < 1 || cell->height() < 1)
                continue;
            
            validCellCount++;
            
            HTMLTableCellElement* cellElement = static_cast<HTMLTableCellElement*>(cellNode);
            
            // 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->backgroundColor();
            if (table->hBorderSpacing() > 0 && table->vBorderSpacing() > 0 && 
                tableBGColor != cellColor && cellColor.alpha() != 1)
//.........这里部分代码省略.........

AccessibilityTableCell* AccessibilityTable::cellForColumnAndRow(unsigned column, unsigned row)
{
    if (!m_renderer)
        return 0;
    
    if (!hasChildren())
        addChildren();
    
    RenderTable* table = static_cast<RenderTable*>(m_renderer);
    RenderTableSection* tableSection = table->header();
    if (!tableSection)
        tableSection = table->firstBody();
    
    RenderTableCell* cell = 0;
    unsigned rowCount = 0;
    unsigned rowOffset = 0;
    while (tableSection) {
        
        rowCount += tableSection->numRows();
        unsigned numCols = tableSection->numColumns();
        
        if (row < rowCount && column < numCols) {
            int sectionSpecificRow = row - rowOffset;
            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 += rowCount;
        // we didn't find anything between the rows we should have
        if (row < rowOffset)
            break;
        tableSection = table->sectionBelow(tableSection, true);        
    }
    
    if (!cell)
        return 0;
    
    AccessibilityObject* cellObject = axObjectCache()->get(cell);
    ASSERT(cellObject->isTableCell());
    
    return static_cast<AccessibilityTableCell*>(cellObject);
}

void AccessibilityTable::addChildren()
{
    if (!isDataTable()) {
        AccessibilityRenderObject::addChildren();
        return;
    }
    
    ASSERT(!m_haveChildren); 
    
    m_haveChildren = true;
    if (!m_renderer)
        return;
    
    RenderTable* table = static_cast<RenderTable*>(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->get(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);
                m_children.append(row);
                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->get(ColumnRole));
        column->setColumnIndex((int)i);
        column->setParentTable(this);
        m_columns.append(column);
        m_children.append(column);
    }
    
    AccessibilityObject* headerContainerObject = headerContainer();
    if (headerContainerObject)
        m_children.append(headerContainerObject);
}

bool AccessibilityTable::isDataTable() const
{
    if (!m_renderer)
        return false;

    // Do not consider it a data table is it has an ARIA role.
    if (hasARIARole())
        return false;

    // 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.
    
    RenderTable* table = toRenderTable(m_renderer);
    Node* tableNode = table->node();
    if (!tableNode || !tableNode->hasTagName(tableTag))
        return false;

    // 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->primaryCellAt(row, col);
            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 <th> 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++;
//.........这里部分代码省略.........

AccessibilityTableCell* AccessibilityTable::cellForColumnAndRow(unsigned column, unsigned row)
{
    if (!m_renderer || !m_renderer->isTable())
        return 0;
    
    updateChildrenIfNecessary();
    
    RenderTable* table = toRenderTable(m_renderer);
    // FIXME: This will skip a table with just a tfoot. Should fix by using RenderTable::topSection.
    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->primaryCellAt(sectionSpecificRow, column);
            
            // 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->primaryCellAt(testRow, column);
                    // cell overlapped. use this one
                    ASSERT(cell->rowSpan() >= 1);
                    if (cell && ((cell->rowIndex() + (cell->rowSpan() - 1)) >= sectionSpecificRow))
                        break;
                    cell = 0;
                }
                
                if (!cell) {
                    // try cols
                    for (int testCol = column - 1; testCol >= 0; --testCol) {
                        cell = tableSection->primaryCellAt(sectionSpecificRow, testCol);
                        // cell overlapped. use this one
                        ASSERT(cell->rowSpan() >= 1);
                        if (cell && ((cell->col() + (cell->colSpan() - 1)) >= 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, SkipEmptySections);
    }
    
    if (!cell)
        return 0;
    
    AccessibilityObject* cellObject = axObjectCache()->getOrCreate(cell);
    ASSERT(cellObject->isTableCell());
    
    return static_cast<AccessibilityTableCell*>(cellObject);
}

void AccessibilityTable::addChildren()
{
    if (!isAccessibilityTable()) {
        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
    // FIXME: This will skip a table with just a tfoot. Should fix by using RenderTable::topSection.
    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->primaryCellAt(rowIndex, colIndex);
                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, SkipEmptySections);
    }
    
    // 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->setParent(this);
        m_columns.append(column);
        if (!column->accessibilityIsIgnored())
            m_children.append(column);
    }
    
    AccessibilityObject* headerContainerObject = headerContainer();
    if (headerContainerObject && !headerContainerObject->accessibilityIsIgnored())
        m_children.append(headerContainerObject);
}