C++ RenderTableCell类代码示例

AccessibilityObject* AccessibilityTableCell::titleUIElement() const
{
    // Try to find if the first cell in this row is a <th>. If it is,
    // then it can act as the title ui element. (This is only in the
    // case when the table is not appearing as an AXTable.)
    if (isTableCell() || !m_renderer || !m_renderer->isTableCell())
        return 0;

    // Table cells that are th cannot have title ui elements, since by definition
    // they are title ui elements
    Node* node = m_renderer->node();
    if (node && node->hasTagName(thTag))
        return 0;
    
    RenderTableCell* renderCell = toRenderTableCell(m_renderer);

    // If this cell is in the first column, there is no need to continue.
    int col = renderCell->col();
    if (!col)
        return 0;

    int row = renderCell->rowIndex();

    RenderTableSection* section = renderCell->section();
    if (!section)
        return 0;
    
    RenderTableCell* headerCell = section->primaryCellAt(row, 0);
    if (!headerCell || headerCell == renderCell)
        return 0;

    Node* cellElement = headerCell->node();
    if (!cellElement || !cellElement->hasTagName(thTag))
        return 0;
    
    return axObjectCache()->getOrCreate(headerCell);
}

CollapsedBorderValue RenderTableCell::collapsedAfterBorder() const
{
    RenderTable* table = this->table();

    // For after border, we need to check, in order of precedence:
    // (1) Our after border.
    int before = CSSProperty::resolveDirectionAwareProperty(CSSPropertyWebkitBorderBeforeColor, table->style()->direction(), table->style()->writingMode());
    int after = CSSProperty::resolveDirectionAwareProperty(CSSPropertyWebkitBorderAfterColor, table->style()->direction(), table->style()->writingMode());
    CollapsedBorderValue result = CollapsedBorderValue(&style()->borderAfter(), style()->visitedDependentColor(after), BCELL);
    
    RenderTableCell* nextCell = table->cellBelow(this);
    if (nextCell) {
        // (2) An after cell's before border.
        result = chooseBorder(result, CollapsedBorderValue(&nextCell->style()->borderBefore(), nextCell->style()->visitedDependentColor(before), BCELL));
        if (!result.exists())
            return result;
    }
    
    // (3) Our row's after border. (FIXME: Deal with rowspan!)
    result = chooseBorder(result, CollapsedBorderValue(&parent()->style()->borderAfter(), parent()->style()->visitedDependentColor(after), BROW));
    if (!result.exists())
        return result;
    
    // (4) The next row's before border.
    if (nextCell) {
        result = chooseBorder(result, CollapsedBorderValue(&nextCell->parent()->style()->borderBefore(), nextCell->parent()->style()->visitedDependentColor(before), BROW));
        if (!result.exists())
            return result;
    }
    
    // Now check row groups.
    RenderTableSection* currSection = section();
    if (row() + rowSpan() >= currSection->numRows()) {
        // (5) Our row group's after border.
        result = chooseBorder(result, CollapsedBorderValue(&currSection->style()->borderAfter(), currSection->style()->visitedDependentColor(after), BROWGROUP));
        if (!result.exists())
            return result;
        
        // (6) Following row group's before border.
        currSection = table->sectionBelow(currSection);
        if (currSection) {
            result = chooseBorder(result, CollapsedBorderValue(&currSection->style()->borderBefore(), currSection->style()->visitedDependentColor(before), BROWGROUP));
            if (!result.exists())
                return result;
        }
    }
    
    if (!currSection) {
        // (8) Our column and column group's after borders.
        RenderTableCol* colElt = table->colElement(col());
        if (colElt) {
            result = chooseBorder(result, CollapsedBorderValue(&colElt->style()->borderAfter(), colElt->style()->visitedDependentColor(after), BCOL));
            if (!result.exists()) return result;
            if (colElt->parent()->isTableCol()) {
                result = chooseBorder(result, CollapsedBorderValue(&colElt->parent()->style()->borderAfter(), colElt->parent()->style()->visitedDependentColor(after), BCOLGROUP));
                if (!result.exists())
                    return result;
            }
        }
        
        // (9) The table's after border.
        result = chooseBorder(result, CollapsedBorderValue(&table->style()->borderAfter(), table->style()->visitedDependentColor(after), BTABLE));
        if (!result.exists())
            return result;
    }
    
    return result;    
}

CollapsedBorderValue RenderTableCell::collapsedEndBorder() const
{
    RenderTable* table = this->table();
    bool isEndColumn = table->colToEffCol(col() + colSpan() - 1) == table->numEffCols() - 1;

    // For end border, we need to check, in order of precedence:
    // (1) Our end border.
    int start = CSSProperty::resolveDirectionAwareProperty(CSSPropertyWebkitBorderStartColor, table->style()->direction(), table->style()->writingMode());
    int end = CSSProperty::resolveDirectionAwareProperty(CSSPropertyWebkitBorderEndColor, table->style()->direction(), table->style()->writingMode());
    CollapsedBorderValue result = CollapsedBorderValue(&style()->borderEnd(), style()->visitedDependentColor(end), BCELL);
    
    // (2) The start border of the following cell.
    if (!isEndColumn) {
        RenderTableCell* nextCell = table->cellAfter(this);
        if (nextCell && nextCell->style()) {
            CollapsedBorderValue startBorder = CollapsedBorderValue(&nextCell->style()->borderStart(), nextCell->style()->visitedDependentColor(start), BCELL);
            result = chooseBorder(result, startBorder);
            if (!result.exists())
                return result;
        }
    } else {
        // (3) Our row's end border.
        result = chooseBorder(result, CollapsedBorderValue(&parent()->style()->borderEnd(), parent()->style()->visitedDependentColor(end), BROW));
        if (!result.exists())
            return result;
        
        // (4) Our row group's end border.
        result = chooseBorder(result, CollapsedBorderValue(&section()->style()->borderEnd(), section()->style()->visitedDependentColor(end), BROWGROUP));
        if (!result.exists())
            return result;
    }
    
    // (5) Our column and column group's end borders.
    bool startColEdge;
    bool endColEdge;
    RenderTableCol* colElt = table->colElement(col() + colSpan() - 1, &startColEdge, &endColEdge);
    if (colElt && endColEdge) {
        result = chooseBorder(result, CollapsedBorderValue(&colElt->style()->borderEnd(), colElt->style()->visitedDependentColor(end), BCOL));
        if (!result.exists())
            return result;
        if (colElt->parent()->isTableCol() && !colElt->nextSibling()) {
            result = chooseBorder(result, CollapsedBorderValue(&colElt->parent()->style()->borderEnd(), colElt->parent()->style()->visitedDependentColor(end), BCOLGROUP));
            if (!result.exists())
                return result;
        }
    }
    
    // (6) The start border of the next column.
    if (!isEndColumn) {
        colElt = table->colElement(col() + colSpan(), &startColEdge, &endColEdge);
        if (colElt && startColEdge) {
            CollapsedBorderValue startBorder = CollapsedBorderValue(&colElt->style()->borderStart(), colElt->style()->visitedDependentColor(start), BCOL);
            result = chooseBorder(result, startBorder);
            if (!result.exists())
                return result;
        }
    } else {
        // (7) The table's end border.
        result = chooseBorder(result, CollapsedBorderValue(&table->style()->borderEnd(), table->style()->visitedDependentColor(end), BTABLE));
        if (!result.exists())
            return result;
    }
    
    return result;
}

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.........

CollapsedBorderValue RenderTableCell::collapsedTopBorder() const
{
    // For border top, we need to check, in order of precedence:
    // (1) Our top border.
    CollapsedBorderValue result = CollapsedBorderValue(&style()->borderTop(), BCELL);
    
    RenderTableCell* prevCell = table()->cellAbove(this);
    if (prevCell) {
        // (2) A previous cell's bottom border.
        result = compareBorders(CollapsedBorderValue(&prevCell->style()->borderBottom(), BCELL), result);
        if (!result.exists()) 
            return result;
    }
    
    // (3) Our row's top border.
    result = compareBorders(result, CollapsedBorderValue(&parent()->style()->borderTop(), BROW));
    if (!result.exists())
        return result;
    
    // (4) The previous row's bottom border.
    if (prevCell) {
        RenderObject* prevRow = 0;
        if (prevCell->section() == section())
            prevRow = parent()->previousSibling();
        else
            prevRow = prevCell->section()->lastChild();
    
        if (prevRow) {
            result = compareBorders(CollapsedBorderValue(&prevRow->style()->borderBottom(), BROW), result);
            if (!result.exists())
                return result;
        }
    }
    
    // Now check row groups.
    RenderTableSection* currSection = section();
    if (!row()) {
        // (5) Our row group's top border.
        result = compareBorders(result, CollapsedBorderValue(&currSection->style()->borderTop(), BROWGROUP));
        if (!result.exists())
            return result;
        
        // (6) Previous row group's bottom border.
        currSection = table()->sectionAbove(currSection);
        if (currSection) {
            result = compareBorders(CollapsedBorderValue(&currSection->style()->borderBottom(), BROWGROUP), result);
            if (!result.exists())
                return result;
        }
    }
    
    if (!currSection) {
        // (8) Our column and column group's top borders.
        RenderTableCol* colElt = table()->colElement(col());
        if (colElt) {
            result = compareBorders(result, CollapsedBorderValue(&colElt->style()->borderTop(), BCOL));
            if (!result.exists())
                return result;
            if (colElt->parent()->isTableCol()) {
                result = compareBorders(result, CollapsedBorderValue(&colElt->parent()->style()->borderTop(), BCOLGROUP));
                if (!result.exists())
                    return result;
            }
        }
        
        // (9) The table's top border.
        result = compareBorders(result, CollapsedBorderValue(&table()->style()->borderTop(), BTABLE));
        if (!result.exists())
            return result;
    }
    
    return result;
}

int FixedTableLayout::calcWidthArray()
{
    // FIXME: We might want to wait until we have all of the first row before computing for the first time.
    int usedWidth = 0;

    // iterate over all <col> elements
    unsigned nEffCols = m_table->numEffCols();
    m_width.resize(nEffCols);
    m_width.fill(Length(Auto));

    unsigned currentEffectiveColumn = 0;
    for (RenderTableCol* col = m_table->firstColumn(); col; col = col->nextColumn()) {
        // RenderTableCols don't have the concept of preferred logical width, but we need to clear their dirty bits
        // so that if we call setPreferredWidthsDirty(true) on a col or one of its descendants, we'll mark it's
        // ancestors as dirty.
        col->clearPreferredLogicalWidthsDirtyBits();

        // Width specified by column-groups that have column child does not affect column width in fixed layout tables
        if (col->isTableColumnGroupWithColumnChildren())
            continue;

        Length colStyleLogicalWidth = col->style().logicalWidth();
        int effectiveColWidth = 0;
        if (colStyleLogicalWidth.isFixed() && colStyleLogicalWidth.value() > 0)
            effectiveColWidth = colStyleLogicalWidth.value();

        unsigned span = col->span();
        while (span) {
            unsigned spanInCurrentEffectiveColumn;
            if (currentEffectiveColumn >= nEffCols) {
                m_table->appendColumn(span);
                nEffCols++;
                m_width.append(Length());
                spanInCurrentEffectiveColumn = span;
            } else {
                if (span < m_table->spanOfEffCol(currentEffectiveColumn)) {
                    m_table->splitColumn(currentEffectiveColumn, span);
                    nEffCols++;
                    m_width.append(Length());
                }
                spanInCurrentEffectiveColumn = m_table->spanOfEffCol(currentEffectiveColumn);
            }
            if ((colStyleLogicalWidth.isFixed() || colStyleLogicalWidth.isPercent()) && colStyleLogicalWidth.isPositive()) {
                m_width[currentEffectiveColumn] = colStyleLogicalWidth;
                m_width[currentEffectiveColumn] *= spanInCurrentEffectiveColumn;
                usedWidth += effectiveColWidth * spanInCurrentEffectiveColumn;
            }
            span -= spanInCurrentEffectiveColumn;
            currentEffectiveColumn++;
        }
    }

    // Iterate over the first row in case some are unspecified.
    RenderTableSection* section = m_table->topNonEmptySection();
    if (!section)
        return usedWidth;

    unsigned currentColumn = 0;

    RenderTableRow* firstRow = section->firstRow();
    for (RenderTableCell* cell = firstRow->firstCell(); cell; cell = cell->nextCell()) {
        Length logicalWidth = cell->styleOrColLogicalWidth();
        unsigned span = cell->colSpan();
        int fixedBorderBoxLogicalWidth = 0;
        // FIXME: Support other length types. If the width is non-auto, it should probably just use
        // RenderBox::computeLogicalWidthInRegionUsing to compute the width.
        if (logicalWidth.isFixed() && logicalWidth.isPositive()) {
            fixedBorderBoxLogicalWidth = cell->adjustBorderBoxLogicalWidthForBoxSizing(logicalWidth.value());
            logicalWidth.setValue(Fixed, fixedBorderBoxLogicalWidth);
        }

        unsigned usedSpan = 0;
        while (usedSpan < span && currentColumn < nEffCols) {
            float eSpan = m_table->spanOfEffCol(currentColumn);
            // Only set if no col element has already set it.
            if (m_width[currentColumn].isAuto() && logicalWidth.type() != Auto) {
                m_width[currentColumn] = logicalWidth;
                m_width[currentColumn] *= eSpan / span;
                usedWidth += fixedBorderBoxLogicalWidth * eSpan / span;
            }
            usedSpan += eSpan;
            ++currentColumn;
        }

        // FixedTableLayout doesn't use min/maxPreferredLogicalWidths, but we need to clear the
        // dirty bit on the cell so that we'll correctly mark its ancestors dirty
        // in case we later call setPreferredLogicalWidthsDirty(true) on it later.
        if (cell->preferredLogicalWidthsDirty())
            cell->setPreferredLogicalWidthsDirty(false);
    }

    return usedWidth;
}

int FixedTableLayout::calcWidthArray()
{
    int usedWidth = 0;

    // iterate over all <col> elements
    RenderObject *child = table->firstChild();
    int cCol = 0;
    int nEffCols = table->numEffCols();
    width.resize( nEffCols );
    width.fill( Length( Variable ) );

#ifdef DEBUG_LAYOUT
    qDebug("FixedTableLayout::calcWidthArray()" );
    qDebug("    col elements:");
#endif

    Length grpWidth;
    while ( child ) {
	if ( child->isTableCol() ) {
	    RenderTableCol *col = static_cast<RenderTableCol *>(child);
	    int span = col->span();
	    if ( col->firstChild() ) {
		grpWidth = col->style()->width();
	    } else {
		Length w = col->style()->width();
		if ( w.isVariable() )
		    w = grpWidth;
		int effWidth = 0;
		if ( w.isFixed() && w.value() > 0 ) {
                    effWidth = w.value();
		    effWidth = KMIN( effWidth, 32760 );
		}
#ifdef DEBUG_LAYOUT
		qDebug("    col element: effCol=%d, span=%d: %d w=%d type=%d",
                       cCol, span, effWidth,  w.value(), w.type());
#endif
		int usedSpan = 0;
		int i = 0;
		while ( usedSpan < span ) {
		    if( cCol + i >= nEffCols ) {
			table->appendColumn( span - usedSpan );
			nEffCols++;
			width.resize( nEffCols );
			width[nEffCols-1] = Length();
		    }
		    int eSpan = table->spanOfEffCol( cCol+i );
		    if ( (w.isFixed() || w.isPercent()) && w.value() > 0 ) {
			width[cCol+i] = Length( w.value() * eSpan, w.type() );
			usedWidth += effWidth * eSpan;
#ifdef DEBUG_LAYOUT
			qDebug("    setting effCol %d (span=%d) to width %d(type=%d)",
                               cCol+i, eSpan, width[cCol+i].value(), width[cCol+i].type() );
#endif
		    }
		    usedSpan += eSpan;
		    i++;
		}
		cCol += i;
	    }
	} else {
	    break;
	}

	RenderObject *next = child->firstChild();
	if ( !next )
	    next = child->nextSibling();
	if ( !next && child->parent()->isTableCol() ) {
	    next = child->parent()->nextSibling();
	    grpWidth = Length();
	}
	child = next;
    }

#ifdef DEBUG_LAYOUT
    qDebug("    first row:");
#endif
    // iterate over the first row in case some are unspecified.
    RenderTableSection *section = table->head;
    if ( !section )
	section = table->firstBody;
    if ( !section )
	section = table->foot;
    if ( section && section->firstChild() ) {
	cCol = 0;
	// get the first cell in the first row
	child = section->firstChild()->firstChild();
	while ( child ) {
	    if ( child->isTableCell() ) {
		RenderTableCell *cell = static_cast<RenderTableCell *>(child);
		Length w = cell->styleOrColWidth();
		int span = cell->colSpan();
		int effWidth = 0;
		if ( (w.isFixed() || w.isPercent()) && w.value() > 0 ) {
                    effWidth = w.value();
		    effWidth = kMin( effWidth, 32760 );
		}
#ifdef DEBUG_LAYOUT
		qDebug("    table cell: effCol=%d, span=%d: %d",  cCol, span, effWidth);
#endif
		int usedSpan = 0;
//.........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);
}

int FixedTableLayout::calcWidthArray(int)
{
    int usedWidth = 0;

    // iterate over all <col> elements
    RenderObject* child = m_table->firstChild();
    int nEffCols = m_table->numEffCols();
    m_width.resize(nEffCols);
    m_width.fill(Length(Auto));

    int currentEffectiveColumn = 0;
    Length grpWidth;
    while (child && child->isTableCol()) {
        RenderTableCol* col = toRenderTableCol(child);
        if (col->firstChild())
            grpWidth = col->style()->logicalWidth();
        else {
            Length w = col->style()->logicalWidth();
            if (w.isAuto())
                w = grpWidth;
            int effWidth = 0;
            if (w.isFixed() && w.value() > 0)
                effWidth = w.value();

            int span = col->span();
            while (span) {
                int spanInCurrentEffectiveColumn;
                if (currentEffectiveColumn >= nEffCols) {
                    m_table->appendColumn(span);
                    nEffCols++;
                    m_width.append(Length());
                    spanInCurrentEffectiveColumn = span;
                } else {
                    if (span < m_table->spanOfEffCol(currentEffectiveColumn)) {
                        m_table->splitColumn(currentEffectiveColumn, span);
                        nEffCols++;
                        m_width.append(Length());
                    }
                    spanInCurrentEffectiveColumn = m_table->spanOfEffCol(currentEffectiveColumn);
                }
                if ((w.isFixed() || w.isPercent()) && w.isPositive()) {
                    m_width[currentEffectiveColumn] = w;
                    m_width[currentEffectiveColumn] *= spanInCurrentEffectiveColumn;
                    usedWidth += effWidth * spanInCurrentEffectiveColumn;
                }
                span -= spanInCurrentEffectiveColumn;
                currentEffectiveColumn++;
            }
        }
        col->computePreferredLogicalWidths();

        RenderObject* next = child->firstChild();
        if (!next)
            next = child->nextSibling();
        if (!next && child->parent()->isTableCol()) {
            next = child->parent()->nextSibling();
            grpWidth = Length();
        }
        child = next;
    }

    // Iterate over the first row in case some are unspecified.
    RenderTableSection* section = m_table->topNonEmptySection();
    if (section) {
        int cCol = 0;
        RenderObject* firstRow = section->firstChild();
        child = firstRow->firstChild();
        while (child) {
            if (child->isTableCell()) {
                RenderTableCell* cell = toRenderTableCell(child);
                if (cell->preferredLogicalWidthsDirty())
                    cell->computePreferredLogicalWidths();

                Length w = cell->styleOrColLogicalWidth();
                int span = cell->colSpan();
                int effWidth = 0;
                if (w.isFixed() && w.isPositive())
                    effWidth = w.value();

                int usedSpan = 0;
                int i = 0;
                while (usedSpan < span && cCol + i < nEffCols) {
                    float eSpan = m_table->spanOfEffCol(cCol + i);
                    // Only set if no col element has already set it.
                    if (m_width[cCol + i].isAuto() && w.type() != Auto) {
                        m_width[cCol + i] = w;
                        m_width[cCol + i] *= eSpan / span;
                        usedWidth += effWidth * eSpan / span;
                    }
                    usedSpan += eSpan;
                    i++;
                }
                cCol += i;
            }
            child = child->nextSibling();
        }
    }

    return usedWidth;
}

int FixedTableLayout::calcWidthArray(int tableWidth)
{
    int usedWidth = 0;

    // iterate over all <col> elements
    RenderObject* child = m_table->firstChild();
    int cCol = 0;
    int nEffCols = m_table->numEffCols();
    m_width.resize(nEffCols);
    m_width.fill(Length(Auto));

    Length grpWidth;
    while (child) {
        if (child->isTableCol()) {
            RenderTableCol *col = static_cast<RenderTableCol *>(child);
            int span = col->span();
            if (col->firstChild())
                grpWidth = col->style()->width();
            else {
                Length w = col->style()->width();
                if (w.isAuto())
                    w = grpWidth;
                int effWidth = 0;
                if (w.isFixed() && w.value() > 0)
                    effWidth = w.value();
                
                int usedSpan = 0;
                int i = 0;
                while (usedSpan < span) {
                    if(cCol + i >= nEffCols) {
                        m_table->appendColumn(span - usedSpan);
                        nEffCols++;
                        m_width.resize(nEffCols);
                        m_width[nEffCols-1] = Length();
                    }
                    int eSpan = m_table->spanOfEffCol(cCol+i);
                    if ((w.isFixed() || w.isPercent()) && w.isPositive()) {
                        m_width[cCol + i].setRawValue(w.type(), w.rawValue() * eSpan);
                        usedWidth += effWidth * eSpan;
                    }
                    usedSpan += eSpan;
                    i++;
                }
                cCol += i;
            }
        } else
            break;

        RenderObject *next = child->firstChild();
        if (!next)
            next = child->nextSibling();
        if (!next && child->parent()->isTableCol()) {
            next = child->parent()->nextSibling();
            grpWidth = Length();
        }
        child = next;
    }

    // Iterate over the first row in case some are unspecified.
    RenderTableSection* section = m_table->header();
    if (!section)
        section = m_table->firstBody();
    if (!section)
        section = m_table->footer();
    if (section && !section->numRows())
        section = m_table->sectionBelow(section, true);
    if (section) {
        cCol = 0;
        RenderObject* firstRow = section->firstChild();
        child = firstRow->firstChild();
        while (child) {
            if (child->isTableCell()) {
                RenderTableCell* cell = static_cast<RenderTableCell*>(child);
                if (cell->prefWidthsDirty())
                    cell->calcPrefWidths();

                Length w = cell->styleOrColWidth();
                int span = cell->colSpan();
                int effWidth = 0;
                if (w.isFixed() && w.isPositive())
                    effWidth = w.value();
                
                int usedSpan = 0;
                int i = 0;
                while (usedSpan < span) {
                    ASSERT(cCol + i < nEffCols);
                    int eSpan = m_table->spanOfEffCol(cCol + i);
                    // Only set if no col element has already set it.
                    if (m_width[cCol + i].isAuto() && w.type() != Auto) {
                        m_width[cCol + i].setRawValue(w.type(), w.rawValue() * eSpan / span);
                        usedWidth += effWidth * eSpan / span;
                    }
                    usedSpan += eSpan;
                    i++;
                }
                cCol += i;
            }
            child = child->nextSibling();
        }
    }
//.........这里部分代码省略.........

/* recalculates the full structure needed to do layouting and minmax calculations.
   This is usually calculated on the fly, but needs to be done fully when table cells change
   dynamically
*/
void AutoTableLayout::recalcColumn( int effCol )
{
    Layout &l = layoutStruct[effCol];

    RenderObject *child = table->firstChild();
    // first we iterate over all rows.

    RenderTableCell *fixedContributor = 0;
    RenderTableCell *maxContributor = 0;

    while ( child ) {
	if ( child->isTableSection() ) {
	    RenderTableSection *section = static_cast<RenderTableSection *>(child);
	    int numRows = section->numRows();
	    RenderTableCell *last = 0;
	    for ( int i = 0; i < numRows; i++ ) {
		RenderTableCell *cell = section->cellAt( i,  effCol );
		if ( cell == (RenderTableCell *)-1 )
		    continue;
		if ( cell && cell->colSpan() == 1 ) {
                    // A cell originates in this column.  Ensure we have
                    // a min/max width of at least 1px for this column now.
                    l.minWidth = kMax(int( l.minWidth ), 1);
                    l.maxWidth = kMax(int( l.maxWidth ), 1);

		    if ( !cell->minMaxKnown() )
			cell->calcMinMaxWidth();
		    if ( cell->minWidth() > l.minWidth )
			l.minWidth = cell->minWidth();
		    if ( cell->maxWidth() > l.maxWidth ) {
			l.maxWidth = cell->maxWidth();
			maxContributor = cell;
		    }

		    Length w = cell->styleOrColWidth();
                    w.l.value = kMin( 32767, kMax( 0, w.value() ) );
		    switch( w.type() ) {
		    case Fixed:
			// ignore width=0
			if ( w.value() > 0 && !l.width.isPercent() ) {
                            int wval = cell->calcBoxWidth(w.value());
			    if ( l.width.isFixed() ) {
                                // Nav/IE weirdness
				if ((wval > l.width.value()) ||
				    ((l.width.value() == wval) && (maxContributor == cell))) {
				    l.width.l.value = wval;
				    fixedContributor = cell;
				}
			    } else {
                                l.width = Length( wval, Fixed );
				fixedContributor = cell;
			    }
			}
			break;
		    case Percent:
                        hasPercent = true;
                        if ( w.value() > 0 && (!l.width.isPercent() || w.value() > l.width.value() ) )
                            l.width = w;
			break;
		    case Relative:
			if ( w.isVariable() || (w.isRelative() && w.value() > l.width.value() ) )
				l.width = w;
		    default:
			break;
		    }
		} else {
		    if ( cell && (!effCol || section->cellAt( i, effCol-1 ) != cell) ) {
                        // This spanning cell originates in this column.  Ensure we have
                        // a min/max width of at least 1px for this column now.
                        l.minWidth = kMax(int( l.minWidth ), 1);
                        l.maxWidth = kMax(int( l.maxWidth ), 1);
			insertSpanCell( cell );
		    }
		    last = cell;
		}
	    }
	}
	child = child->nextSibling();
    }

    // Nav/IE weirdness
    if ( l.width.isFixed() ) {
	if ( table->style()->htmlHacks()
	     && (l.maxWidth > l.width.value()) && (fixedContributor != maxContributor)) {
	    l.width = Length();
	    fixedContributor = 0;
	}
    }

    l.maxWidth = kMax(l.maxWidth, int(l.minWidth));
#ifdef DEBUG_LAYOUT
    qDebug("col %d, final min=%d, max=%d, width=%d(%d)", effCol, l.minWidth, l.maxWidth, l.width.value(),  l.width.type() );
#endif

    // ### we need to add col elements aswell
}

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.........

/*
  This method takes care of colspans.
  effWidth is the same as width for cells without colspans. If we have colspans, they get modified.
 */
int AutoTableLayout::calcEffectiveWidth()
{
    int tMaxWidth = 0;

    unsigned int nEffCols = layoutStruct.size();
    int hspacing = table->borderHSpacing();
#ifdef DEBUG_LAYOUT
    qDebug("AutoTableLayout::calcEffectiveWidth for %d cols", nEffCols );
#endif
    for ( unsigned int i = 0; i < nEffCols; i++ ) {
	layoutStruct[i].effWidth = layoutStruct[i].width;
	layoutStruct[i].effMinWidth = layoutStruct[i].minWidth;
	layoutStruct[i].effMaxWidth = layoutStruct[i].maxWidth;
    }

    for ( unsigned int i = 0; i < spanCells.size(); i++ ) {
	RenderTableCell *cell = spanCells[i];
	if ( !cell || cell == (RenderTableCell *)-1 )
	    break;
	int span = cell->colSpan();

	Length w = cell->styleOrColWidth();
	if ( !w.isRelative() && w.value() == 0 )
	    w = Length(); // make it Variable

	int col = table->colToEffCol( cell->col() );
	unsigned int lastCol = col;
	int cMinWidth = cell->minWidth() + hspacing;
	int cMaxWidth = cell->maxWidth() + hspacing;
	int totalPercent = 0;
	int minWidth = 0;
	int maxWidth = 0;
	bool allColsArePercent = true;
	bool allColsAreFixed = true;
	bool haveVariable = false;
	int fixedWidth = 0;
#ifdef DEBUG_LAYOUT
	int cSpan = span;
#endif
	while ( lastCol < nEffCols && span > 0 ) {
	    switch( layoutStruct[lastCol].width.type() ) {
	    case Percent:
		totalPercent += layoutStruct[lastCol].width.value();
		allColsAreFixed = false;
		break;
	    case Fixed:
                if (layoutStruct[lastCol].width.value() > 0) {
                    fixedWidth += layoutStruct[lastCol].width.value();
                    allColsArePercent = false;
                    // IE resets effWidth to Variable here, but this breaks the konqueror about page and seems to be some bad
                    // legacy behavior anyway. mozilla doesn't do this so I decided we don't either.
                    break;
                }
                // fall through
	    case Variable:
		haveVariable = true;
		// fall through
	    default:
                // If the column is a percentage width, do not let the spanning cell overwrite the
                // width value.  This caused a mis-rendering on amazon.com.
                // Sample snippet:
                // <table border=2 width=100%><
                //   <tr><td>1</td><td colspan=2>2-3</tr>
                //   <tr><td>1</td><td colspan=2 width=100%>2-3</td></tr>
                // </table>
                if (!layoutStruct[lastCol].effWidth.isPercent()) {
                    layoutStruct[lastCol].effWidth = Length();
                    allColsArePercent = false;
                }
                else
                    totalPercent += layoutStruct[lastCol].effWidth.value();
                allColsAreFixed = false;
            }
            span -= table->spanOfEffCol( lastCol );
	    minWidth += layoutStruct[lastCol].effMinWidth;
	    maxWidth += layoutStruct[lastCol].effMaxWidth;
	    lastCol++;
	    cMinWidth -= hspacing;
	    cMaxWidth -= hspacing;
	}
#ifdef DEBUG_LAYOUT
	qDebug("    colspan cell %p at effCol %d, span %d, type %d, value %d cmin=%d min=%d fixedwidth=%d", cell, col, cSpan, w.type(), w.value(), cMinWidth, minWidth, fixedWidth );
#endif

	// adjust table max width if needed
	if ( w.isPercent() ) {
	    if ( totalPercent > w.value() || allColsArePercent ) {
		// can't satify this condition, treat as variable
		w = Length();
	    } else {
		int spanMax = kMax( maxWidth, cMaxWidth );
#ifdef DEBUG_LAYOUT
		qDebug("    adjusting tMaxWidth (%d): spanMax=%d, value=%d, totalPercent=%d", tMaxWidth, spanMax, w.value(), totalPercent );
#endif
		tMaxWidth = kMax( tMaxWidth, spanMax * 100 / w.value() );

//.........这里部分代码省略.........

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);
}