Ejemplo n.º 1
0
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++;

            // 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->hasTagName(tdTag) || cellElement->hasTagName(thTag)) {
                HTMLTableCellElement* tableCellElement = toHTMLTableCellElement(cellElement);
                if (!tableCellElement->headers().isEmpty() || !tableCellElement->abbr().isEmpty()
                    || !tableCellElement->axis().isEmpty() || !tableCellElement->scope().isEmpty())
                    return true;
            }
            const RenderStyle& renderStyle = cell->style();

            // If the empty-cells style is set, we'll call it a data table.
            if (renderStyle.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 = 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->isBoxModelObject() || !toRenderBoxModelObject(renderRow)->isTableRow())
                    continue;
                const RenderStyle& rowRenderStyle = renderRow->style();
                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
        || 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;
}
CollapsedBorderValue RenderTableCell::collapsedBeforeBorder() const
{
    RenderTable* table = this->table();

    // For before border, we need to check, in order of precedence:
    // (1) Our before 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()->borderBefore(), style()->visitedDependentColor(before), BCELL);
    
    RenderTableCell* prevCell = table->cellAbove(this);
    if (prevCell) {
        // (2) A before cell's after border.
        result = chooseBorder(CollapsedBorderValue(&prevCell->style()->borderAfter(), prevCell->style()->visitedDependentColor(after), BCELL), result);
        if (!result.exists())
            return result;
    }
    
    // (3) Our row's before border.
    result = chooseBorder(result, CollapsedBorderValue(&parent()->style()->borderBefore(), parent()->style()->visitedDependentColor(before), BROW));
    if (!result.exists())
        return result;
    
    // (4) The previous row's after border.
    if (prevCell) {
        RenderObject* prevRow = 0;
        if (prevCell->section() == section())
            prevRow = parent()->previousSibling();
        else
            prevRow = prevCell->section()->lastChild();
    
        if (prevRow) {
            result = chooseBorder(CollapsedBorderValue(&prevRow->style()->borderAfter(), prevRow->style()->visitedDependentColor(after), BROW), result);
            if (!result.exists())
                return result;
        }
    }
    
    // Now check row groups.
    RenderTableSection* currSection = section();
    if (!row()) {
        // (5) Our row group's before border.
        result = chooseBorder(result, CollapsedBorderValue(&currSection->style()->borderBefore(), currSection->style()->visitedDependentColor(before), BROWGROUP));
        if (!result.exists())
            return result;
        
        // (6) Previous row group's after border.
        currSection = table->sectionAbove(currSection);
        if (currSection) {
            result = chooseBorder(CollapsedBorderValue(&currSection->style()->borderAfter(), currSection->style()->visitedDependentColor(after), BROWGROUP), result);
            if (!result.exists())
                return result;
        }
    }
    
    if (!currSection) {
        // (8) Our column and column group's before borders.
        RenderTableCol* colElt = table->colElement(col());
        if (colElt) {
            result = chooseBorder(result, CollapsedBorderValue(&colElt->style()->borderBefore(), colElt->style()->visitedDependentColor(before), BCOL));
            if (!result.exists())
                return result;
            if (colElt->parent()->isTableCol()) {
                result = chooseBorder(result, CollapsedBorderValue(&colElt->parent()->style()->borderBefore(), colElt->parent()->style()->visitedDependentColor(before), BCOLGROUP));
                if (!result.exists())
                    return result;
            }
        }
        
        // (9) The table's before border.
        result = chooseBorder(result, CollapsedBorderValue(&table->style()->borderBefore(), table->style()->visitedDependentColor(before), BTABLE));
        if (!result.exists())
            return result;
    }
    
    return result;
}
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;    
}
int FixedTableLayout::calcWidthArray( int tableWidth )
{
    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( %d )", tableWidth );
    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->style()->width();
		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;
		int i = 0;
		while ( usedSpan < span ) {
		    Q_ASSERT( cCol + i < nEffCols );
		    int eSpan = table->spanOfEffCol( cCol+i );
		    // only set if no col element has already set it.
		    if ( width[cCol+i].isVariable() && !w.isVariable() ) {
			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
		    }
#ifdef DEBUG_LAYOUT
		    else {
			qDebug("    width of col %d already defined (span=%d)", cCol, table->spanOfEffCol( cCol ) );
		    }
#endif
		    usedSpan += eSpan;
		    i++;
		}
		cCol += i;
	    } else {
		Q_ASSERT( false );
	    }
	    child = child->nextSibling();
	}
    }

    return usedWidth;

}
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;
}
/* 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 ) {
		    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->style()->width();
                    w.l.value = kMin( 32767, kMax( 0, w.value() ) );
		    switch( w.type() ) {
		    case Fixed:
			// ignore width=0
			if ( w.value() > 0 && !l.width.isPercent() ) {
                            // ### we should use box'es paddings here I guess.
                            int wval = w.value() + table->cellPadding() * 2;
			    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 ( !effCol || section->cellAt( i, effCol-1 ) != cell )
			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, 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
}
/*
  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 spacing = table->cellSpacing();
#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->style()->width();
	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() + spacing;
	int cMaxWidth = cell->maxWidth() + spacing;
	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 behaviour anyway. mozilla doesn't do this so I decided we don't neither.
                    break;
                }
                // fall through
	    case Variable:
		haveVariable = true;
		// fall through
	    default:
		layoutStruct[lastCol].effWidth = Length();
		allColsArePercent = false;
		allColsAreFixed = false;
	    }
	    span -= table->spanOfEffCol( lastCol );
	    minWidth += layoutStruct[lastCol].effMinWidth;
	    maxWidth += layoutStruct[lastCol].effMaxWidth;
	    lastCol++;
	    cMinWidth -= spacing;
	    cMaxWidth -= spacing;
	}
#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 = QMAX( maxWidth, cMaxWidth );
#ifdef DEBUG_LAYOUT
		qDebug("    adjusting tMaxWidth (%d): spanMax=%d, value=%d, totalPercent=%d", tMaxWidth, spanMax, w.value(), totalPercent );
#endif
		tMaxWidth = QMAX( tMaxWidth, spanMax * 100 / w.value() );

		// all non percent columns in the span get percent vlaues to sum up correctly.
		int percentMissing = w.value() - totalPercent;
		int totalWidth = 0;
		for ( unsigned int pos = col; pos < lastCol; pos++ ) {
		    if ( !(layoutStruct[pos].width.isPercent() ) )
			totalWidth += layoutStruct[pos].effMaxWidth;
		}

		for ( unsigned int pos = col; pos < lastCol && totalWidth > 0; pos++ ) {
		    if ( !(layoutStruct[pos].width.isPercent() ) ) {
			int percent = percentMissing * layoutStruct[pos].effMaxWidth / totalWidth;
#ifdef DEBUG_LAYOUT
			qDebug("   col %d: setting percent value %d effMaxWidth=%d totalWidth=%d", pos, percent, layoutStruct[pos].effMaxWidth, totalWidth );
#endif
			totalWidth -= layoutStruct[pos].effMaxWidth;
			percentMissing -= percent;
			if ( percent > 0 )
			    layoutStruct[pos].effWidth = Length( percent, Percent );
			else
			    layoutStruct[pos].effWidth = Length();
		    }
		}

	    }
	}

	// make sure minWidth and maxWidth of the spanning cell are honoured
	if ( cMinWidth > minWidth ) {
	    if ( allColsAreFixed ) {
#ifdef DEBUG_LAYOUT
		qDebug("extending minWidth of cols %d-%d to %dpx currentMin=%d accroding to fixed sum %d", col, lastCol-1, cMinWidth, minWidth, fixedWidth );
#endif
		for ( unsigned int pos = col; fixedWidth > 0 && pos < lastCol; pos++ ) {
		    int w = QMAX( layoutStruct[pos].effMinWidth, cMinWidth * layoutStruct[pos].width.value() / fixedWidth );
#ifdef DEBUG_LAYOUT
		    qDebug("   col %d: min=%d, effMin=%d, new=%d", pos, layoutStruct[pos].effMinWidth, layoutStruct[pos].effMinWidth, w );
#endif
		    fixedWidth -= layoutStruct[pos].width.value();
		    cMinWidth -= w;
		    layoutStruct[pos].effMinWidth = w;
		}

	    } else {
#ifdef DEBUG_LAYOUT
		qDebug("extending minWidth of cols %d-%d to %dpx currentMin=%d", col, lastCol-1, cMinWidth, minWidth );
#endif
		int maxw = maxWidth;
		for ( unsigned int pos = col; minWidth > 0 && pos < lastCol; pos++ ) {

		    int w;
		    if ( layoutStruct[pos].width.isFixed() && haveVariable && fixedWidth <= cMinWidth ) {
			w = QMAX( layoutStruct[pos].effMinWidth, layoutStruct[pos].width.value() );
			fixedWidth -= layoutStruct[pos].width.value();
		    } else {
			w = QMAX( layoutStruct[pos].effMinWidth, cMinWidth * layoutStruct[pos].effMaxWidth / maxw );
		    }
#ifdef DEBUG_LAYOUT
		    qDebug("   col %d: min=%d, effMin=%d, new=%d", pos, layoutStruct[pos].effMinWidth, layoutStruct[pos].effMinWidth, w );
#endif
		    maxw -= layoutStruct[pos].effMaxWidth;
		    cMinWidth -= w;
		    layoutStruct[pos].effMinWidth = w;
		}
	    }
	}
	if ( !w.isPercent() ) {
	    if ( cMaxWidth > maxWidth ) {
#ifdef DEBUG_LAYOUT
		qDebug("extending maxWidth of cols %d-%d to %dpx", col, lastCol-1, cMaxWidth );
#endif
		for ( unsigned int pos = col; maxWidth > 0 && pos < lastCol; pos++ ) {
		    int w = QMAX( layoutStruct[pos].effMaxWidth, cMaxWidth * layoutStruct[pos].effMaxWidth / maxWidth );
#ifdef DEBUG_LAYOUT
		    qDebug("   col %d: max=%d, effMax=%d, new=%d", pos, layoutStruct[pos].effMaxWidth, layoutStruct[pos].effMaxWidth, w );
#endif
		    maxWidth -= layoutStruct[pos].effMaxWidth;
		    cMaxWidth -= w;
		    layoutStruct[pos].effMaxWidth = w;
		}
	    }
	} else {
	    for ( unsigned int pos = col; pos < lastCol; pos++ )
		layoutStruct[pos].maxWidth = QMAX(layoutStruct[pos].maxWidth, layoutStruct[pos].minWidth );
	}
    }
    effWidthDirty = false;

//     qDebug("calcEffectiveWidth: tMaxWidth=%d",  tMaxWidth );
    return tMaxWidth;
}
Ejemplo n.º 8
0
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)
                backgroundDifferenceCellCount++;
            
            // if we've found 10 "good" cells, we don't need to keep searching
            if (borderedCellCount >= 10 || backgroundDifferenceCellCount >= 10)
                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;

    return false;
}
Ejemplo n.º 9
0
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++;
            
            // 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->isBoxModelObject() || !toRenderBoxModelObject(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;
}
CollapsedBorderValue RenderTableCell::collapsedBottomBorder() const
{
    // For border top, we need to check, in order of precedence:
    // (1) Our bottom border.
    CollapsedBorderValue result = CollapsedBorderValue(&style()->borderBottom(), BCELL);
    
    RenderTableCell* nextCell = table()->cellBelow(this);
    if (nextCell) {
        // (2) A following cell's top border.
        result = compareBorders(result, CollapsedBorderValue(&nextCell->style()->borderTop(), BCELL));
        if (!result.exists())
            return result;
    }
    
    // (3) Our row's bottom border. (FIXME: Deal with rowspan!)
    result = compareBorders(result, CollapsedBorderValue(&parent()->style()->borderBottom(), BROW));
    if (!result.exists())
        return result;
    
    // (4) The next row's top border.
    if (nextCell) {
        result = compareBorders(result, CollapsedBorderValue(&nextCell->parent()->style()->borderTop(), BROW));
        if (!result.exists())
            return result;
    }
    
    // Now check row groups.
    RenderTableSection* currSection = section();
    if (row() + rowSpan() >= currSection->numRows()) {
        // (5) Our row group's bottom border.
        result = compareBorders(result, CollapsedBorderValue(&currSection->style()->borderBottom(), BROWGROUP));
        if (!result.exists())
            return result;
        
        // (6) Following row group's top border.
        currSection = table()->sectionBelow(currSection);
        if (currSection) {
            result = compareBorders(result, CollapsedBorderValue(&currSection->style()->borderTop(), BROWGROUP));
            if (!result.exists())
                return result;
        }
    }
    
    if (!currSection) {
        // (8) Our column and column group's bottom borders.
        RenderTableCol* colElt = table()->colElement(col());
        if (colElt) {
            result = compareBorders(result, CollapsedBorderValue(&colElt->style()->borderBottom(), BCOL));
            if (!result.exists()) return result;
            if (colElt->parent()->isTableCol()) {
                result = compareBorders(result, CollapsedBorderValue(&colElt->parent()->style()->borderBottom(), BCOLGROUP));
                if (!result.exists())
                    return result;
            }
        }
        
        // (9) The table's bottom border.
        result = compareBorders(result, CollapsedBorderValue(&table()->style()->borderBottom(), BTABLE));
        if (!result.exists())
            return result;
    }
    
    return result;    
}
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;
}
CollapsedBorderValue RenderTableCell::collapsedRightBorder(bool rtl) const
{
    RenderTable* tableElt = table();
    bool rightmostColumn;
    if (rtl)
        rightmostColumn = col() == 0;
    else {
        int effCol = tableElt->colToEffCol(col() + colSpan() - 1);
        rightmostColumn = effCol == tableElt->numEffCols() - 1;
    }
    
    // For border right, we need to check, in order of precedence:
    // (1) Our right border.
    CollapsedBorderValue result = CollapsedBorderValue(&style()->borderRight(), BCELL);
    
    // (2) The left border of the cell to the right.
    if (!rightmostColumn) {
        RenderTableCell* nextCell = rtl ? tableElt->cellBefore(this) : tableElt->cellAfter(this);
        if (nextCell && nextCell->style()) {
            result = rtl ? compareBorders(CollapsedBorderValue(&nextCell->style()->borderLeft(), BCELL), result) : compareBorders(result, CollapsedBorderValue(&nextCell->style()->borderLeft(), BCELL));
            if (!result.exists())
                return result;
        }
    } else {
        // (3) Our row's right border.
        result = compareBorders(result, CollapsedBorderValue(&parent()->style()->borderRight(), BROW));
        if (!result.exists())
            return result;
        
        // (4) Our row group's right border.
        result = compareBorders(result, CollapsedBorderValue(&section()->style()->borderRight(), BROWGROUP));
        if (!result.exists())
            return result;
    }
    
    // (5) Our column and column group's right borders.
    bool startColEdge;
    bool endColEdge;
    RenderTableCol* colElt = tableElt->colElement(col() + (rtl ? 0 : colSpan() - 1), &startColEdge, &endColEdge);
    if (colElt && (!rtl ? endColEdge : startColEdge)) {
        result = compareBorders(result, CollapsedBorderValue(&colElt->style()->borderRight(), BCOL));
        if (!result.exists())
            return result;
        if (colElt->parent()->isTableCol() && (!rtl ? !colElt->nextSibling() : !colElt->previousSibling())) {
            result = compareBorders(result, CollapsedBorderValue(&colElt->parent()->style()->borderRight(), BCOLGROUP));
            if (!result.exists())
                return result;
        }
    }
    
    // (6) The left border of the column to the right.
    if (!rightmostColumn) {
        colElt = tableElt->colElement(col() + (rtl ? -1 : colSpan()), &startColEdge, &endColEdge);
        if (colElt && (!rtl ? startColEdge : endColEdge)) {
            result = rtl ? compareBorders(CollapsedBorderValue(&colElt->style()->borderLeft(), BCOL), result) : compareBorders(result, CollapsedBorderValue(&colElt->style()->borderLeft(), BCOL));
            if (!result.exists())
                return result;
        }
    } else {
        // (7) The table's right border.
        result = compareBorders(result, CollapsedBorderValue(&tableElt->style()->borderRight(), BTABLE));
        if (!result.exists())
            return result;
    }
    
    return result;
}