protected function displayRowSpanningColumns($row, $next_row, $count)
    {
        $tr_tag = new SwatHtmlTag('tr');
        $tr_tag->class = $this->getRowClassString($row, $count);

        if ($this->rowHasMessage($row)) {
            $tr_tag->class = $tr_tag->class . ' swat-error';
        }

        $tr_tag->class .= ' swat-table-view-spanning-column';

        foreach ($this->spanning_columns as $column) {
            if ($column->visible && $column->hasVisibleRenderer($row)) {
                $tr_tag->open();
                $column->display($row);
                $tr_tag->close();
            }
        }
    }