public function displayHeader()
    {
        $anchor = new SwatHtmlTag('a');
        $anchor->href = $this->getLink();
        $anchor->class = 'swat-table-view-orderable-column';

        // Set direction-specific CSS class on the anchor.
        if ($this->direction == self::ORDER_BY_DIR_DESCENDING) {
            $anchor->class .= ' swat-table-view-orderable-column-descending';
        } elseif ($this->direction == self::ORDER_BY_DIR_ASCENDING) {
            $anchor->class .= ' swat-table-view-orderable-column-ascending';
        }

        $anchor->open();

        if ($this->abbreviated_title === null) {
            $this->displayTitle($this->title, $this->title_content_type);
        } else {
            $abbr_tag = new SwatHtmlTag('abbr');
            $abbr_tag->title = $this->title;
            $abbr_tag->open();

            $this->displayTitle(
                $this->abbreviated_title,
                $this->abbreviated_title_content_type
            );

            $abbr_tag->close();
        }

        $anchor->close();
    }