当前路径：Classes/PHPExcel/Style/Alignment.php
<?php
/**
 * PHPExcel_Style_Alignment
 *
 * Copyright (c) 2006 - 2015 PHPExcel
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2.1 of the License, or (at your option) any later version.
 *
 * This library is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with this library; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
 *
 * @category   PHPExcel
 * @package    PHPExcel_Style
 * @copyright  Copyright (c) 2006 - 2015 PHPExcel (http://www.codeplex.com/PHPExcel)
 * @license    http://www.gnu.org/licenses/old-licenses/lgpl-2.1.txt    LGPL
 * @version    ##VERSION##, ##DATE##
 */
class PHPExcel_Style_Alignment extends PHPExcel_Style_Supervisor implements PHPExcel_IComparable
{
    /* Horizontal alignment styles */
    const HORIZONTAL_GENERAL           = 'general';
    const HORIZONTAL_LEFT              = 'left';
    const HORIZONTAL_RIGHT             = 'right';
    const HORIZONTAL_CENTER            = 'center';
    const HORIZONTAL_CENTER_CONTINUOUS = 'centerContinuous';
    const HORIZONTAL_JUSTIFY           = 'justify';
    const HORIZONTAL_FILL              = 'fill';
    const HORIZONTAL_DISTRIBUTED       = 'distributed';        // Excel2007 only

    /* Vertical alignment styles */
    const VERTICAL_BOTTOM      = 'bottom';
    const VERTICAL_TOP         = 'top';
    const VERTICAL_CENTER      = 'center';
    const VERTICAL_JUSTIFY     = 'justify';
    const VERTICAL_DISTRIBUTED = 'distributed';        // Excel2007 only

    /* Read order */
    const READORDER_CONTEXT = 0;
    const READORDER_LTR     = 1;
    const READORDER_RTL     = 2;

    /**
     * Horizontal alignment
     *
     * @var string
     */
    protected $horizontal = PHPExcel_Style_Alignment::HORIZONTAL_GENERAL;

    /**
     * Vertical alignment
     *
     * @var string
     */
    protected $vertical = PHPExcel_Style_Alignment::VERTICAL_BOTTOM;

    /**
     * Text rotation
     *
     * @var integer
     */
    protected $textRotation = 0;

    /**
     * Wrap text
     *
     * @var boolean
     */
    protected $wrapText = false;

    /**
     * Shrink to fit
     *
     * @var boolean
     */
    protected $shrinkToFit = false;

...