<?php

/**
 *  PEL: PHP Exif Library.  A library with support for reading and
 *  writing all Exif headers in JPEG and TIFF images using PHP.
 *
 *  Copyright (C) 2005, 2007  Martin Geisler.
 *
 *  This program is free software; you can redistribute it and/or modify
 *  it under the terms of the GNU General Public License as published by
 *  the Free Software Foundation; either version 2 of the License, or
 *  (at your option) any later version.
 *
 *  This program 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 General Public License for more details.
 *
 *  You should have received a copy of the GNU General Public License
 *  along with this program in the file COPYING; if not, write to the
 *  Free Software Foundation, Inc., 51 Franklin St, Fifth Floor,
 *  Boston, MA 02110-1301 USA
 */

/* $Id$ */


/**
 * Class for dealing with JPEG comments.
 *
 * @author Martin Geisler <mgeisler@users.sourceforge.net>
 * @version $Revision$
 * @date $Date$
 * @license http://www.gnu.org/licenses/gpl.html GNU General Public
 * License (GPL)
 * @package PEL
 */

/**#@+ Required class definitions. */
require_once('PelJpegContent.php');
/**#@-*/


/**
 * Class representing JPEG comments.
 *
 * @author Martin Geisler <mgeisler@users.sourceforge.net>
 * @package PEL
 */
class PelJpegComment extends PelJpegContent {

    /**
     * The comment.
     *
     * @var string
     */
    private $comment = '';

    /**
     * Construct a new JPEG comment.
     *
     * The new comment will contain the string given.
     */
    function __construct($comment = '') {
        $this->comment = $comment;
    }


    /**
     * Load and parse data.
     *
     * This will load the comment from the data window passed.
     */
    function load(PelDataWindow $d) {
        $this->comment = $d->getBytes();
    }


    /**
     * Update the value with a new comment.
     *
     * Any old comment will be overwritten.
     *
     * @param string the new comment.
     */
    function setValue($comment) {
        $this->comment = $comment;
    }


    /**
     * Get the comment.
     *
     * @return string the comment.
     */
    function getValue() {
        return $this->comment;
    }


    /**
     * Turn this comment into bytes.
     *
     * @return string bytes representing this comment.
     */
    function getBytes() {
        return $this->comment;
    }


    /**
     * Return a string representation of this object.
     *
     * @return string the same as {@link getValue()}.
     */
    function __toString() {
        return $this->getValue();
    }

}

