<?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
 */
namespace lsolesen\pel;

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

/**
 * 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.
     *
     * @param string $comment
     */
    public function __construct($comment = '')
    {
        $this->comment = $comment;
    }

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

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

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

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

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