<?php

/**

 * Zend Framework

 *

 * LICENSE

 *

 * This source file is subject to the new BSD license that is bundled

 * with this package in the file LICENSE.txt.

 * It is also available through the world-wide-web at this URL:

 * http://framework.zend.com/license/new-bsd

 * If you did not receive a copy of the license and are unable to

 * obtain it through the world-wide-web, please send an email

 * to license@zend.com so we can send you a copy immediately.

 *

 * @category   Zend

 * @package    Zend_Pdf

 * @subpackage FileParser

 * @copyright  Copyright (c) 2005-2010 Zend Technologies USA Inc. (http://www.zend.com)

 * @license    http://framework.zend.com/license/new-bsd     New BSD License

 * @version    $Id: String.php 20096 2010-01-06 02:05:09Z bkarwin $

 */

/** Zend_Pdf_FileParserDataSource */

require_once 'Zend/Pdf/FileParserDataSource.php';

/**

 * Concrete subclass of {@link Zend_Pdf_FileParserDataSource} that provides an

 * interface to binary strings.

 *

 * @package    Zend_Pdf

 * @subpackage FileParser

 * @copyright  Copyright (c) 2005-2010 Zend Technologies USA Inc. (http://www.zend.com)

 * @license    http://framework.zend.com/license/new-bsd     New BSD License

 */

class Zend_Pdf_FileParserDataSource_String extends Zend_Pdf_FileParserDataSource

{

  /**** Instance Variables ****/

    /**

     * The string to parse.

     * @var string

     */

    protected $_string = '';

  /**** Public Interface ****/

  /* Concrete Class Implementation */

    /**

     * Object constructor.

     *

     * Verifies that the string is not empty.

     *

     * @param string $string String to parse.

     */

    public function __construct($string)

    {

        if (empty($string)) {

            require_once 'Zend/Pdf/Exception.php';

            throw new Zend_Pdf_Exception('String is empty',

                                         Zend_Pdf_Exception::PARAMETER_VALUE_OUT_OF_RANGE);

        }

        $this->_size = strlen($string);

        $this->_string = $string;

    }

    /**

     * Object destructor.

     */

    public function __destruct()

    {

        $this->_string = '';

    }

    /**

     * Returns the specified number of raw bytes from the string at the byte

     * offset of the current read position.

     *

     * Advances the read position by the number of bytes read.

     *

     * Throws an exception if there is insufficient data to completely fulfill

     * the request.

     *

     * @param integer $byteCount Number of bytes to read.

     * @return string

     * @throws Zend_Pdf_Exception

     */

    public function readBytes($byteCount)

    {

        if (($this->_offset + $byteCount) > $this->_size) {

            require_once 'Zend/Pdf/Exception.php';

            throw new Zend_Pdf_Exception("Insufficient data to read $byteCount bytes",

                                         Zend_Pdf_Exception::INSUFFICIENT_DATA);

        }

        $bytes = substr($this->_string, $this->_offset, $byteCount);

        $this->_offset += $byteCount;

        return $bytes;

    }

    /**

     * Returns the entire string.

     *

     * Preserves the current read position.

     *

     * @return string

     */

    public function readAllBytes()

    {

        return $this->_string;

    }

  /* Object Magic Methods */

    /**

     * Returns a string containing the parsed string's length.

     *

     * @return string

     */

    public function __toString()

    {

        return "String ($this->_size bytes)";

    }

}