<?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) 2005-2012 Zend Technologies USA Inc. (http://www.zend.com)
   * @license    http://framework.zend.com/license/new-bsd     New BSD License
   * @version    $Id: String.php 24593 2012-01-05 20:35:02Z matthew $
   */
  
  /** 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) 2005-2012 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)";
      }
  }