<?php
//
//  FPDI - Version 1.3
//
//    Copyright 2004-2009 Setasign - Jan Slabon
//
//  Licensed under the Apache License, Version 2.0 (the "License");
//  you may not use this file except in compliance with the License.
//  You may obtain a copy of the License at
//
//      http://www.apache.org/licenses/LICENSE-2.0
//
//  Unless required by applicable law or agreed to in writing, software
//  distributed under the License is distributed on an "AS IS" BASIS,
//  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
//  See the License for the specific language governing permissions and
//  limitations under the License.
//

class pdf_context {

    /**
     * Modi
     *
     * @var integer 0 = file | 1 = string
     */
    var $_mode = 0;
    
	var $file;
	var $buffer;
	var $offset;
	var $length;

	var $stack;

	// Constructor

	function pdf_context(&$f) {
		$this->file =& $f;
		if (is_string($this->file))
		    $this->_mode = 1;
		$this->reset();
	}

	// Optionally move the file
	// pointer to a new location
	// and reset the buffered data

	function reset($pos = null, $l = 100) {
	    if ($this->_mode == 0) {
        	if (!is_null ($pos)) {
    			fseek ($this->file, $pos);
    		}
    
    		$this->buffer = $l > 0 ? fread($this->file, $l) : '';
    		$this->length = strlen($this->buffer);
    		if ($this->length < $l)
                $this->increase_length($l - $this->length);
	    } else {
	        $this->buffer = $this->file;
	        $this->length = strlen($this->buffer);
	    }
		$this->offset = 0;
		$this->stack = array();
	}

	// Make sure that there is at least one
	// character beyond the current offset in
	// the buffer to prevent the tokenizer
	// from attempting to access data that does
	// not exist

	function ensure_content() {
		if ($this->offset >= $this->length - 1) {
			return $this->increase_length();
		} else {
			return true;
		}
	}

	// Forcefully read more data into the buffer

	function increase_length($l=100) {
		if ($this->_mode == 0 && feof($this->file)) {
			return false;
		} else if ($this->_mode == 0) {
		    $totalLength = $this->length + $l;
		    do {
                $this->buffer .= fread($this->file, $totalLength-$this->length);
            } while ((($this->length = strlen($this->buffer)) != $totalLength) && !feof($this->file));
			
			return true;
		} else {
	        return false;
		}
	}
}