source: branches/version-2_11-dev/data/module/fpdi/pdf_context.php @ 20993

<?php
//
//  FPDI - Version 1.4.1
//
//    Copyright 2004-2011 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.
//

if (!class_exists('pdf_context', false)) {
    
    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 {
                    $toRead = $totalLength - $this->length;
                    if ($toRead < 1)
                        break;
                
                    $this->buffer .= fread($this->file, $toRead);
                } while ((($this->length = strlen($this->buffer)) != $totalLength) && !feof($this->file));
                
                return true;
            } else {
                return false;
            }
        }
    }
}