class.ilGhostscriptRenderer.php

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<?php
/* Copyright (c) 1998-2013 ILIAS open source, Extended GPL, see docs/LICENSE */
 
include_once("./Services/Preview/classes/class.ilFilePreviewRenderer.php");
 
class ilGhostscriptRenderer extends ilFilePreviewRenderer
{
    // constants
    const SUPPORTED_FORMATS = "eps,pdf,pdfa,ps";
    
    // variables
    private static $supported_formats = null;
    
    public function getSupportedFileFormats()
    {
        // build formats only once
        if (self::$supported_formats == null) {
            self::$supported_formats = explode(",", self::SUPPORTED_FORMATS);
        }
        
        return self::$supported_formats;
    }
    
    public static function isGhostscriptInstalled()
    {
        return (PATH_TO_GHOSTSCRIPT != "");
    }
    
    protected function renderImages($obj)
    {
        $numOfPreviews = $this->getMaximumNumberOfPreviews();
        
        // get file path
        $filepath = $obj->getFile();
        $inputFile = $this->prepareFileForExec($filepath);
        
        // create a temporary file name and remove its extension
        $output = str_replace(".tmp", "", ilUtil::ilTempnam());
        
        // use '#' instead of '%' as it gets replaced by 'escapeShellArg' on windows!
        $outputFile = $output . "_#02d.png";
 
        // create images with ghostscript (we use PNG here as it has better transparency quality)
        // gswin32c -dBATCH -dNOPAUSE -dSAFER -dFirstPage=1 -dLastPage=5 -sDEVICE=pngalpha -dEPSCrop -r72 -o $outputFile $inputFile
        // gswin32c -dBATCH -dNOPAUSE -dSAFER -dFirstPage=1 -dLastPage=5 -sDEVICE=jpeg -dJPEGQ=90 -r72 -o $outputFile $inputFile
        $args = sprintf(
            "-dBATCH -dNOPAUSE -dSAFER -dFirstPage=1 -dLastPage=%d -sDEVICE=pngalpha -dEPSCrop -r72 -o %s %s",
            $numOfPreviews,
            str_replace("#", "%", ilUtil::escapeShellArg($outputFile)),
            ilUtil::escapeShellArg($inputFile)
        );
        
        ilUtil::execQuoted(PATH_TO_GHOSTSCRIPT, $args);
        
        // was a temporary file created? then delete it
        if ($filepath != $inputFile) {
            @unlink($inputFile);
        }
        
        // check each file and add it
        $images = array();
        $outputFile = str_replace("#", "%", $outputFile);
        
        for ($i = 1; $i <= $numOfPreviews; $i++) {
            $imagePath = sprintf($outputFile, $i);
            if (!file_exists($imagePath)) {
                break;
            }
            
            $images[] = new ilRenderedImage($imagePath);
        }
        
        return $images;
    }
}