Preview renderer class that is able to create previews from PDF, PS and EPS by using GhostScript. More...

Inheritance diagram for ilGhostscriptRenderer:

Collaboration diagram for ilGhostscriptRenderer:

Public Member Functions
	getSupportedFileFormats ()
	Gets an array containing the file formats that are supported by the renderer. More...

Public Member Functions inherited from ilFilePreviewRenderer
	getSupportedRepositoryTypes ()
	Gets an array containing the repository types (e.g. More...

	supports ($preview)
	Determines whether the specified preview object is supported by the renderer. More...

	prepareFileForExec ($filepath)
	Checks whether the specified file path can be used with exec() commands. More...

	getSupportedFileFormats ()
	Gets an array containing the file formats that are supported by the renderer. More...

Public Member Functions inherited from ilPreviewRenderer
	getName ()
	Gets the name of the renderer. More...

	isPlugin ()
	Determines whether the renderer is a plugin or a built in one. More...

	getSupportedRepositoryTypes ()
	Gets an array containing the repository types (e.g. More...

	supports ($preview)
	Determines whether the specified preview object is supported by the renderer. More...

	render ($preview, $obj, $async)
	Creates the preview of the specified preview object. More...

Static Public Member Functions
static	isGhostscriptInstalled ()
	Determines whether Ghostscript is installed. More...

Data Fields
const	SUPPORTED_FORMATS = "eps,pdf,pdfa,ps"

Protected Member Functions
	renderImages ($obj)
	Renders the specified object into images. More...

Protected Member Functions inherited from ilPreviewRenderer
	renderImages ($obj)
	Renders the specified object into images. More...

	getImageSize ()
	Gets the size of the preview images in pixels. More...

	getImageQuality ()
	Gets the quality (compression) of the preview images (1-100). More...

	getMaximumNumberOfPreviews ()
	Gets the maximum number of preview pictures per object. More...

Static Private Attributes
static	$supported_formats = null

Detailed Description

Preview renderer class that is able to create previews from PDF, PS and EPS by using GhostScript.

Author: Stefan Born stefa.nosp@m.n.bo.nosp@m.rn@ph.nosp@m.zh.c.nosp@m.h

Version: $Id$

Definition at line 14 of file class.ilGhostscriptRenderer.php.

Member Function Documentation

◆ getSupportedFileFormats()

ilGhostscriptRenderer::getSupportedFileFormats ( )

Gets an array containing the file formats that are supported by the renderer.

Returns: array An array containing the supported file formats.

Definition at line 27 of file class.ilGhostscriptRenderer.php.

     {
         // build formats only once
         if (self::$supported_formats == null) {
             self::$supported_formats = explode(",", self::SUPPORTED_FORMATS);
         }
         
         return self::$supported_formats;
     }

◆ isGhostscriptInstalled()

static ilGhostscriptRenderer::isGhostscriptInstalled ( )

static

Determines whether Ghostscript is installed.

Definition at line 40 of file class.ilGhostscriptRenderer.php.

Referenced by ilObjFileAccessSettingsGUI\editPreviewSettings(), and ilRendererFactory\loadAvailableRenderers().

     {
         return (PATH_TO_GHOSTSCRIPT != "");
     }

Here is the caller graph for this function:

◆ renderImages()

ilGhostscriptRenderer::renderImages ( $obj )

protected

Renders the specified object into images.

The images do not need to be of the preview image size.

Parameters

ilObjFile $obj The object to create images from.

Returns: array An array of ilRenderedImage containing the absolute file paths to the images.

Definition at line 52 of file class.ilGhostscriptRenderer.php.

References $i, Sabre\VObject\$output, $outputFile, ilUtil\escapeShellArg(), ilUtil\execQuoted(), ilPreviewRenderer\getMaximumNumberOfPreviews(), ilUtil\ilTempnam(), and ilFilePreviewRenderer\prepareFileForExec().

     {
         $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;
     }