includes/media/PNG.php

   1 <?php
   2 /**
   3  * Handler for PNG images.
   4  *
   5  * This program is free software; you can redistribute it and/or modify
   6  * it under the terms of the GNU General Public License as published by
   7  * the Free Software Foundation; either version 2 of the License, or
   8  * (at your option) any later version.
   9  *
  10  * This program is distributed in the hope that it will be useful,
  11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  13  * GNU General Public License for more details.
  14  *
  15  * You should have received a copy of the GNU General Public License along
  16  * with this program; if not, write to the Free Software Foundation, Inc.,
  17  * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
  18  * http://www.gnu.org/copyleft/gpl.html
  19  *
  20  * @file
  21  * @ingroup Media
  22  */
  23
  24 /**
  25  * Handler for PNG images.
  26  *
  27  * @ingroup Media
  28  */
  29 class PNGHandler extends BitmapHandler {
  30
  31         const BROKEN_FILE = '0';
  32
  33         /**
  34          * @param File $image
  35          * @param string $filename
  36          * @return string
  37          */
  38         function getMetadata( $image, $filename ) {
  39                 try {
  40                         $metadata = BitmapMetadataHandler::PNG( $filename );
  41                 } catch ( Exception $e ) {
  42                         // Broken file?
  43                         wfDebug( __METHOD__ . ': ' . $e->getMessage() . "\n" );
  44                         return self::BROKEN_FILE;
  45                 }
  46
  47                 return serialize( $metadata );
  48         }
  49
  50         /**
  51          * @param $image File
  52          * @return array|bool
  53          */
  54         function formatMetadata( $image ) {
  55                 $meta = $image->getMetadata();
  56
  57                 if ( !$meta ) {
  58                         return false;
  59                 }
  60                 $meta = unserialize( $meta );
  61                 if ( !isset( $meta['metadata'] ) || count( $meta['metadata'] ) <= 1 ) {
  62                         return false;
  63                 }
  64
  65                 if ( isset( $meta['metadata']['_MW_PNG_VERSION'] ) ) {
  66                         unset( $meta['metadata']['_MW_PNG_VERSION'] );
  67                 }
  68                 return $this->formatMetadataHelper( $meta['metadata'] );
  69         }
  70
  71         /**
  72          * @param $image File
  73          * @return bool
  74          */
  75         function isAnimatedImage( $image ) {
  76                 $ser = $image->getMetadata();
  77                 if ( $ser ) {
  78                         $metadata = unserialize( $ser );
  79                         if ( $metadata['frameCount'] > 1 ) {
  80                                 return true;
  81                         }
  82                 }
  83                 return false;
  84         }
  85         /**
  86          * We do not support making APNG thumbnails, so always false
  87          * @param $image File
  88          * @return bool false
  89          */
  90         function canAnimateThumbnail( $image ) {
  91                 return false;
  92         }
  93
  94         function getMetadataType( $image ) {
  95                 return 'parsed-png';
  96         }
  97
  98         function isMetadataValid( $image, $metadata ) {
  99
 100                 if ( $metadata === self::BROKEN_FILE ) {
 101                         // Do not repetitivly regenerate metadata on broken file.
 102                         return self::METADATA_GOOD;
 103                 }
 104
 105                 wfSuppressWarnings();
 106                 $data = unserialize( $metadata );
 107                 wfRestoreWarnings();
 108
 109                 if ( !$data || !is_array( $data ) ) {
 110                         wfDebug( __METHOD__ . " invalid png metadata\n" );
 111                         return self::METADATA_BAD;
 112                 }
 113
 114                 if ( !isset( $data['metadata']['_MW_PNG_VERSION'] )
 115                         || $data['metadata']['_MW_PNG_VERSION'] != PNGMetadataExtractor::VERSION ) {
 116                         wfDebug( __METHOD__ . " old but compatible png metadata\n" );
 117                         return self::METADATA_COMPATIBLE;
 118                 }
 119                 return self::METADATA_GOOD;
 120         }
 121
 122         /**
 123          * @param $image File
 124          * @return string
 125          */
 126         function getLongDesc( $image ) {
 127                 global $wgLang;
 128                 $original = parent::getLongDesc( $image );
 129
 130                 wfSuppressWarnings();
 131                 $metadata = unserialize( $image->getMetadata() );
 132                 wfRestoreWarnings();
 133
 134                 if ( !$metadata || $metadata['frameCount'] <= 0 ) {
 135                         return $original;
 136                 }
 137
 138                 $info = array();
 139                 $info[] = $original;
 140
 141                 if ( $metadata['loopCount'] == 0 ) {
 142                         $info[] = wfMessage( 'file-info-png-looped' )->parse();
 143                 } elseif ( $metadata['loopCount'] > 1 ) {
 144                         $info[] = wfMessage( 'file-info-png-repeat' )->numParams( $metadata['loopCount'] )->parse();
 145                 }
 146
 147                 if ( $metadata['frameCount'] > 0 ) {
 148                         $info[] = wfMessage( 'file-info-png-frames' )->numParams( $metadata['frameCount'] )->parse();
 149                 }
 150
 151                 if ( $metadata['duration'] ) {
 152                         $info[] = $wgLang->formatTimePeriod( $metadata['duration'] );
 153                 }
 154
 155                 return $wgLang->commaList( $info );
 156         }
 157
 158 }