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         const BROKEN_FILE = '0';
  31
  32         /**
  33          * @param File $image
  34          * @param string $filename
  35          * @return string
  36          */
  37         function getMetadata( $image, $filename ) {
  38                 try {
  39                         $metadata = BitmapMetadataHandler::PNG( $filename );
  40                 } catch ( Exception $e ) {
  41                         // Broken file?
  42                         wfDebug( __METHOD__ . ': ' . $e->getMessage() . "\n" );
  43
  44                         return self::BROKEN_FILE;
  45                 }
  46
  47                 return serialize( $metadata );
  48         }
  49
  50         /**
  51          * @param File $image
  52          * @param bool|IContextSource $context Context to use (optional)
  53          * @return array|bool
  54          */
  55         function formatMetadata( $image, $context = false ) {
  56                 $meta = $this->getCommonMetaArray( $image );
  57                 if ( count( $meta ) === 0 ) {
  58                         return false;
  59                 }
  60
  61                 return $this->formatMetadataHelper( $meta, $context );
  62         }
  63
  64         /**
  65          * Get a file type independent array of metadata.
  66          *
  67          * @param File $image
  68          * @return array The metadata array
  69          */
  70         public function getCommonMetaArray( File $image ) {
  71                 $meta = $image->getMetadata();
  72
  73                 if ( !$meta ) {
  74                         return array();
  75                 }
  76                 $meta = unserialize( $meta );
  77                 if ( !isset( $meta['metadata'] ) ) {
  78                         return array();
  79                 }
  80                 unset( $meta['metadata']['_MW_PNG_VERSION'] );
  81
  82                 return $meta['metadata'];
  83         }
  84
  85         /**
  86          * @param File $image
  87          * @return bool
  88          */
  89         function isAnimatedImage( $image ) {
  90                 $ser = $image->getMetadata();
  91                 if ( $ser ) {
  92                         $metadata = unserialize( $ser );
  93                         if ( $metadata['frameCount'] > 1 ) {
  94                                 return true;
  95                         }
  96                 }
  97
  98                 return false;
  99         }
 100
 101         /**
 102          * We do not support making APNG thumbnails, so always false
 103          * @param File $image
 104          * @return bool False
 105          */
 106         function canAnimateThumbnail( $image ) {
 107                 return false;
 108         }
 109
 110         function getMetadataType( $image ) {
 111                 return 'parsed-png';
 112         }
 113
 114         function isMetadataValid( $image, $metadata ) {
 115
 116                 if ( $metadata === self::BROKEN_FILE ) {
 117                         // Do not repetitivly regenerate metadata on broken file.
 118                         return self::METADATA_GOOD;
 119                 }
 120
 121                 MediaWiki\suppressWarnings();
 122                 $data = unserialize( $metadata );
 123                 MediaWiki\restoreWarnings();
 124
 125                 if ( !$data || !is_array( $data ) ) {
 126                         wfDebug( __METHOD__ . " invalid png metadata\n" );
 127
 128                         return self::METADATA_BAD;
 129                 }
 130
 131                 if ( !isset( $data['metadata']['_MW_PNG_VERSION'] )
 132                         || $data['metadata']['_MW_PNG_VERSION'] != PNGMetadataExtractor::VERSION
 133                 ) {
 134                         wfDebug( __METHOD__ . " old but compatible png metadata\n" );
 135
 136                         return self::METADATA_COMPATIBLE;
 137                 }
 138
 139                 return self::METADATA_GOOD;
 140         }
 141
 142         /**
 143          * @param File $image
 144          * @return string
 145          */
 146         function getLongDesc( $image ) {
 147                 global $wgLang;
 148                 $original = parent::getLongDesc( $image );
 149
 150                 MediaWiki\suppressWarnings();
 151                 $metadata = unserialize( $image->getMetadata() );
 152                 MediaWiki\restoreWarnings();
 153
 154                 if ( !$metadata || $metadata['frameCount'] <= 0 ) {
 155                         return $original;
 156                 }
 157
 158                 $info = array();
 159                 $info[] = $original;
 160
 161                 if ( $metadata['loopCount'] == 0 ) {
 162                         $info[] = wfMessage( 'file-info-png-looped' )->parse();
 163                 } elseif ( $metadata['loopCount'] > 1 ) {
 164                         $info[] = wfMessage( 'file-info-png-repeat' )->numParams( $metadata['loopCount'] )->parse();
 165                 }
 166
 167                 if ( $metadata['frameCount'] > 0 ) {
 168                         $info[] = wfMessage( 'file-info-png-frames' )->numParams( $metadata['frameCount'] )->parse();
 169                 }
 170
 171                 if ( $metadata['duration'] ) {
 172                         $info[] = $wgLang->formatTimePeriod( $metadata['duration'] );
 173                 }
 174
 175                 return $wgLang->commaList( $info );
 176         }
 177
 178         // PNGs should be easy to support, but it will need some sharpening applied
 179         // and another user test to check if the perceived quality change is noticeable
 180
 181         public function supportsBucketing() {
 182                 return false;
 183         }
 184 }