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   1  <?php
   2  /**
   3   * Handler for GIF 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 GIF images.
  26   *
  27   * @ingroup Media
  28   */
  29  class GIFHandler extends BitmapHandler {
  30      const BROKEN_FILE = '0'; // value to store in img_metadata if error extracting metadata.
  31  
  32  	function getMetadata( $image, $filename ) {
  33          try {
  34              $parsedGIFMetadata = BitmapMetadataHandler::GIF( $filename );
  35          } catch ( Exception $e ) {
  36              // Broken file?
  37              wfDebug( __METHOD__ . ': ' . $e->getMessage() . "\n" );
  38  
  39              return self::BROKEN_FILE;
  40          }
  41  
  42          return serialize( $parsedGIFMetadata );
  43      }
  44  
  45      /**
  46       * @param File $image
  47       * @return array|bool
  48       */
  49  	function formatMetadata( $image ) {
  50          $meta = $this->getCommonMetaArray( $image );
  51          if ( count( $meta ) === 0 ) {
  52              return false;
  53          }
  54  
  55          return $this->formatMetadataHelper( $meta );
  56      }
  57  
  58      /**
  59       * Return the standard metadata elements for #filemetadata parser func.
  60       * @param File $image
  61       * @return array|bool
  62       */
  63  	public function getCommonMetaArray( File $image ) {
  64          $meta = $image->getMetadata();
  65  
  66          if ( !$meta ) {
  67              return array();
  68          }
  69          $meta = unserialize( $meta );
  70          if ( !isset( $meta['metadata'] ) ) {
  71              return array();
  72          }
  73          unset( $meta['metadata']['_MW_GIF_VERSION'] );
  74  
  75          return $meta['metadata'];
  76      }
  77  
  78      /**
  79       * @todo Add unit tests
  80       *
  81       * @param File $image
  82       * @return bool
  83       */
  84  	function getImageArea( $image ) {
  85          $ser = $image->getMetadata();
  86          if ( $ser ) {
  87              $metadata = unserialize( $ser );
  88  
  89              return $image->getWidth() * $image->getHeight() * $metadata['frameCount'];
  90          } else {
  91              return $image->getWidth() * $image->getHeight();
  92          }
  93      }
  94  
  95      /**
  96       * @param File $image
  97       * @return bool
  98       */
  99  	function isAnimatedImage( $image ) {
 100          $ser = $image->getMetadata();
 101          if ( $ser ) {
 102              $metadata = unserialize( $ser );
 103              if ( $metadata['frameCount'] > 1 ) {
 104                  return true;
 105              }
 106          }
 107  
 108          return false;
 109      }
 110  
 111      /**
 112       * We cannot animate thumbnails that are bigger than a particular size
 113       * @param File $file
 114       * @return bool
 115       */
 116  	function canAnimateThumbnail( $file ) {
 117          global $wgMaxAnimatedGifArea;
 118          $answer = $this->getImageArea( $file ) <= $wgMaxAnimatedGifArea;
 119  
 120          return $answer;
 121      }
 122  
 123  	function getMetadataType( $image ) {
 124          return 'parsed-gif';
 125      }
 126  
 127  	function isMetadataValid( $image, $metadata ) {
 128          if ( $metadata === self::BROKEN_FILE ) {
 129              // Do not repetitivly regenerate metadata on broken file.
 130              return self::METADATA_GOOD;
 131          }
 132  
 133          wfSuppressWarnings();
 134          $data = unserialize( $metadata );
 135          wfRestoreWarnings();
 136  
 137          if ( !$data || !is_array( $data ) ) {
 138              wfDebug( __METHOD__ . " invalid GIF metadata\n" );
 139  
 140              return self::METADATA_BAD;
 141          }
 142  
 143          if ( !isset( $data['metadata']['_MW_GIF_VERSION'] )
 144              || $data['metadata']['_MW_GIF_VERSION'] != GIFMetadataExtractor::VERSION
 145          ) {
 146              wfDebug( __METHOD__ . " old but compatible GIF metadata\n" );
 147  
 148              return self::METADATA_COMPATIBLE;
 149          }
 150  
 151          return self::METADATA_GOOD;
 152      }
 153  
 154      /**
 155       * @param File $image
 156       * @return string
 157       */
 158  	function getLongDesc( $image ) {
 159          global $wgLang;
 160  
 161          $original = parent::getLongDesc( $image );
 162  
 163          wfSuppressWarnings();
 164          $metadata = unserialize( $image->getMetadata() );
 165          wfRestoreWarnings();
 166  
 167          if ( !$metadata || $metadata['frameCount'] <= 1 ) {
 168              return $original;
 169          }
 170  
 171          /* Preserve original image info string, but strip the last char ')' so we can add even more */
 172          $info = array();
 173          $info[] = $original;
 174  
 175          if ( $metadata['looped'] ) {
 176              $info[] = wfMessage( 'file-info-gif-looped' )->parse();
 177          }
 178  
 179          if ( $metadata['frameCount'] > 1 ) {
 180              $info[] = wfMessage( 'file-info-gif-frames' )->numParams( $metadata['frameCount'] )->parse();
 181          }
 182  
 183          if ( $metadata['duration'] ) {
 184              $info[] = $wgLang->formatTimePeriod( $metadata['duration'] );
 185          }
 186  
 187          return $wgLang->commaList( $info );
 188      }
 189  }