PNGHandler.php

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<?php
class PNGHandler extends BitmapHandler {
    const BROKEN_FILE = '0';
 
    function getMetadata( $image, $filename ) {
        try {
            $metadata = BitmapMetadataHandler::PNG( $filename );
        } catch ( Exception $e ) {
            // Broken file?
            wfDebug( __METHOD__ . ': ' . $e->getMessage() . "\n" );
 
            return self::BROKEN_FILE;
        }
 
        return serialize( $metadata );
    }
 
    function formatMetadata( $image, $context = false ) {
        $meta = $this->getCommonMetaArray( $image );
        if ( count( $meta ) === 0 ) {
            return false;
        }
 
        return $this->formatMetadataHelper( $meta, $context );
    }
 
    public function getCommonMetaArray( File $image ) {
        $meta = $image->getMetadata();
 
        if ( !$meta ) {
            return [];
        }
        $meta = unserialize( $meta );
        if ( !isset( $meta['metadata'] ) ) {
            return [];
        }
        unset( $meta['metadata']['_MW_PNG_VERSION'] );
 
        return $meta['metadata'];
    }
 
    function isAnimatedImage( $image ) {
        $ser = $image->getMetadata();
        if ( $ser ) {
            $metadata = unserialize( $ser );
            if ( $metadata['frameCount'] > 1 ) {
                return true;
            }
        }
 
        return false;
    }
 
    function canAnimateThumbnail( $image ) {
        return false;
    }
 
    function getMetadataType( $image ) {
        return 'parsed-png';
    }
 
    function isMetadataValid( $image, $metadata ) {
        if ( $metadata === self::BROKEN_FILE ) {
            // Do not repetitivly regenerate metadata on broken file.
            return self::METADATA_GOOD;
        }
 
        Wikimedia\suppressWarnings();
        $data = unserialize( $metadata );
        Wikimedia\restoreWarnings();
 
        if ( !$data || !is_array( $data ) ) {
            wfDebug( __METHOD__ . " invalid png metadata\n" );
 
            return self::METADATA_BAD;
        }
 
        if ( !isset( $data['metadata']['_MW_PNG_VERSION'] )
            || $data['metadata']['_MW_PNG_VERSION'] != PNGMetadataExtractor::VERSION
        ) {
            wfDebug( __METHOD__ . " old but compatible png metadata\n" );
 
            return self::METADATA_COMPATIBLE;
        }
 
        return self::METADATA_GOOD;
    }
 
    function getLongDesc( $image ) {
        global $wgLang;
        $original = parent::getLongDesc( $image );
 
        Wikimedia\suppressWarnings();
        $metadata = unserialize( $image->getMetadata() );
        Wikimedia\restoreWarnings();
 
        if ( !$metadata || $metadata['frameCount'] <= 0 ) {
            return $original;
        }
 
        $info = [];
        $info[] = $original;
 
        if ( $metadata['loopCount'] == 0 ) {
            $info[] = wfMessage( 'file-info-png-looped' )->parse();
        } elseif ( $metadata['loopCount'] > 1 ) {
            $info[] = wfMessage( 'file-info-png-repeat' )->numParams( $metadata['loopCount'] )->parse();
        }
 
        if ( $metadata['frameCount'] > 0 ) {
            $info[] = wfMessage( 'file-info-png-frames' )->numParams( $metadata['frameCount'] )->parse();
        }
 
        if ( $metadata['duration'] ) {
            $info[] = $wgLang->formatTimePeriod( $metadata['duration'] );
        }
 
        return $wgLang->commaList( $info );
    }
 
    public function getLength( $file ) {
        $serMeta = $file->getMetadata();
        Wikimedia\suppressWarnings();
        $metadata = unserialize( $serMeta );
        Wikimedia\restoreWarnings();
 
        if ( !$metadata || !isset( $metadata['duration'] ) || !$metadata['duration'] ) {
            return 0.0;
        } else {
            return (float)$metadata['duration'];
        }
    }
 
    // PNGs should be easy to support, but it will need some sharpening applied
    // and another user test to check if the perceived quality change is noticeable
    public function supportsBucketing() {
        return false;
    }
}