ExifBitmapHandler.php

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<?php
class ExifBitmapHandler extends BitmapHandler {
    const BROKEN_FILE = '-1'; // error extracting metadata
    const OLD_BROKEN_FILE = '0'; // outdated error extracting metadata.
 
    function convertMetadataVersion( $metadata, $version = 1 ) {
        // basically flattens arrays.
        $version = intval( explode( ';', $version, 2 )[0] );
        if ( $version < 1 || $version >= 2 ) {
            return $metadata;
        }
 
        $avoidHtml = true;
 
        if ( !is_array( $metadata ) ) {
            $metadata = unserialize( $metadata );
        }
        if ( !isset( $metadata['MEDIAWIKI_EXIF_VERSION'] ) || $metadata['MEDIAWIKI_EXIF_VERSION'] != 2 ) {
            return $metadata;
        }
 
        // Treat Software as a special case because in can contain
        // an array of (SoftwareName, Version).
        if ( isset( $metadata['Software'] )
            && is_array( $metadata['Software'] )
            && is_array( $metadata['Software'][0] )
            && isset( $metadata['Software'][0][0] )
            && isset( $metadata['Software'][0][1] )
        ) {
            $metadata['Software'] = $metadata['Software'][0][0] . ' (Version '
                . $metadata['Software'][0][1] . ')';
        }
 
        $formatter = new FormatMetadata;
 
        // ContactInfo also has to be dealt with specially
        if ( isset( $metadata['Contact'] ) ) {
            $metadata['Contact'] =
                $formatter->collapseContactInfo(
                    $metadata['Contact'] );
        }
 
        foreach ( $metadata as &$val ) {
            if ( is_array( $val ) ) {
                $val = $formatter->flattenArrayReal( $val, 'ul', $avoidHtml );
            }
        }
        $metadata['MEDIAWIKI_EXIF_VERSION'] = 1;
 
        return $metadata;
    }
 
    public function isMetadataValid( $image, $metadata ) {
        global $wgShowEXIF;
        if ( !$wgShowEXIF ) {
            # Metadata disabled and so an empty field is expected
            return self::METADATA_GOOD;
        }
        if ( $metadata === self::OLD_BROKEN_FILE ) {
            # Old special value indicating that there is no Exif data in the file.
            # or that there was an error well extracting the metadata.
            wfDebug( __METHOD__ . ": back-compat version\n" );
 
            return self::METADATA_COMPATIBLE;
        }
        if ( $metadata === self::BROKEN_FILE ) {
            return self::METADATA_GOOD;
        }
        Wikimedia\suppressWarnings();
        $exif = unserialize( $metadata );
        Wikimedia\restoreWarnings();
        if ( !isset( $exif['MEDIAWIKI_EXIF_VERSION'] )
            || $exif['MEDIAWIKI_EXIF_VERSION'] != Exif::version()
        ) {
            if ( isset( $exif['MEDIAWIKI_EXIF_VERSION'] )
                && $exif['MEDIAWIKI_EXIF_VERSION'] == 1
            ) {
                // back-compatible but old
                wfDebug( __METHOD__ . ": back-compat version\n" );
 
                return self::METADATA_COMPATIBLE;
            }
            # Wrong (non-compatible) version
            wfDebug( __METHOD__ . ": wrong version\n" );
 
            return self::METADATA_BAD;
        }
 
        return self::METADATA_GOOD;
    }
 
    public function formatMetadata( $image, $context = false ) {
        $meta = $this->getCommonMetaArray( $image );
        if ( count( $meta ) === 0 ) {
            return false;
        }
 
        return $this->formatMetadataHelper( $meta, $context );
    }
 
    public function getCommonMetaArray( File $file ) {
        $metadata = $file->getMetadata();
        if ( $metadata === self::OLD_BROKEN_FILE
            || $metadata === self::BROKEN_FILE
            || $this->isMetadataValid( $file, $metadata ) === self::METADATA_BAD
        ) {
            // So we don't try and display metadata from PagedTiffHandler
            // for example when using InstantCommons.
            return [];
        }
 
        $exif = unserialize( $metadata );
        if ( !$exif ) {
            return [];
        }
        unset( $exif['MEDIAWIKI_EXIF_VERSION'] );
 
        return $exif;
    }
 
    function getMetadataType( $image ) {
        return 'exif';
    }
 
    function getImageSize( $image, $path ) {
        $gis = parent::getImageSize( $image, $path );
 
        // Don't just call $image->getMetadata(); FSFile::getPropsFromPath() calls us with a bogus object.
        // This may mean we read EXIF data twice on initial upload.
        if ( $this->autoRotateEnabled() ) {
            $meta = $this->getMetadata( $image, $path );
            $rotation = $this->getRotationForExif( $meta );
        } else {
            $rotation = 0;
        }
 
        if ( $rotation == 90 || $rotation == 270 ) {
            $width = $gis[0];
            $gis[0] = $gis[1];
            $gis[1] = $width;
        }
 
        return $gis;
    }
 
    public function getRotation( $file ) {
        if ( !$this->autoRotateEnabled() ) {
            return 0;
        }
 
        $data = $file->getMetadata();
 
        return $this->getRotationForExif( $data );
    }
 
    protected function getRotationForExif( $data ) {
        if ( !$data ) {
            return 0;
        }
        Wikimedia\suppressWarnings();
        $data = unserialize( $data );
        Wikimedia\restoreWarnings();
        if ( isset( $data['Orientation'] ) ) {
            # See http://sylvana.net/jpegcrop/exif_orientation.html
            switch ( $data['Orientation'] ) {
                case 8:
                    return 90;
                case 3:
                    return 180;
                case 6:
                    return 270;
                default:
                    return 0;
            }
        }
 
        return 0;
    }
}