ExifBitmap.php

Go to the documentation of this file.

<?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        const OLD_BROKEN_FILE = '0'; // outdated error extracting metadata.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 = explode(';', $version, 2);
                $version = intval($version[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] . ')';
                }

                // ContactInfo also has to be dealt with specially
                if ( isset( $metadata['Contact'] ) ) {
                        $metadata['Contact'] =
                                FormatMetadata::collapseContactInfo(
                                        $metadata['Contact'] );
                }

                foreach ( $metadata as &$val ) {
                        if ( is_array( $val ) ) {
                                $val = FormatMetadata::flattenArray( $val, 'ul', $avoidHtml );
                        }
                }
                $metadata['MEDIAWIKI_EXIF_VERSION'] = 1;
                return $metadata;
        }

        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;
                }
                wfSuppressWarnings();
                $exif = unserialize( $metadata );
                wfRestoreWarnings();
                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;
        }

        function formatMetadata( $image ) {
                $metadata = $image->getMetadata();
                if ( $metadata === self::OLD_BROKEN_FILE ||
                        $metadata === self::BROKEN_FILE ||
                        $this->isMetadataValid( $image, $metadata ) === self::METADATA_BAD )
                {
                        // So we don't try and display metadata from PagedTiffHandler
                        // for example when using InstantCommons.
                        return false;
                }

                $exif = unserialize( $metadata );
                if ( !$exif ) {
                        return false;
                }
                unset( $exif['MEDIAWIKI_EXIF_VERSION'] );
                if ( count( $exif ) == 0 ) {
                        return false;
                }
                return $this->formatMetadataHelper( $exif );
        }

        function getMetadataType( $image ) {
                return 'exif';
        }

        function getImageSize( $image, $path ) {
                global $wgEnableAutoRotation;
                $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 ( $wgEnableAutoRotation ) {
                        $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 ) {
                global $wgEnableAutoRotation;
                if ( !$wgEnableAutoRotation ) {
                        return 0;
                }

                $data = $file->getMetadata();
                return $this->getRotationForExif( $data );
        }

        protected function getRotationForExif( $data ) {
                if ( !$data ) {
                        return 0;
                }
                wfSuppressWarnings();
                $data = unserialize( $data );
                wfRestoreWarnings();
                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;
        }
}