SVG.php

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<?php
class SvgHandler extends ImageHandler {
        const SVG_METADATA_VERSION = 2;

        function isEnabled() {
                global $wgSVGConverters, $wgSVGConverter;
                if ( !isset( $wgSVGConverters[$wgSVGConverter] ) ) {
                        wfDebug( "\$wgSVGConverter is invalid, disabling SVG rendering.\n" );
                        return false;
                } else {
                        return true;
                }
        }

        function mustRender( $file ) {
                return true;
        }

        function isVectorized( $file ) {
                return true;
        }

        function isAnimatedImage( $file ) {
                # TODO: detect animated SVGs
                $metadata = $file->getMetadata();
                if ( $metadata ) {
                        $metadata = $this->unpackMetadata( $metadata );
                        if( isset( $metadata['animated'] ) ) {
                                return $metadata['animated'];
                        }
                }
                return false;
        }

        function canAnimateThumb( $file ) {
                return false;
        }

        function normaliseParams( $image, &$params ) {
                global $wgSVGMaxSize;
                if ( !parent::normaliseParams( $image, $params ) ) {
                        return false;
                }
                # Don't make an image bigger than wgMaxSVGSize on the smaller side
                if ( $params['physicalWidth'] <= $params['physicalHeight'] ) {
                        if ( $params['physicalWidth'] > $wgSVGMaxSize ) {
                                $srcWidth = $image->getWidth( $params['page'] );
                                $srcHeight = $image->getHeight( $params['page'] );
                                $params['physicalWidth'] = $wgSVGMaxSize;
                                $params['physicalHeight'] = File::scaleHeight( $srcWidth, $srcHeight, $wgSVGMaxSize );
                        }
                } else {
                        if ( $params['physicalHeight'] > $wgSVGMaxSize ) {
                                $srcWidth = $image->getWidth( $params['page'] );
                                $srcHeight = $image->getHeight( $params['page'] );
                                $params['physicalWidth'] = File::scaleHeight( $srcHeight, $srcWidth, $wgSVGMaxSize );
                                $params['physicalHeight'] = $wgSVGMaxSize;
                        }
                }
                return true;
        }

        function doTransform( $image, $dstPath, $dstUrl, $params, $flags = 0 ) {
                if ( !$this->normaliseParams( $image, $params ) ) {
                        return new TransformParameterError( $params );
                }
                $clientWidth = $params['width'];
                $clientHeight = $params['height'];
                $physicalWidth = $params['physicalWidth'];
                $physicalHeight = $params['physicalHeight'];

                if ( $flags & self::TRANSFORM_LATER ) {
                        return new ThumbnailImage( $image, $dstUrl, $dstPath, $params );
                }

                $metadata = $this->unpackMetadata( $image->getMetadata() );
                if ( isset( $metadata['error'] ) ) { // sanity check
                        $err = wfMessage( 'svg-long-error', $metadata['error']['message'] )->text();
                        return new MediaTransformError( 'thumbnail_error', $clientWidth, $clientHeight, $err );
                }

                if ( !wfMkdirParents( dirname( $dstPath ), null, __METHOD__ ) ) {
                        return new MediaTransformError( 'thumbnail_error', $clientWidth, $clientHeight,
                                wfMessage( 'thumbnail_dest_directory' )->text() );
                }

                $srcPath = $image->getLocalRefPath();
                $status = $this->rasterize( $srcPath, $dstPath, $physicalWidth, $physicalHeight );
                if ( $status === true ) {
                        return new ThumbnailImage( $image, $dstUrl, $dstPath, $params );
                } else {
                        return $status; // MediaTransformError
                }
        }

        public function rasterize( $srcPath, $dstPath, $width, $height ) {
                global $wgSVGConverters, $wgSVGConverter, $wgSVGConverterPath;
                $err = false;
                $retval = '';
                if ( isset( $wgSVGConverters[$wgSVGConverter] ) ) {
                        if ( is_array( $wgSVGConverters[$wgSVGConverter] ) ) {
                                // This is a PHP callable
                                $func = $wgSVGConverters[$wgSVGConverter][0];
                                $args = array_merge( array( $srcPath, $dstPath, $width, $height ),
                                        array_slice( $wgSVGConverters[$wgSVGConverter], 1 ) );
                                if ( !is_callable( $func ) ) {
                                        throw new MWException( "$func is not callable" );
                                }
                                $err = call_user_func_array( $func, $args );
                                $retval = (bool)$err;
                        } else {
                                // External command
                                $cmd = str_replace(
                                        array( '$path/', '$width', '$height', '$input', '$output' ),
                                        array( $wgSVGConverterPath ? wfEscapeShellArg( "$wgSVGConverterPath/" ) : "",
                                                intval( $width ),
                                                intval( $height ),
                                                wfEscapeShellArg( $srcPath ),
                                                wfEscapeShellArg( $dstPath ) ),
                                        $wgSVGConverters[$wgSVGConverter]
                                ) . " 2>&1";
                                wfProfileIn( 'rsvg' );
                                wfDebug( __METHOD__ . ": $cmd\n" );
                                $err = wfShellExec( $cmd, $retval );
                                wfProfileOut( 'rsvg' );
                        }
                }
                $removed = $this->removeBadFile( $dstPath, $retval );
                if ( $retval != 0 || $removed ) {
                        wfDebugLog( 'thumbnail', sprintf( 'thumbnail failed on %s: error %d "%s" from "%s"',
                                        wfHostname(), $retval, trim( $err ), $cmd ) );
                        return new MediaTransformError( 'thumbnail_error', $width, $height, $err );
                }
                return true;
        }

        public static function rasterizeImagickExt( $srcPath, $dstPath, $width, $height ) {
                $im = new Imagick( $srcPath );
                $im->setImageFormat( 'png' );
                $im->setBackgroundColor( 'transparent' );
                $im->setImageDepth( 8 );

                if ( !$im->thumbnailImage( intval( $width ), intval( $height ), /* fit */ false ) ) {
                        return 'Could not resize image';
                }
                if ( !$im->writeImage( $dstPath ) ) {
                        return "Could not write to $dstPath";
                }
        }

        function getImageSize( $file, $path, $metadata = false ) {
                if ( $metadata === false ) {
                        $metadata = $file->getMetaData();
                }
                $metadata = $this->unpackMetaData( $metadata );

                if ( isset( $metadata['width'] ) && isset( $metadata['height'] ) ) {
                        return array( $metadata['width'], $metadata['height'], 'SVG',
                                        "width=\"{$metadata['width']}\" height=\"{$metadata['height']}\"" );
                } else { // error
                        return array( 0, 0, 'SVG', "width=\"0\" height=\"0\"" );
                }
        }

        function getThumbType( $ext, $mime, $params = null ) {
                return array( 'png', 'image/png' );
        }

        function getLongDesc( $file ) {
                global $wgLang;

                $metadata = $this->unpackMetadata( $file->getMetadata() );
                if ( isset( $metadata['error'] ) ) {
                        return wfMessage( 'svg-long-error', $metadata['error']['message'] )->text();
                }

                $size = $wgLang->formatSize( $file->getSize() );

                if ( $this->isAnimatedImage( $file ) ) {
                        $msg = wfMessage( 'svg-long-desc-animated' );
                } else {
                        $msg = wfMessage( 'svg-long-desc' );
                }

                $msg->numParams( $file->getWidth(), $file->getHeight() )->params( $size );

                return $msg->parse();
        }

        function getMetadata( $file, $filename ) {
                $metadata = array( 'version' => self::SVG_METADATA_VERSION );
                try {
                        $metadata += SVGMetadataExtractor::getMetadata( $filename );
                } catch( MWException $e ) { // @TODO: SVG specific exceptions
                        // File not found, broken, etc.
                        $metadata['error'] = array(
                                'message' => $e->getMessage(),
                                'code'    => $e->getCode()
                        );
                        wfDebug( __METHOD__ . ': ' . $e->getMessage() . "\n" );
                }
                return serialize( $metadata );
        }

        function unpackMetadata( $metadata ) {
                wfSuppressWarnings();
                $unser = unserialize( $metadata );
                wfRestoreWarnings();
                if ( isset( $unser['version'] ) && $unser['version'] == self::SVG_METADATA_VERSION ) {
                        return $unser;
                } else {
                        return false;
                }
        }

        function getMetadataType( $image ) {
                return 'parsed-svg';
        }

        function isMetadataValid( $image, $metadata ) {
                $meta = $this->unpackMetadata( $metadata );
                if ( $meta === false ) {
                        return self::METADATA_BAD;
                }
                if ( !isset( $meta['originalWidth'] ) ) {
                        // Old but compatible
                        return self::METADATA_COMPATIBLE;
                }
                return self::METADATA_GOOD;
        }

        function visibleMetadataFields() {
                $fields = array( 'objectname', 'imagedescription' );
                return $fields;
        }

        function formatMetadata( $file ) {
                $result = array(
                        'visible' => array(),
                        'collapsed' => array()
                );
                $metadata = $file->getMetadata();
                if ( !$metadata ) {
                        return false;
                }
                $metadata = $this->unpackMetadata( $metadata );
                if ( !$metadata || isset( $metadata['error'] ) ) {
                        return false;
                }

                /* TODO: add a formatter
                $format = new FormatSVG( $metadata );
                $formatted = $format->getFormattedData();
                */

                // Sort fields into visible and collapsed
                $visibleFields = $this->visibleMetadataFields();

                // Rename fields to be compatible with exif, so that
                // the labels for these fields work and reuse existing messages.
                $conversion = array(
                        'originalwidth' => 'imagewidth',
                        'originalheight' => 'imagelength',
                        'description' => 'imagedescription',
                        'title' => 'objectname',
                );
                foreach ( $metadata as $name => $value ) {
                        $tag = strtolower( $name );
                        if ( isset( $conversion[$tag] ) ) {
                                $tag = $conversion[$tag];
                        } else {
                                // Do not output other metadata not in list
                                continue;
                        }
                        self::addMeta( $result,
                                in_array( $tag, $visibleFields ) ? 'visible' : 'collapsed',
                                'exif',
                                $tag,
                                $value
                        );
                }
                return $result;
        }
}