includes/media/SVG.php

   1 <?php
   2 /**
   3  * Handler for SVG 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 use Wikimedia\ScopedCallback;
  24
  25 /**
  26  * Handler for SVG images.
  27  *
  28  * @ingroup Media
  29  */
  30 class SvgHandler extends ImageHandler {
  31         const SVG_METADATA_VERSION = 2;
  32
  33         /** @var array A list of metadata tags that can be converted
  34          *  to the commonly used exif tags. This allows messages
  35          *  to be reused, and consistent tag names for {{#formatmetadata:..}}
  36          */
  37         private static $metaConversion = [
  38                 'originalwidth' => 'ImageWidth',
  39                 'originalheight' => 'ImageLength',
  40                 'description' => 'ImageDescription',
  41                 'title' => 'ObjectName',
  42         ];
  43
  44         function isEnabled() {
  45                 global $wgSVGConverters, $wgSVGConverter;
  46                 if ( !isset( $wgSVGConverters[$wgSVGConverter] ) ) {
  47                         wfDebug( "\$wgSVGConverter is invalid, disabling SVG rendering.\n" );
  48
  49                         return false;
  50                 } else {
  51                         return true;
  52                 }
  53         }
  54
  55         public function mustRender( $file ) {
  56                 return true;
  57         }
  58
  59         function isVectorized( $file ) {
  60                 return true;
  61         }
  62
  63         /**
  64          * @param File $file
  65          * @return bool
  66          */
  67         function isAnimatedImage( $file ) {
  68                 # @todo Detect animated SVGs
  69                 $metadata = $file->getMetadata();
  70                 if ( $metadata ) {
  71                         $metadata = $this->unpackMetadata( $metadata );
  72                         if ( isset( $metadata['animated'] ) ) {
  73                                 return $metadata['animated'];
  74                         }
  75                 }
  76
  77                 return false;
  78         }
  79
  80         /**
  81          * Which languages (systemLanguage attribute) is supported.
  82          *
  83          * @note This list is not guaranteed to be exhaustive.
  84          * To avoid OOM errors, we only look at first bit of a file.
  85          * Thus all languages on this list are present in the file,
  86          * but its possible for the file to have a language not on
  87          * this list.
  88          *
  89          * @param File $file
  90          * @return array Array of language codes, or empty if no language switching supported.
  91          */
  92         public function getAvailableLanguages( File $file ) {
  93                 $metadata = $file->getMetadata();
  94                 $langList = [];
  95                 if ( $metadata ) {
  96                         $metadata = $this->unpackMetadata( $metadata );
  97                         if ( isset( $metadata['translations'] ) ) {
  98                                 foreach ( $metadata['translations'] as $lang => $langType ) {
  99                                         if ( $langType === SVGReader::LANG_FULL_MATCH ) {
 100                                                 $langList[] = $lang;
 101                                         }
 102                                 }
 103                         }
 104                 }
 105                 return $langList;
 106         }
 107
 108         /**
 109          * What language to render file in if none selected.
 110          *
 111          * @param File $file
 112          * @return string Language code.
 113          */
 114         public function getDefaultRenderLanguage( File $file ) {
 115                 return 'en';
 116         }
 117
 118         /**
 119          * We do not support making animated svg thumbnails
 120          * @param File $file
 121          * @return bool
 122          */
 123         function canAnimateThumbnail( $file ) {
 124                 return false;
 125         }
 126
 127         /**
 128          * @param File $image
 129          * @param array $params
 130          * @return bool
 131          */
 132         function normaliseParams( $image, &$params ) {
 133                 global $wgSVGMaxSize;
 134                 if ( !parent::normaliseParams( $image, $params ) ) {
 135                         return false;
 136                 }
 137                 # Don't make an image bigger than wgMaxSVGSize on the smaller side
 138                 if ( $params['physicalWidth'] <= $params['physicalHeight'] ) {
 139                         if ( $params['physicalWidth'] > $wgSVGMaxSize ) {
 140                                 $srcWidth = $image->getWidth( $params['page'] );
 141                                 $srcHeight = $image->getHeight( $params['page'] );
 142                                 $params['physicalWidth'] = $wgSVGMaxSize;
 143                                 $params['physicalHeight'] = File::scaleHeight( $srcWidth, $srcHeight, $wgSVGMaxSize );
 144                         }
 145                 } else {
 146                         if ( $params['physicalHeight'] > $wgSVGMaxSize ) {
 147                                 $srcWidth = $image->getWidth( $params['page'] );
 148                                 $srcHeight = $image->getHeight( $params['page'] );
 149                                 $params['physicalWidth'] = File::scaleHeight( $srcHeight, $srcWidth, $wgSVGMaxSize );
 150                                 $params['physicalHeight'] = $wgSVGMaxSize;
 151                         }
 152                 }
 153
 154                 return true;
 155         }
 156
 157         /**
 158          * @param File $image
 159          * @param string $dstPath
 160          * @param string $dstUrl
 161          * @param array $params
 162          * @param int $flags
 163          * @return bool|MediaTransformError|ThumbnailImage|TransformParameterError
 164          */
 165         function doTransform( $image, $dstPath, $dstUrl, $params, $flags = 0 ) {
 166                 if ( !$this->normaliseParams( $image, $params ) ) {
 167                         return new TransformParameterError( $params );
 168                 }
 169                 $clientWidth = $params['width'];
 170                 $clientHeight = $params['height'];
 171                 $physicalWidth = $params['physicalWidth'];
 172                 $physicalHeight = $params['physicalHeight'];
 173                 $lang = isset( $params['lang'] ) ? $params['lang'] : $this->getDefaultRenderLanguage( $image );
 174
 175                 if ( $flags & self::TRANSFORM_LATER ) {
 176                         return new ThumbnailImage( $image, $dstUrl, $dstPath, $params );
 177                 }
 178
 179                 $metadata = $this->unpackMetadata( $image->getMetadata() );
 180                 if ( isset( $metadata['error'] ) ) { // sanity check
 181                         $err = wfMessage( 'svg-long-error', $metadata['error']['message'] )->text();
 182
 183                         return new MediaTransformError( 'thumbnail_error', $clientWidth, $clientHeight, $err );
 184                 }
 185
 186                 if ( !wfMkdirParents( dirname( $dstPath ), null, __METHOD__ ) ) {
 187                         return new MediaTransformError( 'thumbnail_error', $clientWidth, $clientHeight,
 188                                 wfMessage( 'thumbnail_dest_directory' )->text() );
 189                 }
 190
 191                 $srcPath = $image->getLocalRefPath();
 192                 if ( $srcPath === false ) { // Failed to get local copy
 193                         wfDebugLog( 'thumbnail',
 194                                 sprintf( 'Thumbnail failed on %s: could not get local copy of "%s"',
 195                                         wfHostname(), $image->getName() ) );
 196
 197                         return new MediaTransformError( 'thumbnail_error',
 198                                 $params['width'], $params['height'],
 199                                 wfMessage( 'filemissing' )->text()
 200                         );
 201                 }
 202
 203                 // Make a temp dir with a symlink to the local copy in it.
 204                 // This plays well with rsvg-convert policy for external entities.
 205                 // https://git.gnome.org/browse/librsvg/commit/?id=f01aded72c38f0e18bc7ff67dee800e380251c8e
 206                 $tmpDir = wfTempDir() . '/svg_' . wfRandomString( 24 );
 207                 $lnPath = "$tmpDir/" . basename( $srcPath );
 208                 $ok = mkdir( $tmpDir, 0771 ) && symlink( $srcPath, $lnPath );
 209                 /** @noinspection PhpUnusedLocalVariableInspection */
 210                 $cleaner = new ScopedCallback( function () use ( $tmpDir, $lnPath ) {
 211                         MediaWiki\suppressWarnings();
 212                         unlink( $lnPath );
 213                         rmdir( $tmpDir );
 214                         MediaWiki\restoreWarnings();
 215                 } );
 216                 if ( !$ok ) {
 217                         wfDebugLog( 'thumbnail',
 218                                 sprintf( 'Thumbnail failed on %s: could not link %s to %s',
 219                                         wfHostname(), $lnPath, $srcPath ) );
 220                         return new MediaTransformError( 'thumbnail_error',
 221                                 $params['width'], $params['height'],
 222                                 wfMessage( 'thumbnail-temp-create' )->text()
 223                         );
 224                 }
 225
 226                 $status = $this->rasterize( $lnPath, $dstPath, $physicalWidth, $physicalHeight, $lang );
 227                 if ( $status === true ) {
 228                         return new ThumbnailImage( $image, $dstUrl, $dstPath, $params );
 229                 } else {
 230                         return $status; // MediaTransformError
 231                 }
 232         }
 233
 234         /**
 235          * Transform an SVG file to PNG
 236          * This function can be called outside of thumbnail contexts
 237          * @param string $srcPath
 238          * @param string $dstPath
 239          * @param string $width
 240          * @param string $height
 241          * @param bool|string $lang Language code of the language to render the SVG in
 242          * @throws MWException
 243          * @return bool|MediaTransformError
 244          */
 245         public function rasterize( $srcPath, $dstPath, $width, $height, $lang = false ) {
 246                 global $wgSVGConverters, $wgSVGConverter, $wgSVGConverterPath;
 247                 $err = false;
 248                 $retval = '';
 249                 if ( isset( $wgSVGConverters[$wgSVGConverter] ) ) {
 250                         if ( is_array( $wgSVGConverters[$wgSVGConverter] ) ) {
 251                                 // This is a PHP callable
 252                                 $func = $wgSVGConverters[$wgSVGConverter][0];
 253                                 $args = array_merge( [ $srcPath, $dstPath, $width, $height, $lang ],
 254                                         array_slice( $wgSVGConverters[$wgSVGConverter], 1 ) );
 255                                 if ( !is_callable( $func ) ) {
 256                                         throw new MWException( "$func is not callable" );
 257                                 }
 258                                 $err = call_user_func_array( $func, $args );
 259                                 $retval = (bool)$err;
 260                         } else {
 261                                 // External command
 262                                 $cmd = str_replace(
 263                                         [ '$path/', '$width', '$height', '$input', '$output' ],
 264                                         [ $wgSVGConverterPath ? wfEscapeShellArg( "$wgSVGConverterPath/" ) : "",
 265                                                 intval( $width ),
 266                                                 intval( $height ),
 267                                                 wfEscapeShellArg( $srcPath ),
 268                                                 wfEscapeShellArg( $dstPath ) ],
 269                                         $wgSVGConverters[$wgSVGConverter]
 270                                 );
 271
 272                                 $env = [];
 273                                 if ( $lang !== false ) {
 274                                         $env['LANG'] = $lang;
 275                                 }
 276
 277                                 wfDebug( __METHOD__ . ": $cmd\n" );
 278                                 $err = wfShellExecWithStderr( $cmd, $retval, $env );
 279                         }
 280                 }
 281                 $removed = $this->removeBadFile( $dstPath, $retval );
 282                 if ( $retval != 0 || $removed ) {
 283                         $this->logErrorForExternalProcess( $retval, $err, $cmd );
 284                         return new MediaTransformError( 'thumbnail_error', $width, $height, $err );
 285                 }
 286
 287                 return true;
 288         }
 289
 290         public static function rasterizeImagickExt( $srcPath, $dstPath, $width, $height ) {
 291                 $im = new Imagick( $srcPath );
 292                 $im->setImageFormat( 'png' );
 293                 $im->setBackgroundColor( 'transparent' );
 294                 $im->setImageDepth( 8 );
 295
 296                 if ( !$im->thumbnailImage( intval( $width ), intval( $height ), /* fit */ false ) ) {
 297                         return 'Could not resize image';
 298                 }
 299                 if ( !$im->writeImage( $dstPath ) ) {
 300                         return "Could not write to $dstPath";
 301                 }
 302         }
 303
 304         /**
 305          * @param File|FSFile $file
 306          * @param string $path Unused
 307          * @param bool|array $metadata
 308          * @return array
 309          */
 310         function getImageSize( $file, $path, $metadata = false ) {
 311                 if ( $metadata === false && $file instanceof File ) {
 312                         $metadata = $file->getMetadata();
 313                 }
 314                 $metadata = $this->unpackMetadata( $metadata );
 315
 316                 if ( isset( $metadata['width'] ) && isset( $metadata['height'] ) ) {
 317                         return [ $metadata['width'], $metadata['height'], 'SVG',
 318                                 "width=\"{$metadata['width']}\" height=\"{$metadata['height']}\"" ];
 319                 } else { // error
 320                         return [ 0, 0, 'SVG', "width=\"0\" height=\"0\"" ];
 321                 }
 322         }
 323
 324         function getThumbType( $ext, $mime, $params = null ) {
 325                 return [ 'png', 'image/png' ];
 326         }
 327
 328         /**
 329          * Subtitle for the image. Different from the base
 330          * class so it can be denoted that SVG's have
 331          * a "nominal" resolution, and not a fixed one,
 332          * as well as so animation can be denoted.
 333          *
 334          * @param File $file
 335          * @return string
 336          */
 337         function getLongDesc( $file ) {
 338                 global $wgLang;
 339
 340                 $metadata = $this->unpackMetadata( $file->getMetadata() );
 341                 if ( isset( $metadata['error'] ) ) {
 342                         return wfMessage( 'svg-long-error', $metadata['error']['message'] )->text();
 343                 }
 344
 345                 $size = $wgLang->formatSize( $file->getSize() );
 346
 347                 if ( $this->isAnimatedImage( $file ) ) {
 348                         $msg = wfMessage( 'svg-long-desc-animated' );
 349                 } else {
 350                         $msg = wfMessage( 'svg-long-desc' );
 351                 }
 352
 353                 $msg->numParams( $file->getWidth(), $file->getHeight() )->params( $size );
 354
 355                 return $msg->parse();
 356         }
 357
 358         /**
 359          * @param File|FSFile $file
 360          * @param string $filename
 361          * @return string Serialised metadata
 362          */
 363         function getMetadata( $file, $filename ) {
 364                 $metadata = [ 'version' => self::SVG_METADATA_VERSION ];
 365                 try {
 366                         $metadata += SVGMetadataExtractor::getMetadata( $filename );
 367                 } catch ( Exception $e ) { // @todo SVG specific exceptions
 368                         // File not found, broken, etc.
 369                         $metadata['error'] = [
 370                                 'message' => $e->getMessage(),
 371                                 'code' => $e->getCode()
 372                         ];
 373                         wfDebug( __METHOD__ . ': ' . $e->getMessage() . "\n" );
 374                 }
 375
 376                 return serialize( $metadata );
 377         }
 378
 379         function unpackMetadata( $metadata ) {
 380                 MediaWiki\suppressWarnings();
 381                 $unser = unserialize( $metadata );
 382                 MediaWiki\restoreWarnings();
 383                 if ( isset( $unser['version'] ) && $unser['version'] == self::SVG_METADATA_VERSION ) {
 384                         return $unser;
 385                 } else {
 386                         return false;
 387                 }
 388         }
 389
 390         function getMetadataType( $image ) {
 391                 return 'parsed-svg';
 392         }
 393
 394         function isMetadataValid( $image, $metadata ) {
 395                 $meta = $this->unpackMetadata( $metadata );
 396                 if ( $meta === false ) {
 397                         return self::METADATA_BAD;
 398                 }
 399                 if ( !isset( $meta['originalWidth'] ) ) {
 400                         // Old but compatible
 401                         return self::METADATA_COMPATIBLE;
 402                 }
 403
 404                 return self::METADATA_GOOD;
 405         }
 406
 407         protected function visibleMetadataFields() {
 408                 $fields = [ 'objectname', 'imagedescription' ];
 409
 410                 return $fields;
 411         }
 412
 413         /**
 414          * @param File $file
 415          * @param bool|IContextSource $context Context to use (optional)
 416          * @return array|bool
 417          */
 418         function formatMetadata( $file, $context = false ) {
 419                 $result = [
 420                         'visible' => [],
 421                         'collapsed' => []
 422                 ];
 423                 $metadata = $file->getMetadata();
 424                 if ( !$metadata ) {
 425                         return false;
 426                 }
 427                 $metadata = $this->unpackMetadata( $metadata );
 428                 if ( !$metadata || isset( $metadata['error'] ) ) {
 429                         return false;
 430                 }
 431
 432                 /* @todo Add a formatter
 433                 $format = new FormatSVG( $metadata );
 434                 $formatted = $format->getFormattedData();
 435                 */
 436
 437                 // Sort fields into visible and collapsed
 438                 $visibleFields = $this->visibleMetadataFields();
 439
 440                 $showMeta = false;
 441                 foreach ( $metadata as $name => $value ) {
 442                         $tag = strtolower( $name );
 443                         if ( isset( self::$metaConversion[$tag] ) ) {
 444                                 $tag = strtolower( self::$metaConversion[$tag] );
 445                         } else {
 446                                 // Do not output other metadata not in list
 447                                 continue;
 448                         }
 449                         $showMeta = true;
 450                         self::addMeta( $result,
 451                                 in_array( $tag, $visibleFields ) ? 'visible' : 'collapsed',
 452                                 'exif',
 453                                 $tag,
 454                                 $value
 455                         );
 456                 }
 457
 458                 return $showMeta ? $result : false;
 459         }
 460
 461         /**
 462          * @param string $name Parameter name
 463          * @param mixed $value Parameter value
 464          * @return bool Validity
 465          */
 466         public function validateParam( $name, $value ) {
 467                 if ( in_array( $name, [ 'width', 'height' ] ) ) {
 468                         // Reject negative heights, widths
 469                         return ( $value > 0 );
 470                 } elseif ( $name == 'lang' ) {
 471                         // Validate $code
 472                         if ( $value === '' || !Language::isValidBuiltInCode( $value ) ) {
 473                                 wfDebug( "Invalid user language code\n" );
 474
 475                                 return false;
 476                         }
 477
 478                         return true;
 479                 }
 480
 481                 // Only lang, width and height are acceptable keys
 482                 return false;
 483         }
 484
 485         /**
 486          * @param array $params Name=>value pairs of parameters
 487          * @return string Filename to use
 488          */
 489         public function makeParamString( $params ) {
 490                 $lang = '';
 491                 if ( isset( $params['lang'] ) && $params['lang'] !== 'en' ) {
 492                         $params['lang'] = strtolower( $params['lang'] );
 493                         $lang = "lang{$params['lang']}-";
 494                 }
 495                 if ( !isset( $params['width'] ) ) {
 496                         return false;
 497                 }
 498
 499                 return "$lang{$params['width']}px";
 500         }
 501
 502         public function parseParamString( $str ) {
 503                 $m = false;
 504                 if ( preg_match( '/^lang([a-z]+(?:-[a-z]+)*)-(\d+)px$/', $str, $m ) ) {
 505                         return [ 'width' => array_pop( $m ), 'lang' => $m[1] ];
 506                 } elseif ( preg_match( '/^(\d+)px$/', $str, $m ) ) {
 507                         return [ 'width' => $m[1], 'lang' => 'en' ];
 508                 } else {
 509                         return false;
 510                 }
 511         }
 512
 513         public function getParamMap() {
 514                 return [ 'img_lang' => 'lang', 'img_width' => 'width' ];
 515         }
 516
 517         /**
 518          * @param array $params
 519          * @return array
 520          */
 521         function getScriptParams( $params ) {
 522                 $scriptParams = [ 'width' => $params['width'] ];
 523                 if ( isset( $params['lang'] ) ) {
 524                         $scriptParams['lang'] = $params['lang'];
 525                 }
 526
 527                 return $scriptParams;
 528         }
 529
 530         public function getCommonMetaArray( File $file ) {
 531                 $metadata = $file->getMetadata();
 532                 if ( !$metadata ) {
 533                         return [];
 534                 }
 535                 $metadata = $this->unpackMetadata( $metadata );
 536                 if ( !$metadata || isset( $metadata['error'] ) ) {
 537                         return [];
 538                 }
 539                 $stdMetadata = [];
 540                 foreach ( $metadata as $name => $value ) {
 541                         $tag = strtolower( $name );
 542                         if ( $tag === 'originalwidth' || $tag === 'originalheight' ) {
 543                                 // Skip these. In the exif metadata stuff, it is assumed these
 544                                 // are measured in px, which is not the case here.
 545                                 continue;
 546                         }
 547                         if ( isset( self::$metaConversion[$tag] ) ) {
 548                                 $tag = self::$metaConversion[$tag];
 549                                 $stdMetadata[$tag] = $value;
 550                         }
 551                 }
 552
 553                 return $stdMetadata;
 554         }
 555 }