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