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 = array(
  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         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 = array();
  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                 $cleaner = new ScopedCallback( function () use ( $tmpDir, $lnPath ) {
 209                         MediaWiki\suppressWarnings();
 210                         unlink( $lnPath );
 211                         rmdir( $tmpDir );
 212                         MediaWiki\restoreWarnings();
 213                 } );
 214                 if ( !$ok ) {
 215                         wfDebugLog( 'thumbnail',
 216                                 sprintf( 'Thumbnail failed on %s: could not link %s to %s',
 217                                         wfHostname(), $lnPath, $srcPath ) );
 218                         return new MediaTransformError( 'thumbnail_error',
 219                                 $params['width'], $params['height'],
 220                                 wfMessage( 'thumbnail-temp-create' )->text()
 221                         );
 222                 }
 223
 224                 $status = $this->rasterize( $lnPath, $dstPath, $physicalWidth, $physicalHeight, $lang );
 225                 if ( $status === true ) {
 226                         return new ThumbnailImage( $image, $dstUrl, $dstPath, $params );
 227                 } else {
 228                         return $status; // MediaTransformError
 229                 }
 230         }
 231
 232         /**
 233          * Transform an SVG file to PNG
 234          * This function can be called outside of thumbnail contexts
 235          * @param string $srcPath
 236          * @param string $dstPath
 237          * @param string $width
 238          * @param string $height
 239          * @param bool|string $lang Language code of the language to render the SVG in
 240          * @throws MWException
 241          * @return bool|MediaTransformError
 242          */
 243         public function rasterize( $srcPath, $dstPath, $width, $height, $lang = false ) {
 244                 global $wgSVGConverters, $wgSVGConverter, $wgSVGConverterPath;
 245                 $err = false;
 246                 $retval = '';
 247                 if ( isset( $wgSVGConverters[$wgSVGConverter] ) ) {
 248                         if ( is_array( $wgSVGConverters[$wgSVGConverter] ) ) {
 249                                 // This is a PHP callable
 250                                 $func = $wgSVGConverters[$wgSVGConverter][0];
 251                                 $args = array_merge( array( $srcPath, $dstPath, $width, $height, $lang ),
 252                                         array_slice( $wgSVGConverters[$wgSVGConverter], 1 ) );
 253                                 if ( !is_callable( $func ) ) {
 254                                         throw new MWException( "$func is not callable" );
 255                                 }
 256                                 $err = call_user_func_array( $func, $args );
 257                                 $retval = (bool)$err;
 258                         } else {
 259                                 // External command
 260                                 $cmd = str_replace(
 261                                         array( '$path/', '$width', '$height', '$input', '$output' ),
 262                                         array( $wgSVGConverterPath ? wfEscapeShellArg( "$wgSVGConverterPath/" ) : "",
 263                                                 intval( $width ),
 264                                                 intval( $height ),
 265                                                 wfEscapeShellArg( $srcPath ),
 266                                                 wfEscapeShellArg( $dstPath ) ),
 267                                         $wgSVGConverters[$wgSVGConverter]
 268                                 );
 269
 270                                 $env = array();
 271                                 if ( $lang !== false ) {
 272                                         $env['LANG'] = $lang;
 273                                 }
 274
 275                                 wfDebug( __METHOD__ . ": $cmd\n" );
 276                                 $err = wfShellExecWithStderr( $cmd, $retval, $env );
 277                         }
 278                 }
 279                 $removed = $this->removeBadFile( $dstPath, $retval );
 280                 if ( $retval != 0 || $removed ) {
 281                         $this->logErrorForExternalProcess( $retval, $err, $cmd );
 282                         return new MediaTransformError( 'thumbnail_error', $width, $height, $err );
 283                 }
 284
 285                 return true;
 286         }
 287
 288         public static function rasterizeImagickExt( $srcPath, $dstPath, $width, $height ) {
 289                 $im = new Imagick( $srcPath );
 290                 $im->setImageFormat( 'png' );
 291                 $im->setBackgroundColor( 'transparent' );
 292                 $im->setImageDepth( 8 );
 293
 294                 if ( !$im->thumbnailImage( intval( $width ), intval( $height ), /* fit */ false ) ) {
 295                         return 'Could not resize image';
 296                 }
 297                 if ( !$im->writeImage( $dstPath ) ) {
 298                         return "Could not write to $dstPath";
 299                 }
 300         }
 301
 302         /**
 303          * @param File $file
 304          * @param string $path Unused
 305          * @param bool|array $metadata
 306          * @return array
 307          */
 308         function getImageSize( $file, $path, $metadata = false ) {
 309                 if ( $metadata === false ) {
 310                         $metadata = $file->getMetadata();
 311                 }
 312                 $metadata = $this->unpackMetadata( $metadata );
 313
 314                 if ( isset( $metadata['width'] ) && isset( $metadata['height'] ) ) {
 315                         return array( $metadata['width'], $metadata['height'], 'SVG',
 316                                 "width=\"{$metadata['width']}\" height=\"{$metadata['height']}\"" );
 317                 } else { // error
 318                         return array( 0, 0, 'SVG', "width=\"0\" height=\"0\"" );
 319                 }
 320         }
 321
 322         function getThumbType( $ext, $mime, $params = null ) {
 323                 return array( 'png', 'image/png' );
 324         }
 325
 326         /**
 327          * Subtitle for the image. Different from the base
 328          * class so it can be denoted that SVG's have
 329          * a "nominal" resolution, and not a fixed one,
 330          * as well as so animation can be denoted.
 331          *
 332          * @param File $file
 333          * @return string
 334          */
 335         function getLongDesc( $file ) {
 336                 global $wgLang;
 337
 338                 $metadata = $this->unpackMetadata( $file->getMetadata() );
 339                 if ( isset( $metadata['error'] ) ) {
 340                         return wfMessage( 'svg-long-error', $metadata['error']['message'] )->text();
 341                 }
 342
 343                 $size = $wgLang->formatSize( $file->getSize() );
 344
 345                 if ( $this->isAnimatedImage( $file ) ) {
 346                         $msg = wfMessage( 'svg-long-desc-animated' );
 347                 } else {
 348                         $msg = wfMessage( 'svg-long-desc' );
 349                 }
 350
 351                 $msg->numParams( $file->getWidth(), $file->getHeight() )->params( $size );
 352
 353                 return $msg->parse();
 354         }
 355
 356         /**
 357          * @param File $file
 358          * @param string $filename
 359          * @return string Serialised metadata
 360          */
 361         function getMetadata( $file, $filename ) {
 362                 $metadata = array( 'version' => self::SVG_METADATA_VERSION );
 363                 try {
 364                         $metadata += SVGMetadataExtractor::getMetadata( $filename );
 365                 } catch ( Exception $e ) { // @todo SVG specific exceptions
 366                         // File not found, broken, etc.
 367                         $metadata['error'] = array(
 368                                 'message' => $e->getMessage(),
 369                                 'code' => $e->getCode()
 370                         );
 371                         wfDebug( __METHOD__ . ': ' . $e->getMessage() . "\n" );
 372                 }
 373
 374                 return serialize( $metadata );
 375         }
 376
 377         function unpackMetadata( $metadata ) {
 378                 MediaWiki\suppressWarnings();
 379                 $unser = unserialize( $metadata );
 380                 MediaWiki\restoreWarnings();
 381                 if ( isset( $unser['version'] ) && $unser['version'] == self::SVG_METADATA_VERSION ) {
 382                         return $unser;
 383                 } else {
 384                         return false;
 385                 }
 386         }
 387
 388         function getMetadataType( $image ) {
 389                 return 'parsed-svg';
 390         }
 391
 392         function isMetadataValid( $image, $metadata ) {
 393                 $meta = $this->unpackMetadata( $metadata );
 394                 if ( $meta === false ) {
 395                         return self::METADATA_BAD;
 396                 }
 397                 if ( !isset( $meta['originalWidth'] ) ) {
 398                         // Old but compatible
 399                         return self::METADATA_COMPATIBLE;
 400                 }
 401
 402                 return self::METADATA_GOOD;
 403         }
 404
 405         protected function visibleMetadataFields() {
 406                 $fields = array( 'objectname', 'imagedescription' );
 407
 408                 return $fields;
 409         }
 410
 411         /**
 412          * @param File $file
 413          * @param bool|IContextSource $context Context to use (optional)
 414          * @return array|bool
 415          */
 416         function formatMetadata( $file, $context = false ) {
 417                 $result = array(
 418                         'visible' => array(),
 419                         'collapsed' => array()
 420                 );
 421                 $metadata = $file->getMetadata();
 422                 if ( !$metadata ) {
 423                         return false;
 424                 }
 425                 $metadata = $this->unpackMetadata( $metadata );
 426                 if ( !$metadata || isset( $metadata['error'] ) ) {
 427                         return false;
 428                 }
 429
 430                 /* @todo Add a formatter
 431                 $format = new FormatSVG( $metadata );
 432                 $formatted = $format->getFormattedData();
 433                 */
 434
 435                 // Sort fields into visible and collapsed
 436                 $visibleFields = $this->visibleMetadataFields();
 437
 438                 $showMeta = false;
 439                 foreach ( $metadata as $name => $value ) {
 440                         $tag = strtolower( $name );
 441                         if ( isset( self::$metaConversion[$tag] ) ) {
 442                                 $tag = strtolower( self::$metaConversion[$tag] );
 443                         } else {
 444                                 // Do not output other metadata not in list
 445                                 continue;
 446                         }
 447                         $showMeta = true;
 448                         self::addMeta( $result,
 449                                 in_array( $tag, $visibleFields ) ? 'visible' : 'collapsed',
 450                                 'exif',
 451                                 $tag,
 452                                 $value
 453                         );
 454                 }
 455
 456                 return $showMeta ? $result : false;
 457         }
 458
 459         /**
 460          * @param string $name Parameter name
 461          * @param mixed $value Parameter value
 462          * @return bool Validity
 463          */
 464         function validateParam( $name, $value ) {
 465                 if ( in_array( $name, array( 'width', 'height' ) ) ) {
 466                         // Reject negative heights, widths
 467                         return ( $value > 0 );
 468                 } elseif ( $name == 'lang' ) {
 469                         // Validate $code
 470                         if ( $value === '' || !Language::isValidBuiltinCode( $value ) ) {
 471                                 wfDebug( "Invalid user language code\n" );
 472
 473                                 return false;
 474                         }
 475
 476                         return true;
 477                 }
 478
 479                 // Only lang, width and height are acceptable keys
 480                 return false;
 481         }
 482
 483         /**
 484          * @param array $params Name=>value pairs of parameters
 485          * @return string Filename to use
 486          */
 487         function makeParamString( $params ) {
 488                 $lang = '';
 489                 if ( isset( $params['lang'] ) && $params['lang'] !== 'en' ) {
 490                         $params['lang'] = strtolower( $params['lang'] );
 491                         $lang = "lang{$params['lang']}-";
 492                 }
 493                 if ( !isset( $params['width'] ) ) {
 494                         return false;
 495                 }
 496
 497                 return "$lang{$params['width']}px";
 498         }
 499
 500         function parseParamString( $str ) {
 501                 $m = false;
 502                 if ( preg_match( '/^lang([a-z]+(?:-[a-z]+)*)-(\d+)px$/', $str, $m ) ) {
 503                         return array( 'width' => array_pop( $m ), 'lang' => $m[1] );
 504                 } elseif ( preg_match( '/^(\d+)px$/', $str, $m ) ) {
 505                         return array( 'width' => $m[1], 'lang' => 'en' );
 506                 } else {
 507                         return false;
 508                 }
 509         }
 510
 511         function getParamMap() {
 512                 return array( 'img_lang' => 'lang', 'img_width' => 'width' );
 513         }
 514
 515         /**
 516          * @param array $params
 517          * @return array
 518          */
 519         function getScriptParams( $params ) {
 520                 $scriptParams = array( 'width' => $params['width'] );
 521                 if ( isset( $params['lang'] ) ) {
 522                         $scriptParams['lang'] = $params['lang'];
 523                 }
 524
 525                 return $scriptParams;
 526         }
 527
 528         public function getCommonMetaArray( File $file ) {
 529                 $metadata = $file->getMetadata();
 530                 if ( !$metadata ) {
 531                         return array();
 532                 }
 533                 $metadata = $this->unpackMetadata( $metadata );
 534                 if ( !$metadata || isset( $metadata['error'] ) ) {
 535                         return array();
 536                 }
 537                 $stdMetadata = array();
 538                 foreach ( $metadata as $name => $value ) {
 539                         $tag = strtolower( $name );
 540                         if ( $tag === 'originalwidth' || $tag === 'originalheight' ) {
 541                                 // Skip these. In the exif metadata stuff, it is assumed these
 542                                 // are measured in px, which is not the case here.
 543                                 continue;
 544                         }
 545                         if ( isset( self::$metaConversion[$tag] ) ) {
 546                                 $tag = self::$metaConversion[$tag];
 547                                 $stdMetadata[$tag] = $value;
 548                         }
 549                 }
 550
 551                 return $stdMetadata;
 552         }
 553 }