includes/media/Generic.php

   1 <?php
   2 /**
   3  * Media-handling base classes and generic functionality
   4  *
   5  * @file
   6  * @ingroup Media
   7  */
   8
   9 /**
  10  * Base media handler class
  11  *
  12  * @ingroup Media
  13  */
  14 abstract class MediaHandler {
  15         const TRANSFORM_LATER = 1;
  16
  17         /**
  18          * Instance cache
  19          */
  20         static $handlers = array();
  21
  22         /**
  23          * Get a MediaHandler for a given MIME type from the instance cache
  24          *
  25          * @return MediaHandler
  26          */
  27         static function getHandler( $type ) {
  28                 global $wgMediaHandlers;
  29                 if ( !isset( $wgMediaHandlers[$type] ) ) {
  30                         wfDebug( __METHOD__ . ": no handler found for $type.\n");
  31                         return false;
  32                 }
  33                 $class = $wgMediaHandlers[$type];
  34                 if ( !isset( self::$handlers[$class] ) ) {
  35                         self::$handlers[$class] = new $class;
  36                         if ( !self::$handlers[$class]->isEnabled() ) {
  37                                 self::$handlers[$class] = false;
  38                         }
  39                 }
  40                 return self::$handlers[$class];
  41         }
  42
  43         /**
  44          * Get an associative array mapping magic word IDs to parameter names.
  45          * Will be used by the parser to identify parameters.
  46          */
  47         abstract function getParamMap();
  48
  49         /*
  50          * Validate a thumbnail parameter at parse time.
  51          * Return true to accept the parameter, and false to reject it.
  52          * If you return false, the parser will do something quiet and forgiving.
  53          */
  54         abstract function validateParam( $name, $value );
  55
  56         /**
  57          * Merge a parameter array into a string appropriate for inclusion in filenames
  58          */
  59         abstract function makeParamString( $params );
  60
  61         /**
  62          * Parse a param string made with makeParamString back into an array
  63          */
  64         abstract function parseParamString( $str );
  65
  66         /**
  67          * Changes the parameter array as necessary, ready for transformation.
  68          * Should be idempotent.
  69          * Returns false if the parameters are unacceptable and the transform should fail
  70          */
  71         abstract function normaliseParams( $image, &$params );
  72
  73         /**
  74          * Get an image size array like that returned by getimagesize(), or false if it
  75          * can't be determined.
  76          *
  77          * @param $image File: the image object, or false if there isn't one
  78          * @param $path String: the filename
  79          * @return Array
  80          */
  81         abstract function getImageSize( $image, $path );
  82
  83         /**
  84          * Get handler-specific metadata which will be saved in the img_metadata field.
  85          *
  86          * @param $image File: the image object, or false if there isn't one
  87          * @param $path String: the filename
  88          * @return String
  89          */
  90         function getMetadata( $image, $path ) { return ''; }
  91
  92         /**
  93          * Get a string describing the type of metadata, for display purposes.
  94          */
  95         function getMetadataType( $image ) { return false; }
  96
  97         /**
  98          * Check if the metadata string is valid for this handler.
  99          * If it returns false, Image will reload the metadata from the file and update the database
 100          */
 101         function isMetadataValid( $image, $metadata ) { return true; }
 102
 103
 104         /**
 105          * Get a MediaTransformOutput object representing an alternate of the transformed
 106          * output which will call an intermediary thumbnail assist script.
 107          *
 108          * Used when the repository has a thumbnailScriptUrl option configured.
 109          *
 110          * Return false to fall back to the regular getTransform().
 111          */
 112         function getScriptedTransform( $image, $script, $params ) {
 113                 return false;
 114         }
 115
 116         /**
 117          * Get a MediaTransformOutput object representing the transformed output. Does not
 118          * actually do the transform.
 119          *
 120          * @param $image File: the image object
 121          * @param $dstPath String: filesystem destination path
 122          * @param $dstUrl String: Destination URL to use in output HTML
 123          * @param $params Array: Arbitrary set of parameters validated by $this->validateParam()
 124          */
 125         function getTransform( $image, $dstPath, $dstUrl, $params ) {
 126                 return $this->doTransform( $image, $dstPath, $dstUrl, $params, self::TRANSFORM_LATER );
 127         }
 128
 129         /**
 130          * Get a MediaTransformOutput object representing the transformed output. Does the
 131          * transform unless $flags contains self::TRANSFORM_LATER.
 132          *
 133          * @param $image File: the image object
 134          * @param $dstPath String: filesystem destination path
 135          * @param $dstUrl String: destination URL to use in output HTML
 136          * @param $params Array: arbitrary set of parameters validated by $this->validateParam()
 137          * @param $flags Integer: a bitfield, may contain self::TRANSFORM_LATER
 138          */
 139         abstract function doTransform( $image, $dstPath, $dstUrl, $params, $flags = 0 );
 140
 141         /**
 142          * Get the thumbnail extension and MIME type for a given source MIME type
 143          * @return array thumbnail extension and MIME type
 144          */
 145         function getThumbType( $ext, $mime, $params = null ) {
 146                 $magic = MimeMagic::singleton();
 147                 if ( !$ext || $magic->isMatchingExtension( $ext, $mime ) === false ) {
 148                         // The extension is not valid for this mime type and we do
 149                         // recognize the mime type
 150                         $extensions = $magic->getExtensionsForType( $mime );
 151                         if ( $extensions ) {
 152                                 return array( strtok( $extensions, ' ' ), $mime );
 153                         }
 154                 }
 155
 156                 // The extension is correct (true) or the mime type is unknown to
 157                 // MediaWiki (null)
 158                 return array( $ext, $mime );
 159         }
 160
 161         /**
 162          * True if the handled types can be transformed
 163          */
 164         function canRender( $file ) { return true; }
 165         /**
 166          * True if handled types cannot be displayed directly in a browser
 167          * but can be rendered
 168          */
 169         function mustRender( $file ) { return false; }
 170         /**
 171          * True if the type has multi-page capabilities
 172          */
 173         function isMultiPage( $file ) { return false; }
 174         /**
 175          * Page count for a multi-page document, false if unsupported or unknown
 176          */
 177         function pageCount( $file ) { return false; }
 178         /**
 179          * The material is vectorized and thus scaling is lossless
 180          */
 181         function isVectorized( $file ) { return false; }
 182         /**
 183          * False if the handler is disabled for all files
 184          */
 185         function isEnabled() { return true; }
 186
 187         /**
 188          * Get an associative array of page dimensions
 189          * Currently "width" and "height" are understood, but this might be
 190          * expanded in the future.
 191          * Returns false if unknown or if the document is not multi-page.
 192          *
 193          * @param $image File
 194          */
 195         function getPageDimensions( $image, $page ) {
 196                 $gis = $this->getImageSize( $image, $image->getPath() );
 197                 return array(
 198                         'width' => $gis[0],
 199                         'height' => $gis[1]
 200                 );
 201         }
 202
 203         /**
 204          * Generic getter for text layer.
 205          * Currently overloaded by PDF and DjVu handlers
 206          */
 207         function getPageText( $image, $page ) {
 208                 return false;
 209         }
 210
 211         /**
 212          * Get an array structure that looks like this:
 213          *
 214          * array(
 215          *    'visible' => array(
 216          *       'Human-readable name' => 'Human readable value',
 217          *       ...
 218          *    ),
 219          *    'collapsed' => array(
 220          *       'Human-readable name' => 'Human readable value',
 221          *       ...
 222          *    )
 223          * )
 224          * The UI will format this into a table where the visible fields are always
 225          * visible, and the collapsed fields are optionally visible.
 226          *
 227          * The function should return false if there is no metadata to display.
 228          */
 229
 230         /**
 231          * FIXME: I don't really like this interface, it's not very flexible
 232          * I think the media handler should generate HTML instead. It can do
 233          * all the formatting according to some standard. That makes it possible
 234          * to do things like visual indication of grouped and chained streams
 235          * in ogg container files.
 236          */
 237         function formatMetadata( $image ) {
 238                 return false;
 239         }
 240
 241         /**
 242          * @todo Fixme: document this!
 243          * 'value' thingy goes into a wikitext table; it used to be escaped but
 244          * that was incompatible with previous practice of customized display
 245          * with wikitext formatting via messages such as 'exif-model-value'.
 246          * So the escaping is taken back out, but generally this seems a confusing
 247          * interface.
 248          */
 249         protected static function addMeta( &$array, $visibility, $type, $id, $value, $param = false ) {
 250                 $array[$visibility][] = array(
 251                         'id' => "$type-$id",
 252                         'name' => wfMsg( "$type-$id", $param ),
 253                         'value' => $value
 254                 );
 255         }
 256
 257         /**
 258          * @param $file File
 259          * @return string
 260          */
 261         function getShortDesc( $file ) {
 262                 global $wgLang;
 263                 $nbytes = wfMsgExt( 'nbytes', array( 'parsemag', 'escape' ),
 264                         $wgLang->formatNum( $file->getSize() ) );
 265                 return "$nbytes";
 266         }
 267
 268         /**
 269          * @param $file File
 270          * @return string
 271          */
 272         function getLongDesc( $file ) {
 273                 global $wgUser;
 274                 $sk = $wgUser->getSkin();
 275                 return wfMsgExt( 'file-info', 'parseinline',
 276                         $sk->formatSize( $file->getSize() ),
 277                         $file->getMimeType() );
 278         }
 279
 280         /**
 281          * @param $file File
 282          * @return string
 283          */
 284         static function getGeneralShortDesc( $file ) {
 285                 global $wgLang;
 286                 $nbytes = wfMsgExt( 'nbytes', array( 'parsemag', 'escape' ),
 287                         $wgLang->formatNum( $file->getSize() ) );
 288                 return "$nbytes";
 289         }
 290
 291         /**
 292          * @param $file File
 293          * @return string
 294          */
 295         static function getGeneralLongDesc( $file ) {
 296                 global $wgUser;
 297                 $sk = $wgUser->getSkin();
 298                 return wfMsgExt( 'file-info', 'parseinline',
 299                         $sk->formatSize( $file->getSize() ),
 300                         $file->getMimeType() );
 301         }
 302
 303         function getDimensionsString( $file ) {
 304                 return '';
 305         }
 306
 307         /**
 308          * Modify the parser object post-transform
 309          */
 310         function parserTransformHook( $parser, $file ) {}
 311
 312         /**
 313          * File validation hook called on upload.
 314          *
 315          * If the file at the given local path is not valid, or its MIME type does not
 316          * match the handler class, a Status object should be returned containing
 317          * relevant errors.
 318          *
 319          * @param $fileName The local path to the file.
 320          * @return Status object
 321          */
 322         function verifyUpload( $fileName ) {
 323                 return Status::newGood();
 324         }
 325
 326         /**
 327          * Check for zero-sized thumbnails. These can be generated when
 328          * no disk space is available or some other error occurs
 329          *
 330          * @param $dstPath The location of the suspect file
 331          * @param $retval Return value of some shell process, file will be deleted if this is non-zero
 332          * @return true if removed, false otherwise
 333          */
 334         function removeBadFile( $dstPath, $retval = 0 ) {
 335                 if( file_exists( $dstPath ) ) {
 336                         $thumbstat = stat( $dstPath );
 337                         if( $thumbstat['size'] == 0 || $retval != 0 ) {
 338                                 wfDebugLog( 'thumbnail',
 339                                         sprintf( 'Removing bad %d-byte thumbnail "%s"',
 340                                                 $thumbstat['size'], $dstPath ) );
 341                                 unlink( $dstPath );
 342                                 return true;
 343                         }
 344                 }
 345                 return false;
 346         }
 347 }
 348
 349 /**
 350  * Media handler abstract base class for images
 351  *
 352  * @ingroup Media
 353  */
 354 abstract class ImageHandler extends MediaHandler {
 355
 356         /**
 357          * @param $file File
 358          * @return bool
 359          */
 360         function canRender( $file ) {
 361                 return ( $file->getWidth() && $file->getHeight() );
 362         }
 363
 364         function getParamMap() {
 365                 return array( 'img_width' => 'width' );
 366         }
 367
 368         function validateParam( $name, $value ) {
 369                 if ( in_array( $name, array( 'width', 'height' ) ) ) {
 370                         if ( $value <= 0 ) {
 371                                 return false;
 372                         } else {
 373                                 return true;
 374                         }
 375                 } else {
 376                         return false;
 377                 }
 378         }
 379
 380         function makeParamString( $params ) {
 381                 if ( isset( $params['physicalWidth'] ) ) {
 382                         $width = $params['physicalWidth'];
 383                 } elseif ( isset( $params['width'] ) ) {
 384                         $width = $params['width'];
 385                 } else {
 386                         throw new MWException( 'No width specified to '.__METHOD__ );
 387                 }
 388                 # Removed for ProofreadPage
 389                 #$width = intval( $width );
 390                 return "{$width}px";
 391         }
 392
 393         function parseParamString( $str ) {
 394                 $m = false;
 395                 if ( preg_match( '/^(\d+)px$/', $str, $m ) ) {
 396                         return array( 'width' => $m[1] );
 397                 } else {
 398                         return false;
 399                 }
 400         }
 401
 402         function getScriptParams( $params ) {
 403                 return array( 'width' => $params['width'] );
 404         }
 405
 406         /**
 407          * @param $image File
 408          * @param  $params
 409          * @return bool
 410          */
 411         function normaliseParams( $image, &$params ) {
 412                 $mimeType = $image->getMimeType();
 413
 414                 if ( !isset( $params['width'] ) ) {
 415                         return false;
 416                 }
 417
 418                 if ( !isset( $params['page'] ) ) {
 419                         $params['page'] = 1;
 420                 } else  {
 421                         if ( $params['page'] > $image->pageCount() ) {
 422                                 $params['page'] = $image->pageCount();
 423                         }
 424
 425                         if ( $params['page'] < 1 ) {
 426                                 $params['page'] = 1;
 427                         }
 428                 }
 429
 430                 $srcWidth = $image->getWidth( $params['page'] );
 431                 $srcHeight = $image->getHeight( $params['page'] );
 432                 if ( isset( $params['height'] ) && $params['height'] != -1 ) {
 433                         if ( $params['width'] * $srcHeight > $params['height'] * $srcWidth ) {
 434                                 $params['width'] = wfFitBoxWidth( $srcWidth, $srcHeight, $params['height'] );
 435                         }
 436                 }
 437                 $params['height'] = File::scaleHeight( $srcWidth, $srcHeight, $params['width'] );
 438                 if ( !$this->validateThumbParams( $params['width'], $params['height'], $srcWidth, $srcHeight, $mimeType ) ) {
 439                         return false;
 440                 }
 441                 return true;
 442         }
 443
 444         /**
 445          * Get a transform output object without actually doing the transform
 446          */
 447         function getTransform( $image, $dstPath, $dstUrl, $params ) {
 448                 return $this->doTransform( $image, $dstPath, $dstUrl, $params, self::TRANSFORM_LATER );
 449         }
 450
 451         /**
 452          * Validate thumbnail parameters and fill in the correct height
 453          *
 454          * @param $width Integer: specified width (input/output)
 455          * @param $height Integer: height (output only)
 456          * @param $srcWidth Integer: width of the source image
 457          * @param $srcHeight Integer: height of the source image
 458          * @param $mimeType Unused
 459          * @return false to indicate that an error should be returned to the user.
 460          */
 461         function validateThumbParams( &$width, &$height, $srcWidth, $srcHeight, $mimeType ) {
 462                 $width = intval( $width );
 463
 464                 # Sanity check $width
 465                 if( $width <= 0) {
 466                         wfDebug( __METHOD__.": Invalid destination width: $width\n" );
 467                         return false;
 468                 }
 469                 if ( $srcWidth <= 0 ) {
 470                         wfDebug( __METHOD__.": Invalid source width: $srcWidth\n" );
 471                         return false;
 472                 }
 473
 474                 $height = File::scaleHeight( $srcWidth, $srcHeight, $width );
 475                 return true;
 476         }
 477
 478         /**
 479          * @param $image File
 480          * @param  $script
 481          * @param  $params
 482          * @return bool|ThumbnailImage
 483          */
 484         function getScriptedTransform( $image, $script, $params ) {
 485                 if ( !$this->normaliseParams( $image, $params ) ) {
 486                         return false;
 487                 }
 488                 $url = $script . '&' . wfArrayToCGI( $this->getScriptParams( $params ) );
 489                 $page = isset( $params['page'] ) ? $params['page'] : false;
 490
 491                 if( $image->mustRender() || $params['width'] < $image->getWidth() ) {
 492                         return new ThumbnailImage( $image, $url, $params['width'], $params['height'], $page );
 493                 }
 494         }
 495
 496         function getImageSize( $image, $path ) {
 497                 wfSuppressWarnings();
 498                 $gis = getimagesize( $path );
 499                 wfRestoreWarnings();
 500                 return $gis;
 501         }
 502
 503         function isAnimatedImage( $image ) {
 504                 return false;
 505         }
 506
 507         /**
 508          * @param $file File
 509          * @return string
 510          */
 511         function getShortDesc( $file ) {
 512                 global $wgLang;
 513                 $nbytes = wfMsgExt( 'nbytes', array( 'parsemag', 'escape' ),
 514                         $wgLang->formatNum( $file->getSize() ) );
 515                 $widthheight = wfMsgHtml( 'widthheight', $wgLang->formatNum( $file->getWidth() ) ,$wgLang->formatNum( $file->getHeight() ) );
 516
 517                 return "$widthheight ($nbytes)";
 518         }
 519
 520         /**
 521          * @param $file File
 522          * @return string
 523          */
 524         function getLongDesc( $file ) {
 525                 global $wgLang;
 526                 return wfMsgExt('file-info-size', 'parseinline',
 527                         $wgLang->formatNum( $file->getWidth() ),
 528                         $wgLang->formatNum( $file->getHeight() ),
 529                         $wgLang->formatSize( $file->getSize() ),
 530                         $file->getMimeType() );
 531         }
 532
 533         /**
 534          * @param $file File
 535          * @return string
 536          */
 537         function getDimensionsString( $file ) {
 538                 global $wgLang;
 539                 $pages = $file->pageCount();
 540                 $width = $wgLang->formatNum( $file->getWidth() );
 541                 $height = $wgLang->formatNum( $file->getHeight() );
 542                 $pagesFmt = $wgLang->formatNum( $pages );
 543
 544                 if ( $pages > 1 ) {
 545                         return wfMsgExt( 'widthheightpage', 'parsemag', $width, $height, $pagesFmt );
 546                 } else {
 547                         return wfMsg( 'widthheight', $width, $height );
 548                 }
 549         }
 550 }