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