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          * False if the handler is disabled for all files
 166          */
 167         function isEnabled() { return true; }
 168
 169         /**
 170          * Get an associative array of page dimensions
 171          * Currently "width" and "height" are understood, but this might be
 172          * expanded in the future.
 173          * Returns false if unknown or if the document is not multi-page.
 174          */
 175         function getPageDimensions( $image, $page ) {
 176                 $gis = $this->getImageSize( $image, $image->getPath() );
 177                 return array(
 178                         'width' => $gis[0],
 179                         'height' => $gis[1]
 180                 );
 181         }
 182
 183         /**
 184          * Generic getter for text layer.
 185          * Currently overloaded by PDF and DjVu handlers
 186          */
 187         function getPageText( $image, $page ) {
 188                 return false;
 189         }
 190
 191         /**
 192          * Get an array structure that looks like this:
 193          *
 194          * array(
 195          *    'visible' => array(
 196          *       'Human-readable name' => 'Human readable value',
 197          *       ...
 198          *    ),
 199          *    'collapsed' => array(
 200          *       'Human-readable name' => 'Human readable value',
 201          *       ...
 202          *    )
 203          * )
 204          * The UI will format this into a table where the visible fields are always
 205          * visible, and the collapsed fields are optionally visible.
 206          *
 207          * The function should return false if there is no metadata to display.
 208          */
 209
 210         /**
 211          * FIXME: I don't really like this interface, it's not very flexible
 212          * I think the media handler should generate HTML instead. It can do
 213          * all the formatting according to some standard. That makes it possible
 214          * to do things like visual indication of grouped and chained streams
 215          * in ogg container files.
 216          */
 217         function formatMetadata( $image ) {
 218                 return false;
 219         }
 220
 221         /**
 222          * @todo Fixme: document this!
 223          * 'value' thingy goes into a wikitext table; it used to be escaped but
 224          * that was incompatible with previous practice of customized display
 225          * with wikitext formatting via messages such as 'exif-model-value'.
 226          * So the escaping is taken back out, but generally this seems a confusing
 227          * interface.
 228          */
 229         protected static function addMeta( &$array, $visibility, $type, $id, $value, $param = false ) {
 230                 $array[$visibility][] = array(
 231                         'id' => "$type-$id",
 232                         'name' => wfMsg( "$type-$id", $param ),
 233                         'value' => $value
 234                 );
 235         }
 236
 237         function getShortDesc( $file ) {
 238                 global $wgLang;
 239                 $nbytes = '(' . wfMsgExt( 'nbytes', array( 'parsemag', 'escape' ),
 240                         $wgLang->formatNum( $file->getSize() ) ) . ')';
 241                 return "$nbytes";
 242         }
 243
 244         function getLongDesc( $file ) {
 245                 global $wgUser;
 246                 $sk = $wgUser->getSkin();
 247                 return wfMsgExt( 'file-info', 'parseinline',
 248                         $sk->formatSize( $file->getSize() ),
 249                         $file->getMimeType() );
 250         }
 251
 252         static function getGeneralShortDesc( $file ) {
 253                 global $wgLang;
 254                 $nbytes = '(' . wfMsgExt( 'nbytes', array( 'parsemag', 'escape' ),
 255                         $wgLang->formatNum( $file->getSize() ) ) . ')';
 256                 return "$nbytes";
 257         }
 258
 259         static function getGeneralLongDesc( $file ) {
 260                 global $wgUser;
 261                 $sk = $wgUser->getSkin();
 262                 return wfMsgExt( 'file-info', 'parseinline',
 263                         $sk->formatSize( $file->getSize() ),
 264                         $file->getMimeType() );
 265         }
 266
 267         function getDimensionsString( $file ) {
 268                 return '';
 269         }
 270
 271         /**
 272          * Modify the parser object post-transform
 273          */
 274         function parserTransformHook( $parser, $file ) {}
 275
 276         /**
 277          * Check for zero-sized thumbnails. These can be generated when
 278          * no disk space is available or some other error occurs
 279          *
 280          * @param $dstPath The location of the suspect file
 281          * @param $retval Return value of some shell process, file will be deleted if this is non-zero
 282          * @return true if removed, false otherwise
 283          */
 284         function removeBadFile( $dstPath, $retval = 0 ) {
 285                 if( file_exists( $dstPath ) ) {
 286                         $thumbstat = stat( $dstPath );
 287                         if( $thumbstat['size'] == 0 || $retval != 0 ) {
 288                                 wfDebugLog( 'thumbnail',
 289                                         sprintf( 'Removing bad %d-byte thumbnail "%s"',
 290                                                 $thumbstat['size'], $dstPath ) );
 291                                 unlink( $dstPath );
 292                                 return true;
 293                         }
 294                 }
 295                 return false;
 296         }
 297 }
 298
 299 /**
 300  * Media handler abstract base class for images
 301  *
 302  * @ingroup Media
 303  */
 304 abstract class ImageHandler extends MediaHandler {
 305         function canRender( $file ) {
 306                 if ( $file->getWidth() && $file->getHeight() ) {
 307                         return true;
 308                 } else {
 309                         return false;
 310                 }
 311         }
 312
 313         function getParamMap() {
 314                 return array( 'img_width' => 'width' );
 315         }
 316
 317         function validateParam( $name, $value ) {
 318                 if ( in_array( $name, array( 'width', 'height' ) ) ) {
 319                         if ( $value <= 0 ) {
 320                                 return false;
 321                         } else {
 322                                 return true;
 323                         }
 324                 } else {
 325                         return false;
 326                 }
 327         }
 328
 329         function makeParamString( $params ) {
 330                 if ( isset( $params['physicalWidth'] ) ) {
 331                         $width = $params['physicalWidth'];
 332                 } elseif ( isset( $params['width'] ) ) {
 333                         $width = $params['width'];
 334                 } else {
 335                         throw new MWException( 'No width specified to '.__METHOD__ );
 336                 }
 337                 # Removed for ProofreadPage
 338                 #$width = intval( $width );
 339                 return "{$width}px";
 340         }
 341
 342         function parseParamString( $str ) {
 343                 $m = false;
 344                 if ( preg_match( '/^(\d+)px$/', $str, $m ) ) {
 345                         return array( 'width' => $m[1] );
 346                 } else {
 347                         return false;
 348                 }
 349         }
 350
 351         function getScriptParams( $params ) {
 352                 return array( 'width' => $params['width'] );
 353         }
 354
 355         function normaliseParams( $image, &$params ) {
 356                 $mimeType = $image->getMimeType();
 357
 358                 if ( !isset( $params['width'] ) ) {
 359                         return false;
 360                 }
 361
 362                 if ( !isset( $params['page'] ) ) {
 363                         $params['page'] = 1;
 364                 } else  {
 365                         if ( $params['page'] > $image->pageCount() ) {
 366                                 $params['page'] = $image->pageCount();
 367                         }
 368
 369                         if ( $params['page'] < 1 ) {
 370                                 $params['page'] = 1;
 371                         }
 372                 }
 373
 374                 $srcWidth = $image->getWidth( $params['page'] );
 375                 $srcHeight = $image->getHeight( $params['page'] );
 376                 if ( isset( $params['height'] ) && $params['height'] != -1 ) {
 377                         if ( $params['width'] * $srcHeight > $params['height'] * $srcWidth ) {
 378                                 $params['width'] = wfFitBoxWidth( $srcWidth, $srcHeight, $params['height'] );
 379                         }
 380                 }
 381                 $params['height'] = File::scaleHeight( $srcWidth, $srcHeight, $params['width'] );
 382                 if ( !$this->validateThumbParams( $params['width'], $params['height'], $srcWidth, $srcHeight, $mimeType ) ) {
 383                         return false;
 384                 }
 385                 return true;
 386         }
 387
 388         /**
 389          * Get a transform output object without actually doing the transform
 390          */
 391         function getTransform( $image, $dstPath, $dstUrl, $params ) {
 392                 return $this->doTransform( $image, $dstPath, $dstUrl, $params, self::TRANSFORM_LATER );
 393         }
 394
 395         /**
 396          * Validate thumbnail parameters and fill in the correct height
 397          *
 398          * @param $width Integer: specified width (input/output)
 399          * @param $height Integer: height (output only)
 400          * @param $srcWidth Integer: width of the source image
 401          * @param $srcHeight Integer: height of the source image
 402          * @param $mimeType Unused
 403          * @return false to indicate that an error should be returned to the user.
 404          */
 405         function validateThumbParams( &$width, &$height, $srcWidth, $srcHeight, $mimeType ) {
 406                 $width = intval( $width );
 407
 408                 # Sanity check $width
 409                 if( $width <= 0) {
 410                         wfDebug( __METHOD__.": Invalid destination width: $width\n" );
 411                         return false;
 412                 }
 413                 if ( $srcWidth <= 0 ) {
 414                         wfDebug( __METHOD__.": Invalid source width: $srcWidth\n" );
 415                         return false;
 416                 }
 417
 418                 $height = File::scaleHeight( $srcWidth, $srcHeight, $width );
 419                 return true;
 420         }
 421
 422         function getScriptedTransform( $image, $script, $params ) {
 423                 if ( !$this->normaliseParams( $image, $params ) ) {
 424                         return false;
 425                 }
 426                 $url = $script . '&' . wfArrayToCGI( $this->getScriptParams( $params ) );
 427                 $page = isset( $params['page'] ) ? $params['page'] : false;
 428
 429                 if( $image->mustRender() || $params['width'] < $image->getWidth() ) {
 430                         return new ThumbnailImage( $image, $url, $params['width'], $params['height'], $page );
 431                 }
 432         }
 433
 434         function getImageSize( $image, $path ) {
 435                 wfSuppressWarnings();
 436                 $gis = getimagesize( $path );
 437                 wfRestoreWarnings();
 438                 return $gis;
 439         }
 440
 441         function isAnimatedImage( $image ) {
 442                 return false;
 443         }
 444
 445         function getShortDesc( $file ) {
 446                 global $wgLang;
 447                 $nbytes = wfMsgExt( 'nbytes', array( 'parsemag', 'escape' ),
 448                         $wgLang->formatNum( $file->getSize() ) );
 449                 $widthheight = wfMsgHtml( 'widthheight', $wgLang->formatNum( $file->getWidth() ) ,$wgLang->formatNum( $file->getHeight() ) );
 450
 451                 return "$widthheight ($nbytes)";
 452         }
 453
 454         function getLongDesc( $file ) {
 455                 global $wgLang;
 456                 return wfMsgExt('file-info-size', 'parseinline',
 457                         $wgLang->formatNum( $file->getWidth() ),
 458                         $wgLang->formatNum( $file->getHeight() ),
 459                         $wgLang->formatSize( $file->getSize() ),
 460                         $file->getMimeType() );
 461         }
 462
 463         function getDimensionsString( $file ) {
 464                 global $wgLang;
 465                 $pages = $file->pageCount();
 466                 $width = $wgLang->formatNum( $file->getWidth() );
 467                 $height = $wgLang->formatNum( $file->getHeight() );
 468                 $pagesFmt = $wgLang->formatNum( $pages );
 469
 470                 if ( $pages > 1 ) {
 471                         return wfMsgExt( 'widthheightpage', 'parsemag', $width, $height, $pagesFmt );
 472                 } else {
 473                         return wfMsg( 'widthheight', $width, $height );
 474                 }
 475         }
 476 }