includes/media/Generic.php

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