includes/media/Generic.php

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