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