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Diffstat (limited to 'includes/media/MediaHandler.php')
| -rw-r--r-- | includes/media/MediaHandler.php | 560 |
1 files changed, 560 insertions, 0 deletions
diff --git a/includes/media/MediaHandler.php b/includes/media/MediaHandler.php new file mode 100644 index 00000000..965099fd --- /dev/null +++ b/includes/media/MediaHandler.php @@ -0,0 +1,560 @@ +<?php +/** + * Media-handling base classes and generic functionality. + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; either version 2 of the License, or + * (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License along + * with this program; if not, write to the Free Software Foundation, Inc., + * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA. + * http://www.gnu.org/copyleft/gpl.html + * + * @file + * @ingroup Media + */ + +/** + * Base media handler class + * + * @ingroup Media + */ +abstract class MediaHandler { + const TRANSFORM_LATER = 1; + const METADATA_GOOD = true; + const METADATA_BAD = false; + const METADATA_COMPATIBLE = 2; // for old but backwards compatible. + /** + * Instance cache + */ + static $handlers = array(); + + /** + * Get a MediaHandler for a given MIME type from the instance cache + * + * @param $type string + * + * @return MediaHandler + */ + static function getHandler( $type ) { + global $wgMediaHandlers; + if ( !isset( $wgMediaHandlers[$type] ) ) { + wfDebug( __METHOD__ . ": no handler found for $type.\n"); + return false; + } + $class = $wgMediaHandlers[$type]; + if ( !isset( self::$handlers[$class] ) ) { + self::$handlers[$class] = new $class; + if ( !self::$handlers[$class]->isEnabled() ) { + self::$handlers[$class] = false; + } + } + return self::$handlers[$class]; + } + + /** + * Get an associative array mapping magic word IDs to parameter names. + * Will be used by the parser to identify parameters. + */ + abstract function getParamMap(); + + /** + * Validate a thumbnail parameter at parse time. + * Return true to accept the parameter, and false to reject it. + * If you return false, the parser will do something quiet and forgiving. + * + * @param $name + * @param $value + */ + abstract function validateParam( $name, $value ); + + /** + * Merge a parameter array into a string appropriate for inclusion in filenames + * + * @param $params array + */ + abstract function makeParamString( $params ); + + /** + * Parse a param string made with makeParamString back into an array + * + * @param $str string + */ + abstract function parseParamString( $str ); + + /** + * Changes the parameter array as necessary, ready for transformation. + * Should be idempotent. + * Returns false if the parameters are unacceptable and the transform should fail + * @param $image + * @param $params + */ + abstract function normaliseParams( $image, &$params ); + + /** + * Get an image size array like that returned by getimagesize(), or false if it + * can't be determined. + * + * @param $image File: the image object, or false if there isn't one + * @param $path String: the filename + * @return Array Follow the format of PHP getimagesize() internal function. See http://www.php.net/getimagesize + */ + abstract function getImageSize( $image, $path ); + + /** + * Get handler-specific metadata which will be saved in the img_metadata field. + * + * @param $image File: the image object, or false if there isn't one. + * Warning, FSFile::getPropsFromPath might pass an (object)array() instead (!) + * @param $path String: the filename + * @return String + */ + function getMetadata( $image, $path ) { return ''; } + + /** + * Get metadata version. + * + * This is not used for validating metadata, this is used for the api when returning + * metadata, since api content formats should stay the same over time, and so things + * using ForiegnApiRepo can keep backwards compatibility + * + * All core media handlers share a common version number, and extensions can + * use the GetMetadataVersion hook to append to the array (they should append a unique + * string so not to get confusing). If there was a media handler named 'foo' with metadata + * version 3 it might add to the end of the array the element 'foo=3'. if the core metadata + * version is 2, the end version string would look like '2;foo=3'. + * + * @return string version string + */ + static function getMetadataVersion () { + $version = Array( '2' ); // core metadata version + wfRunHooks('GetMetadataVersion', Array(&$version)); + return implode( ';', $version); + } + + /** + * Convert metadata version. + * + * By default just returns $metadata, but can be used to allow + * media handlers to convert between metadata versions. + * + * @param $metadata Mixed String or Array metadata array (serialized if string) + * @param $version Integer target version + * @return Array serialized metadata in specified version, or $metadata on fail. + */ + function convertMetadataVersion( $metadata, $version = 1 ) { + if ( !is_array( $metadata ) ) { + + //unserialize to keep return parameter consistent. + wfSuppressWarnings(); + $ret = unserialize( $metadata ); + wfRestoreWarnings(); + return $ret; + } + return $metadata; + } + + /** + * Get a string describing the type of metadata, for display purposes. + * + * @return string + */ + function getMetadataType( $image ) { return false; } + + /** + * Check if the metadata string is valid for this handler. + * If it returns MediaHandler::METADATA_BAD (or false), Image + * will reload the metadata from the file and update the database. + * MediaHandler::METADATA_GOOD for if the metadata is a-ok, + * MediaHanlder::METADATA_COMPATIBLE if metadata is old but backwards + * compatible (which may or may not trigger a metadata reload). + * @return bool + */ + function isMetadataValid( $image, $metadata ) { + return self::METADATA_GOOD; + } + + + /** + * Get a MediaTransformOutput object representing an alternate of the transformed + * output which will call an intermediary thumbnail assist script. + * + * Used when the repository has a thumbnailScriptUrl option configured. + * + * Return false to fall back to the regular getTransform(). + * @return bool + */ + function getScriptedTransform( $image, $script, $params ) { + return false; + } + + /** + * Get a MediaTransformOutput object representing the transformed output. Does not + * actually do the transform. + * + * @param $image File: the image object + * @param $dstPath String: filesystem destination path + * @param $dstUrl String: Destination URL to use in output HTML + * @param $params Array: Arbitrary set of parameters validated by $this->validateParam() + * @return MediaTransformOutput + */ + final function getTransform( $image, $dstPath, $dstUrl, $params ) { + return $this->doTransform( $image, $dstPath, $dstUrl, $params, self::TRANSFORM_LATER ); + } + + /** + * Get a MediaTransformOutput object representing the transformed output. Does the + * transform unless $flags contains self::TRANSFORM_LATER. + * + * @param $image File: the image object + * @param $dstPath String: filesystem destination path + * @param $dstUrl String: destination URL to use in output HTML + * @param $params Array: arbitrary set of parameters validated by $this->validateParam() + * @param $flags Integer: a bitfield, may contain self::TRANSFORM_LATER + * + * @return MediaTransformOutput + */ + abstract function doTransform( $image, $dstPath, $dstUrl, $params, $flags = 0 ); + + /** + * Get the thumbnail extension and MIME type for a given source MIME type + * @return array thumbnail extension and MIME type + */ + function getThumbType( $ext, $mime, $params = null ) { + $magic = MimeMagic::singleton(); + if ( !$ext || $magic->isMatchingExtension( $ext, $mime ) === false ) { + // The extension is not valid for this mime type and we do + // recognize the mime type + $extensions = $magic->getExtensionsForType( $mime ); + if ( $extensions ) { + return array( strtok( $extensions, ' ' ), $mime ); + } + } + + // The extension is correct (true) or the mime type is unknown to + // MediaWiki (null) + return array( $ext, $mime ); + } + + /** + * True if the handled types can be transformed + * @return bool + */ + function canRender( $file ) { return true; } + /** + * True if handled types cannot be displayed directly in a browser + * but can be rendered + * @return bool + */ + function mustRender( $file ) { return false; } + /** + * True if the type has multi-page capabilities + * @return bool + */ + function isMultiPage( $file ) { return false; } + /** + * Page count for a multi-page document, false if unsupported or unknown + * @return bool + */ + function pageCount( $file ) { return false; } + /** + * The material is vectorized and thus scaling is lossless + * @return bool + */ + function isVectorized( $file ) { return false; } + /** + * The material is an image, and is animated. + * In particular, video material need not return true. + * @note Before 1.20, this was a method of ImageHandler only + * @return bool + */ + function isAnimatedImage( $file ) { return false; } + /** + * If the material is animated, we can animate the thumbnail + * @since 1.20 + * @return bool If material is not animated, handler may return any value. + */ + function canAnimateThumbnail( $file ) { return true; } + /** + * False if the handler is disabled for all files + * @return bool + */ + function isEnabled() { return true; } + + /** + * Get an associative array of page dimensions + * Currently "width" and "height" are understood, but this might be + * expanded in the future. + * Returns false if unknown or if the document is not multi-page. + * + * @param $image File + * @param $page Unused, left for backcompatibility? + * @return array + */ + function getPageDimensions( $image, $page ) { + $gis = $this->getImageSize( $image, $image->getLocalRefPath() ); + return array( + 'width' => $gis[0], + 'height' => $gis[1] + ); + } + + /** + * Generic getter for text layer. + * Currently overloaded by PDF and DjVu handlers + * @return bool + */ + function getPageText( $image, $page ) { + return false; + } + + /** + * Get an array structure that looks like this: + * + * array( + * 'visible' => array( + * 'Human-readable name' => 'Human readable value', + * ... + * ), + * 'collapsed' => array( + * 'Human-readable name' => 'Human readable value', + * ... + * ) + * ) + * The UI will format this into a table where the visible fields are always + * visible, and the collapsed fields are optionally visible. + * + * The function should return false if there is no metadata to display. + */ + + /** + * @todo FIXME: I don't really like this interface, it's not very flexible + * I think the media handler should generate HTML instead. It can do + * all the formatting according to some standard. That makes it possible + * to do things like visual indication of grouped and chained streams + * in ogg container files. + * @return bool + */ + function formatMetadata( $image ) { + return false; + } + + /** sorts the visible/invisible field. + * Split off from ImageHandler::formatMetadata, as used by more than + * one type of handler. + * + * This is used by the media handlers that use the FormatMetadata class + * + * @param $metadataArray Array metadata array + * @return array for use displaying metadata. + */ + function formatMetadataHelper( $metadataArray ) { + $result = array( + 'visible' => array(), + 'collapsed' => array() + ); + + $formatted = FormatMetadata::getFormattedData( $metadataArray ); + // Sort fields into visible and collapsed + $visibleFields = $this->visibleMetadataFields(); + foreach ( $formatted as $name => $value ) { + $tag = strtolower( $name ); + self::addMeta( $result, + in_array( $tag, $visibleFields ) ? 'visible' : 'collapsed', + 'exif', + $tag, + $value + ); + } + return $result; + } + + /** + * Get a list of metadata items which should be displayed when + * the metadata table is collapsed. + * + * @return array of strings + * @access protected + */ + function visibleMetadataFields() { + $fields = array(); + $lines = explode( "\n", wfMessage( 'metadata-fields' )->inContentLanguage()->text() ); + foreach( $lines as $line ) { + $matches = array(); + if( preg_match( '/^\\*\s*(.*?)\s*$/', $line, $matches ) ) { + $fields[] = $matches[1]; + } + } + $fields = array_map( 'strtolower', $fields ); + return $fields; + } + + + /** + * This is used to generate an array element for each metadata value + * That array is then used to generate the table of metadata values + * on the image page + * + * @param &$array Array An array containing elements for each type of visibility + * and each of those elements being an array of metadata items. This function adds + * a value to that array. + * @param $visibility string ('visible' or 'collapsed') if this value is hidden + * by default. + * @param $type String type of metadata tag (currently always 'exif') + * @param $id String the name of the metadata tag (like 'artist' for example). + * its name in the table displayed is the message "$type-$id" (Ex exif-artist ). + * @param $value String thingy goes into a wikitext table; it used to be escaped but + * that was incompatible with previous practise of customized display + * with wikitext formatting via messages such as 'exif-model-value'. + * So the escaping is taken back out, but generally this seems a confusing + * interface. + * @param $param String value to pass to the message for the name of the field + * as $1. Currently this parameter doesn't seem to ever be used. + * + * Note, everything here is passed through the parser later on (!) + */ + protected static function addMeta( &$array, $visibility, $type, $id, $value, $param = false ) { + $msg = wfMessage( "$type-$id", $param ); + if ( $msg->exists() ) { + $name = $msg->text(); + } else { + // This is for future compatibility when using instant commons. + // So as to not display as ugly a name if a new metadata + // property is defined that we don't know about + // (not a major issue since such a property would be collapsed + // by default). + wfDebug( __METHOD__ . ' Unknown metadata name: ' . $id . "\n" ); + $name = wfEscapeWikiText( $id ); + } + $array[$visibility][] = array( + 'id' => "$type-$id", + 'name' => $name, + 'value' => $value + ); + } + + /** + * @param $file File + * @return string + */ + function getShortDesc( $file ) { + global $wgLang; + return htmlspecialchars( $wgLang->formatSize( $file->getSize() ) ); + } + + /** + * @param $file File + * @return string + */ + function getLongDesc( $file ) { + global $wgLang; + return wfMessage( 'file-info', htmlspecialchars( $wgLang->formatSize( $file->getSize() ) ), + $file->getMimeType() )->parse(); + } + + /** + * @param $file File + * @return string + */ + static function getGeneralShortDesc( $file ) { + global $wgLang; + return $wgLang->formatSize( $file->getSize() ); + } + + /** + * @param $file File + * @return string + */ + static function getGeneralLongDesc( $file ) { + global $wgLang; + return wfMessage( 'file-info', $wgLang->formatSize( $file->getSize() ), + $file->getMimeType() )->parse(); + } + + /** + * Calculate the largest thumbnail width for a given original file size + * such that the thumbnail's height is at most $maxHeight. + * @param $boxWidth Integer Width of the thumbnail box. + * @param $boxHeight Integer Height of the thumbnail box. + * @param $maxHeight Integer Maximum height expected for the thumbnail. + * @return Integer. + */ + public static function fitBoxWidth( $boxWidth, $boxHeight, $maxHeight ) { + $idealWidth = $boxWidth * $maxHeight / $boxHeight; + $roundedUp = ceil( $idealWidth ); + if( round( $roundedUp * $boxHeight / $boxWidth ) > $maxHeight ) { + return floor( $idealWidth ); + } else { + return $roundedUp; + } + } + + function getDimensionsString( $file ) { + return ''; + } + + /** + * Modify the parser object post-transform + */ + function parserTransformHook( $parser, $file ) {} + + /** + * File validation hook called on upload. + * + * If the file at the given local path is not valid, or its MIME type does not + * match the handler class, a Status object should be returned containing + * relevant errors. + * + * @param $fileName string The local path to the file. + * @return Status object + */ + function verifyUpload( $fileName ) { + return Status::newGood(); + } + + /** + * Check for zero-sized thumbnails. These can be generated when + * no disk space is available or some other error occurs + * + * @param $dstPath string The location of the suspect file + * @param $retval int Return value of some shell process, file will be deleted if this is non-zero + * @return bool True if removed, false otherwise + */ + function removeBadFile( $dstPath, $retval = 0 ) { + if( file_exists( $dstPath ) ) { + $thumbstat = stat( $dstPath ); + if( $thumbstat['size'] == 0 || $retval != 0 ) { + $result = unlink( $dstPath ); + + if ( $result ) { + wfDebugLog( 'thumbnail', + sprintf( 'Removing bad %d-byte thumbnail "%s". unlink() succeeded', + $thumbstat['size'], $dstPath ) ); + } else { + wfDebugLog( 'thumbnail', + sprintf( 'Removing bad %d-byte thumbnail "%s". unlink() failed', + $thumbstat['size'], $dstPath ) ); + } + return true; + } + } + return false; + } + + /** + * Remove files from the purge list + * + * @param array $files + * @param array $options + */ + public function filterThumbnailPurgeList( &$files, $options ) { + // Do nothing + } +} |