/*
XOWA: the XOWA Offline Wiki Application
Copyright (C) 2012-2017 gnosygnu@gmail.com
XOWA is licensed under the terms of the General Public License (GPL) Version 3,
or alternatively under the terms of the Apache License Version 2.0.
You may use XOWA according to either of these licenses as is most appropriate
for your project on a case-by-case basis.
The terms of each license can be found in the source code repository:
GPLv3 License: https://github.com/gnosygnu/xowa/blob/master/LICENSE-GPLv3.txt
Apache License: https://github.com/gnosygnu/xowa/blob/master/LICENSE-APACHE2.txt
*/
package gplx.xowa.mediawiki.includes.media; import gplx.*; import gplx.xowa.*; import gplx.xowa.mediawiki.*; import gplx.xowa.mediawiki.includes.*;
import gplx.xowa.mediawiki.includes.filerepo.file.*;
import gplx.xowa.mediawiki.includes.parsers.lnkis.*;
public abstract class XomwMediaHandler {
public byte[] Key() {return key;} private byte[] key;
public XomwMediaHandler(byte[] key) {
this.key = key;
}
private static final int TRANSFORM_LATER = 1;
// static final METADATA_GOOD = true;
// static final METADATA_BAD = false;
// static final METADATA_COMPATIBLE = 2; // for old but backwards compatible.
// /**
// * Max length of error logged by logErrorForExternalProcess()
// */
// static final MAX_ERR_LOG_SIZE = 65535;
//
// /**
// * Get a MediaHandler for a given MIME type from the instance cache
// *
// * @param String $type
// * @return MediaHandler|boolean
// */
// static function getHandler($type) {
// return MediaWikiServices::getInstance()
// ->getMediaHandlerFactory()->getHandler($type);
// }
/**
* Get an associative array mapping magic word IDs to parameter names.
* Will be used by the parser to identify parameters.
*/
public abstract Xomw_param_map 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 String $name
* @param mixed $value
*/
public abstract boolean validateParam(int name_uid, byte[] val_bry, int val_int);
/**
* Merge a parameter array into a String appropriate for inclusion in filenames
*
* @param array paramsVar Array of parameters that have been through normaliseParams.
* @return String
*/
public abstract byte[] makeParamString(Xomw_params_handler handlerParams);
// /**
// * Parse a param String made with makeParamString back into an array
// *
// * @param String $str The parameter String without file name (e.g. 122px)
// * @return array|boolean Array of parameters or false on failure.
// */
// abstract public function parseParamString($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 File $image
* @param array $paramsVar
*/
public abstract boolean normaliseParams(XomwFile image, Xomw_params_handler handlerParams);
// /**
// * Get an image size array like that returned by getimagesize(), or false if it
// * can't be determined.
// *
// * This function is used for determining the width, height and bitdepth directly
// * from an image. The results are stored in the database in the img_width,
// * img_height, img_bits fields.
// *
// * @note If this is a multipage file, return the width and height of the
// * first page.
// *
// * @param File|FSFile $image The image Object, or false if there isn't one.
// * Warning, FSFile::getPropsFromPath might pass an FSFile instead of File (!)
// * @param String $path The filename
// * @return array|boolean Follow the format of PHP getimagesize() @gplx.Internal protected function.
// * See https://secure.php.net/getimagesize. MediaWiki will only ever use the
// * first two array keys (the width and height), and the 'bits' associative
// * key. All other array keys are ignored. Returning a 'bits' key is optional
// * as not all formats have a notion of "bitdepth". Returns false on failure.
// */
// abstract function getImageSize($image, $path);
//
// /**
// * Get handler-specific metadata which will be saved in the img_metadata field.
// *
// * @param File|FSFile $image The image Object, or false if there isn't one.
// * Warning, FSFile::getPropsFromPath might pass an FSFile instead of File (!)
// * @param String $path The filename
// * @return String A String of metadata in php serialized form (Run through serialize())
// */
// function getMetadata($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 ForeignApiRepo 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() {
// $version = [ '2' ]; // core metadata version
// Hooks::run('GetMetadataVersion', [ &$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 String|array $metadata Metadata array (serialized if String)
// * @param int $version 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.
// MediaWiki\suppressWarnings();
// $ret = unserialize($metadata);
// MediaWiki\restoreWarnings();
//
// return $ret;
// }
//
// return $metadata;
// }
//
// /**
// * Get a String describing the type of metadata, for display purposes.
// *
// * @note This method is currently unused.
// * @param File $image
// * @return String
// */
// function getMetadataType($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,
// * MediaHandler::METADATA_COMPATIBLE if metadata is old but backwards
// * compatible (which may or may not trigger a metadata reload).
// *
// * @note Returning self::METADATA_BAD will trigger a metadata reload from
// * file on page view. Always returning this from a broken file, or suddenly
// * triggering as bad metadata for a large number of files can cause
// * performance problems.
// * @param File $image
// * @param String $metadata The metadata in serialized form
// * @return boolean
// */
// function isMetadataValid($image, $metadata) {
// return self::METADATA_GOOD;
// }
//
// /**
// * Get an array of standard (FormatMetadata type) metadata values.
// *
// * The returned data is largely the same as that from getMetadata(),
// * but formatted in a standard, stable, handler-independent way.
// * The idea being that some values like ImageDescription or Artist
// * are universal and should be retrievable in a handler generic way.
// *
// * The specific properties are the type of properties that can be
// * handled by the FormatMetadata class. These values are exposed to the
// * user via the filemetadata parser function.
// *
// * Details of the response format of this function can be found at
// * https://www.mediawiki.org/wiki/Manual:File_metadata_handling
// * tl/dr: the response is an associative array of
// * properties keyed by name, but the value can be complex. You probably
// * want to call one of the FormatMetadata::flatten* functions on the
// * property values before using them, or call
// * FormatMetadata::getFormattedData() on the full response array, which
// * transforms all values into prettified, human-readable text.
// *
// * Subclasses overriding this function must return a value which is a
// * valid API response fragment (all associative array keys are valid
// * XML tagnames).
// *
// * Note, if the file simply has no metadata, but the handler supports
// * this interface, it should return an empty array, not false.
// *
// * @param File $file
// * @return array|boolean False if interface not supported
// * @since 1.23
// */
// public function getCommonMetaArray(File $file) {
// return false;
// }
//
// /**
// * 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().
// * @param File $image
// * @param String $script
// * @param array $paramsVar
// * @return boolean|ThumbnailImage
// */
// function getScriptedTransform($image, $script, $paramsVar) {
// return false;
// }
/**
* Get a MediaTransformOutput Object representing the transformed output. Does not
* actually do the transform.
*
* @param File $image The image Object
* @param String $dstPath Filesystem destination path
* @param String $dstUrl Destination URL to use in output HTML
* @param array $paramsVar Arbitrary set of parameters validated by $this->validateParam()
* @return MediaTransformOutput
*/
public XomwMediaTransformOutput getTransform(XomwFile image, byte[] dstPath, byte[] dstUrl, Xomw_params_handler handlerParams) {
return this.doTransform(image, dstPath, dstUrl, handlerParams, TRANSFORM_LATER);
}
/**
* Get a MediaTransformOutput Object representing the transformed output. Does the
* transform unless $flags contains self::TRANSFORM_LATER.
*
* @param File $image The image Object
* @param String $dstPath Filesystem destination path
* @param String $dstUrl Destination URL to use in output HTML
* @param array $paramsVar Arbitrary set of parameters validated by $this->validateParam()
* Note: These parameters have *not* gone through $this->normaliseParams()
* @param int $flags A bitfield, may contain self::TRANSFORM_LATER
* @return MediaTransformOutput
*/
public XomwMediaTransformOutput doTransform(XomwFile image, byte[] dstPath, byte[] dstUrl, Xomw_params_handler handlerParams) {return doTransform(image, dstPath, dstUrl, handlerParams, 0);}
public abstract XomwMediaTransformOutput doTransform(XomwFile image, byte[] dstPath, byte[] dstUrl, Xomw_params_handler handlerParams, int flags);
// /**
// * Get the thumbnail extension and MIME type for a given source MIME type
// *
// * @param String $ext Extension of original file
// * @param String $mime MIME type of original file
// * @param array $paramsVar Handler specific rendering parameters
// * @return array Thumbnail extension and MIME type
// */
// function getThumbType($ext, $mime, $paramsVar = 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 ($extensions) {
// return [ strtok($extensions, ' '), $mime ];
// }
// }
//
// // The extension is correct (true) or the MIME type is unknown to
// // MediaWiki (null)
// return [ $ext, $mime ];
// }
//
// /**
// * Get useful response headers for GET/HEAD requests for a file with the given metadata
// *
// * @param mixed $metadata Result of the getMetadata() function of this handler for a file
// * @return array
// */
// public function getStreamHeaders($metadata) {
// return [];
// }
/**
* True if the handled types can be transformed
*
* @param File $file
* @return boolean
*/
@gplx.Virtual public boolean canRender(XomwFile file) {
return true;
}
/**
* True if handled types cannot be displayed directly in a browser
* but can be rendered
*
* @param File $file
* @return boolean
*/
public boolean mustRender(XomwFile file) {
return false;
}
// /**
// * True if the type has multi-page capabilities
// *
// * @param File $file
// * @return boolean
// */
// public function isMultiPage($file) {
// return false;
// }
//
// /**
// * Page count for a multi-page document, false if unsupported or unknown
// *
// * @param File $file
// * @return boolean
// */
// function pageCount(File $file) {
// return false;
// }
//
// /**
// * The material is vectorized and thus scaling is lossless
// *
// * @param File $file
// * @return boolean
// */
// function isVectorized($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
// *
// * @param File $file
// * @return boolean
// */
// function isAnimatedImage($file) {
// return false;
// }
//
// /**
// * If the material is animated, we can animate the thumbnail
// * @since 1.20
// *
// * @param File $file
// * @return boolean If material is not animated, handler may return any value.
// */
// function canAnimateThumbnail($file) {
// return true;
// }
//
// /**
// * False if the handler is disabled for all files
// * @return boolean
// */
// 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.
// *
// * It is expected that handlers for paged media (e.g. DjVuHandler)
// * will override this method so that it gives the correct results
// * for each specific page of the file, using the $page argument.
// *
// * @note For non-paged media, use getImageSize.
// *
// * @param File $image
// * @param int $page What page to get dimensions of
// * @return array|boolean
// */
// function getPageDimensions(File $image, $page) {
// $gis = $this->getImageSize($image, $image->getLocalRefPath());
// if ($gis) {
// return [
// 'width' => $gis[0],
// 'height' => $gis[1]
// ];
// } else {
// return false;
// }
// }
//
// /**
// * Generic getter for text layer.
// * Currently overloaded by PDF and DjVu handlers
// * @param File $image
// * @param int $page Page number to get information for
// * @return boolean|String Page text or false when no text found or if
// * unsupported.
// */
// function getPageText(File $image, $page) {
// return false;
// }
//
// /**
// * Get the text of the entire document.
// * @param File $file
// * @return boolean|String The text of the document or false if unsupported.
// */
// public function getEntireText(File $file) {
// $numPages = $file->pageCount();
// if (!$numPages) {
// // Not a multipage document
// return $this->getPageText($file, 1);
// }
// $document = '';
// for ($i = 1; $i <= $numPages; $i++) {
// $curPage = $this->getPageText($file, $i);
// if (is_string($curPage)) {
// $document .= $curPage . "\n";
// }
// }
// if ($document !== '') {
// return $document;
// }
// return false;
// }
//
// /**
// * Get an array structure that looks like this:
// *
// * [
// * 'visible' => [
// * 'Human-readable name' => 'Human readable value',
// * ...
// * ],
// * 'collapsed' => [
// * '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: This interface is not very flexible. 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.
// * @param File $image
// * @param boolean|IContextSource $context Context to use (optional)
// * @return array|boolean
// */
// function formatMetadata($image, $context = false) {
// 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 array $metadataArray Metadata array
// * @param boolean|IContextSource $context Context to use (optional)
// * @return array Array for use displaying metadata.
// */
// function formatMetadataHelper($metadataArray, $context = false) {
// $result = [
// 'visible' => [],
// 'collapsed' => []
// ];
//
// $formatted = FormatMetadata::getFormattedData($metadataArray, $context);
// // 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 $result;
// }
//
// /**
// * Get a list of metadata items which should be displayed when
// * the metadata table is collapsed.
// *
// * @return array Array of strings
// */
// protected function visibleMetadataFields() {
// return FormatMetadata::getVisibleFields();
// }
//
// /**
// * This is used to generate an array element for each metadata value
// * That array is then used to generate the table of metadata values
// * on the image page
// *
// * @param array &$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 String $visibility ('visible' or 'collapsed') if this value is hidden
// * by default.
// * @param String $type Type of metadata tag (currently always 'exif')
// * @param String $id The name of the metadata tag (like 'artist' for example).
// * its name in the table displayed is the message "$type-$id" (Ex exif-artist).
// * @param String $value 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 boolean|String $param 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][] = [
// 'id' => "$type-$id",
// 'name' => $name,
// 'value' => $value
// ];
// }
//
// /**
// * Short description. Shown on Special:Search results.
// *
// * @param File $file
// * @return String
// */
// function getShortDesc($file) {
// return self::getGeneralShortDesc($file);
// }
//
// /**
// * Long description. Shown under image on image description page surounded by ().
// *
// * @param File $file
// * @return String
// */
// function getLongDesc($file) {
// return self::getGeneralLongDesc($file);
// }
//
// /**
// * Used instead of getShortDesc if there is no handler registered for file.
// *
// * @param File $file
// * @return String
// */
// static function getGeneralShortDesc($file) {
// global $wgLang;
//
// return htmlspecialchars($wgLang->formatSize($file->getSize()));
// }
//
// /**
// * Used instead of getLongDesc if there is no handler registered for file.
// *
// * @param File $file
// * @return String
// */
// static function getGeneralLongDesc($file) {
// return wfMessage('file-info')->sizeParams($file->getSize())
// ->paramsVar('<span class="mime-type">' . $file->getMimeType() . '</span>')->parse();
// }
/**
* Calculate the largest thumbnail width for a given original file size
* such that the thumbnail's height is at most $maxHeight.
* @param int $boxWidth Width of the thumbnail box.
* @param int $boxHeight Height of the thumbnail box.
* @param int $maxHeight Maximum height expected for the thumbnail.
* @return int
*/
public static int fitBoxWidth(int boxWidth, int boxHeight, int maxHeight) {
double idealWidth = boxWidth * maxHeight / boxHeight;
int roundedUp = Math_.Ceil_as_int(idealWidth);
if (Math_.Round(roundedUp * boxHeight / boxWidth, 0) > maxHeight) {
return Math_.Floor_as_int(idealWidth);
} else {
return roundedUp;
}
}
// /**
// * Shown in file history box on image description page.
// *
// * @param File $file
// * @return String Dimensions
// */
// function getDimensionsString($file) {
// return '';
// }
//
// /**
// * Modify the parser Object post-transform.
// *
// * This is often used to do $parser->addOutputHook(),
// * in order to add some javascript to render a viewer.
// * See TimedMediaHandler or OggHandler for an example.
// *
// * @param Parser $parser
// * @param File $file
// */
// function parserTransformHook($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 String $fileName The local path to the file.
// * @return Status
// */
// function verifyUpload($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 String $dstPath The location of the suspect file
// * @param int $retval Return value of some shell process, file will be deleted if this is non-zero
// * @return boolean True if removed, false otherwise
// */
// function removeBadFile($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.
// *
// * This is used by some video handlers to prevent ?action=purge
// * from removing a transcoded video, which is expensive to
// * regenerate.
// *
// * @see LocalFile::purgeThumbnails
// *
// * @param array $files
// * @param array $options Purge options. Currently will always be
// * an array with a single key 'forThumbRefresh' set to true.
// */
// public function filterThumbnailPurgeList(&$files, $options) {
// // Do nothing
// }
//
// /**
// * True if the handler can rotate the media
// * @since 1.24 non-static. From 1.21-1.23 was static
// * @return boolean
// */
// public function canRotate() {
// return false;
// }
//
// /**
// * On supporting image formats, try to read out the low-level orientation
// * of the file and return the angle that the file needs to be rotated to
// * be viewed.
// *
// * This information is only useful when manipulating the original file;
// * the width and height we normally work with is logical, and will match
// * any produced output views.
// *
// * For files we don't know, we return 0.
// *
// * @param File $file
// * @return int 0, 90, 180 or 270
// */
// public function getRotation($file) {
// return 0;
// }
//
// /**
// * Log an error that occurred in an external process
// *
// * Moved from BitmapHandler to MediaHandler with MediaWiki 1.23
// *
// * @since 1.23
// * @param int $retval
// * @param String $err Error reported by command. Anything longer than
// * MediaHandler::MAX_ERR_LOG_SIZE is stripped off.
// * @param String $cmd
// */
// protected function logErrorForExternalProcess($retval, $err, $cmd) {
// # Keep error output limited (bug 57985)
// $errMessage = trim(substr($err, 0, self::MAX_ERR_LOG_SIZE));
//
// wfDebugLog('thumbnail',
// sprintf('thumbnail failed on %s: error %d "%s" from "%s"',
// wfHostname(), $retval, $errMessage, $cmd));
// }
//
// /**
// * Get list of languages file can be viewed in.
// *
// * @param File $file
// * @return String[] Array of language codes, or empty array if unsupported.
// * @since 1.23
// */
// public function getAvailableLanguages(File $file) {
// return [];
// }
//
// /**
// * On file types that support renderings in multiple languages,
// * which language is used by default if unspecified.
// *
// * If getAvailableLanguages returns a non-empty array, this must return
// * a valid language code. Otherwise can return null if files of this
// * type do not support alternative language renderings.
// *
// * @param File $file
// * @return String|null Language code or null if multi-language not supported for filetype.
// * @since 1.23
// */
// public function getDefaultRenderLanguage(File $file) {
// return null;
// }
//
// /**
// * If its an audio file, return the length of the file. Otherwise 0.
// *
// * File::getLength() existed for a long time, but was calling a method
// * that only existed in some subclasses of this class (The TMH ones).
// *
// * @param File $file
// * @return float length in seconds
// * @since 1.23
// */
// public function getLength($file) {
// return 0.0;
// }
//
// /**
// * True if creating thumbnails from the file is large or otherwise resource-intensive.
// * @param File $file
// * @return boolean
// */
// public function isExpensiveToThumbnail($file) {
// return false;
// }
//
// /**
// * Returns whether or not this handler supports the chained generation of thumbnails according
// * to buckets
// * @return boolean
// * @since 1.24
// */
// public function supportsBucketing() {
// return false;
// }
//
// /**
// * Returns a normalised paramsVar array for which parameters have been cleaned up for bucketing
// * purposes
// * @param array $paramsVar
// * @return array
// */
// public function sanitizeParamsForBucketing($paramsVar) {
// return $paramsVar;
// }
//
// /**
// * Gets configuration for the file warning message. Return value of
// * the following structure:
// * [
// * // Required, module with messages loaded for the client
// * 'module' => 'example.filewarning.messages',
// * // Required, array of names of messages
// * 'messages' => [
// * // Required, main warning message
// * 'main' => 'example-filewarning-main',
// * // Optional, header for warning dialog
// * 'header' => 'example-filewarning-header',
// * // Optional, footer for warning dialog
// * 'footer' => 'example-filewarning-footer',
// * // Optional, text for more-information link (see below)
// * 'info' => 'example-filewarning-info',
// * ],
// * // Optional, link for more information
// * 'link' => 'http://example.com',
// * ]
// *
// * Returns null if no warning is necessary.
// * @param File $file
// * @return array|null
// */
// public function getWarningConfig($file) {
// return null;
// }
}