3 * Base class for handlers which require transforming images in a
4 * similar way as BitmapHandler does.
6 * This was split from BitmapHandler on the basis that some extensions
7 * might want to work in a similar way to BitmapHandler, but for
10 * This program is free software; you can redistribute it and/or modify
11 * it under the terms of the GNU General Public License as published by
12 * the Free Software Foundation; either version 2 of the License, or
13 * (at your option) any later version.
15 * This program is distributed in the hope that it will be useful,
16 * but WITHOUT ANY WARRANTY; without even the implied warranty of
17 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
18 * GNU General Public License for more details.
20 * You should have received a copy of the GNU General Public License along
21 * with this program; if not, write to the Free Software Foundation, Inc.,
22 * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
23 * http://www.gnu.org/copyleft/gpl.html
30 * Handler for images that need to be transformed
35 abstract class TransformationalImageHandler
extends ImageHandler
{
38 * @param array $params Transform parameters. Entries with the keys 'width'
39 * and 'height' are the respective screen width and height, while the keys
40 * 'physicalWidth' and 'physicalHeight' indicate the thumbnail dimensions.
43 function normaliseParams( $image, &$params ) {
44 if ( !parent
::normaliseParams( $image, $params ) ) {
48 # Obtain the source, pre-rotation dimensions
49 $srcWidth = $image->getWidth( $params['page'] );
50 $srcHeight = $image->getHeight( $params['page'] );
52 # Don't make an image bigger than the source
53 if ( $params['physicalWidth'] >= $srcWidth ) {
54 $params['physicalWidth'] = $srcWidth;
55 $params['physicalHeight'] = $srcHeight;
57 # Skip scaling limit checks if no scaling is required
58 # due to requested size being bigger than source.
59 if ( !$image->mustRender() ) {
64 # Check if the file is smaller than the maximum image area for thumbnailing
65 # For historical reasons, hook starts with BitmapHandler
66 $checkImageAreaHookResult = null;
68 'BitmapHandlerCheckImageArea',
69 array( $image, &$params, &$checkImageAreaHookResult )
72 if ( is_null( $checkImageAreaHookResult ) ) {
73 global $wgMaxImageArea;
75 if ( $srcWidth * $srcHeight > $wgMaxImageArea
76 && !( $image->getMimeType() == 'image/jpeg'
77 && $this->getScalerType( false, false ) == 'im' )
79 # Only ImageMagick can efficiently downsize jpg images without loading
80 # the entire file in memory
84 return $checkImageAreaHookResult;
91 * Extracts the width/height if the image will be scaled before rotating
93 * This will match the physical size/aspect ratio of the original image
94 * prior to application of the rotation -- so for a portrait image that's
95 * stored as raw landscape with 90-degress rotation, the resulting size
96 * will be wider than it is tall.
98 * @param array $params Parameters as returned by normaliseParams
99 * @param int $rotation The rotation angle that will be applied
100 * @return array ($width, $height) array
102 public function extractPreRotationDimensions( $params, $rotation ) {
103 if ( $rotation == 90 ||
$rotation == 270 ) {
104 # We'll resize before rotation, so swap the dimensions again
105 $width = $params['physicalHeight'];
106 $height = $params['physicalWidth'];
108 $width = $params['physicalWidth'];
109 $height = $params['physicalHeight'];
112 return array( $width, $height );
116 * Create a thumbnail.
118 * This sets up various parameters, and then calls a helper method
119 * based on $this->getScalerType in order to scale the image.
122 * @param string $dstPath
123 * @param string $dstUrl
124 * @param array $params
126 * @return MediaTransformError|ThumbnailImage|TransformParameterError
128 function doTransform( $image, $dstPath, $dstUrl, $params, $flags = 0 ) {
129 if ( !$this->normaliseParams( $image, $params ) ) {
130 return new TransformParameterError( $params );
133 # Create a parameter array to pass to the scaler
134 $scalerParams = array(
135 # The size to which the image will be resized
136 'physicalWidth' => $params['physicalWidth'],
137 'physicalHeight' => $params['physicalHeight'],
138 'physicalDimensions' => "{$params['physicalWidth']}x{$params['physicalHeight']}",
139 # The size of the image on the page
140 'clientWidth' => $params['width'],
141 'clientHeight' => $params['height'],
142 # Comment as will be added to the Exif of the thumbnail
143 'comment' => isset( $params['descriptionUrl'] )
144 ?
"File source: {$params['descriptionUrl']}"
146 # Properties of the original image
147 'srcWidth' => $image->getWidth(),
148 'srcHeight' => $image->getHeight(),
149 'mimeType' => $image->getMimeType(),
150 'dstPath' => $dstPath,
154 if ( isset( $params['quality'] ) && $params['quality'] === 'low' ) {
155 $scalerParams['quality'] = 30;
158 // For subclasses that might be paged.
159 if ( $image->isMultipage() && isset( $params['page'] ) ) {
160 $scalerParams['page'] = intval( $params['page'] );
163 # Determine scaler type
164 $scaler = $this->getScalerType( $dstPath );
166 wfDebug( __METHOD__
. ": creating {$scalerParams['physicalDimensions']} " .
167 "thumbnail at $dstPath using scaler $scaler\n" );
169 if ( !$image->mustRender() &&
170 $scalerParams['physicalWidth'] == $scalerParams['srcWidth']
171 && $scalerParams['physicalHeight'] == $scalerParams['srcHeight']
172 && !isset( $scalerParams['quality'] )
175 # normaliseParams (or the user) wants us to return the unscaled image
176 wfDebug( __METHOD__
. ": returning unscaled image\n" );
178 return $this->getClientScalingThumbnailImage( $image, $scalerParams );
181 if ( $scaler == 'client' ) {
182 # Client-side image scaling, use the source URL
183 # Using the destination URL in a TRANSFORM_LATER request would be incorrect
184 return $this->getClientScalingThumbnailImage( $image, $scalerParams );
187 if ( $flags & self
::TRANSFORM_LATER
) {
188 wfDebug( __METHOD__
. ": Transforming later per flags.\n" );
190 'width' => $scalerParams['clientWidth'],
191 'height' => $scalerParams['clientHeight']
193 if ( isset( $params['quality'] ) ) {
194 $newParams['quality'] = $params['quality'];
196 if ( isset( $params['page'] ) && $params['page'] ) {
197 $newParams['page'] = $params['page'];
199 return new ThumbnailImage( $image, $dstUrl, false, $newParams );
202 # Try to make a target path for the thumbnail
203 if ( !wfMkdirParents( dirname( $dstPath ), null, __METHOD__
) ) {
204 wfDebug( __METHOD__
. ": Unable to create thumbnail destination " .
205 "directory, falling back to client scaling\n" );
207 return $this->getClientScalingThumbnailImage( $image, $scalerParams );
210 # Transform functions and binaries need a FS source file
211 $thumbnailSource = $this->getThumbnailSource( $image, $params );
213 $scalerParams['srcPath'] = $thumbnailSource['path'];
214 $scalerParams['srcWidth'] = $thumbnailSource['width'];
215 $scalerParams['srcHeight'] = $thumbnailSource['height'];
217 if ( $scalerParams['srcPath'] === false ) { // Failed to get local copy
218 wfDebugLog( 'thumbnail',
219 sprintf( 'Thumbnail failed on %s: could not get local copy of "%s"',
220 wfHostname(), $image->getName() ) );
222 return new MediaTransformError( 'thumbnail_error',
223 $scalerParams['clientWidth'], $scalerParams['clientHeight'],
224 wfMessage( 'filemissing' )->text()
228 # Try a hook. Called "Bitmap" for historical reasons.
229 /** @var $mto MediaTransformOutput */
231 wfRunHooks( 'BitmapHandlerTransform', array( $this, $image, &$scalerParams, &$mto ) );
232 if ( !is_null( $mto ) ) {
233 wfDebug( __METHOD__
. ": Hook to BitmapHandlerTransform created an mto\n" );
234 $scaler = 'hookaborted';
237 // $scaler will return a MediaTransformError on failure, or false on success.
238 // If the scaler is succesful, it will have created a thumbnail at the destination
240 if ( is_array( $scaler ) && is_callable( $scaler ) ) {
241 // Allow subclasses to specify their own rendering methods.
242 $err = call_user_func( $scaler, $image, $scalerParams );
246 # Handled by the hook above
247 $err = $mto->isError() ?
$mto : false;
250 $err = $this->transformImageMagick( $image, $scalerParams );
253 $err = $this->transformCustom( $image, $scalerParams );
256 $err = $this->transformImageMagickExt( $image, $scalerParams );
260 $err = $this->transformGd( $image, $scalerParams );
265 # Remove the file if a zero-byte thumbnail was created, or if there was an error
266 $removed = $this->removeBadFile( $dstPath, (bool)$err );
268 # transform returned MediaTransforError
270 } elseif ( $removed ) {
271 # Thumbnail was zero-byte and had to be removed
272 return new MediaTransformError( 'thumbnail_error',
273 $scalerParams['clientWidth'], $scalerParams['clientHeight'],
274 wfMessage( 'unknown-error' )->text()
280 'width' => $scalerParams['clientWidth'],
281 'height' => $scalerParams['clientHeight']
283 if ( isset( $params['quality'] ) ) {
284 $newParams['quality'] = $params['quality'];
286 if ( isset( $params['page'] ) && $params['page'] ) {
287 $newParams['page'] = $params['page'];
289 return new ThumbnailImage( $image, $dstUrl, $dstPath, $newParams );
294 * Get the source file for the transform
297 * @param $params Array
298 * @return Array Array with keys width, height and path.
300 protected function getThumbnailSource( $file, $params ) {
301 return $file->getThumbnailSource( $params );
305 * Returns what sort of scaler type should be used.
307 * Values can be one of client, im, custom, gd, imext, or an array
308 * of object, method-name to call that specific method.
310 * If specifying a custom scaler command with array( Obj, method ),
311 * the method in question should take 2 parameters, a File object,
312 * and a $scalerParams array with various options (See doTransform
313 * for what is in $scalerParams). On error it should return a
314 * MediaTransformError object. On success it should return false,
315 * and simply make sure the thumbnail file is located at
316 * $scalerParams['dstPath'].
318 * If there is a problem with the output path, it returns "client"
319 * to do client side scaling.
321 * @param string $dstPath
322 * @param bool $checkDstPath Check that $dstPath is valid
323 * @return string|Callable One of client, im, custom, gd, imext, or a Callable array.
325 abstract protected function getScalerType( $dstPath, $checkDstPath = true );
328 * Get a ThumbnailImage that respresents an image that will be scaled
331 * @param File $image File associated with this thumbnail
332 * @param array $scalerParams Array with scaler params
333 * @return ThumbnailImage
335 * @todo FIXME: No rotation support
337 protected function getClientScalingThumbnailImage( $image, $scalerParams ) {
339 'width' => $scalerParams['clientWidth'],
340 'height' => $scalerParams['clientHeight']
343 return new ThumbnailImage( $image, $image->getURL(), null, $params );
347 * Transform an image using ImageMagick
349 * This is a stub method. The real method is in BitmapHander.
351 * @param File $image File associated with this thumbnail
352 * @param array $params Array with scaler params
354 * @return MediaTransformError Error object if error occurred, false (=no error) otherwise
356 protected function transformImageMagick( $image, $params ) {
357 return $this->getMediaTransformError( $params, "Unimplemented" );
361 * Transform an image using the Imagick PHP extension
363 * This is a stub method. The real method is in BitmapHander.
365 * @param File $image File associated with this thumbnail
366 * @param array $params Array with scaler params
368 * @return MediaTransformError Error object if error occurred, false (=no error) otherwise
370 protected function transformImageMagickExt( $image, $params ) {
371 return $this->getMediaTransformError( $params, "Unimplemented" );
375 * Transform an image using a custom command
377 * This is a stub method. The real method is in BitmapHander.
379 * @param File $image File associated with this thumbnail
380 * @param array $params Array with scaler params
382 * @return MediaTransformError Error object if error occurred, false (=no error) otherwise
384 protected function transformCustom( $image, $params ) {
385 return $this->getMediaTransformError( $params, "Unimplemented" );
389 * Get a MediaTransformError with error 'thumbnail_error'
391 * @param array $params Parameter array as passed to the transform* functions
392 * @param string $errMsg Error message
393 * @return MediaTransformError
395 public function getMediaTransformError( $params, $errMsg ) {
396 return new MediaTransformError( 'thumbnail_error', $params['clientWidth'],
397 $params['clientHeight'], $errMsg );
401 * Transform an image using the built in GD library
403 * This is a stub method. The real method is in BitmapHander.
405 * @param File $image File associated with this thumbnail
406 * @param array $params Array with scaler params
408 * @return MediaTransformError Error object if error occurred, false (=no error) otherwise
410 protected function transformGd( $image, $params ) {
411 return $this->getMediaTransformError( $params, "Unimplemented" );
415 * Escape a string for ImageMagick's property input (e.g. -set -comment)
416 * See InterpretImageProperties() in magick/property.c
420 function escapeMagickProperty( $s ) {
421 // Double the backslashes
422 $s = str_replace( '\\', '\\\\', $s );
423 // Double the percents
424 $s = str_replace( '%', '%%', $s );
425 // Escape initial - or @
426 if ( strlen( $s ) > 0 && ( $s[0] === '-' ||
$s[0] === '@' ) ) {
434 * Escape a string for ImageMagick's input filenames. See ExpandFilenames()
435 * and GetPathComponent() in magick/utility.c.
437 * This won't work with an initial ~ or @, so input files should be prefixed
438 * with the directory name.
440 * Glob character unescaping is broken in ImageMagick before 6.6.1-5, but
441 * it's broken in a way that doesn't involve trying to convert every file
442 * in a directory, so we're better off escaping and waiting for the bugfix
443 * to filter down to users.
445 * @param string $path The file path
446 * @param bool|string $scene The scene specification, or false if there is none
447 * @throws MWException
450 function escapeMagickInput( $path, $scene = false ) {
451 # Die on initial metacharacters (caller should prepend path)
452 $firstChar = substr( $path, 0, 1 );
453 if ( $firstChar === '~' ||
$firstChar === '@' ) {
454 throw new MWException( __METHOD__
. ': cannot escape this path name' );
458 $path = preg_replace( '/[*?\[\]{}]/', '\\\\\0', $path );
460 return $this->escapeMagickPath( $path, $scene );
464 * Escape a string for ImageMagick's output filename. See
465 * InterpretImageFilename() in magick/image.c.
466 * @param string $path The file path
467 * @param bool|string $scene The scene specification, or false if there is none
470 function escapeMagickOutput( $path, $scene = false ) {
471 $path = str_replace( '%', '%%', $path );
473 return $this->escapeMagickPath( $path, $scene );
477 * Armour a string against ImageMagick's GetPathComponent(). This is a
478 * helper function for escapeMagickInput() and escapeMagickOutput().
480 * @param string $path The file path
481 * @param bool|string $scene The scene specification, or false if there is none
482 * @throws MWException
485 protected function escapeMagickPath( $path, $scene = false ) {
486 # Die on format specifiers (other than drive letters). The regex is
487 # meant to match all the formats you get from "convert -list format"
488 if ( preg_match( '/^([a-zA-Z0-9-]+):/', $path, $m ) ) {
489 if ( wfIsWindows() && is_dir( $m[0] ) ) {
490 // OK, it's a drive letter
491 // ImageMagick has a similar exception, see IsMagickConflict()
493 throw new MWException( __METHOD__
. ': unexpected colon character in path name' );
497 # If there are square brackets, add a do-nothing scene specification
498 # to force a literal interpretation
499 if ( $scene === false ) {
500 if ( strpos( $path, '[' ) !== false ) {
511 * Retrieve the version of the installed ImageMagick
512 * You can use PHPs version_compare() to use this value
513 * Value is cached for one hour.
514 * @return string Representing the IM version.
516 protected function getMagickVersion() {
519 $cache = $wgMemc->get( "imagemagick-version" );
521 global $wgImageMagickConvertCommand;
522 $cmd = wfEscapeShellArg( $wgImageMagickConvertCommand ) . ' -version';
523 wfDebug( __METHOD__
. ": Running convert -version\n" );
525 $return = wfShellExec( $cmd, $retval );
526 $x = preg_match( '/Version: ImageMagick ([0-9]*\.[0-9]*\.[0-9]*)/', $return, $matches );
528 wfDebug( __METHOD__
. ": ImageMagick version check failed\n" );
532 $wgMemc->set( "imagemagick-version", $matches[1], 3600 );
541 * Returns whether the current scaler supports rotation.
543 * @since 1.24 No longer static
546 public function canRotate() {
551 * Should we automatically rotate an image based on exif
553 * @since 1.24 No longer static
554 * @see $wgEnableAutoRotation
555 * @return bool Whether auto rotation is enabled
557 public function autoRotateEnabled() {
562 * Rotate a thumbnail.
564 * This is a stub. See BitmapHandler::rotate.
567 * @param array $params Rotate parameters.
568 * 'rotation' clockwise rotation in degrees, allowed are multiples of 90
569 * @since 1.24 Is non-static. From 1.21 it was static
572 public function rotate( $file, $params ) {
573 return new MediaTransformError( 'thumbnail_error', 0, 0,
574 "$scaler rotation not implemented" );
578 * Returns whether the file needs to be rendered. Returns true if the
579 * file requires rotation and we are able to rotate it.
584 public function mustRender( $file ) {
585 return $this->canRotate() && $this->getRotation( $file ) != 0;