From ef3c0a92b4a64e6a960d2c44c7378817755ee6b8 Mon Sep 17 00:00:00 2001
From: Bryan Tong Minh <btongminh@users.mediawiki.org>
Date: Fri, 18 Mar 2011 22:28:19 +0000
Subject: [PATCH] Added hook BitmapHandlerTransform to allow extension to
 transform a file without overriding the entire handler.

---
 RELEASE-NOTES             |  2 ++
 docs/hooks.txt            |  7 +++++++
 includes/media/Bitmap.php | 19 +++++++++++++++++--
 3 files changed, 26 insertions(+), 2 deletions(-)

diff --git a/RELEASE-NOTES b/RELEASE-NOTES
index 54b60b2ff1..52d60a8886 100644
--- a/RELEASE-NOTES
+++ b/RELEASE-NOTES
@@ -116,6 +116,8 @@ PHP if you have not done so prior to upgrading MediaWiki.
   file description page. The sizes are set by $wgImageLimits.
 * (bug 28031) Add pageCount support to ArchivedFile
 * (bug 27924) PhpHttpRequest doesn't return response body if HTTP != 200
+* Added hook BitmapHandlerTransform to allow extension to transform a file 
+  without overriding the entire handler.
 
 === Bug fixes in 1.18 ===
 * (bug 23119) WikiError class and subclasses are now marked as deprecated
diff --git a/docs/hooks.txt b/docs/hooks.txt
index 9349acb8ed..a30bf9f52b 100644
--- a/docs/hooks.txt
+++ b/docs/hooks.txt
@@ -578,6 +578,13 @@ $mediaWiki: Mediawiki object
 &$parser: Parser object
 &$ig: ImageGallery object
 
+'BitmapHandlerTransform': before a file is transformed, gives extension the 
+possibility to transform it themselves
+$handler: BitmapHandler 
+$image: File
+&$scalerParams: Array with scaler parameters 
+&$mto: null, set to a MediaTransformOutput
+
 'BlockIp': before an IP address or user is blocked
 $block: the Block object about to be saved
 $user: the user _doing_ the block (not the one being blocked)
diff --git a/includes/media/Bitmap.php b/includes/media/Bitmap.php
index f001333340..ff2e56d988 100644
--- a/includes/media/Bitmap.php
+++ b/includes/media/Bitmap.php
@@ -101,6 +101,7 @@ class BitmapHandler extends ImageHandler {
 			'mimeType' => $image->getMimeType(),
 			'srcPath' => $image->getPath(),
 			'dstPath' => $dstPath,
+			'dstUrl' => $dstUrl,
 		);
 
 		wfDebug( __METHOD__ . ": creating {$scalerParams['physicalDimensions']} thumbnail at $dstPath\n" );
@@ -135,8 +136,20 @@ class BitmapHandler extends ImageHandler {
 			wfDebug( __METHOD__ . ": Unable to create thumbnail destination directory, falling back to client scaling\n" );
 			return $this->getClientScalingThumbnailImage( $image, $scalerParams );
 		}
-
+		
+		# Try a hook
+		$mto = null;
+		wfRunHooks( 'BitmapHandlerTransform', array( $this, $image, &$scalerParams, &$mto ) );
+		if ( !is_null( $mto ) ) {
+			wfDebug( __METHOD__ . ": Hook to BitmapHandlerTransform created an mto\n" );
+			$scaler = 'hookaborted';
+		}
+		
 		switch ( $scaler ) {
+			case 'hookaborted':
+				# Handled by the hook above
+				$err = $mto->isError() ? $mto : false;
+				break;
 			case 'im':
 				$err = $this->transformImageMagick( $image, $scalerParams );
 				break;
@@ -161,6 +174,8 @@ class BitmapHandler extends ImageHandler {
 			# Thumbnail was zero-byte and had to be removed
 			return new MediaTransformError( 'thumbnail_error',
 				$scalerParams['clientWidth'], $scalerParams['clientHeight'] );
+		} elseif ( $mto ) {
+			return $mto;
 		} else {
 			return new ThumbnailImage( $image, $dstUrl, $scalerParams['clientWidth'],
 				$scalerParams['clientHeight'], $dstPath );
@@ -443,7 +458,7 @@ class BitmapHandler extends ImageHandler {
 	 * @param $errMsg string Error message
 	 * @return MediaTransformError
 	 */
-	protected function getMediaTransformError( $params, $errMsg ) {
+	public function getMediaTransformError( $params, $errMsg ) {
 		return new MediaTransformError( 'thumbnail_error', $params['clientWidth'],
 					$params['clientHeight'], $errMsg );
 	}
-- 
2.20.1