Merge pull request #4949 from owncloud/improve_unknown_preview_backend

use svg to generate filetype icon if imagick available

lib/private/preview/provider.php

@@ -11,9 +11,15 @@ abstract class Provider {
 	abstract public function getMimeType();
 
 	/**
-	 * search for $query
-	 * @param string $query
-	 * @return
+	 * get thumbnail for file at path $path
+	 * @param string $path Path of file
+	 * @param int $maxX The maximum X size of the thumbnail. It can be smaller depending on the shape of the image
+	 * @param int $maxY The maximum Y size of the thumbnail. It can be smaller depending on the shape of the image
+	 * @param bool $scalingUp Disable/Enable upscaling of previews
+	 * @param object $fileview fileview object of user folder
+	 * @return mixed
+	 * 		false if no preview was generated
+	 *		OC_Image object of the preview
 	 */
 	abstract public function getThumbnail($path, $maxX, $maxY, $scalingup, $fileview);
 }

lib/private/preview/unknown.php

@@ -20,8 +20,30 @@ class Unknown extends Provider {
 		$path = \OC_Helper::mimetypeIcon($mimetype);
 		$path = \OC::$SERVERROOT . substr($path, strlen(\OC::$WEBROOT));
 
-		return new \OC_Image($path);
+		$svgPath = substr_replace($path, 'svg', -3);
+
+		if (extension_loaded('imagick') && file_exists($svgPath)) {
+
+			// http://www.php.net/manual/de/imagick.setresolution.php#85284
+			$svg = new \Imagick();
+			$svg->readImage($svgPath);
+			$res = $svg->getImageResolution();
+			$x_ratio = $res['x'] / $svg->getImageWidth();
+			$y_ratio = $res['y'] / $svg->getImageHeight();
+			$svg->removeImage();
+			$svg->setResolution($maxX * $x_ratio, $maxY * $y_ratio);
+			$svg->setBackgroundColor(new \ImagickPixel('transparent'));
+			$svg->readImage($svgPath);
+			$svg->setImageFormat('png32');
+
+			$image = new \OC_Image();
+			$image->loadFromData($svg);
+		} else {
+			$image = new \OC_Image($path);
+		}
+
+		return $image;
 	}
 }
 
-\OC\Preview::registerProvider('OC\Preview\Unknown');
\ No newline at end of file
+\OC\Preview::registerProvider('OC\Preview\Unknown');