4 files changed, 64 insertions, 4 deletions
diff --git a/lib/private/preview.php b/lib/private/preview.php
index 6172519c7d1..aeb9806904a 100755
--- a/lib/private/preview.php
+++ b/lib/private/preview.php
@@ -13,6 +13,7 @@
  */
 namespace OC;
 
+use OC\Files\Filesystem;
 use OC\Preview\Provider;
 
 require_once 'preview/image.php';
@@ -732,6 +733,35 @@ class Preview {
 	}
 
 	/**
+	 * Check if a preview can be generated for a file
+	 *
+	 * @param \OC\Files\FileInfo $file
+	 * @return bool
+	 */
+	public static function isAvailable($file) {
+		if (!\OC_Config::getValue('enable_previews', true)) {
+			return false;
+		}
+
+		//check if there are preview backends
+		if (empty(self::$providers)) {
+			self::initProviders();
+		}
+
+		//remove last element because it has the mimetype *
+		$providers = array_slice(self::$providers, 0, -1);
+		foreach ($providers as $supportedMimeType => $provider) {
+			/**
+			 * @var \OC\Preview\Provider $provider
+			 */
+			if (preg_match($supportedMimeType, $file->getMimetype())) {
+				return $provider->isAvailable($file);
+			}
+		}
+		return false;
+	}
+
+	/**
 	 * @param string $mimeType
 	 * @return bool
 	 */
diff --git a/lib/private/preview/provider.php b/lib/private/preview/provider.php
index f769823f6e6..f544c2c4b13 100644
--- a/lib/private/preview/provider.php
+++ b/lib/private/preview/provider.php
@@ -11,6 +11,16 @@ abstract class Provider {
 	abstract public function getMimeType();
 
 	/**
+	 * Check if a preview can be generated for $path
+	 *
+	 * @param string $path
+	 * @return bool
+	 */
+	public function isAvailable($path) {
+		return true;
+	}
+
+	/**
 	 * 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
diff --git a/lib/private/preview/txt.php b/lib/private/preview/txt.php
index 063543c6279..b81436baa06 100644
--- a/lib/private/preview/txt.php
+++ b/lib/private/preview/txt.php
@@ -14,6 +14,16 @@ class TXT extends Provider {
 	}
 
 	/**
+	 * Check if a preview can be generated for $path
+	 *
+	 * @param \OC\Files\FileInfo $file
+	 * @return bool
+	 */
+	public function isAvailable($file) {
+		return $file->getSize() > 5;
+	}
+
+	/**
 	 * @param string $path
 	 * @param int $maxX
 	 * @param int $maxY
diff --git a/lib/private/previewmanager.php b/lib/private/previewmanager.php
index 23dbee13c7d..85bf609743d 100755
--- a/lib/private/previewmanager.php
+++ b/lib/private/previewmanager.php
@@ -14,25 +14,35 @@ use OCP\IPreview;
 class PreviewManager implements IPreview {
 	/**
 	 * return a preview of a file
+	 *
 	 * @param string $file The path to the file where you want a thumbnail from
 	 * @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 boolean $scaleUp Scale smaller images up to the thumbnail size or not. Might look ugly
 	 * @return \OCP\Image
 	 */
-	function createPreview($file, $maxX = 100, $maxY = 75, $scaleUp = false)
-	{
+	function createPreview($file, $maxX = 100, $maxY = 75, $scaleUp = false) {
 		$preview = new \OC\Preview('', '/', $file, $maxX, $maxY, $scaleUp);
 		return $preview->getPreview();
 	}
 
 	/**
 	 * returns true if the passed mime type is supported
+	 *
 	 * @param string $mimeType
 	 * @return boolean
 	 */
-	function isMimeSupported($mimeType = '*')
-	{
+	function isMimeSupported($mimeType = '*') {
 		return \OC\Preview::isMimeSupported($mimeType);
 	}
+
+	/**
+	 * Check if a preview can be generated for a file
+	 *
+	 * @param \OC\Files\FileInfo $file
+	 * @return bool
+	 */
+	function isAvailable($file) {
+		return \OC\Preview::isAvailable($file);
+	}
 }