Added "smart thumbnails"

Author: maxpavlov

jQuery-File-Upload.MVC3/Files/FileUploader.zip

@@ -34,11 +34,18 @@ private void SetValues(string fileName, int fileLength, string fullPath)
             delete_url = HandlerPath + "FileTransferHandler.ashx?f=" + fileName;
             delete_type = "DELETE";
 
+            var ext = Path.GetExtension(fullPath);
+            
             var fileSize = ConvertBytesToMegabytes(new FileInfo(fullPath).Length);
-            if (size > 3) thumbnail_url = "/Content/img/generalFile.png";
+            if (fileSize > 3 || !IsImage(ext)) thumbnail_url = "/Content/img/generalFile.png";
             else thumbnail_url = @"data:image/png;base64," + EncodeFile(fullPath);
         }
 
+        private bool IsImage(string ext)
+        {
+            return ext == ".gif" || ext == ".jpg" || ext == ".png";
+        }
+
         private string EncodeFile(string fileName)
         {
             return Convert.ToBase64String(System.IO.File.ReadAllBytes(fileName));