     private var previewTransitionViews: [UIView?]?
     private var previewAttachmentPhotos: [PreviewAttachmentPhoto] = []
     private var previewMessagePhotos: [PreviewMessagePhoto] = []
+    private var previewMessagePhotoInitialIndex: Int = 0
 
     deinit {
         NSNotificationCenter.defaultCenter().removeObserver(self)

                return previewTransitionViews?[index]
            }

        } else if photo is PreviewMessagePhoto {
            return (previewTransitionViews?.first)!
        }

        return nil


                        let previewMessagePhotos = mediaMessages.map({ PreviewMessagePhoto(message: $0) })
                        self.previewMessagePhotos = previewMessagePhotos
                        self.previewMessagePhotoInitialIndex = index

                        let photos: [Photo] = previewMessagePhotos.map({ $0 })
                        let initialPhoto = photos[index]
