@Override
 public void onDismissed(Snackbar snackbar, @DismissEvent int event) {
   mIsDismissed = true;
   if (mCallback != null) {
     mCallback.onTransitionToIdle();
   }
 }
 @Override
 public void onShown(Snackbar snackbar) {
   mIsShown = true;
   if (mCallback != null) {
     mCallback.onTransitionToIdle();
   }
 }