Snackbar is one of the most interesting component added in material design. We can use this as a toast message or as a toast message with an action button. In most of the applications we see a “Retry” button in Snackbar when the application unable to reach the internet. The same can be implemented very easily programmatically as follows-

Snackbar mSnackbar = Snackbar.make(getView(), "Unable to connect", Snackbar.LENGTH_LONG)
        .setAction("RETRY", new View.OnClickListener() {
            public void onClick(View view) {
                Snackbar.make(getView(), "CheckIn Cancelled", Snackbar.LENGTH_SHORT).show();