DecoupledSnackbar.kt

setContent{
    val snackbarHostState = remember{SnackbarHostState()}

    Column {
        Button(
            onClick = {
                lifecycleScope.launch {
                    val time = System.currentTimeMillis()
                    Log.d(TAG, "showing snackbar")
                    snackbarHostState.showSnackbar(
                        message = "Hey look a snackbar",
                        actionLabel = "Hide",
                        duration = SnackbarDuration.Short
                    )
                    Log.d(TAG, "done ${System.currentTimeMillis()-time}") // <-- Never called
                }
            }
        ) {
            Text("Show snackbar")
        }
        DecoupledSnackbarDemo(snackbarHostState = snackbarHostState)
    }
}

@ExperimentalMaterialApi
@Composable
fun DecoupledSnackbarDemo(
    snackbarHostState: SnackbarHostState
){
    ConstraintLayout(modifier = Modifier.fillMaxSize()) {
        val snackbar = createRef()
        SnackbarHost(
            modifier = Modifier.constrainAs(snackbar) {
                bottom.linkTo(parent.bottom)
                start.linkTo(parent.start)
                end.linkTo(parent.end)
            },
            hostState = snackbarHostState,
            snackbar = {
                Snackbar(
                    action = {
                        TextButton(
                            onClick = {
                                snackbarHostState.currentSnackbarData?.dismiss()
                            }
                        ){
                            Text(
                                text = snackbarHostState.currentSnackbarData?.actionLabel?: "",
                                style = TextStyle(color = Color.White)
                            )
                        }
                    }
                ) {
                    Text(snackbarHostState.currentSnackbarData?.message?: "")
                }
            }
        )
    }
}