Snackbars provide brief messages about app processes at the bottom of the screen.
ScaffoldWithCustomSnackbar
@Preview
@Composable
fun ScaffoldWithCustomSnackbar() {
class SnackbarVisualsWithError(override val message: String, val isError: Boolean) :
SnackbarVisuals {
override val actionLabel: String
get() = if (isError) "Error" else "OK"
override val withDismissAction: Boolean
get() = false
override val duration: SnackbarDuration
get() = SnackbarDuration.Indefinite
}
val snackbarHostState = remember { SnackbarHostState() }
val scope = rememberCoroutineScope()
Scaffold(
snackbarHost = {
// reuse default SnackbarHost to have default animation and timing handling
SnackbarHost(snackbarHostState) { data ->
// custom snackbar with the custom action button color and border
val isError = (data.visuals as? SnackbarVisualsWithError)?.isError ?: false
val buttonColor =
if (isError) {
ButtonDefaults.textButtonColors(
containerColor = MaterialTheme.colorScheme.errorContainer,
contentColor = MaterialTheme.colorScheme.error,
)
} else {
ButtonDefaults.textButtonColors(
contentColor = MaterialTheme.colorScheme.inversePrimary
)
}
Snackbar(
modifier =
Modifier.border(2.dp, MaterialTheme.colorScheme.secondary).padding(12.dp),
action = {
TextButton(
onClick = { if (isError) data.dismiss() else data.performAction() },
colors = buttonColor,
) {
Text(data.visuals.actionLabel ?: "")
}
},
) {
Text(data.visuals.message)
}
}
},
floatingActionButton = {
var clickCount by remember { mutableStateOf(0) }
ExtendedFloatingActionButton(
onClick = {
scope.launch {
snackbarHostState.showSnackbar(
SnackbarVisualsWithError(
"Snackbar # ${++clickCount}",
isError = clickCount % 2 != 0,
)
)
}
}
) {
Text("Show snackbar")
}
},
content = { innerPadding ->
Text(
text = "Custom Snackbar Demo",
modifier = Modifier.padding(innerPadding).fillMaxSize().wrapContentSize(),
)
},
)
}
ScaffoldWithIndefiniteSnackbar
@Preview
@Composable
fun ScaffoldWithIndefiniteSnackbar() {
val snackbarHostState = remember { SnackbarHostState() }
val scope = rememberCoroutineScope()
Scaffold(
snackbarHost = { SnackbarHost(snackbarHostState) },
floatingActionButton = {
var clickCount by remember { mutableStateOf(0) }
ExtendedFloatingActionButton(
onClick = {
// show snackbar as a suspend function
scope.launch {
snackbarHostState.showSnackbar(
message = "Snackbar # ${++clickCount}",
actionLabel = "Action",
withDismissAction = true,
duration = SnackbarDuration.Indefinite,
)
}
}
) {
Text("Show snackbar")
}
},
content = { innerPadding ->
Text(
text = "Body content",
modifier = Modifier.padding(innerPadding).fillMaxSize().wrapContentSize(),
)
},
)
}
ScaffoldWithMultilineSnackbar
@Preview
@Composable
fun ScaffoldWithMultilineSnackbar() {
val snackbarHostState = remember { SnackbarHostState() }
val scope = rememberCoroutineScope()
Scaffold(
snackbarHost = {
SnackbarHost(snackbarHostState) { data ->
Snackbar {
// The Material spec recommends a maximum of 2 lines of text.
Text(data.visuals.message, maxLines = 2, overflow = TextOverflow.Ellipsis)
}
}
},
floatingActionButton = {
ExtendedFloatingActionButton(
onClick = {
scope.launch {
val longMessage =
"Very very very very very very very very very very very very very " +
"very very very very very very very very very very very very " +
"very very very very very very very very very very long message"
snackbarHostState.showSnackbar(longMessage)
}
}
) {
Text("Show snackbar")
}
},
content = { innerPadding ->
Text(
text = "Multiline Snackbar Demo",
modifier = Modifier.padding(innerPadding).fillMaxSize().wrapContentSize(),
)
},
)
}
ScaffoldWithSimpleSnackbar
@Preview
@Composable
fun ScaffoldWithSimpleSnackbar() {
val snackbarHostState = remember { SnackbarHostState() }
val scope = rememberCoroutineScope()
Scaffold(
snackbarHost = { SnackbarHost(snackbarHostState) },
floatingActionButton = {
var clickCount by remember { mutableStateOf(0) }
ExtendedFloatingActionButton(
onClick = {
// show snackbar as a suspend function
scope.launch { snackbarHostState.showSnackbar("Snackbar # ${++clickCount}") }
}
) {
Text("Show snackbar")
}
},
content = { innerPadding ->
Text(
text = "Body content",
modifier = Modifier.padding(innerPadding).fillMaxSize().wrapContentSize(),
)
},
)
}