Scaffold

Composable Component

Scaffold implements the basic Material Design visual layout structure.

Common

@Composable
fun Scaffold(
    modifier: Modifier = Modifier,
    topBar: @Composable () -> Unit = {},
    bottomBar: @Composable () -> Unit = {},
    snackbarHost: @Composable () -> Unit = {},
    floatingActionButton: @Composable () -> Unit = {},
    floatingActionButtonPosition: FabPosition = FabPosition.End,
    containerColor: Color = MaterialTheme.colorScheme.background,
    contentColor: Color = contentColorFor(containerColor),
    contentWindowInsets: WindowInsets = ScaffoldDefaults.contentWindowInsets,
    content: @Composable (PaddingValues) -> Unit,
)

Parameters


modifier	the `Modifier` to be applied to this scaffold
topBar	top app bar of the screen, typically a `TopAppBar`
bottomBar	bottom bar of the screen, typically a `NavigationBar`
snackbarHost	component to host `Snackbar`s that are pushed to be shown via `SnackbarHostState.showSnackbar`, typically a `SnackbarHost`
floatingActionButton	Main action button of the screen, typically a `FloatingActionButton`
floatingActionButtonPosition	position of the FAB on the screen. See `FabPosition`.
containerColor	the color used for the background of this scaffold. Use `Color.Transparent` to have no color.
contentColor	the preferred color for content inside this scaffold. Defaults to either the matching content color for `containerColor`, or to the current `LocalContentColor` if `containerColor` is not a color from the theme.
contentWindowInsets	window insets to be passed to `content` slot via `PaddingValues` params. Scaffold will take the insets into account from the top/bottom only if the `topBar`/ `bottomBar` are not present, as the scaffold expect `topBar`/`bottomBar` to handle insets instead. Any insets consumed by other insets padding modifiers or `consumeWindowInsets` on a parent layout will be excluded from `contentWindowInsets`.
content	content of the screen. The lambda receives a `PaddingValues` that should be applied to the content root via `Modifier.padding` and `Modifier.consumeWindowInsets` to properly offset top and bottom bars. If using `Modifier.verticalScroll`, apply this modifier to the child of the scroll, and not on the scroll itself.

Code Examples

SimpleScaffoldWithTopBar

@OptIn(ExperimentalMaterial3Api::class)
@Preview
@Composable
fun SimpleScaffoldWithTopBar() {
    val colors =
        listOf(
            Color(0xFFffd7d7.toInt()),
            Color(0xFFffe9d6.toInt()),
            Color(0xFFfffbd0.toInt()),
            Color(0xFFe3ffd9.toInt()),
            Color(0xFFd0fff8.toInt()),
        )
    Scaffold(
        topBar = {
            TopAppBar(
                title = { Text("Simple Scaffold Screen") },
                navigationIcon = {
                    IconButton(onClick = { /* "Open nav drawer" */ }) {
                        Icon(Icons.Filled.Menu, contentDescription = "Localized description")
                    }
                },
            )
        },
        floatingActionButtonPosition = FabPosition.End,
        floatingActionButton = {
            ExtendedFloatingActionButton(onClick = { /* fab click handler */ }) { Text("Inc") }
        },
        content = { innerPadding ->
            LazyColumn(
                // consume insets as scaffold doesn't do it by default
                modifier = Modifier.consumeWindowInsets(innerPadding),
                contentPadding = innerPadding,
            ) {
                items(count = 100) {
                    Box(Modifier.fillMaxWidth().height(50.dp).background(colors[it % colors.size]))
                }
            }
        },
    )
}

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(),
            )
        },
    )
}