LargeFloatingActionButton

Component in Material 3 Compose

The FAB represents the most important action on a screen. It puts key actions within reach.

Last updated: 2024-10-22 13:47

Installation

dependencies {
   implementation("androidx.compose.material3:material3:1.4.0-alpha02")
}

Overloads

@Composable
fun LargeFloatingActionButton(
    onClick: () -> Unit,
    modifier: Modifier = Modifier,
    shape: Shape = FloatingActionButtonDefaults.largeShape,
    containerColor: Color = FloatingActionButtonDefaults.containerColor,
    contentColor: Color = contentColorFor(containerColor),
    elevation: FloatingActionButtonElevation = FloatingActionButtonDefaults.elevation(),
    interactionSource: MutableInteractionSource? = null,
    content: @Composable () -> Unit,
)

Parameters

name	description
onClick	called when this FAB is clicked
modifier	the [Modifier] to be applied to this FAB
shape	defines the shape of this FAB's container and shadow (when using [elevation])
containerColor	the color used for the background of this FAB. Use [Color.Transparent] to have no color.
contentColor	the preferred color for content inside this FAB. Defaults to either the matching content color for [containerColor], or to the current [LocalContentColor] if [containerColor] is not a color from the theme.
elevation	[FloatingActionButtonElevation] used to resolve the elevation for this FAB in different states. This controls the size of the shadow below the FAB. Additionally, when the container color is [ColorScheme.surface], this controls the amount of primary color applied as an overlay. See also: [Surface].
interactionSource	an optional hoisted [MutableInteractionSource] for observing and emitting [Interaction]s for this FAB. You can use this to change the FAB's appearance or preview the FAB in different states. Note that if null is provided, interactions will still happen internally.
content	the content of this FAB, typically an [Icon]

Code Examples

LargeFloatingActionButtonSample

@Preview
@Composable
fun LargeFloatingActionButtonSample() {
    LargeFloatingActionButton(
        onClick = { /* do something */ },
    ) {
        Icon(
            Icons.Filled.Add,
            contentDescription = "Localized description",
            modifier = Modifier.size(FloatingActionButtonDefaults.LargeIconSize),
        )
    }
}

AnimatedFloatingActionButtonSample

@OptIn(ExperimentalMaterial3ExpressiveApi::class)
@Preview
@Composable
fun AnimatedFloatingActionButtonSample() {
    val listState = rememberLazyListState()
    // The FAB is initially shown. Upon scrolling past the first item we hide the FAB by using a
    // remembered derived state to minimize unnecessary compositions.
    val fabVisible by remember { derivedStateOf { listState.firstVisibleItemIndex == 0 } }

    Scaffold(
        floatingActionButton = {
            MediumFloatingActionButton(
                modifier =
                    Modifier.animateFloatingActionButton(
                        visible = fabVisible,
                        alignment = Alignment.BottomEnd
                    ),
                onClick = { /* do something */ },
            ) {
                Icon(
                    Icons.Filled.Add,
                    contentDescription = "Localized description",
                    modifier = Modifier.size(FloatingActionButtonDefaults.MediumIconSize),
                )
            }
        },
        floatingActionButtonPosition = FabPosition.End,
    ) {
        LazyColumn(state = listState, modifier = Modifier.fillMaxSize()) {
            for (index in 0 until 100) {
                item { Text(text = "List item - $index", modifier = Modifier.padding(24.dp)) }
            }
        }
    }
}