BottomAppBar

Functions summary

`Unit`	`@Composable BottomAppBar( modifier: Modifier, backgroundColor: Color, contentColor: Color, cutoutShape: Shape?, elevation: Dp, contentPadding: PaddingValues, content: @Composable RowScope.() -> Unit )` Material Design bottom app bar	Cmn
`Unit`	`@Composable BottomAppBar( windowInsets: WindowInsets, modifier: Modifier, backgroundColor: Color, contentColor: Color, cutoutShape: Shape?, elevation: Dp, contentPadding: PaddingValues, content: @Composable RowScope.() -> Unit )` Material Design bottom app bar	Cmn

Functions

BottomAppBar

Cmn

Artifact: androidx.compose.material:material

View Source

@Composable
fun BottomAppBar(
    modifier: Modifier = Modifier,
    backgroundColor: Color = MaterialTheme.colors.primarySurface,
    contentColor: Color = contentColorFor(backgroundColor),
    cutoutShape: Shape? = null,
    elevation: Dp = AppBarDefaults.BottomAppBarElevation,
    contentPadding: PaddingValues = AppBarDefaults.ContentPadding,
    content: @Composable RowScope.() -> Unit
): Unit

Material Design bottom app bar

A bottom app bar displays navigation and key actions at the bottom of screens.

App bars: bottom
image

It can also optionally display a FloatingActionButton, which is either overlaid on top of the BottomAppBar, or inset, carving a cutout in the BottomAppBar.

See BottomAppBar anatomy for the recommended content depending on the FloatingActionButton position.

Note that when you pass a non-null cutoutShape this makes the AppBar shape concave. The shadows for such shapes will not be drawn on Android versions less than 10.

The LocalContentAlpha inside a BottomAppBar is ContentAlpha.medium - this is the default for trailing and overflow icons. It is recommended that any leading icons at the start of the BottomAppBar, such as a menu icon, use ContentAlpha.high instead. This is demonstrated in the sample below.

Also see BottomNavigation.

import androidx.compose.foundation.layout.Spacer
import androidx.compose.material.AppBarDefaults
import androidx.compose.material.BottomAppBar
import androidx.compose.material.ContentAlpha
import androidx.compose.material.Icon
import androidx.compose.material.IconButton
import androidx.compose.material.LocalContentAlpha
import androidx.compose.material.icons.Icons
import androidx.compose.material.icons.filled.Favorite
import androidx.compose.material.icons.filled.Menu
import androidx.compose.runtime.CompositionLocalProvider
import androidx.compose.ui.Modifier

BottomAppBar(windowInsets = AppBarDefaults.bottomAppBarWindowInsets) {
    // Leading icons should typically have a high content alpha
    CompositionLocalProvider(LocalContentAlpha provides ContentAlpha.high) {
        IconButton(onClick = { /* doSomething() */ }) {
            Icon(Icons.Filled.Menu, contentDescription = "Localized description")
        }
    }
    // The actions should be at the end of the BottomAppBar. They use the default medium
    // content alpha provided by BottomAppBar
    Spacer(Modifier.weight(1f, true))
    IconButton(onClick = { /* doSomething() */ }) {
        Icon(Icons.Filled.Favorite, contentDescription = "Localized description")
    }
    IconButton(onClick = { /* doSomething() */ }) {
        Icon(Icons.Filled.Favorite, contentDescription = "Localized description")
    }
}

Parameters
`modifier: Modifier = Modifier`	The `Modifier` to be applied to this BottomAppBar
`backgroundColor: Color = MaterialTheme.colors.primarySurface`	The background color for the BottomAppBar. Use `Color.Transparent` to have no color.
`contentColor: Color = contentColorFor(backgroundColor)`	The preferred content color provided by this BottomAppBar to its children. Defaults to either the matching content color for `backgroundColor`, or if `backgroundColor` is not a color from the theme, this will keep the same value set above this BottomAppBar.
`cutoutShape: Shape? = null`	the shape of the cutout that will be added to the BottomAppBar - this should typically be the same shape used inside the `FloatingActionButton`, when `BottomAppBar` and `FloatingActionButton` are being used together in `Scaffold`. This shape will be drawn with an offset around all sides. If null, where will be no cutout.
`elevation: Dp = AppBarDefaults.BottomAppBarElevation`	the elevation of this BottomAppBar.
`contentPadding: PaddingValues = AppBarDefaults.ContentPadding`	the padding applied to the content of this BottomAppBar
`content: @Composable RowScope.() -> Unit`	the content of this BottomAppBar. The default layout here is a `Row`, so content inside will be placed horizontally.

BottomAppBar

Cmn

Artifact: androidx.compose.material:material

View Source

@Composable
fun BottomAppBar(
    windowInsets: WindowInsets,
    modifier: Modifier = Modifier,
    backgroundColor: Color = MaterialTheme.colors.primarySurface,
    contentColor: Color = contentColorFor(backgroundColor),
    cutoutShape: Shape? = null,
    elevation: Dp = AppBarDefaults.BottomAppBarElevation,
    contentPadding: PaddingValues = AppBarDefaults.ContentPadding,
    content: @Composable RowScope.() -> Unit
): Unit

Material Design bottom app bar

A bottom app bar displays navigation and key actions at the bottom of screens.

App bars: bottom
image

This particular overload provides ability to specify WindowInsets. Recommended value can be found in AppBarDefaults.bottomAppBarWindowInsets.

It can also optionally display a FloatingActionButton, which is either overlaid on top of the BottomAppBar, or inset, carving a cutout in the BottomAppBar.

See BottomAppBar anatomy for the recommended content depending on the FloatingActionButton position.

Note that when you pass a non-null cutoutShape this makes the AppBar shape concave. The shadows for such shapes will not be drawn on Android versions less than 10.

Also see BottomNavigation.

import androidx.compose.foundation.layout.Spacer
import androidx.compose.material.AppBarDefaults
import androidx.compose.material.BottomAppBar
import androidx.compose.material.ContentAlpha
import androidx.compose.material.Icon
import androidx.compose.material.IconButton
import androidx.compose.material.LocalContentAlpha
import androidx.compose.material.icons.Icons
import androidx.compose.material.icons.filled.Favorite
import androidx.compose.material.icons.filled.Menu
import androidx.compose.runtime.CompositionLocalProvider
import androidx.compose.ui.Modifier

BottomAppBar(windowInsets = AppBarDefaults.bottomAppBarWindowInsets) {
    // Leading icons should typically have a high content alpha
    CompositionLocalProvider(LocalContentAlpha provides ContentAlpha.high) {
        IconButton(onClick = { /* doSomething() */ }) {
            Icon(Icons.Filled.Menu, contentDescription = "Localized description")
        }
    }
    // The actions should be at the end of the BottomAppBar. They use the default medium
    // content alpha provided by BottomAppBar
    Spacer(Modifier.weight(1f, true))
    IconButton(onClick = { /* doSomething() */ }) {
        Icon(Icons.Filled.Favorite, contentDescription = "Localized description")
    }
    IconButton(onClick = { /* doSomething() */ }) {
        Icon(Icons.Filled.Favorite, contentDescription = "Localized description")
    }
}

Parameters
`windowInsets: WindowInsets`	a window insets that app bar will respect.
`modifier: Modifier = Modifier`	The `Modifier` to be applied to this BottomAppBar
`backgroundColor: Color = MaterialTheme.colors.primarySurface`	The background color for the BottomAppBar. Use `Color.Transparent` to have no color.
`contentColor: Color = contentColorFor(backgroundColor)`	The preferred content color provided by this BottomAppBar to its children. Defaults to either the matching content color for `backgroundColor`, or if `backgroundColor` is not a color from the theme, this will keep the same value set above this BottomAppBar.
`cutoutShape: Shape? = null`	the shape of the cutout that will be added to the BottomAppBar - this should typically be the same shape used inside the `FloatingActionButton`, when `BottomAppBar` and `FloatingActionButton` are being used together in `Scaffold`. This shape will be drawn with an offset around all sides. If null, where will be no cutout.
`elevation: Dp = AppBarDefaults.BottomAppBarElevation`	the elevation of this BottomAppBar.
`contentPadding: PaddingValues = AppBarDefaults.ContentPadding`	the padding applied to the content of this BottomAppBar
`content: @Composable RowScope.() -> Unit`	the content of this BottomAppBar. The default layout here is a `Row`, so content inside will be placed horizontally.