Common
```kotlin
@JvmDefaultWithCompatibility
interface Horizontal
```
Used to specify the horizontal arrangement of the layout's children in layouts like [Row](/jetpack-compose/androidx.compose.foundation/foundation-layout/composable-functions/Row).
## Properties
Common
```kotlin
val spacing
```
Spacing that should be added between any two adjacent layout children.
## Functions
arrange
```kotlin
fun Density.arrange(
totalSize: Int,
sizes: IntArray,
layoutDirection: LayoutDirection,
outPositions: IntArray,
)
```
Horizontally places the layout children.
#### Parameters
| | |
| --- | --- |
| totalSize | Available space that can be occupied by the children, in pixels. |
| sizes | An array of sizes of all children, in pixels. |
| layoutDirection | A layout direction, left-to-right or right-to-left, of the parent layout that should be taken into account when determining positions of the children. |
| outPositions | An array of the size of `sizes` that returns the calculated positions relative to the left, in pixels. |