MyVerticalBox.kt

@Composable
inline fun MyVerticalBox(
    name: String,
    modifier: Modifier = Modifier,
    content: @Composable () -> Unit = {}
) {
    Layout(
        content = { content() },
        modifier = modifier
    ) { measurables: List<Measurable>,
        constraints: Constraints ->
        // ① Measure children
        val placeables = measurables.mapIndexed { index, measurable ->
            measurable.measure(constraints)
        }

        // ② Decide own size
        val height = maxOf(placeables.sumOf { it.height }, constraints.minHeight)
        val width = maxOf(placeables.maxOfOrNull { it.width } ?: 0, constraints.minWidth)
        val layout = layout(width, height) {
            // ③ Place children
            var y = 0
            placeables.forEach { placable: Placeable ->
                placable.placeRelative(x = 0, y = y)
                y += placable.height
            }
        }
        layout
    }
}