Bottom sheet

bottomsheet.kt

enum class States {
    EXPANDED,
    COLLAPSED
}

@ExperimentalMaterialApi
@Composable
fun FullHeightBottomSheet(
    header: @Composable () -> Unit,
    body: @Composable () -> Unit
) {
    val swipeableState = rememberSwipeableState(initialValue = States.EXPANDED)
    val scrollState = rememberScrollState()

    BoxWithConstraints {
        val constraintsScope = this
        val maxHeight = with(LocalDensity.current) {
            constraintsScope.maxHeight.toPx()
        }

        val connection = remember {
            object : NestedScrollConnection {

                override fun onPreScroll(
                    available: Offset,
                    source: NestedScrollSource
                ): Offset {
                    val delta = available.y
                    return if (delta < 0) {
                        swipeableState.performDrag(delta).toOffset()
                    } else {
                        Offset.Zero
                    }
                }

                override fun onPostScroll(
                    consumed: Offset,
                    available: Offset,
                    source: NestedScrollSource
                ): Offset {
                    val delta = available.y
                    return swipeableState.performDrag(delta).toOffset()
                }

                override suspend fun onPreFling(available: Velocity): Velocity {
                    return if (available.y < 0 && scrollState.value == 0) {
                        swipeableState.performFling(available.y)
                        available
                    } else {
                        Velocity.Zero
                    }
                }

                override suspend fun onPostFling(
                    consumed: Velocity,
                    available: Velocity
                ): Velocity {
                    swipeableState.performFling(velocity = available.y)
                    return super.onPostFling(consumed, available)
                }

                private fun Float.toOffset() = Offset(0f, this)
            }
        }

        Box(
            Modifier
                .swipeable(
                    state = swipeableState,
                    orientation = Orientation.Vertical,
                    anchors = mapOf(
                        0f to States.EXPANDED,
                        maxHeight to States.COLLAPSED,
                    )
                )
                .nestedScroll(connection)
                .offset {
                    IntOffset(
                        0,
                        swipeableState.offset.value.roundToInt()
                    )
                }
        ) {
            Column(
                Modifier
                    .fillMaxHeight()
                    .background(Color.White)
            ) {
                header()
                Box(
                    Modifier
                        .fillMaxWidth()
                        .verticalScroll(scrollState)
                ) {
                    body()
                }
            }
        }
    }
}

This is amazing @arcadefire 🪨 ⭐ !!