OverlayBottomSheetScaffold.kt

@ExperimentalMaterialApi
@Composable
fun OverlayBottomSheetScaffold(
    sheetContent: @Composable ColumnScope.() -> Unit,
    scaffoldState: BottomSheetScaffoldState = rememberBottomSheetScaffoldState(),
    sheetPeekHeight: Dp = 0.dp,
    maxOverlayAlpha: Float = 0.7f,
    overlayColor: Color = Color.Black,
    cancelable: Boolean = true,
    content: @Composable (PaddingValues) -> Unit,
) {
    BottomSheetScaffold(
        sheetContent = sheetContent,
        scaffoldState = scaffoldState,
        sheetPeekHeight = sheetPeekHeight
    ) {
        Box {
            content(it)

            val bottomSheetState = scaffoldState.bottomSheetState
            val bottomSheetProgress = bottomSheetState.progress
            val coroutineScope = rememberCoroutineScope()

            if ((bottomSheetProgress.to == BottomSheetValue.Expanded) or (bottomSheetState.currentValue == BottomSheetValue.Expanded)) {
                val fraction = bottomSheetProgress.fraction
                val alpha = min(fraction, maxOverlayAlpha)
                val alphaDifference = maxOverlayAlpha.minus(alpha)

                Box(
                    modifier = Modifier
                        .fillMaxSize()
                        .alpha(if (bottomSheetProgress.to == BottomSheetValue.Collapsed) alphaDifference else maxOverlayAlpha)
                        .background(color = overlayColor)
                        .clickable(
                            enabled = cancelable,
                            interactionSource = remember { MutableInteractionSource() },
                            indication = null
                        ) {
                            if (bottomSheetState.isExpanded) {
                                coroutineScope.launch {
                                    scaffoldState.bottomSheetState.collapse()
                                }
                            }
                        }
                )
            }
        }
    }
}

@ExperimentalMaterialApi
@Composable
fun SampleScreen() {
    val scaffoldState = rememberBottomSheetScaffoldState()
    val coroutineScope = rememberCoroutineScope()

    OverlayBottomSheetScaffold(
        sheetContent = {
            Column(modifier = Modifier.padding(16.dp)) {
                Box(modifier = Modifier.fillMaxWidth(), contentAlignment = Alignment.Center) {
                    Box(
                        modifier = Modifier
                            .height(5.dp)
                            .width(35.dp)
                            .clip(RoundedCornerShape(percent = 50))
                            .background(Color.Gray)
                    )
                }
                Spacer(modifier = Modifier.height(16.dp))
                Text(text = "Lorem ipsum dolor sit amet", style = MaterialTheme.typography.h6)
                Spacer(modifier = Modifier.height(16.dp))
                Text(text = "Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam, quis nostrud exercitation ullamco laboris nisi ut aliquip ex ea commodo consequat. Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam, quis nostrud exercitation ullamco laboris nisi ut aliquip ex ea commodo consequat.")
            }
        },
        scaffoldState = scaffoldState
    ) {
        Column(
            modifier = Modifier
                .fillMaxSize()
                .padding(16.dp),
            verticalArrangement = Arrangement.Center,
            horizontalAlignment = Alignment.CenterHorizontally
        ) {
            Button(
                modifier = Modifier.fillMaxWidth(),
                onClick = {
                    coroutineScope.launch {
                        scaffoldState.bottomSheetState.expand()
                    }
                }) {
                Text("Expand")
            }
        }
    }
}