An example of using the WindowInsetRulers to drive content padding for a LazyColumn

WindowInsetRulersContentPadding.kt

// Copyright 2025 Google LLC.
// SPDX-License-Identifier: Apache-2.0
@Preview
@Composable
fun WindowInsetRulersContentPadding() {
    val paddingValues = remember {
        object : PaddingValues {
            var start by mutableStateOf(0.dp)
            var end by mutableStateOf(0.dp)
            var top by mutableStateOf(0.dp)
            var bottom by mutableStateOf(0.dp)

            override fun calculateLeftPadding(layoutDirection: LayoutDirection): Dp =
                when (layoutDirection) {
                    LayoutDirection.Ltr -> start
                    LayoutDirection.Rtl -> end
                }

            override fun calculateTopPadding(): Dp = top

            override fun calculateRightPadding(layoutDirection: LayoutDirection): Dp =
                when (layoutDirection) {
                    LayoutDirection.Ltr -> end
                    LayoutDirection.Rtl -> start
                }

            override fun calculateBottomPadding(): Dp = bottom
        }
    }

    Box(
        modifier = Modifier
            .fillMaxSize()
            .layout { measurable, constraints ->
                val width = constraints.maxWidth
                val height = constraints.maxHeight
                layout(width, height) {
                    val rectRulers = WindowInsetsRulers.SafeDrawing.current
                    val leftContentPadding = rectRulers.left.current(0f).toDp()
                    val rightContentPadding = (width - rectRulers.right.current(0f)).toDp()

                    when (layoutDirection) {
                        LayoutDirection.Ltr -> {
                            paddingValues.start = leftContentPadding
                            paddingValues.end = rightContentPadding
                        }
                        LayoutDirection.Rtl -> {
                            paddingValues.start = rightContentPadding
                            paddingValues.end = leftContentPadding
                        }
                    }
                    paddingValues.top = rectRulers.top.current(0f).toDp()
                    paddingValues.bottom = (height - rectRulers.bottom.current(0f)).toDp()

                    val placeable = measurable.measure(constraints)
                    placeable.placeRelative(0, 0)
                }
            }
    ) {
        LazyColumn(
            contentPadding = paddingValues,
            modifier = Modifier.fillMaxSize(),
        ) {
            items(100) {
                TextField(
                    state = rememberTextFieldState(),
                    modifier = Modifier.fillMaxWidth(),
                )
            }
        }
    }
}