LayoutAwareModifierNode

LayoutAwareModifierNodeSample

@Composable
fun LayoutAwareModifierNodeSample() {
    class SizeLoggerNode(var id: String) : LayoutAwareModifierNode, Modifier.Node() {
        override fun onRemeasured(size: IntSize) {
            println("The size of $id was $size")
        }
    }
    data class LogSizeElement(val id: String) : ModifierNodeElement<SizeLoggerNode>() {
        override fun create(): SizeLoggerNode = SizeLoggerNode(id)
        override fun update(node: SizeLoggerNode) {
            node.id = id
        }
        override fun InspectorInfo.inspectableProperties() {
            name = "logSize"
            properties["id"] = id
        }
    }
    fun Modifier.logSize(id: String) = this then LogSizeElement(id)
}

OnPlaced

@Composable
fun OnPlaced() {
    fun Modifier.animatePlacement(): Modifier = composed {
        val scope = rememberCoroutineScope()
        var targetOffset by remember { mutableStateOf(IntOffset.Zero) }
        var animatable by remember {
            mutableStateOf<Animatable<IntOffset, AnimationVector2D>?>(null)
        }
        this.onPlaced {
                // Calculate the position in the parent layout
                targetOffset = it.positionInParent().round()
            }
            .offset {
                // Animate to the new target offset when alignment changes.
                val anim =
                    animatable
                        ?: Animatable(targetOffset, IntOffset.VectorConverter).also {
                            animatable = it
                        }
                if (anim.targetValue != targetOffset) {
                    scope.launch {
                        anim.animateTo(targetOffset, spring(stiffness = StiffnessMediumLow))
                    }
                }
                // Offset the child in the opposite direction to the targetOffset, and slowly catch
                // up to zero offset via an animation to achieve an overall animated movement.
                animatable?.let { it.value - targetOffset } ?: IntOffset.Zero
            }
    }
    @Composable
    fun AnimatedChildAlignment(alignment: Alignment) {
        Box(Modifier.fillMaxSize().padding(4.dp).border(1.dp, Color.Red)) {
            Box(
                modifier =
                    Modifier.animatePlacement().align(alignment).size(100.dp).background(Color.Red)
            )
        }
    }
}

OnSizeChangedSample

@Composable
fun OnSizeChangedSample(name: String) {
    // Use onSizeChanged() for diagnostics. Use Layout or SubcomposeLayout if you want
    // to use the size of one component to affect the size of another component.
    Text(
        "Hello $name",
        Modifier.onSizeChanged { size -> println("The size of the Text in pixels is $size") },
    )
}