Android Compose - Composable(View) onExpose Implementation

ComposeOnExposeExample.kt

@SuppressLint("CoroutineCreationDuringComposition", "UnnecessaryComposedModifier")
@Composable
fun Modifier.onExpose(
    onVisibilityChanged: (Boolean) -> Unit,
    exposeCriteriaSizeRate: Float = 1f,
): Modifier = composed {
    this.onGloballyPositioned { layoutCoordinates ->
        val boundsInWindow = layoutCoordinates.boundsInWindow()
        val totalArea = layoutCoordinates.size.run { width * height }.toFloat()
        val visibleArea = boundsInWindow.width * boundsInWindow.height
        val visibilityRate = visibleArea / totalArea
        onVisibilityChanged(visibilityRate >= exposeCriteriaSizeRate)
    }
}

// Usage
Row(
    modifier =
        Modifier.onExpose(
            onVisibilityChanged = { isVisible -> viewState.value = isVisible },
            exposeCriteriaSizeRate = 0.5f,
        ),
) {
    Text(
        text = "이 뷰가 절반정도 보여지면 onVisibilityChanged 콜백 트리거링",
        style = PrexTheme.typeScale.textXXS,
        color = PrexTheme.fdsColor.contentAccentInfo,
        maxLines = 1,
    )
}