Toolbar composable

MainActivity.kt

@Composable
private fun Toolbar(scroll: ScrollState, headerHeightPx: Float, toolbarHeightPx: Float) {
    val toolbarBottom = headerHeightPx - toolbarHeightPx
    val showToolbar by remember {
        derivedStateOf { scroll.value >= toolbarBottom }
    }

    AnimatedVisibility(
        visible = showToolbar,
        enter = fadeIn(animationSpec = tween(300)),
        exit = fadeOut(animationSpec = tween(300))
    ) {
.
.