Regarding Android Jetpack-Compose it is common practice to put your logic-parts inside your view-model.
Thats why I am using UI-States to abstract my businesslogic from what I display.
But where should I put necessary “visual-decision-logic” at.

This question is intended as a generic question of architecture best-practice in android compose.

visual-decision-logic := what is to be displayed depending on UI-State

Example – allowing simple logic inside nested composables

/**
 * this is the topmost Composable which is called by the Activity
 */
@Composable
fun DashboardScreen(dashboardViewModel: DashboardViewModel = hiltViewModel()) {
    val dashboardLayoutState: DashboardLayoutState? by
    dashboardViewModel.dashboardLayoutState.collectAsStateWithLifecycle()

    val isLongpressHintDisplayed: Boolean by
    dashboardViewModel.isLongpressHintDisplayed.collectAsStateWithLifecycle(
        initialValue = false
    )

    DashboardComposable(
        isLongpressHintDisplayed,
        dashboardLayoutState
    )
}

@Composable
private fun DashboardComposable(
    isHintDisplayed: Boolean,
    dashboardLayoutState: DashboardLayoutState?
) {
    val pagerState = rememberPagerState(pageCount = { dashboardLayoutState.pages.size })
    HorizontalPager(
        state = pagerState
    ) { index ->

        // question is about this if statement/logic
        // also a longer when-statement could be here instead
        if (isHintDisplayed) {
            HintComposable()
        } else {
            DashboardPageComposable(
                pageIndex = index
            )
        }
    }
}

pro: straight forward coding, local-variables like pagerState are stored and used where needed
con: nested components are not “good” testable because of “hidden” paths and may get worst in bigger compose-trees