Is there something like a navigation listener?

[DevAtHeart]

A Listener I can subscribe to that is fired, whenever a navigation happens?

This could be useful to show interstitials for instance.

In the meantime I have come up with the following code:

@Composable
fun NavigationEffect(onNavigate: (prev: Screen, next: Screen) -> Unit) {
    val nextRoute = LocalNavigator.currentOrThrow.lastItem
    val previousRoute = rememberPreviousState(value = nextRoute)

    LaunchedEffect(nextRoute) {
        onNavigate(previousRoute, nextRoute)
    }
}

@Composable
fun <T> rememberPreviousState(value: T): T {
    var previous by remember { mutableStateOf(value) }

    SideEffect {
        if (value != previous) previous = value
    }

    return previous
}

Used like:

NavigationEffect { prev, next ->
    if (prev is MyScreen1 && next is MyScreen2)
        println("Navigation from MyScreen1 to MyScreen2 happened!")
}

There's still a few kinks to work out.

[RaedGhazal]

I'm also interested in this, but looks like no one worked on that since a year and a half 🥲, I'm going to try your solution for now