IllegalArgumentException: Key Screen:transition was used multiple times about voyager

[diegoberaldin]

I had a similar problem or, rather, the same exception in a slightly different scenario.

I had a screen showing a detail about an item which could optionally open a screen to show the detail about a "related" item.

These were two different instances of the same Screen subclass. Without transitions everything worked fine, when adding transitions opening the related screen crashed with the transition was used multiple times error.

Solution: overriding the key property and return a custom unique key, in my case concatenating the item ID was enough since in my context the relation is not reflexive so no two instances of the same screen with the same ID can ever be adjacent.

PS: If the navigation is A -> B -> A (the relation is symmetric) no issue and no crash whatsoever.

[j-roskopf]

For now, I just ended up doing my own debouncing click operator in my compose

private const val DEBOUNCE_TIME_MILLIS = 1000L

internal interface EventProcessor {
    fun processEvent(event: () -> Unit)

    companion object {
        val buttonClickMap = mutableMapOf<String, EventProcessor>()
    }
}

internal fun EventProcessor.Companion.get(id: String): EventProcessor {
    return buttonClickMap.getOrPut(
        id
    ) {
        EventProcessorImpl()
    }
}

private class EventProcessorImpl : EventProcessor {
    private val now: Long
        get() = Clock.System.now().toEpochMilliseconds()

    private var lastEventTimeMs: Long = 0

    override fun processEvent(event: () -> Unit) {
        if (now - lastEventTimeMs >= DEBOUNCE_TIME_MILLIS) {
            event.invoke()
        }
        lastEventTimeMs = now
    }
}

@Composable
fun debouncedClick(
    id: String = randomUUID(),
    onClick: () -> Unit,
): () -> Unit {
    val multipleEventsCutter = remember { EventProcessor.get(id) }
    val newOnClick: () -> Unit = {
        multipleEventsCutter.processEvent { onClick() }
    }
    return newOnClick
}

Usage:

Button(
    onClick = debouncedClick {
        // clicked
    },
) {
    Text("Button")
}

[hypergonial]

I ran into this while trying to nest a TabNavigator into a Navigator funnily enough.