Any(better) approach to pass compose desktop's `onClick` through `callbackFow`?

Question

I was wondering if it is possible to pass onClik [handling onClick] through callbackFlow as I saw from this this post. I was having hard time implementing since the onClick Callback was inside parameter also Button is function so wasn`t able to implement extension function

anyways I tried something like


    lateinit var buttonListener :Flow<Unit>



    fun <T >offers(t: T) = callbackFlow {
        offer(t)
    awaitClose { null }
    }

    CoroutineScope(IO).launch {
        if(::buttonListener.itInitalized){
            buttonListener.collect {
                println("it => Kotlin.Unit")
            }        
        }
    }
    MaterialTheme {

                  Button(
                    onClick = {
                        println("buttonClicked")
                        buttonListener = offers(Unit)

                    } //...
                ) { /** designs */}

    }

which is callable only 1 times on every runtime

buttonClicked                 <--\ 
Kotlin.Unit => Kotlin.Unit    <--/\__first click
buttonClicked
buttonClicked
buttonClicked

yet expecting someting like

buttonClicked
Kotlin.Unit => Kotlin.Unit
buttonClicked
Kotlin.Unit => Kotlin.Unit
buttonClicked
Kotlin.Unit => Kotlin.Unit

score 1 · Accepted Answer · answered May 31 '21 at 18:45

You can use coroutine Channel instead of Flow to receive events from outside the coroutine. Then convert it to Flow using consumeAsFlow() method.

Now the flow operators like collect can be called on this Flow.

It can receive multiple onClick events from the button composable.

var buttonListener = Channel<Unit>()

CoroutineScope(Dispatchers.IO).launch {
    buttonListener.consumeAsFlow().collect {
        Log.d(TAG, "onCreate: $it => Kotlin.Unit")
    }
}

MaterialTheme {
    Button(
        onClick = {
            Log.d(TAG, "onCreate: buttonClicked")
            buttonListener.offer(Unit)
        }
    ){
        Text(text = "Button")
    }
}

Any(better) approach to pass compose desktop's `onClick` through `callbackFow`?

1 Answers1