Hi everyone! I want to update a composable dependi...

# compose

[Alejo]

Hi everyone!
I want to update a composable depending on if a user is touching the screen or not. What I want is to update the UI if the user stops interacting with the app for 5 seconds.

[Alejo]

So far I have something like this:

val showSky = remember { mutableStateOf(false) }
    val skyAlpha by animateFloatAsState(if (showSky.value) 1f else .3f)
    val userInteracting = MutableSharedFlow<Long>(replay = 0)
    val coroutineScope = rememberCoroutineScope()

    Box(
        modifier = modifier
            .fillMaxSize()
            .pointerInteropFilter {
                coroutineScope.launch {
                    userInteracting.emit(System.currentTimeMillis())
                }
                false
            }
    ) {
        coroutineScope.launch {
            userInteracting.collectLatest {
                Log.d("pointerInteropFilter", "$it received")
                showSky.value = false
                delay(5000)
                showSky.value = true
                Log.d("pointerInteropFilter", "$it processed")
            }
        }
    }

[Alejo]

The problem I'm facing is that the second time I start interacting with the composable the collectLatest reach showSky.value = true in an old event.
Any help is appreciated to fix this problem or maybe to go in a different direction. Thanks in advanced.

[Alejo]

Here some logs of the first & second time I interact with the composable

First attemp 
2021-06-27 13:27:25.901 1308-1308/com.example.androiddevchallenge.mock D/pointerInteropFilter: 1624811245901 received
2021-06-27 13:27:26.477 1308-1308/com.example.androiddevchallenge.mock D/pointerInteropFilter: 1624811246477 received
2021-06-27 13:27:27.011 1308-1308/com.example.androiddevchallenge.mock D/pointerInteropFilter: 1624811247010 received
2021-06-27 13:27:27.539 1308-1308/com.example.androiddevchallenge.mock D/pointerInteropFilter: 1624811247538 received
2021-06-27 13:27:28.072 1308-1308/com.example.androiddevchallenge.mock D/pointerInteropFilter: 1624811248071 received
2021-06-27 13:27:28.596 1308-1308/com.example.androiddevchallenge.mock D/pointerInteropFilter: 1624811248595 received
2021-06-27 13:27:29.090 1308-1308/com.example.androiddevchallenge.mock D/pointerInteropFilter: 1624811249089 received
2021-06-27 13:27:29.603 1308-1308/com.example.androiddevchallenge.mock D/pointerInteropFilter: 1624811249603 received
2021-06-27 13:27:30.133 1308-1308/com.example.androiddevchallenge.mock D/pointerInteropFilter: 1624811250133 received
2021-06-27 13:27:30.645 1308-1308/com.example.androiddevchallenge.mock D/pointerInteropFilter: 1624811250644 received
2021-06-27 13:27:31.149 1308-1308/com.example.androiddevchallenge.mock D/pointerInteropFilter: 1624811251148 received
2021-06-27 13:27:31.674 1308-1308/com.example.androiddevchallenge.mock D/pointerInteropFilter: 1624811251673 received
2021-06-27 13:27:32.197 1308-1308/com.example.androiddevchallenge.mock D/pointerInteropFilter: 1624811252196 received
2021-06-27 13:27:32.736 1308-1308/com.example.androiddevchallenge.mock D/pointerInteropFilter: 1624811252736 received
2021-06-27 13:27:33.272 1308-1308/com.example.androiddevchallenge.mock D/pointerInteropFilter: 1624811253271 received
2021-06-27 13:27:33.803 1308-1308/com.example.androiddevchallenge.mock D/pointerInteropFilter: 1624811253803 received
2021-06-27 13:27:34.350 1308-1308/com.example.androiddevchallenge.mock D/pointerInteropFilter: 1624811254349 received
2021-06-27 13:27:34.946 1308-1308/com.example.androiddevchallenge.mock D/pointerInteropFilter: 1624811254946 received
2021-06-27 13:27:39.947 1308-1308/com.example.androiddevchallenge.mock D/pointerInteropFilter: 1624811254946 processed
Second attemp
2021-06-27 13:29:06.886 1308-1308/com.example.androiddevchallenge.mock D/pointerInteropFilter: 1624811346886 received
2021-06-27 13:29:07.368 1308-1308/com.example.androiddevchallenge.mock D/pointerInteropFilter: 1624811347367 received
2021-06-27 13:29:07.785 1308-1308/com.example.androiddevchallenge.mock D/pointerInteropFilter: 1624811347784 received
2021-06-27 13:29:08.181 1308-1308/com.example.androiddevchallenge.mock D/pointerInteropFilter: 1624811348181 received
2021-06-27 13:29:08.647 1308-1308/com.example.androiddevchallenge.mock D/pointerInteropFilter: 1624811348646 received
2021-06-27 13:29:09.095 1308-1308/com.example.androiddevchallenge.mock D/pointerInteropFilter: 1624811349095 received
2021-06-27 13:29:09.537 1308-1308/com.example.androiddevchallenge.mock D/pointerInteropFilter: 1624811349536 received
2021-06-27 13:29:09.913 1308-1308/com.example.androiddevchallenge.mock D/pointerInteropFilter: 1624811349912 received
2021-06-27 13:29:10.308 1308-1308/com.example.androiddevchallenge.mock D/pointerInteropFilter: 1624811350307 received
2021-06-27 13:29:10.691 1308-1308/com.example.androiddevchallenge.mock D/pointerInteropFilter: 1624811350690 received
2021-06-27 13:29:11.887 1308-1308/com.example.androiddevchallenge.mock D/pointerInteropFilter: 1624811346886 processed
2021-06-27 13:29:15.692 1308-1308/com.example.androiddevchallenge.mock D/pointerInteropFilter: 1624811350690 processed

[Lukasz Burcon]

Try calling .conflate() on your collect. It stops processing old values when new ones are received

[Lukasz Burcon]

So it would be something like:

.collectLatest{
xxxxx
}.conflate()

[Alejo]

Thanks Lukasz, I try this without luck. Actually my version was

.conflate()
.collectLatest{
xxxxxx
}

but somehow the second time I start interacting with the app the first event scape the collectLatest and completes

[Alejo]

Just in case someone faces the same issue in the future, my problem was not remembering the MutableSharedFlow and that cause the strange behavior. Lesson learned, remember to "remember"