Hi, I have a bit of an issue with my rotary input. My app crashes, with this friendly error message:...

# compose-wear

[Nat Strangerweather]

Hi, I have a bit of an issue with my rotary input. My app crashes, with this friendly error message:
FocusRequester is not initialized. Here are some possible fixes:
1. Remember the FocusRequester: val focusRequester = remember { FocusRequester() }
2. Did you forget to add a Modifier.focusRequester() ?
3. Are you attempting to request focus during composition? Focus requests should be made in
response to some event. Eg Modifier.clickable { focusRequester.requestFocus() }
1 and 2 are done. As for 3, that may be the problem, but I am not sure what I am doing wrong. Please could someone have a look at my code in thread?

[Nat Strangerweather]

My code:

val focusRequester = remember { FocusRequester() }
ScalingLazyColumn(
                state = scalingLazyListState,
                modifier = Modifier
                    .fillMaxSize()
                    .onRotaryScrollEvent {
                        scope.launch {
                            scalingLazyListState.scrollBy(it.verticalScrollPixels)
                        }
                        true
                    }
                    .focusRequester(focusRequester)
                    .focusable(),
                anchorType = ScalingLazyListAnchorType.ItemStart,
                contentPadding = PaddingValues(
                    horizontal = 8.dp,
                ),
                horizontalAlignment = Alignment.CenterHorizontally,
            ) {...}
 LaunchedEffect(key1 = Unit) {
            focusRequester.requestFocus()
        }

[Nat Strangerweather]

This error happens in a very specific situation only. If I update my newsfeed and don't wait for it to load, and click on a different newsfeed while this is happening.

[yschimke]

Does it have 0 items in that state? But I don't see why that would cause it.

[yschimke]

Does it happen while that screen with the SLC is now in the background?

[Nat Strangerweather]

Yes it does. Maybe I could make a video if that would help?

[yschimke]

Possibly. But I think more filing a bug with this info and the video.

[yschimke]

The other thing to try, wear compose 1.2 has some focus helpers, that mean you don't need to call requestFocus yourself.

[yschimke]

And Horologist has a ScalingLazyColumn overload that does all this for you.

[Nat Strangerweather]

ok I am on

wear_compose_version = '1.2.0-alpha07'

[yschimke]

rememberActiveFocusRequester()

[Nat Strangerweather]

Thanks, will give this a shot.

[Nat Strangerweather]

So I have the same problem with Compose 1.2 using rememberActiveFocusRequester()

[Nat Strangerweather]

I'd be happy to try the Horologist ScalingLazyColumn, but is there an example that I can use?

[yschimke]

Tons, for example

https://github.com/google/horologist/blob/main/sample/src/main/java/com/google/android/horologist/sample/MenuScreen.kt

[yschimke]

These all get passed in the column state from the navigation scaffold WearNavScaffold.

[Nat Strangerweather]

Thanks, I was clearly looking in the wrong place lol

[yschimke]

But if you want to try it for a single screen just pass in ScalingLazyColumnDefaults.belowTimeText().create()

[yschimke]

It handles the RSB scrolling for you.

[yschimke]

If you want it wired up to the TimeText and position indicator, you can use that WearNavScaffold I mentioned, like https://github.com/google/horologist/blob/main/sample/src/main/java/com/google/android/horologist/sample/SampleWearApp.kt

[Nat Strangerweather]

Ok brilliant, many thanks!

[Nat Strangerweather]

This works fine! 😊