Hey, what’s the best way to smooth scroll to a particular position in `LazyColumnFor` I’m using alph...

# compose

[Hitanshu Dhawan]

Hey, what’s the best way to smooth scroll to a particular position in LazyColumnFor
I’m using alpha08, and I can find methods like LazyListState.snapToItemIndex but this is without smooth scrolling and the method LazyListState.smoothScrollBy doesn’t take the index.
How to smooth scroll to a specific index? Does the API exists for this right now?

[Adam Powell]

https://cs.android.com/androidx/platform/frameworks/support/+/androidx-master-dev:compose/foundation/foundation/src/commonMain/kotlin/androidx/compose/foundation/lazy/LazyListState.kt;l=227?q=LazyListState the .scroll {} api lets you take full control over smooth scrolling over time

[Hitanshu Dhawan]

Thanks for the quick response.
I tried the .scroll {} API, and I’m not sure if I’m using it correctly.
There is only one method for ScrollScope and that is fun scrollBy(pixels: Float): Float
So, I tried this piece of code

onClick = {
    coroutineScope.launch {
        state.scroll {
            state.snapToItemIndex(15)
        }
    }
}

But there is not scrolling or snapping to the index in this case, am I doing something wrong here?

[Adam Powell]

You can animate the scroll yourself by using scrollBy and withFrameNanos or any of the other suspending animation APIs; you can check the current visible items in between frames

[Dominaezzz]

There should be a smoothScrollTo available iirc.

[Marcin Środa]

Agree with @Dominaezzz, right now the easiest way is to forget about smooth and use snapToItemIndex.