IssueTracker

We could add an API to make the weighted distance customizable, aosp/3271691 has more info.

Also facing this, if restarting a scroll during an active scroll then the bottom sheet will intercept and dismiss instead of allowing the nested component to scroll.

As a temporary workaround in consumeSwipeWithinBottomSheetBoundsNestedScrollConnection have onPreFling and onPostFling always return Velocity.Zero to not mess with the scrolling components.

Not 100% perfect but still a millions times better than unwanted closing and broken interactions.

As mentioned in https://issuetracker.google.com/issues/353304855#comment2, this looks like a regression after fixing bottom sheet overshoot animation.

As a temporary fix, we can revert BottomSheetAnimationSpec to what it was before:

    /**
     * Latest Material3 Compose library (1.3.0) has a bug in BottomSheetScaffold where scrolling
     * content sometimes bottom sheet takes scroll event and collapses.
     * Open issue to track this: https://issuetracker.google.com/issues/353304855
     * This hack should be removed once the open issue on Google Tracker is fixed.
     */
    private fun modifyBottomSheetAnimationSpec() {
        runCatching {
            Class
                .forName("androidx.compose.material3.SheetDefaultsKt")
                .getDeclaredField("BottomSheetAnimationSpec").apply {
                    isAccessible = true
                }.set(null, SpringSpec<Float>())
        }
    }

This fixes the issue of bottomsheet taking scroll events instead of actual content.

Just dropping this as it might be related to potential fix

https://github.com/androidx/androidx/commit/48c8610152dfb807c2c3dfa0a69ab0ec69e3bcfc

I am having difficulty replicating this bug at head. Is there some additional context we can add here, devices or APIs where this is observed?

Levi are you familiar with similar nested scroll issues occuring with LazyColumn, and could you point us in the right direction in terms of proper nested scroll hierarchy setup here. It is difficult to diagnose given this doesn't consistently happen. Perhaps something to do with touch slop or as users have noted, conflicting animation times?

The easy way to reproduce is fling up any scrollable content then press and drag down. Not necessarily a lazy column.

80% of the time the bottom sheet will be dragged down and not the scrollable content.

My current solution is to disable user drag when nested content can scroll down.

I also observed that flinging up does not close the bottom sheet as often as scrolling slowly. Maybe something to do with scroll velocity.

I'm using a local copy of M3 BottomSheet due to this and quite a few other issues with statusbar, theming and everything.

But mostly the sheetState have a disableNestedScroll and use it in the nestedScollConnection to ignore handling when true.

And then use a Composable to handle this depending on the case.

@Composable
fun NestedScrollStateHandler(navigator: BottomSheetNavigator, scrollState: ScrollState?) {
    if (scrollState != null) {
        val canScroll by remember { derivedStateOf { scrollState.canScrollBackward } }
        navigator.disableNestedScroll(canScroll)
    }
    DisposableEffect(scrollState) {
        onDispose {
            navigator.disableNestedScroll(false)
        }
    }
}

There's other ways to handle this but it works :)

Hi @serniebanders, the usage of nested scrolling seems fine, but this could be a gesture clashing issue. I wasn't able to reproduce it at head as well, though I could reproduce it in 1.3, so I believe this issue has been fixed already, in fact I wasn't able to reproduce it in 1.4.0-alpha01.

For reporter, please re-open the issue if you can reproduce it starting on 1.4.0-alpha01.

Thank you.