IssueTracker

The default fling behavior of the horizontal pager sets the snapPositionalThreshold to 0.5. However, in normal cases, we don’t need to scroll beyond half of the screen since the fling behavior calculates the final snapping bound based on flingVelocity. However, when scrolling from a nested pager to a nearby page, DefaultPagerNestedScrollConnection always returns a velocity of zero. As a result, we are forced to scroll beyond half of the screen to reach the next page.

private class DefaultPagerNestedScrollConnection(
    val state: PagerState,
    val orientation: Orientation
) : NestedScrollConnection {

    fun Velocity.consumeOnOrientation(orientation: Orientation): Velocity {
        return if (orientation == Orientation.Vertical) {
            copy(x = 0f)
        } else {
            copy(y = 0f)
        }
    }

    override suspend fun onPostFling(consumed: Velocity, available: Velocity): Velocity {
        return available.consumeOnOrientation(orientation)
    }
}

In my case, I choose to return the unconsumed velocity. Additionally, as DefaultPagerNestedScrollConnection is a private class, I have to do something like this.

class PagerNestedScrollConnection(
    private val connection: NestedScrollConnection
) : NestedScrollConnection {

    override fun onPreScroll(available: Offset, source: NestedScrollSource): Offset {
        return connection.onPreScroll(available, source)
    }

    override fun onPostScroll(
        consumed: Offset,
        available: Offset,
        source: NestedScrollSource
    ): Offset {
        return connection.onPostScroll(consumed, available, source)
    }

    override suspend fun onPostFling(consumed: Velocity, available: Velocity): Velocity {
        return -consumed
    }
}

@Composable
fun fixPagerNestedScrollConnection(
    pagerState: PagerState,
    orientation: Orientation
): NestedScrollConnection {
    val connection = PagerDefaults.pageNestedScrollConnection(state = pagerState, orientation = orientation)
    return remember(pagerState, orientation) {
        PagerNestedScrollConnection(connection)
    }
}

So I can use it like

HorizontalPager(
    state = pagerState,
    modifier = Modifier.weight(1f),
    pageNestedScrollConnection = fixPagerNestedScrollConnection(pagerState, Orientation.Horizontal)
) { page ->
    
}

I believe there might be a better solution, and I hope this issue can be resolved in future updates.