Hi folks, I’m trying to use `PinnedScrollBehavior`...

# compose

[Jakub Ledwon]

Hi folks, I’m trying to use PinnedScrollBehavior for TopBar, the thing is that my LazyColumn has reverseLayout set to true. Because of that TopBar only changes color when I scroll to the top and then start scrolling to the bottom again, which is not the desired behaviour. Has anyone dealt with the same case?

[Jakub Ledwon]

I’ve come up with something like:

class ReversedPinnedScrollBehaviour(
    override val state: TopAppBarState,
    val canScroll: () -> Boolean = { true }
) : TopAppBarScrollBehavior {
    override val isPinned: Boolean = true
    override val flingAnimationSpec: DecayAnimationSpec<Float>? = null
    override val snapAnimationSpec: AnimationSpec<Float>? = null
    override val nestedScrollConnection: NestedScrollConnection =
        object : NestedScrollConnection {
            override fun onPostScroll(
                consumed: Offset,
                available: Offset,
                source: NestedScrollSource
            ): Offset {
                if (!canScroll()) return Offset.Zero
                if (consumed.y == 0f && available.y < 0f) {
                    // Reset the total content offset to zero when scrolling all the way down.
                    // This will eliminate some float precision inaccuracies.
                    state.contentOffset = 0f
                } else {
                    state.contentOffset -= consumed.y
                }
                return Offset.Zero
            }
        }
}

But I wonder if there is out of the box solution for that 🤔 ?

[Jakub Ledwon]

If anyone’s interested I’ve added it to issue tracker https://issuetracker.google.com/issues/262234750