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Project: platform/frameworks/support
Branch: androidx-main
Author: Jossi Wolf <jossiwolf@google.com>
Link:      https://android-review.googlesource.com/3278651

Update AnchoredDraggable target calculation logic

Update AnchoredDraggable target calculation logic

We were previously relying on currentValue and the next closest anchor in the drag direction, but the simpler and more reliable way is to look at the left and right anchors as the window.

Relnote: Fixed a bug where positional thresholds passed to AnchoredDraggableDefaults.flingBehavior were not considered correctly in some scenarios.
Test: anchoredDraggable_fling_offsetPastHalfwayBetweenAnchors_beforePosThreshold_doesntAdvance
Bug: 367660226
Bug: 366003852
Change-Id: Ifdf0dfcf3d7ff8288affee56e7092bbed473d6ab

The following release(s) address this bug.It is possible this bug has only been partially addressed:

• androidx.compose.foundation:foundation:1.8.0-alpha04
• androidx.compose.foundation:foundation-android:1.8.0-alpha04
• androidx.compose.foundation:foundation-jvmstubs:1.8.0-alpha04

Using the new version 1.8.0-alpha04 does not seem to resolve the issue for me. I tested with the same setting as the reported issue:

            // it doesn't matter what you put here a the multiplier, the positionalThreshold is always 50%
            positionalThreshold = { d -> d * 0.9f },
            velocityThreshold = { Float.POSITIVE_INFINITY },

Same. I've run this again on 1.8.0-alpha04. When using

positionalThreshold = { d -> d * 0.1f }

Dragging up to 10% or between 50% and 90% will cause it to snap back to the start anchor. Dragging between 10% and 50% or past 90% will cause it to snap to the end anchor.

I would expect It to only return if dragged less than or equal to 10% and snap to the end if dragged greater than 10%.

When using

positionalThreshold = { d -> d * 0.9f }

It acts as if the threshold has been set to 50%.

From what I can tell, nothing has changed about the behavior.

Thanks, we will investigate and update this issue.

Project: platform/frameworks/support
Branch: androidx-main
Author: Jossi Wolf <jossiwolf@google.com>
Link:      https://android-review.googlesource.com/3343747

Update AnchoredDraggable target calculation logic

Update AnchoredDraggable target calculation logic 
 
There was a missed case when the velocity was negative. 
 
Test: New tests with more parameter permutations 
Fixes: 367660226 
Bug: 376931805 
Relnote: "Follow-up fix for an issue in AnchoredDraggable's target calculation where it could settle at the wrong anchor for specific swipes." 
Change-Id: I23b8773d3a694aa3c8de6a8f34b9d7fb54cfe560

What is the fix version?

We will comment on the issue when it has been included in a release. Until then, you can try the snapshot versions from androidx.dev.

The following release(s) address this bug.It is possible this bug has only been partially addressed:

• androidx.compose.foundation:foundation:1.8.0-alpha07
• androidx.compose.foundation:foundation-android:1.8.0-alpha07
• androidx.compose.foundation:foundation-jvmstubs:1.8.0-alpha07
• androidx.compose.foundation:foundation-linuxx64stubs:1.8.0-alpha07

#15, please report a new issue with a full reproduction case and the versions you are using. Thank you!

Running compose foundation 1.8.0-alpha07

I'm using AnchoredDraggable with nested scrolling. When I drag and release the lazy layout sometimes the draggable settles correctly and sometimes it doesn't even when i drag and release past the threshold (positionalThreshold = { distance -> distance / 2f }.

    internal fun nestedScrollConnection(
        dragState: AnchoredDraggableState<Anchors>,
        decayAnimationSpec: DecayAnimationSpec<Float>,
        orientation: Orientation = Orientation.Vertical,
    ): NestedScrollConnection = object : NestedScrollConnection {

        override fun onPreScroll(
            available: Offset,
            source: NestedScrollSource,
        ): Offset {
            val availableDelta = available.toFloat()

            return if (
                availableDelta < 0f
            ) dragState.dispatchRawDelta(availableDelta).toOffset()
            else Offset.Zero
        }

        override fun onPostScroll(
            consumed: Offset,
            available: Offset,
            source: NestedScrollSource,
        ): Offset {
            val availableDelta = available.toFloat()

            return if (
                availableDelta >= 0f
            ) dragState.dispatchRawDelta(availableDelta).toOffset()
            else Offset.Zero
        }

        override suspend fun onPreFling(
            available: Velocity,
        ): Velocity {
            val availableDelta = available.toFloat()

            val consumedOffset = if (availableDelta < 0f) dragState.animateToWithDecay(
                velocity = availableDelta,
                targetValue = Anchors.Collapsed,
                decayAnimationSpec = decayAnimationSpec,
            ) else 0f

            return Velocity(
                x = 0f,
                y = consumedOffset,
            )
        }

        override suspend fun onPostFling(
            consumed: Velocity,
            available: Velocity,
        ): Velocity {
            val availableDelta = available.toFloat()

            if (
                availableDelta > 0f
            ) dragState.animateToWithDecay(
                velocity = availableDelta,
                targetValue = Anchors.Expanded,
                decayAnimationSpec = decayAnimationSpec,
            )

            dragState.settle(animationSpec = spring())

            return Velocity(x = 0f, y = availableDelta)
        }

        private fun Float.toOffset(): Offset = Offset(
            y = if (orientation == Orientation.Vertical) this else 0f,
            x = if (orientation == Orientation.Horizontal) this else 0f,
        )

        @JvmName("offsetToFloat")
        private fun Offset.toFloat() = if (orientation == Orientation.Horizontal) x else y

        @JvmName("velocityToFloat")
        private fun Velocity.toFloat() = if (orientation == Orientation.Horizontal) x else y
    }