When adding a RecyclerView as a child/grand-child to the MotionLayout, the Motion-Layout cannot progress across transitions.

[eddardsnarf]

Context: I'm using a modified version of the fragment-transition example, in which we have a MotionLayout containing the TouchFrameLayout. Inside of it I've replaced the fragments in the example with the ListFragment. Afterwards I've modified the main_scene.xml to have multiple transitions like:

MotionScene xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:motion="http://schemas.android.com/apk/res-auto"
    android:id="@+id/motionLayout">
    <Transition
        android:id="@+id/transition_start_mid"
        motion:constraintSetEnd="@id/mid"
        motion:constraintSetStart="@id/start"
        motion:duration="500"
        motion:motionInterpolator="linear" >

        <OnSwipe
            motion:touchAnchorId="@id/container"
            motion:touchAnchorSide="top"
            motion:onTouchUp="decelerateAndComplete"
            motion:dragDirection="dragUp"
            />
    </Transition>

    <Transition
        android:id="@+id/transition_mid_end"
        motion:constraintSetEnd="@id/end"
        motion:constraintSetStart="@id/mid"
        motion:duration="500"
        motion:motionInterpolator="linear" >

        <OnSwipe
            motion:touchAnchorId="@id/container"
            motion:touchAnchorSide="top"
            motion:onTouchUp="decelerateAndComplete"
            motion:dragDirection="dragUp"/>
    </Transition>

    <ConstraintSet android:id="@+id/start">
        <Constraint
            android:id="@id/main"
            android:layout_width="0dp"
            android:layout_height="100dp"
            motion:layout_constraintStart_toStartOf="parent"
            motion:layout_constraintEnd_toEndOf="parent"
            motion:layout_constraintBottom_toBottomOf="parent">
            <CustomAttribute
                motion:attributeName="BackgroundColor"
                motion:customColorValue="@color/colorPrimary" />
        </Constraint>
    </ConstraintSet>

    <ConstraintSet android:id="@+id/mid">
        <Constraint
            android:id="@id/container"
            android:layout_width="0dp"
            android:layout_height="400dp"
            motion:layout_constraintStart_toStartOf="parent"
            motion:layout_constraintEnd_toEndOf="parent"
            motion:layout_constraintBottom_toBottomOf="parent">
            <CustomAttribute
                motion:attributeName="BackgroundColor"
                motion:customColorValue="@color/colorPrimary" />
        </Constraint>
    </ConstraintSet>

    <ConstraintSet android:id="@+id/end">
        <Constraint
            android:id="@id/container"
            android:layout_width="0dp"
            android:layout_height="0dp"
            motion:layout_constraintStart_toStartOf="parent"
            motion:layout_constraintEnd_toEndOf="parent"
            motion:layout_constraintTop_toTopOf="parent"
            motion:layout_constraintBottom_toBottomOf="parent">
            <CustomAttribute
                motion:attributeName="BackgroundColor"
                motion:customColorValue="@color/colorAccent" />
        </Constraint>
    </ConstraintSet>

</MotionScene>

The issue is that if the user tries to scroll the "bottom-sheet" up and down by using the recycler-view, the motionlayout won't progress from one transition to another. Thus making the whole interaction a bit unintuitive.

Is there some way to tell the MotionLayout to use the nested scrolling to progress across transitions?

I'll attach a video of my tests (Please ignore the sticky navy blue view at the bottom.).

https://user-images.githubusercontent.com/33248263/231482798-575bf6de-4261-48f6-b3e8-6dfb2f8f55f1.mov