Why MotionLayout collapsing animation not auto completed with NestedScrollView?

Question

I have created custom collapsing view using MotionLayout instead of Coordinator everything is working except auto completion of animation or in coordinator we can call it snapping, like when we scroll and stop scroll in between then Collapsing view will auto snap either top or bottom. but this is not happening if i use NestedScrollView inside MotionLayout. I have created sample to demo this. I have also added app:onTouchUp="autoComplete" but it does not work.

motion_layout.xml

<androidx.constraintlayout.motion.widget.MotionLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
android:layout_width="match_parent"
android:layout_height="match_parent"
app:layoutDescription="@xml/motion_scene">

<View
    android:id="@+id/collapsible"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:background="@color/red" />

<androidx.core.widget.NestedScrollView
    android:id="@+id/nested_scroll_view"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content">

    <LinearLayout
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:orientation="vertical">

        <View
            android:layout_width="match_parent"
            android:layout_height="100dp"
            android:background="#EEE" />

    ///.......///

    </LinearLayout>

</androidx.core.widget.NestedScrollView>

motion_scene.xml

<MotionScene xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto">

    <Transition
        app:constraintSetEnd="@id/end"
        app:constraintSetStart="@id/start"
        app:duration="1000">

        <OnSwipe
            app:dragDirection="dragUp"
            app:onTouchUp="autoComplete"
            app:touchAnchorId="@id/nested_scroll_view"
            app:touchAnchorSide="top" />

    </Transition>

    <ConstraintSet android:id="@+id/start">

        <Constraint
            android:id="@+id/collapsible"
            android:layout_width="0dp"
            android:layout_height="300dp"
            app:layout_constraintEnd_toEndOf="parent"
            app:layout_constraintStart_toStartOf="parent"
            app:layout_constraintTop_toTopOf="parent" />

        <Constraint
            android:id="@id/nested_scroll_view"
            android:layout_width="0dp"
            android:layout_height="0dp"
            app:layout_constraintBottom_toBottomOf="parent"
            app:layout_constraintEnd_toEndOf="parent"
            app:layout_constraintStart_toStartOf="parent"
            app:layout_constraintTop_toBottomOf="@id/collapsible" />

    </ConstraintSet>

    <ConstraintSet
        android:id="@+id/end"
        app:deriveConstraintsFrom="@id/start">

        <Constraint
            android:id="@+id/collapsible"
            android:layout_width="0dp"
            android:layout_height="100dp"
            app:layout_constraintEnd_toEndOf="parent"
            app:layout_constraintStart_toStartOf="parent"
            app:layout_constraintTop_toTopOf="parent" />

        <Constraint
            android:id="@id/nested_scroll_view"
            android:layout_width="0dp"
            android:layout_height="0dp"
            app:layout_constraintBottom_toBottomOf="parent"
            app:layout_constraintEnd_toEndOf="parent"
            app:layout_constraintStart_toStartOf="parent"
            app:layout_constraintTop_toBottomOf="@id/collapsible" />

    </ConstraintSet>

</MotionScene>

Hi! Did you find any solution for this? – Oleg Nestyuk Jan 11 '20 at 15:36 — Oleg Nestyuk, Jan 11 '20 at 15:36
@OlegNestyuk no, still not found anything. – Kulwinder Singh Rahal Jan 12 '20 at 06:56 — Kulwinder Singh Rahal, Jan 12 '20 at 06:56

score 2 · Answer 1 · answered Jan 22 '20 at 16:05

2

Just Add to The NestedScrollView > LinearLayout

android:descendantFocusability="blocksDescendants"

answered Jan 22 '20 at 16:05

Mohhamed Nabil

4,104
1
15
11

This should be the accepted answer. – Catalin Ghita Nov 15 '21 at 14:41

Why MotionLayout collapsing animation not auto completed with NestedScrollView?

1 Answers1