packages/SystemUI/res/xml/combined_qs_header_scene.xml

<?xml version="1.0" encoding="utf-8"?>
<!--
  ~ Copyright (C) 2021 The Android Open Source Project
  ~
  ~ Licensed under the Apache License, Version 2.0 (the "License");
  ~ you may not use this file except in compliance with the License.
  ~ You may obtain a copy of the License at
  ~
  ~      http://www.apache.org/licenses/LICENSE-2.0
  ~
  ~ Unless required by applicable law or agreed to in writing, software
  ~ distributed under the License is distributed on an "AS IS" BASIS,
  ~ WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  ~ See the License for the specific language governing permissions and
  ~ limitations under the License.
  -->
<MotionScene
    xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto">

    <Transition
        android:id="@+id/header_transition"
        app:constraintSetEnd="@id/qs_header_constraint"
        app:constraintSetStart="@id/qqs_header_constraint">
        <KeyFrameSet>
            <KeyPosition
                app:keyPositionType="pathRelative"
                app:percentX="0"
                app:framePosition="50"
                app:motionTarget="@id/date" />
        </KeyFrameSet>
    </Transition>

    <Transition
        android:id="@+id/split_header_transition"
        app:constraintSetStart="@id/split_header_constraint"
        app:constraintSetEnd="@id/split_header_constraint"/>

    <!--
        Placeholder ConstraintSet. They are populated in the controller for this class.
        This is needed because there's no easy way to just refer to a `ConstraintSet` file. The
        options are either a layout file or inline the ConstraintSets.
     -->
    <ConstraintSet android:id="@id/qqs_header_constraint"/>

    <ConstraintSet android:id="@id/qs_header_constraint"/>

    <ConstraintSet android:id="@id/split_header_constraint" />

</MotionScene>