RotaryPlayground/res/layout/surface_view_fragment.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
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  ~ 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
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  -->
<FrameLayout
    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">
    <!-- The two FocusAreas are overlapping and nudge targeting is ambiguous. So set its
         "app:startBoundOffset" to fix that. -->
    <com.android.car.ui.FocusArea
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        app:startBoundOffset="300dp">
        <com.android.car.rotaryplayground.CustomSurfaceView
            android:id="@+id/surface_view"
            android:layout_width="match_parent"
            android:layout_height="match_parent"
            android:focusable="true"
            android:background="#A0A0A0"/>
    </com.android.car.ui.FocusArea>
    <com.android.car.ui.FocusArea
        android:layout_width="wrap_content"
        android:layout_height="match_parent"
        android:layout_margin="16dp"
        android:background="#808080"
        android:orientation="vertical">
        <Button
            android:layout_width="200dp"
            android:layout_height="100dp"
            android:text="Button 1"/>
        <Button
            android:layout_width="200dp"
            android:layout_height="100dp"
            android:text="Button 2"/>
        <Button
            android:layout_width="200dp"
            android:layout_height="100dp"
            android:text="Button 3"/>
        <Button
            android:layout_width="200dp"
            android:layout_height="100dp"
            android:text="Button 4"/>
    </com.android.car.ui.FocusArea>
</FrameLayout>