car/res/layout/car_list_dialog.xml

<?xml version="1.0" encoding="utf-8"?>
<!-- Copyright (C) 2018 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.
-->

<FrameLayout
    xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    android:id="@+id/container"
    android:background="@android:color/transparent"
    android:layout_width="match_parent"
    android:layout_height="match_parent" >

    <!-- Note: the width is 0dp because ColumnCardView will automatically set a width based
         on the number of columns it should take up. See ColumnCardView for more details. -->
    <androidx.car.widget.ColumnCardView
        android:layout_gravity="center"
        android:layout_width="0dp"
        android:layout_height="wrap_content"
        android:layout_marginTop="@dimen/car_padding_4"
        android:layout_marginBottom="@dimen/car_padding_4"
        android:elevation="@dimen/car_dialog_elevation"
        app:cardBackgroundColor="?attr/dialogBackgroundColor"
        app:cardCornerRadius="@dimen/car_radius_3">

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

            <!-- Note: the title needs a background in order for elevation to show up. -->
            <TextView
                android:id="@+id/title"
                android:background="?attr/dialogBackgroundColor"
                android:layout_width="match_parent"
                android:layout_height="@dimen/car_dialog_header_height"
                android:paddingStart="@dimen/car_keyline_1"
                android:paddingEnd="@dimen/car_keyline_1"
                android:gravity="center_vertical|start"
                android:visibility="gone"
                style="?attr/dialogTitleStyle" />

            <!-- Hide the scrollbar for this PagedListView because it will be implemented by
                 @id/scrollbar. -->
            <androidx.car.widget.PagedListView
                android:id="@+id/list"
                android:layout_width="match_parent"
                android:layout_height="wrap_content"
                android:theme="?attr/dialogListTheme"
                app:gutter="none"
                app:dividerStartMargin="@dimen/car_keyline_1"
                app:dividerEndMargin="@dimen/car_keyline_1"
                app:showPagedListViewDivider="true"
                app:scrollBarEnabled="false" />
        </LinearLayout>
    </androidx.car.widget.ColumnCardView>

    <!-- Putting this as the last child for highest z-index. It is also clickable to reduce
         the chance of clicks on the buttons accidentally dismissing the dialog. -->
    <androidx.car.widget.PagedScrollBarView
        android:id="@+id/scrollbar"
        android:layout_width="@dimen/car_margin"
        android:layout_height="match_parent"
        android:layout_marginTop="@dimen/car_padding_4"
        android:layout_marginBottom="@dimen/car_padding_4"
        android:layout_gravity="start|top"
        android:clickable="true"
        android:visibility="invisible" />
</FrameLayout>