samples/VirtualDeviceManager/client/res/layout/activity_main.xml

<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout 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"
    android:orientation="vertical">

    <androidx.appcompat.widget.Toolbar
        android:id="@+id/main_tool_bar"
        android:layout_width="0dp"
        android:layout_height="?attr/actionBarSize"
        android:background="?attr/colorPrimary"
        android:elevation="4dp"
        android:theme="@style/ThemeOverlay.AppCompat.ActionBar"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toTopOf="parent"
        app:popupTheme="@style/ThemeOverlay.AppCompat.Light" />

    <androidx.fragment.app.FragmentContainerView
        android:id="@+id/connectivity_fragment_container"
        android:name="com.example.android.vdmdemo.common.ConnectivityFragment"
        android:layout_width="0dp"
        android:layout_height="wrap_content"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toBottomOf="@+id/main_tool_bar" />

    <com.example.android.vdmdemo.client.ClientView
        android:id="@+id/displays"
        android:layout_width="wrap_content"
        android:layout_height="0dp"
        app:layout_constraintBottom_toTopOf="@+id/guideline"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toBottomOf="@+id/connectivity_fragment_container" />

    <androidx.constraintlayout.widget.Guideline
        android:id="@+id/guideline"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:orientation="horizontal"
        app:layout_constraintGuide_percent="0.8" />

    <androidx.fragment.app.FragmentContainerView
        android:id="@+id/dpad_fragment_container"
        android:name="com.example.android.vdmdemo.common.DpadFragment"
        android:layout_width="0dp"
        android:layout_height="0dp"
        android:visibility="gone"
        app:layout_constraintBottom_toBottomOf="parent"
        app:layout_constraintEnd_toStartOf="@+id/nav_touchpad_fragment_container"
        app:layout_constraintHorizontal_chainStyle="packed"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toBottomOf="@+id/guideline" />

    <androidx.fragment.app.FragmentContainerView
        android:id="@+id/nav_touchpad_fragment_container"
        android:name="com.example.android.vdmdemo.common.NavTouchpadFragment"
        android:layout_width="0dp"
        android:layout_height="0dp"
        android:visibility="gone"
        app:layout_constraintBottom_toBottomOf="parent"
        app:layout_constraintEnd_toStartOf="@+id/rotary_fragment_container"
        app:layout_constraintHorizontal_chainStyle="packed"
        app:layout_constraintStart_toEndOf="@+id/dpad_fragment_container"
        app:layout_constraintTop_toBottomOf="@+id/guideline" />

    <androidx.fragment.app.FragmentContainerView
        android:id="@+id/rotary_fragment_container"
        android:name="com.example.android.vdmdemo.common.RotaryFragment"
        android:layout_width="0dp"
        android:layout_height="0dp"
        android:visibility="gone"
        app:layout_constraintBottom_toBottomOf="parent"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintHorizontal_chainStyle="packed"
        app:layout_constraintStart_toEndOf="@+id/nav_touchpad_fragment_container"
        app:layout_constraintTop_toBottomOf="@+id/guideline" />

</androidx.constraintlayout.widget.ConstraintLayout>