rosjava/android_tutorial_teleop/res/layout/main.xml

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent" >

    <org.ros.android.view.visualization.VisualizationView
        android:id="@+id/visualization"
        android:layout_width="match_parent"
        android:layout_height="match_parent" />

    <org.ros.android.view.VirtualJoystickView
        android:id="@+id/virtual_joystick"
        android:layout_width="300dip"
        android:layout_height="300dip"
        android:layout_alignParentBottom="true"
        android:layout_alignParentRight="true" />

</RelativeLayout>