apps/OboeTester/app/src/main/res/layout/activity_test_input.xml

<?xml version="1.0" encoding="utf-8"?>
<ScrollView
    xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:fillViewport="true"
    tools:context="com.mobileer.oboetester.TestInputActivity"
    >
<LinearLayout
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:orientation="vertical"
    android:paddingBottom="@dimen/activity_vertical_margin"
    android:paddingLeft="@dimen/activity_horizontal_margin"
    android:paddingRight="@dimen/activity_horizontal_margin"
    android:paddingTop="@dimen/activity_vertical_margin"
    >

    <include layout="@layout/merge_audio_common"/>

    <com.mobileer.oboetester.CommunicationDeviceView
        android:id="@+id/comm_device_view"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:gravity="center"
        android:orientation="horizontal" />

    <com.mobileer.oboetester.VolumeBarView
        android:id="@+id/volumeBar0"
        android:layout_marginBottom="4dp"
        android:layout_width="fill_parent"
        android:layout_height="20dp" />

    <com.mobileer.oboetester.VolumeBarView
        android:id="@+id/volumeBar1"
        android:layout_marginBottom="4dp"
        android:layout_width="fill_parent"
        android:layout_height="20dp" />

    <com.mobileer.oboetester.VolumeBarView
        android:id="@+id/volumeBar2"
        android:layout_marginBottom="4dp"
        android:layout_width="fill_parent"
        android:layout_height="20dp" />

    <com.mobileer.oboetester.VolumeBarView
        android:id="@+id/volumeBar3"
        android:layout_marginBottom="4dp"
        android:layout_width="fill_parent"
        android:layout_height="20dp" />
</LinearLayout>
</ScrollView>