res/layout/activity_cam.xml

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools" android:layout_width="match_parent"
    android:layout_height="match_parent" android:paddingLeft="@dimen/activity_horizontal_margin"
    android:paddingRight="@dimen/activity_horizontal_margin"
    android:paddingTop="@dimen/activity_vertical_margin"
    android:paddingBottom="@dimen/activity_vertical_margin"
    tools:context="dk.thoerup.android.barcodesample.CamActivity">

    <SurfaceView
        android:layout_width="fill_parent"
        android:layout_height="fill_parent"
        android:id="@+id/surfaceView"
        android:layout_centerVertical="true"
        android:layout_centerHorizontal="true" />

</RelativeLayout>
1	<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
2	xmlns:tools="http://schemas.android.com/tools" android:layout_width="match_parent"
3	android:layout_height="match_parent" android:paddingLeft="@dimen/activity_horizontal_margin"
4	android:paddingRight="@dimen/activity_horizontal_margin"
5	android:paddingTop="@dimen/activity_vertical_margin"
6	android:paddingBottom="@dimen/activity_vertical_margin"
7	tools:context="dk.thoerup.android.barcodesample.CamActivity">
8
9	<SurfaceView
10	android:layout_width="fill_parent"
11	android:layout_height="fill_parent"
12	android:id="@+id/surfaceView"
13	android:layout_centerVertical="true"
14	android:layout_centerHorizontal="true" />
15
16	</RelativeLayout>