BarcodeScanner/vision-sample/src/main/res/layout/activity_full_scanner_fragment.xml

<?xml version="1.0" encoding="utf-8"?>

<FrameLayout 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:orientation="vertical">

    <fragment
        android:id="@+id/scanner_fragment"
        android:name="me.dm7.barcodescanner.vision.sample.FullScannerFragment"
        android:layout_width="match_parent"
        android:layout_height="match_parent"/>

    <ImageView
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_gravity="top"
        android:src="@drawable/ic_launcher"
        tools:ignore="ContentDescription"/>

    <TextView
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_gravity="center|bottom"
        android:text="Place a barcode in the viewfinder rectangle to scan it."
        android:textColor="#ffffff"
        tools:ignore="HardcodedText"/>
</FrameLayout>