To help with https://stackoverflow.com/q/57523822/192373 how texture view can hide behind the activity layout

hide_behind.xml

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

    <com.example.android.camera2basic.AutoFitTextureView
        android:id="@+id/texture"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content" />
    
    <RelativeLayout
        android:background="@android:color/black"
        android:layout_width="match_parent"
        android:layout_height="match_parent">
        <!-- usual content of the Activity, e.g. -->
            <TextView
            android:layout_width="match_parent"
            android:layout_height="match_parent"
            android:id="@+id/txt" />

    </RelativeLayout>

</FrameLayout>