In your activity_main.xml file, which resides in your assets/layouts folder, you need to input the following code:

<?xml version="1.0" encoding="utf-8"?>
<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"
    tools:context="com.example.avinaas.imagelabelling.MainActivity">

<TextureView
    android:id="@+id/preview"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:layout_above="@id/btn_takepic"
    android:layout_alignParentTop="true"/>

    <Button
        android:id="@+id/btn_takepic"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_alignParentBottom="true"
        android:layout_centerHorizontal="true"
        android:layout_marginBottom="16dp"
        android:layout_marginTop="16dp"
        android:text="Start Labeling"
        />
</RelativeLayout>

In the preceding XML, we have added a button to receive events, and a texture view, which serves as a placeholder for the camera stream.

The design view of the preceding layout will look like this: