Android 9 Development Cookbook - Third Edition

How to do it...

We'll use three buttons to initiate each action, so start by opening activity_main.xml and perform the following steps:

1. Replace the existing layout XML with the following layout:

<?xml version="1.0" encoding="utf-8"?><RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"    xmlns:app="http://schemas.android.com/apk/res-auto"    xmlns:tools="http://schemas.android.com/tools"    android:layout_width="match_parent"    android:layout_height="match_parent"    tools:context=".MainActivity">    <ToggleButton        android:id="@+id/buttonLights"        android:layout_width="wrap_content"        android:layout_height="wrap_content"        android:text="Lights"        android:layout_centerHorizontal="true"        android:layout_above="@+id/buttonAction" ...