29.9 Designing the User Interface

This example application calls for a user interface consisting of a ConstraintLayout view with a GestureOverlayView layered on top of it to intercept any gestures performed by the user. Locate the app -> res -> layout -> activity_main.xml file, double-click on it to load it into the Layout Editor tool and select and delete the default TextView widget.

Switch the layout editor Code mode and modify the XML so that it reads as follows:

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

<androidx.constraintlayout.widget.ConstraintLayout

    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...