Book Image

Android Studio 3.5 Development Essentials - Java Edition

By : Neil Smyth
Book Image

Android Studio 3.5 Development Essentials - Java Edition

By: Neil Smyth

Overview of this book

Android applications have become an important part of our daily lives and lots of effort goes into developing an Android application. This book will help you to build you own Android applications using Java. Android Studio 3.5 Development Essentials – Java Edition first teaches you to install Android development and test environment on different operating systems. Next, you will create an Android app and a virtual device in Android Studio, and install an Android application on emulator. You will test apps on physical Android devices, then study Android Studio code editor and constraint layout, Android architecture, the anatomy of an Android app, and Android activity state changes. The book then covers advanced topics such as views and widgets implementation, multi-window support integration, and biometric authentication, and finally, you will learn to upload your app to Google Play console and handle the build process with Gradle. By the end of this book, you will have gained enough knowledge to develop powerful Android applications using Java.
Table of Contents (86 chapters)
86
Index

26.7 Implementing the Touch Event Listener

In order to receive touch event notifications it will be necessary to register a touch listener on the layout view within the onCreate() method of the MainActivity activity class. Select the MainActivity.java tab from the Android Studio editor panel to display the source code. Within the onCreate() method, add code to identify the ConstraintLayout view object, register the touch listener and implement code which, in this case, is going to call a second method named handleTouch() to which is passed the MotionEvent object:

package com.ebookfrenzy.motionevent;

 

import androidx.appcompat.app.AppCompatActivity;

import android.os.Bundle;

import android.view.MotionEvent;

import android.view.View;

import androidx.constraintlayout.widget.ConstraintLayout;

import android.widget.TextView;

 

public class MainActivity extends AppCompatActivity {

 

    @Override

   ...