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

37.5 Creating a Lifecycle Owner

The final task in this chapter is to create a custom lifecycle owner class and demonstrate how to trigger events and modify the lifecycle state from within that class.

Add a new class by right-clicking on the app -> java -> com.ebookfrenzy.lifecycledemo entry in the Project tool window and selecting the New -> Java Class... menu option. Name the class DemoOwner in the Create Class dialog before clicking on the OK button. With the new DemoOwner.java file loaded into the code editor, modify it as follows:

package com.ebookfrenzy.lifecycledemo;

 

import androidx.lifecycle.Lifecycle;

import androidx.lifecycle.LifecycleOwner;

import androidx.lifecycle.LifecycleRegistry;

 

public class DemoOwner implements LifecycleOwner {

}

The class is going to need a LifecycleRegistry instance initialized with a reference to itself, and a getLifecycle() method configured to return the LifecycleRegistry instance. Declare a...