Book Image

Android Studio 4.0 Development Essentials - Java Edition

By : Neil Smyth
Book Image

Android Studio 4.0 Development Essentials - Java Edition

By: Neil Smyth

Overview of this book

Android rolls out frequent updates to meet the demands of the dynamic mobile market and to enable its developer community to lead advancements in application development. This book focuses on the updated features of Android Studio (the fully integrated development environment launched by Google) to build reliable Android applications using Java. The book starts by outlining the steps necessary to set up an Android development and testing environment. You’ll then learn how to create user interfaces with the help of Android Studio Layout Editor, XML files, and by writing the code in Java. The book introduces you to Android architecture components and advanced topics such as intents, touchscreen handling, gesture recognition, multi-window support integration, and biometric authentication, and lets you explore key features of Android Studio 4.0, including the layout editor, direct reply notifications, and dynamic delivery. You’ll also cover Android Jetpack in detail and create a sample app project using the ViewModel component. Finally, you’ll upload your app to the Google Play Console and handle the build process with Gradle. By the end of this book, you’ll have gained the skills necessary to develop applications using Android Studio 4.0 and Java.
Table of Contents (88 chapters)
88
Index

32.8 Android Lifecycles

The duration from when an Android component is created to the point that it is destroyed is referred to as the lifecycle. During this lifecycle, the component will change between different lifecycle states, usually under the control of the operating system and in response to user actions. An activity, for example, will begin in the initialized state before transitioning to the created state. Once the activity is running it will switch to the started state from which it will cycle through various states including created, started, resumed and destroyed.

Many Android Framework classes and components allow other objects to access their current state. Lifecycle observers may also be used so that an object receives notification when the lifecycle state of another object changes. This is the technique used behind the scenes by the ViewModel component to identify when an observer has restarted or been destroyed. This functionality is not limited to Android framework...