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

38.4 Lifecycle States and Events

When the status of a lifecycle owner changes, the assigned Lifecycle object will be updated with the new state. At any given time, a lifecycle owner will be in one of the following five states:

Lifecycle.State.INITIALIZED

Lifecycle.State.CREATED

Lifecycle.State.STARTED

Lifecycle.State.RESUMED

Lifecycle.State.DESTROYED

As the component transitions through the different states, the Lifecycle object will trigger events on any observers that have been added to the list. The following events are available for implementation within the lifecycle observer:

Lifecycle.Event.ON_CREATE

Lifecycle.Event.ON_START

Lifecycle.Event.ON_RESUME

Lifecycle.Event.ON_PAUSE

Lifecycle.Event.ON_STOP

Lifecycle.Event.ON_DESTROY

Lifecycle.Event.ON_ANY

Annotations are used within the observer class to associate methods with lifecycle events. The...