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

25.6 Using Apply Code Changes

Begin by clicking on the run button and selecting a suitable emulator or physical device as the run target. After clicking the run button, track the amount of time before the example app appears on the device or emulator.

Once running, click on the action button (the button displaying an envelope icon located in the lower right-hand corner of the screen). Note that a Snackbar instance appears displaying text which reads “Replace with your own action” as shown in Figure 25-6:

Figure 25-6

Once the app is running, the Apply Changes buttons should have been enabled indicating that certain project changes can be applied without having to reinstall and restart the app. To see this in action, edit the MainActivity.java file, locate the onCreate method and modify the action code so that a different message is displayed when the action button is selected:

FloatingActionButton fab = findViewById(R.id.fab);

fab.setOnClickListener...