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

55.2 Designing the User Interface

The user interface for the MainActivity class is very simple, consisting solely of a ConstraintLayout and a Button object. Within the Project tool window, locate the app -> res -> layout -> activity_main.xml file and double-click on it to load it into the Layout Editor tool.

Delete the default TextView and, with Autoconnect mode enabled, position a Button widget so that it is centered within the layout. Note that the text on the button (“Show Web Page”) has been extracted to a string resource named show_web_page.

Figure 55-1

With the Button selected use the Attributes tool window to configure the onClick property to call a method named showWebPage().