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

75.5 Designing the User Interface

Once the new project has been created, select the activity_main.xml file from the Project tool window and with the Layout Editor tool in Design mode, select the “Hello World!” TextView and delete it from the layout.

Drag and drop three Button views onto the layout. The positioning of the buttons is not of paramount importance to this example, though Figure 75-1 shows a suggested layout using a vertical chain.

Configure the buttons to display string resources that read Play, Record and Stop and give them view IDs of playButton, recordButton, and stopButton respectively.

Select the Play button and, within the Attributes panel, configure the onClick property to call a method named playAudio when selected by the user. Repeat these steps to configure the remaining buttons to call methods named recordAudio and stopAudio respectively.

Figure 75-1