Book Image

Android Studio 4.0 Development Essentials - Kotlin Edition

By : Neil Smyth
Book Image

Android Studio 4.0 Development Essentials - Kotlin Edition

By: Neil Smyth

Overview of this book

Kotlin as an Android-compatible programming language is becoming increasingly popular. Fully updated for Android Studio 4.0, this book will teach you the skills necessary to develop Android-based applications using Kotlin. Starting with the basics, this book outlines the steps necessary to set up Android development and testing environments, and goes on to introduce you to programming in Kotlin. You’ll practice Java to Kotlin code conversion and explore data types, operators, expressions, loops, functions, as well as the basics of OOP in Kotlin. You’ll then learn about Android architecture components and advanced topics, such as intents, touchscreen handling, gesture recognition, multi-window support integration, and biometric authentication. As you make progress, you’ll explore Android Studio 4.0’s key features, including layout editor, direct reply notifications, and dynamic delivery. You’ll also delve into Android Jetpack and create a sample app project using ViewModel, the Android Jetpack component. Finally, you will upload your app to Google Play Console and model the build process using Gradle. By the end of this Android book, you’ll be fully prepared to develop applications using Android Studio 4.0 and Kotlin.
Table of Contents (97 chapters)
97
Index

79.3 Designing the User Interface

The user interface will need to be comprised of three Button views and a single EditText view. Within the Project tool window, navigate to the activity_main.xml layout file located in app -> res -> layout and double-click on it to load it into the Layout Editor tool. With the tool in Design mode, select and delete the Hello World! TextView object.

Drag and position a Button widget in the top left-hand corner of the layout so that both the left and top dotted margin guidelines appear before dropping the widget in place. Position a second Button such that the center and top margin guidelines appear. The third Button widget should then be placed so that the top and right-hand margin guidelines appear.

Change the text attributes on the three buttons to “New”, “Open” and “Save” respectively. Next, position a Plain Text widget so that it is centered horizontally and positioned beneath the center Button...