Book Image

Android Studio 3.5 Development Essentials - Kotlin Edition

By : Neil Smyth
Book Image

Android Studio 3.5 Development Essentials - Kotlin Edition

By: Neil Smyth

Overview of this book

Popularity of Kotlin as an Android-compatible language keeps growing every day. This book will help you to build your own Android applications using Kotlin. Android Studio 3.5 Development Essentials Kotlin Edition first teaches you to install Android development and test environment on different operating systems. Next, you will create an Android app and a virtual device in Android studio, and install an Android application on emulators. You will test apps on physical android devices, then study Android Studio code editor, Android architecture, and the anatomy of an Android app. The focus then shifts to Kotlin language. You’ll get an overview of Kotlin language and practice converting code from Java to Kotlin. You’ll also explore Kotlin data types, operators, expressions, loops, functions, and the basics of OOP concept in Kotlin. This book will then cover Android Jetpack and how to create an example app project using ViewModel component, as well as advanced topics such as views and widgets implementation, multi-window support integration, and biometric authentication. Finally, you will learn to upload your app to the Google Play Console and handle the build process with Gradle. By the end of this book, you will have gained enough knowledge to develop powerful Android applications using Kotlin.
Table of Contents (93 chapters)
93
Index

50.4 Designing the First Scene

The first scene is going to consist of a layout containing three button views. Create this layout resource file by right-clicking on the app -> res -> layout entry in the Project tool window and selecting the New -> Layout resource file… menu option. In the resulting dialog, name the file scene1_layout and enter androidx.constraintlayout.widget.ConstraintLayout as the root element before clicking on OK.

When the newly created layout file has loaded into the Layout Editor tool, check that Autoconnect mode is enabled, drag a Button view from the Common section of the palette onto the layout canvas and position it in the top left-hand corner of the layout view so that the dashed margin guidelines appear as illustrated in Figure 50-1. Drop the Button view at this position, select it and change the text value in the Attributes tool window to “One”.

Figure 50-1

Drag a second Button view from the palette and position...