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

40.3 Reviewing the Project

When a project is created using the Fragment + ViewModel template, the structure of the project differs in a number of ways from the Empty Activity used when the AndroidSample project was created. The key components of the project are as follows:

40.3.1 The Main Activity

The first point to note is that the user interface of the main activity has been structured so as to allow a single activity to act as a container for all of the screens that will eventually be needed for the completed app. The main user interface layout for the activity is contained within the app -> res -> layout -> main_activity.xml file and provides an empty container space in the form of a FrameLayout (highlighted in Figure 40-1) in which screen content will appear:

Figure 40-1

40.3.2 The Content Fragment

The FrameLayout container is just a placeholder which will be replaced at runtime by the content of the first screen that is to appear when the app launches...