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

8.8 Code Folding

Once a source code file reaches a certain size, even the most carefully formatted and well organized code can become overwhelming and difficult to navigate. Android Studio takes the view that it is not always necessary to have the content of every code block visible at all times. Code navigation can be made easier through the use of the code folding feature of the Android Studio editor. Code folding is controlled using markers appearing in the editor gutter at the beginning and end of each block of code in a source file. Figure 8-13, for example, highlights the start and end markers for a method declaration which is not currently folded:

Figure 8-13

Clicking on either of these markers will fold the statement such that only the signature line is visible as shown in Figure 8-14:

Figure 8-14

To unfold a collapsed section of code, simply click on the ‘+’ marker in the editor gutter. To see the hidden code without unfolding it, hover the...