Book Image

Android Development with Kotlin

By : Igor Wojda, Marcin Moskala
Book Image

Android Development with Kotlin

By: Igor Wojda, Marcin Moskala

Overview of this book

Nowadays, improved application development does not just mean building better performing applications. It has become crucial to find improved ways of writing code. Kotlin is a language that helps developers build amazing Android applications easily and effectively. This book discusses Kotlin features in context of Android development. It demonstrates how common examples that are typical for Android development, can be simplified using Kotlin. It also shows all the benefits, improvements and new possibilities provided by this language. The book is divided in three modules that show the power of Kotlin and teach you how to use it properly. Each module present features in different levels of advancement. The first module covers Kotlin basics. This module will lay a firm foundation for the rest of the chapters so you are able to read and understand most of the Kotlin code. The next module dives deeper into the building blocks of Kotlin, such as functions, classes, and function types. You will learn how Kotlin brings many improvements to the table by improving common Java concepts and decreasing code verbosity. The last module presents features that are not present in Java. You will learn how certain tasks can be achieved in simpler ways thanks to Kotlin. Through the book, you will learn how to use Kotlin for Android development. You will get to know and understand most important Kotlin features, and how they can be used. You will be ready to start your own adventure with Android development with Kotlin.
Table of Contents (16 chapters)
Title Page
About the Authors
About the Reviewers
Customer Feedback
Making Your Marvel Gallery Application

Extension functions

All big Java projects have utility classes, such as StringUtils, ListUtils, and AndroidUtils. They are so popular because util functions capture common patterns and allow them to be tested and used in a simple way. The problem is that Java really poorly supports the creation and usage of such functions because they have to be implemented as static functions of some class. Let's discuss this problem with an example. Every Java Android developer knows well following code which is used to show Toast:

    Toast.makeText(context, text, Toast.LENGTH_SHORT).show(); 

It is commonly used in Android projects to show errors or short messages, and often it is presented at the beginning of most Android tutorials. Code that implements this functionality is verbose because it uses a static function that is used like a builder. Probably every Java Android developer has forgotten at least once to invoke the show method on a returned object, which made him check all the surrounding conditions...