Book Image

Android Programming with Kotlin for Beginners

By : John Horton
5 (1)
Book Image

Android Programming with Kotlin for Beginners

5 (1)
By: John Horton

Overview of this book

Android is the most popular mobile operating system in the world and Kotlin has been declared by Google as a first-class programming language to build Android apps. With the imminent arrival of the most anticipated Android update, Android 10 (Q), this book gets you started building apps compatible with the latest version of Android. It adopts a project-style approach, where we focus on teaching the fundamentals of Android app development and the essentials of Kotlin by building three real-world apps and more than a dozen mini-apps. The book begins by giving you a strong grasp of how Kotlin and Android work together before gradually moving onto exploring the various Android APIs for building stunning apps for Android with ease. You will learn to make your apps more presentable using different layouts. You will dive deep into Kotlin programming concepts such as variables, functions, data structures, Object-Oriented code, and how to connect your Kotlin code to the UI. You will learn to add multilingual text so that your app is accessible to millions of more potential users. You will learn how animation, graphics, and sound effects work and are implemented in your Android app. By the end of the book, you will have sound knowledge about significant Kotlin programming concepts and start building your own fully featured Android apps.
Table of Contents (33 chapters)
Android Programming with Kotlin for Beginners
Contributors
Preface
Index

Looking ahead at the Live Drawing app


As this app is more in-depth and needs to respond in real time, it is necessary to use a slightly more in-depth structure. At first, this may seem like a complication, but in the long run, it will make our code simpler and easier to understand.

We will have four classes in the Live Drawing app, as follows:

  • MainActivity: The Activity class provided by the Android API is the class that interacts with the operating system (OS). We have already seen how the OS interacts with onCreate when the player clicks on the app icon to start an app. Rather than have the MainActivity class that does everything, this Activity-based class will just handle the startup and shutdown of our app, and offer some assistance with initialization by calculating the screen resolution. It makes sense that this class will be of the Activity type and not AppCompatActivity. However, as you will soon see, we will delegate interaction through touches to another class, that is, the same...