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

Chapter 20. Drawing Graphics

This entire chapter will be about the Android Canvas class and some related classes, such as Paint, Color, and Bitmap. When combined, these classes bring great power when it comes to drawing on the screen. Sometimes, the default UI provided by the Android API isn't what we need. If we want to make a drawing app, draw graphs, or perhaps make a game, we need to take control of every pixel that the Android device has to offer.

In this chapter, we will cover the following topics:

  • Gain an understanding of the Canvas class and some related classes

  • Write a Canvas-based demo app

  • Look at the Android coordinate system so that we know where to do our drawing

  • Learn about drawing and manipulating bitmap graphics

  • Write a bitmap graphics-based demo app

So, let's get drawing!