Book Image

Mastering Android Development with Kotlin

By : Miloš Vasić
Book Image

Mastering Android Development with Kotlin

By: Miloš Vasić

Overview of this book

Kotlin is a programming language intended to be a better Java, and it's designed to be usable and readable across large teams with different levels of knowledge. As a language, it helps developers build amazing Android applications in an easy and effective way. This book begins by giving you a strong grasp of Kotlin's features in the context of Android development and its APIs. Moving on, you'll take steps towards building stunning applications for Android. The book will show you how to set up the environment, and the difficulty level will grow steadily with the applications covered in the upcoming chapters. Later on, the book will introduce you to the Android Studio IDE, which plays an integral role in Android development. We'll use Kotlin's basic programming concepts such as functions, lambdas, properties, object-oriented code, safety aspects, type parameterization, testing, and concurrency, which will guide you through writing Kotlin code in production. We'll also show you how to integrate Kotlin into any existing Android project.
Table of Contents (24 chapters)
Title Page
Credits
About the Author
Acknowledgments
About the Reviewer
www.PacktPub.com
Customer Feedback
Preface

Understanding Android Context


All our main screens now have their layouts defined. We will now explain Android Context since each screen we just created represents one Context instance. If you go through the class definition and follow class extension, you will realize that each activity we create extends the Context class.

Context represents the current state of the application or object. It is used to access specific classes and resources of the application. For example, consider the following lines of code:

    resources.getDimension(R.dimen.header_height) 
    getString(R.string.app_name) 

Access we showed is provided by the Context class, which shows our activities are extending. Context is needed when we have to launch another activity, start a service, or send broadcast messages. We will show use of these methods when the time is proper. We already mentioned that each screen (Activity) of an Android application represents a Context instance. Activities are not the only classes that represent...