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 Looper


Let's explain the Looper class. We used it in previous examples but we did not explain it in details.

Looper represents a class that is used to execute messages or runnable instances in a queue. Ordinary threads do not have any queue like the Looper class has.

Where we can use the Looper class? For the execution of multiple messages or runnable instances, Looper is needed! One example of use can be adding new tasks to the queue while, at the same time, the operation of task processing is running.

Preparing the Looper

To use the Looper class, we must first call the prepare() method. When Looper is prepared, we can use the loop() method. This method is used to create a message loop in the current thread. We will give you one short example:

    class LooperHandler : Handler() { 
      override fun handleMessage(message: Message) { 
            ... 
      } 
    } 
 
    class LooperThread : Thread() { 
      var handler: Handler? = null 
 
      override fun run() {...