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

Connecting activities


As you remember, other than MainActivity, we also have some more activities. In our application, we created activities to create/edit Notes and TODOs. Our plan is to connect them to the button click events, and then, when the user clicks on the button, the proper screen will open. We will start by defining an enum that represents an operation that we will perform in an opened activity. When we open it, we can view, create, or update Note or Todo. Create a new package called model and enum with the name MODE. Make sure you have the following enum values:

    enum class MODE(val mode: Int) { 
      CREATE(0), 
      EDIT(1), 
      VIEW(2); 
 
      companion object { 
        val EXTRAS_KEY = "MODE" 
 
        fun getByValue(value: Int): MODE { 
          values().forEach { 
            item -> 
 
            if (item.mode == value) { 
              return item 
            } 
          } 
          return VIEW 
        } 
      }  
    } 

We added a few additions here...