Book Image

Android Programming for Beginners

By : John Horton, Paresh Mayani
Book Image

Android Programming for Beginners

By: John Horton, Paresh Mayani

Overview of this book

Android is the most popular OS in the world. There are millions of devices accessing tens of thousands of applications. It is many people's entry point into the world of technology; it is an operating system for everyone. Despite this, the entry-fee to actually make Android applications is usually a computer science degree, or five years’ worth of Java experience. Android Programming for Beginners will be your companion to create Android applications from scratch—whether you’re looking to start your programming career, make an application for work, be reintroduced to mobile development, or are just looking to program for fun. We will introduce you to all the fundamental concepts of programming in an Android context, from the Java basics to working with the Android API. All examples are created from within Android Studio, the official Android development environment that helps supercharge your application development process. After this crash-course, we’ll dive deeper into Android programming and you’ll learn how to create applications with a professional-standard UI through fragments, make location-aware apps with Google Maps integration, and store your user’s data with SQLite. In addition, you’ll see how to make your apps multilingual, capture images from a device’s camera, and work with graphics, sound, and animations too. By the end of this book, you’ll be ready to start building your own custom applications in Android and Java.
Table of Contents (37 chapters)
Android Programming for Beginners
Credits
About the Author
About the Reviewers
www.PacktPub.com
Preface
Index

Inter-Fragment communications – interfaces revisited


The main point of Fragments is that they have flexibility and reusability. If you remember, back in Chapter 12, Having a Dialogue with the User, when we were passing Note to and from a Fragment dialog, we added a method to Fragment and then called this method from the instance of the dialog in order to pass in the correct note that is to be shown. And when we added a new note in a dialog, we used getActivity() to get a reference to MainActivity in order to return the new note to be added to ArrayList of notes. Here is the code as a reminder:

// Get a reference to MainActivity
MainActivity callingActivity = (MainActivity) getActivity();

// Pass newNote back to MainActivity
callingActivity.createNewNote(newNote);

The problem with this is that it assumes that the communication is with an Activity called MainActivity.

Although this works in the Note To Self scenario, it is inflexible because this means that our fragments can only be used in...