Book Image

Android Programming for Beginners - Third Edition

By : John Horton
Book Image

Android Programming for Beginners - Third Edition

By: John Horton

Overview of this book

Do you want to make a career in programming but don’t know where to start? Do you have a great idea for an app but don't know how to make it a reality? Or are you worried that you’ll have to learn Java programming to become an Android developer? Look no further! This new and expanded third edition of Android Programming for Beginners will be your guide to creating Android applications from scratch. The book starts by introducing you to all the fundamental concepts of programming in an Android context, from the basics of Java to working with the Android API. You’ll learn with the help of examples that use up-to-date API classes and are created within Android Studio, the official Android development environment that helps supercharge your mobile application development process. After a crash course on the key programming concepts, you’ll explore Android programming and get to grips with creating applications with a professional-standard UI using fragments and storing user data with SQLite. This Android Java book also shows you how you can make your apps multilingual, draw on the screen with a finger, and work with graphics, sound, and animations. By the end of this Android programming book, you'll be ready to start building your own custom applications in Android and Java.
Table of Contents (30 chapters)

RecyclerView and RecyclerAdapter

In Chapter 5, Beautiful Layouts with CardView and ScrollView, we used ScrollView and we populated it with a few CardView widgets so we could see it scrolling. We could take what we have just learned about arrays and ArrayList and create an array of TextView widgets, use them to populate a ScrollView, and within each TextView place the title of a note. This sounds like a perfect solution for showing each note so that it is clickable in the Note to Self app.

We could create the TextView widgets dynamically in Java code, set their text property to be the title of a note, and then add the TextView widgets to a LinearLayout contained in a ScrollView. However, this is imperfect.

The problem with displaying lots of widgets

This might seem fine, but what if there were dozens, hundreds, or even thousands of notes? We couldn't have thousands of TextView widgets in memory because the Android device might simply run out of memory or at the very least...