Book Image

Hands-On Android UI Development

By : Jason Morris
Book Image

Hands-On Android UI Development

By: Jason Morris

Overview of this book

A great user interface (UI) can spell the difference between success and failure for any new application. This book will show you not just how to code great UIs, but how to design them as well. It will take novice Android developers on a journey, showing them how to leverage the Android platform to produce stunning Android applications. Begin with the basics of creating Android applications and then move on to topics such as screen and layout design. Next, learn about techniques that will help improve performance for your application. Also, explore how to create reactive applications that are fast, animated, and guide the user toward their goals with minimal distraction. Understand Android architecture components and learn how to build your application to automatically respond to changes made by the user. Great platforms are not always enough, so this book also focuses on creating custom components, layout managers, and 2D graphics. Also, explore many tips and best practices to ease your UI development process. By the end, you'll be able to design and build not only amazing UIs, but also systems that provide the best possible user experience.
Table of Contents (21 chapters)
Title Page
Credits
About the Author
About the Reviewers
www.PacktPub.com
Customer Feedback
Preface
13
Activity Lifecycle

Updating by Delta Events


Up until this point, when the data changes in the database, the ClaimItemAdapter simply tells the RecyclerView that the data has changed. This is not the most efficient use of resources, because the RecyclerView doesn't actually know what in the model has changed, and it's forced to relayout the entire scene as though the entire model has changed (although it will reuse the widgets it has already pooled).

RecyclerView actually has a secondary mechanism that allows you to tell it what has changed, rather than just saying that the data has changed. This is provided through a series of notifications the signal single items, or ranges being added, removed, and moved. The problem is that in order to use these methods, you need to know what has actually changed.

Most developer's first instincts here will be to use more events and signal from the DAO or a delegate layer what is changing, and then catch those events in the Adapter and forward them to the RecyclerView. This...