Search icon CANCEL
Subscription
0
Cart icon
Your Cart (0 item)
Close icon
You have no products in your basket yet
Save more on your purchases now! discount-offer-chevron-icon
Savings automatically calculated. No voucher code required.
Arrow left icon
Explore Products
Best Sellers
New Releases
Books
Videos
Audiobooks
Learning Hub
Conferences
Free Learning
Arrow right icon
Arrow up icon
GO TO TOP
Hands-On Android UI Development

You're reading from   Hands-On Android UI Development Design and develop attractive user interfaces for Android applications

Arrow left icon
Product type Paperback
Published in Nov 2017
Publisher Packt
ISBN-13 9781788475051
Length 348 pages
Edition 1st Edition
Languages
Tools
Arrow right icon
Author (1):
Arrow left icon
Jason Morris Jason Morris
Author Profile Icon Jason Morris
Jason Morris
Arrow right icon
View More author details
Toc

Table of Contents (15) Chapters Close

Preface 1. Creating Android Layouts 2. Designing Form Screens FREE CHAPTER 3. Taking Actions 4. Composing User Interfaces 5. Binding Data to Widgets 6. Storing and Retrieving Data 7. Creating Overview Screens 8. Designing Material Layouts 9. Navigating Effectively 10. Making Overviews Even Better 11. Polishing Your Design 12. Customizing Widgets and Layouts 13. Activity Lifecycle
14. Test Your Knowledge Answers

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...

lock icon The rest of the chapter is locked
Register for a free Packt account to unlock a world of extra content!
A free Packt account unlocks extra newsletters, articles, discounted offers, and much more. Start advancing your knowledge today.
Unlock this book and the full library FREE for 7 days
Get unlimited access to 7000+ expert-authored eBooks and videos courses covering every tech area you can think of
Renews at $19.99/month. Cancel anytime