Book Image

Asynchronous Android

By : Steve Liles
Book Image

Asynchronous Android

By: Steve Liles

Overview of this book

With more than a million apps available from Google Play, it is more important than ever to build apps that stand out from the crowd. To be successful, apps must react quickly to user input, deliver results in a flash, and sync data in the background. The key to this is understanding the right way to implement asynchronous operations that work with the platform, instead of against it. Asynchronous Android is a practical book that guides you through the concurrency constructs provided by the Android platform, illustrating the applications, benefits, and pitfalls of each.Learn to use AsyncTask correctly to perform operations in the background, keeping user-interfaces running smoothly while avoiding treacherous memory leaks. Discover Handler, HandlerThread and Looper, the related and fundamental building blocks of asynchronous programming in Android. Escape from the constraints of the Activity lifecycle to load and cache data efficiently across your entire application with the Loader framework. Keep your data fresh with scheduled tasks, and understand how Services let your application continue to run in the background, even when the user is busy with something else.Asynchronous Android will help you to build well-behaved apps with smooth, responsive user-interfaces that delight users with speedy results and data that's always fresh, and keep the system happy and the battery charged by playing by the rules.
Table of Contents (14 chapters)
Asynchronous Android
Credits
About the Author
About the Reviewers
www.PacktPub.com
Preface
Index

Introducing Loaders


As the name suggests, the job of Loader is to load data on behalf of other parts of the application, and to make that data available across activities and fragments within the same process.

Loaders were introduced to the Android platform at API level 11, but are available for backwards compatibility through the support libraries. The examples in this chapter use the support library to target API levels 7 through 19.

Provided we implement our Loaders correctly, we get a number of benefits:

  • The heavy lifting is automatically performed on a background thread, and the results are safely introduced to the main thread on completion.

  • Loaded data can be cached and redelivered on repeat calls for speed and efficiency.

  • The framework gives us control over when a Loader instance is destroyed, and allows Loaders to live outside the Activity lifecycle, making their data available across the application and across Activity restarts.

  • Loaders monitor their underlying datasource, and reload...