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

Applications of Handler and HandlerThread


The Handler class is incredibly versatile, which makes its range of applications very broad.

So far we looked at Handler and HandlerThread in the context of the Activity lifecycle, which constrains the sort of applications that make sense—ideally we do not want to perform long-running operations (more than a second or so) at all in this context.

With that constraint in mind, good candidate uses include performing calculations, string processing, reading and writing small files on the filesystem, and reading or writing to local databases using a background HandlerThread.

We might consider AsyncTask instead for one-off's, or if we want to display progress or cancel a task part way through. The Android platform also uses Handler extensively as a mechanism for abstracting the work that needs doing from the thread that will do it. A nice example of this can be found in android.hardware.SensorManager, which allows listeners to be registered along with a Handler...