RxAndroid

RxAndroid is an open-source library that provides Android-specific bindings for RxJava, the reactive programming library for composing asynchronous and event-based code with observable sequences. It serves as a companion to RxJava by delivering Android-oriented utilities that simplify threading and UI interaction within reactive streams.

The primary feature of RxAndroid is the Android scheduler ecosystem, notably AndroidSchedulers.mainThread(), which enables observing and performing work on Android’s main (UI) thread. This helps ensure that UI updates and interactions occur on the correct thread while keeping background work off the UI thread. By supplying a readily available main-thread scheduler, RxAndroid reduces boilerplate and helps prevent common threading errors in Android apps. It does not, by itself, provide UI bindings for individual widgets; for widget bindings, developers commonly use separate libraries such as RxBinding.

RxAndroid is maintained as an open-source project and is released in parallel with RxJava versions. Historically, there have been distinct releases to align with RxJava 1.x and RxJava 2.x, with updates continuing as both ecosystems evolve. The library was originally created and maintained by contributors including Jake Wharton, and it remains part of the broader RxJava ecosystem used to simplify asynchronous programming on Android.

Usage in practice typically involves composing observables with subscribeOn for background work and observeOn(AndroidSchedulers.mainThread()) for UI updates, leveraging RxJava’s operators to transform and manage data streams while ensuring correct threading on Android.

See also: RxJava, RxBinding, reactive programming on Android.