EventBus

EventBus is a publish/subscribe event bus optimized for Android.

EventBus...

simplifies the communication between components
- decouples event senders and receivers
- performs well with Activities, Fragments, and background threads
- avoids complex and error-prone dependencies and life cycle issues
makes your code simpler
is fast
is tiny (~50k jar)
is proven in practice by apps with 100,000,000+ installs
has advanced features like delivery threads, subscriber priorities, etc.

EventBus in 3 steps

Define events:

public static class MessageEvent { /* Additional fields if needed */ }

Prepare subscribers: Declare and annotate your subscribing method, optionally specify a thread mode:

@Subscribe(threadMode = ThreadMode.MAIN)  
public void onMessageEvent(MessageEvent event) {/* Do something */};

Register and unregister your subscriber. For example on Android, activities and fragments should usually register according to their life cycle:

 @Override
 public void onStart() {
     super.onStart();
     EventBus.getDefault().register(this);
 }

 @Override
 public void onStop() {
     super.onStop();
     EventBus.getDefault().unregister(this);
 }

Post events:

 EventBus.getDefault().post(new MessageEvent());

Read the full getting started guide.

Add EventBus to your project

Via Gradle:

compile 'org.greenrobot:eventbus:3.0.0'

Via Maven:

<dependency>
    <groupId>org.greenrobot</groupId>
    <artifactId>eventbus</artifactId>
    <version>3.0.0</version>
</dependency>

Or download the latest JAR from Maven Central.

Homepage, Documentation, Links

For more details please check the EventBus website. Here are some direct links you may find useful:

How does EventBus compare to other solutions, like Otto from Square? Check this comparison.

License

EventBus binaries and source code can be used according to the Apache License, Version 2.0.

More Open Source by greenrobot

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