Otto Event Bus
Otto is deprecated in favor of
RxAndroid. These projects permit the same event-driven programming model as Otto, but they’re more capable and offer better control of threading.
Passing an event
This example describes passing an event using the Otto Event Bus.
To use the Otto Event Bus in Android Studio you have to insert the following statement in your modules gradle file:
The event we'd like to pass is a simple Java object:
We need a Bus to send events. This is typically a singleton:
To send an event we only need our BusProvider and it's
post method. Here we send an event if the action of an AsyncTask is completed:
Receiving an event
To receive an event it is necessary to implement a method with the event type as parameter and annotate it using
@Subscribe. Furthermore you have to register/unregister the instance of your object at the
BusProvider (see example Sending an event):
Important: In order to receive that event an instance of the class has to exist. This is usually not the case when you want to send a result from one activity to another activity. So check your use case for the event bus.