I have 3 components the need to talk to each other:
Activity <---> Service <---> Notification
^ ^
| |
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The notification is started from the service and it needs to have custom view with buttons. Clicking on any of the button should send something to the activity and the service.
What is the best way of implementing this?
The options that I see:
Eventbus is definitely not a consideration for interaction here. The Eventbus will only function within the same process in which it's created. That means it's maybe possible to communicate with your Service from your activity with Eventbus, but only if the service is a part of the Activity's process, which generally they shouldn't be (that's what threads are for). So I would strongly advise against that. And notifications are definitely not in the scope of the Eventbus.
You must use Android's documented infrastructure for the interactions you require.
From the Eventbus frontpage:
performs well with Activities, Fragments, and background threads
Broadcast receivers and intents are the best place to start with communications between the components you are using. Check out the answer to this question on how to use the Broadcast Receiver in your fragment to receive intents from a service.
You can also look into Service Binding if you need to have some tighter communication between your service and activity, but again, try to avoid that if you can because it can get very complicated very quickly.
For notifications, it really depends how complicated they are, but start with just building a Notification locally and you will start to understand what you can do with them. You'll notice that they also heavily make use of Intents.
Finally, read this article I wrote about (one) correct use of the EventBus.
