Question

I have a program with about 8 Activity classes, and 1 Application class. I want my Application class to be able to communicate with every Activity, but on its own terms. I don’t want the activity to ask the Application for data, I want the Application to send the Activity data. The problem with this, is that depending on the current state of the program I’m unsure what Activity will be open.

Is there a method of some sort which will send information from the Application to the CURRENT activity?

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The Application class connects with an embedded Bluetooth Device and needs to receive different pieces of data depending on which Activity the user is currently in. I originally had it as a regular class, which was initialized in the MainMenu of my program and passed a Handler. However, it seemed like weak design to pass that Handler from Activity to Activity time and time again.

Answer 1

You could use a Callback Method

Every Activity has it’s own callback method and registers that method onResume() in the Application Class. (it’s like an onApplicationWantsToDoSomethingWithMeListener() 😉

or why not a Service in background? instead of the Application, since what you want sounds like a Service. More details?

EDIT:
I made a similar application with bluetooth, you should definetly use a Service for that, but you can communicate with your service per Application. Say the Service calls the callback in the Application look here for an implementation uf such a thing