Question

I am working on Android application that has several threads – one of them is getting data from GPS receiver 1 time per second. I would like other threads to have access to information from the GPS thread.

I already tried doing it with message queues, but it made the code quite messy – all new threads I created had to handle messages in it’s own way, so I had to do a lot of new implementation in every thread class.

I would like to be able to simply get the data in this manner:

ApplicationState.getLocation();

so I can use the most recent data. How can I accomplish it? I don’t want to create static class with synchronized fields because I don’t want to lock the threads for too long because I am doing some online image analysis in other thread.

What approach would be the best here?

Cheers,
Nebril

Answer 1

Have you considered using an Event Bus system? Otto, an Apache licensed library from Square is pretty neat.

You could create a location updating class that fires new LocationUpdateEvents. Any objects interested in receiving this update can have a method annotated with @Subscribe. It’s sweet method for interprocess communication that doesn’t rely on messy listener interfaces.

Another advantage of Otto is that your LocationUpdater class could have a method annotated with @Produce. With this, any object that begins listening for LocationUpdateEvents will receive one immediately with the last location found by your LocationUpdater.