android returning a "live" object from an AIDL bound service

Question

I'd like to create an AIDL service that returns, for lack of the correct terminology, "live" objects. that is, I would like something like this to work,

IFoo foo = myService.getFoo(x); // calls to myService service to get an IFoo
IBar bar = foo.getBar(y); // IPC to IFoo to get an IBar
IBaz baz = bar.getBaz(z); // IPC to IBar to get an IBaz

baz.setEnabled(false); // IPC to IBaz to modify the service's copy of IBaz

I expect this to be possible, but I can find a good example. The alternative is to do something like,

myService.setBazEnabled(x, y, z, false);

the former being a more OO approach, while the latter is more functional.

Answer 1

So long as IFoo, IBar, and IBaz are all defined via AIDL, that should work just fine.

Answer 2

Providing a clear example of the suggestion in comment #2 from CommonsWare ...

first, define sub-AIDL interfaces to be returned from the main AIDL interface,

interface IMyService {
  IFoo getFoo();
}

IFoo should itself be an AIDL interface,

interface IFoo {
  ...
}

in your implementation of IMyService.getFoo(), construct a new binder, and return that, as an IFoo interface,

public class MyService implements Service {
  public class FooBinder extends IFoo.Stub {
    ...
  }

  public class MyBinder extends IMyService.Stub {
    @Override
    public IFoo getFoo() {
      return IFoo.Stub.asInterface(new FooBinder()); 
    }

  @Override
  public IBinder onBind() {
    return new MyBinder();
  }
}