CODEWITHSUNDEEP
androidroboguicerobospice
Daniel Rusev
Daniel Rusev

Reputation: 1331

Which context is injected by roboguice?

I'd like to know which context Roboguice injects, is it the application context or the current activity?

I'm trying to use both Roboguice and Robospice. I'm injecting Robospice's SpiceManager in a fragment but the fragment doesn't know about the SpiceManager, it sees it through an interface, let's say MyInterface.

public class MyFragment extends RoboFragment {
    //this is where the SpiceManager gets injected
    @Inject MyInterface manager;
    ...
}

//this is the implementation that I'm going to inject
//it is simultaneously an event listener for the fragment's life cycle events so that the
//SpiceManager can be appropriately started and stopped.
public class MyManager implements MyInterface {
    private SpiceManager spiceManager = new SpiceManager(MySpiceService.class);

    //Which context will get injected here? How can I make Roboguice inject a specific context that I want, for example, a specific activity that I want.
    private @Inject Context context;

    //Here, I need to start the SpiceManager
    public void myFragmentOnStart(@Observes OnStartEvent onStart) {
        //SpiceManager requires a context, more specifically an activity which will be destroyed and then garbage collected, so It shouldn't be an application context because the resources SpiceManager uses will never be released.
        spiceManager.start(context);
    }

    public void myFragmentOnStop(@Observes OnStopEvent onStop){
        if (spiceManager.isStarted()) {
            spiceManager.shouldStop();
        }
    }
}

My questions are:

Can RoboGuice observe fragment events beside Activity events, the documentation isn't clear?

Am I right in thinking that SpiceManager needs a context that will be destroyed when the fragment/activity is destroyed? I've had a look at the code of SpiceManager.start(Context context) and it creates a WeakReference to the passed Context.

How can I make RoboGuice inject a specific Context/Activity?

Is it possible to do so without MyFragment knowing that the MyInterface object it uses needs a Context?

By the way I found out that OnStopEvent has a getActivity() method, so there's no problem getting the Activity in onStop, but OnStartEvent is just an empty class.

Upvotes: 1

Views: 241

Answers (1)

Snicolas
Snicolas

Reputation: 38168

So many questions ;)

A) Can RoboGuice observe fragment events beside Activity events, the documentation isn't clear ?

Event can be anything in RG. By default RG offers some nice events to be notified of lifecycle of an activity. Release 3.1 of RG is actually adding some new events for Fragments. This should be released in a couple of weeks.

But what you do on the event side is perfectly legitimate. Just to be clear. You are listening to the activity lifecycle from within a fragment. Why not ?

The only thing you need is to register to this instance of event manager of the activity. Add @Inject EventManager eventManager to your fragment. This is enough for RG to register your listener automatically.

B) RS will need a context only for callbacks, not to execute a request. The request is gonna be executed in a service. The context you pass to RS is just used to say "If this context dies, then all listeners will die, don't notify them. But still, go ahead, execute the request and cache the result."

Here it's a bit complex the way you do it. The easiest is really to manage a spice manager at the activity level. Send events from your fragments to your activity to ask it to launch requests when needed. That the easiest.

But it's also possible to have spicemanager managed at the fragment level. In that case, manage your spicemanager lifecycle in the fragment itself with its onStart/onStop methods.

C) Is it possible to do so without MyFragment knowing that the MyInterface object it uses needs a Context?

I didn't get it.

Upvotes: 1

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