Custom event listener on Android app

Question

I need to set up a simple event listener to refresh a ListView once in a while. The problem is I don\'t know how could I generate an event.

I know that

Answer 1

You can use android life cycle for that.

Create a signal interface, aka your event

interface NewsUpdateSignal{
    void newsUpdateHandler(Mydata data);
}

Than register to it inside your activity or anywhere else you want, there could be many listeners to same Signal.

class MyActivity extends Activity implements NewsUpdateSignal{
    Signal newsUpdateSignal = SignalsBag.inject(NewsUpateSignal.class);

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        newsUpdateSignal.addListener(this);        
    }

    @Override
    public void newsUpdateHandler(final Mydata data){
           //Do something here 
    }
}

And dispatch the signal when you need, from where ever you need.

Class A{
    Signal newsUpdateSignal = SignalsBag.inject(NewsUpateSignal.class);

    void execute(){
        // obtain the data somehow, and dispatch it, the callback will be invoked on the same thread
        newsUpdateSignal.dispatcher.newsUpdateHandler(data);
    }        
}

Disclaimer: I am the author of android life cycle.