How to use an intent to update an activity?

Question

I have a service that is downloading a file. When the download is done, I would like to update my "Downloaded files" list in my Activity, but only if the Activity is running. I do not want the Activity to start if it's not already running.

I was hoping I could do this by making a new Intent with some special flag.

Anyone have any idea how I can achieve this? A tiny code example maybe?

Answer 1

You can create new BroadcastReceiver instance and do something along these lines on your Activity's onResume() method:

registerReceiver(myReceiver, new IntentFilter(DownloadService.ACTION_FILE_DOWNLOADED));

After that, override myReceiver's onReceive() method to call a function that updates the component you want:

@Override 
public void onReceive(Context context, Intent intent) {
...
    updateViewWithData(service.getNewFileData());
...
}

On your Activity's onPause() method, just unregister the receiver:

unregisterReceiver(myReceiver);

I hope that this would help you, feel free to ask if there is something unclear.