Question

My application has a few activities, and a background service. My question is, if I have the context variable in the service, how can I tell which activity is currently open? I need to do this to direct the next action my service takes. For example,

if (context is activity_1) {
//take this action
} else if (context is activity_2) {
//do this instead…
}

That’s the basic gist of what I’m trying to do.

Help much appreciated.

Answer 1

You could set a SharedPreferences entry in each onResume() method of your activities and read that value from the service. To keep it clean you could write an Activity that does that and then extend all your activities from it:

public class MyActivity extends Activity {
    private static final String PREFS_NAME = "MyPrefsFile";
    @Override
    protected void onResume() {
        getContext().getSharedPreferences(PREFS_NAME, Context.MODE_PRIVATE)
            .edit()
            .putInt("activtiyIdRunning", getActivityId() )
            .commit();
        super.onResume();
    }
    abstract protected int getActivityId();
}

public class MyConcreteActivity1 extends MyActivity {
    @Override
    protected int getActivityId() {
        return 1;
    }
    // your normal code
}

in your service than just call:

int currentActivity = getContext().getSharedPreferences(PREFS_NAME, Context.MODE_PRIVATE)
    .getInt("activityIdRunning",-1);