How to access Activity's View objects while running a background service which updates the view

Question

I have an android app which has an internet connectivity service. The service shows a snackbar whenever the application comes online or goes offline. The services works fine, however the when accessing the MainActivity's snackbar or the relative layout on which I will show the snackbar, I get null values. Below is the implementation of the callback from the background service, this method is written inside the mainactivity:

  public void hasInternetConnection() {
    if (!hasInternetMessageShown) {
        showSnackBar("App is online", false);
    }      
}
private void showSnackBar(String message, boolean shouldStick) {
    if (snack != null && snack.isShown()) {
        snack.dismiss();
    }
    snack = Snackbar.make(rootView, message, Snackbar.LENGTH_SHORT);
    snack.getView().setBackgroundColor(activity.getResources().getColor(R.color.blue_light));
    TextView textView = snack.getView().findViewById(android.support.design.R.id.snackbar_text);
    textView.setTextColor(activity.getResources().getColor(R.color.orange));
    Typeface typeface = ResourcesCompat.getFont(activity, R.font.semibold);
    textView.setTypeface(typeface, Typeface.NORMAL);
    if (shouldStick)
        snack.setDuration(BaseTransientBottomBar.LENGTH_INDEFINITE);
    snack.show();
}

The above code only works if I keep the instance of snack and activity static. Which I don't want to do as it will trigger memory leak. Please help me here so that I can handle this efficiently.

Thanks!!

Answer 1

Please try to send a local broadcast on activity from your service and then try to update your snack bar.