Calling back to an Activity in the bottom of the stack from a global Activity

I already know that I can pass Bundled data through setResult from one Activity back to another. However, suppose I have an global Activity that can be launched from anywhere in my app since it is mapped to a button that appears in my title bar in almost all of my activities.

Long story short, after it completes its user-driven process, I want it to signal back to the very first activity in the back stack, basically my Home activity, so that it updates the UI accordingly.

Part of the problem is that since if I use a BroadcastReceiver, it is unregistered when my activity is in the background, and it will not get the signal to refresh its data set.

What I want to achieve is the following:

From either Home (ActivityA), or any other activity (Activity B, C, etc...) that can open out my global activity (ActivityX), it should find a way to call back to ActivityA without bringing it to the front.

Should I use FLAG_ACTIVITY_FORWARD_RESULT and if so, how should I model it from my subsequent activities after Home. In other words, if I launch a child activity from Home, should I launch it with startActivityForResult with whatever request code I define and then pass FLAG_ACTIVITY_FORWARD_RESULT when opening my global activity so that the result will be set from there?

Also, suppose I launch a child activity from Home with a resul开发者_如何学Got, and then from my child activity I add more to the stack, from which I open ActivityX. Would the system still remember the result chain as long as I opened the first child from Home with a result?

EDIT: I am not looking for just clearing the entire stack back to home immediately after the process is completed in ActivityX; just a way to signal the Home activity to refresh it's UI when the user eventually returns to the Home screen. I guess probably setting a SharedPreference flag that Home checks in onStart when the user re-focuses on that Activity which in turn gives me the condition to do the end result, after which the flag is reset.

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Your home-screen should just update it's UI in onResume, this way whenever a user returns to it will be displaying the latest data. There's no need to pass callbacks. Otherwise you could register a Broadcast receiver in onCreate (and unregister in onDestroy... not ideal) in your home activity and then send out a broadcast when you want the home activity to update (although the home activity shouldn't actually update itself until it is resumed).

Here's how to get back to your home activity:

Intent goHome = new Intent(getContext(), HomeActivity.class);
goHome.addFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP);
goHome.addFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
startActivity(goHome);

FLAG_ACTIVITY_CLEAR_TOP: This ensures that when the activity is launched, it displays its initial activity.

FLAG_ACTIVITY_NEW_TASK: we're starting a new task (i.e. the back button should not go back to the previous screen so that pressing back at your home screen will exit your app).

I'll update on the rest tomorrow.