Android - How do I detect if user has chosen to share to Facebook or twitter?

I've created an application which shares to facebook, twitter etc. But I want to perform different functions dependent on who the user is sharing to, for instance if the user is sharing to Facebook do one thing but if the user shares to twitter do another.

How do I do this?

My code so far is below:

Java Code:

        private void ShareSub() {
                Intent i = new Intent(Intent.ACTION_SEND);
                i.setType("text/plain");
                i.putExtra(
                                Intent.EXTRA_TEXT,
                                "You've just shared "
                                                + "Awesome");
                startActivity(i);
        }