Android 'complete action using' back button press handling -

my android app uses

intent = new intent(intent.action_view, uri);             i.setflags(intent.flag_activity_no_history);             startactivity(i); 

to begin twitter oauth process. code triggered button press. button change progress bar when pressed, have implemented.

when new activity started, user prompted 'complete action using' dialog, , if user presses key while dialog box showing, returned activity. handle event , turn progress bar button - how can this?

when user clicks back, onresume() method of fragment called. because of this, can change button normal style.