onStart() is called when the fragment is made visible, whereas onPause()
is called when the fragment looses focus e.g. if a dialog is shown.
Thus:
- there is no need to set the activity's title everytime the fragment
regains focus,
- it is better to listen to event tasks and refresh the state of the UI
while the fragment is actually visible, listening to events until the
fragment is destroyed is useless: if an event is received between
onStop() and onDestroy(), there will be some processing but nothing will
be shown because the fragment is no longer visible.
