title: Show a toast message when an android spinner is empty
body: <p>I have a spinner which is populated from the database. So if the spinner is clicked with no items in it,a spinner with an empty list item is shown.I want to avoid showing the spinner when it is empty and show a toast message. I have the logic to check the count of the items and show the toast message, but I cannot find out where to call the function.What is the event   called when clicking the spinner and loading the spinner items?</p>