Add a short delay to calculator input focus so it doesn't jump to the bottom of…

Add a short delay to calculator input focus so it doesn't jump to the bottom of the screen when you open it.

lms/static/coffee/src/calculator.coffee

@@ -9,11 +9,14 @@ class @Calculator
   toggle: (event) ->
     event.preventDefault()
     $('div.calc-main').toggleClass 'open'
-    $('#calculator_wrapper #calculator_input').focus()
     if $('.calc.closed').length
       $('.calc').attr 'aria-label', 'Open Calculator'
     else
       $('.calc').attr 'aria-label', 'Close Calculator'
+      # TODO: Investigate why doing this without the timeout causes it to jump
+      # down to the bottom of the page. I suspect it's because it's putting the
+      # focus on the text field before it transitions onto the page.
+      setTimeout (-> $('#calculator_wrapper #calculator_input').focus()), 100
 
     $('.calc').toggleClass 'closed'