Helper class for managing the execution of javascript interval tasks.

IntervalManager.coffee

# (written for edX)
# Helper class for managing the execution of interval tasks.
# Handles pausing and restarting.
class IntervalManager
  # Create a manager which will call `fn`
  # after a call to .start every `ms` milliseconds.
  constructor: (@ms, @fn) ->
    @intervalID = null

  # Start or restart firing every `ms` milliseconds.
  # Soes not fire immediately.
  start: ->
    if @intervalID is null
      @intervalID = setInterval @fn, @ms

  # Pause firing.
  stop: ->
    clearInterval @intervalID
    @intervalID = null