StepAction helps to get rid of nesting setTimeout

StepAction.coffee

# StepAction helps to get rid of nesting setTimeout
#
# Function.prototype.bind feature is used.
# Only support IE9+ for now

class StepAction
    constructor: (@steps, @initDelay) ->
        @_timer = null
        @_onStep = 0

        @_timer = setTimeout (-> @play()).bind(@), if @initDelay then @initDelay else 0
    next: (timeout) ->
            clearTimeout @_timer
            @_timer = setTimeout @steps[++@_onStep].bind(@), timeout
    play: ->
        clearTimeout @_timer
        @_timer = setTimeout @steps[0].bind(@), 0
    fin: ->
        clearTimeout @_timer


# Demo
new StepAction [
    ->
        console.log 'Step1: 1000'
        @next 1000
    ->
        console.log 'Step2: 100'
        @next 100
    ->
        console.log 'Step3: last'
        @fin()
]