class window.Tram.FaviconApp extends Backbone.View
  tagName: 'link'
  attributes:
    rel: 'icon'
    type: 'image/x-icon'
  pipColors: Tram.colors.show
  initialize: ->
    @canvas = document.createElement('canvas')
    @canvas.height = 16
    @canvas.width = 16
    @listenTo(@model, 'change', @updateFavicon)
    @updateFavicon()
    @render()
  updateFavicon: ->
    color = @pipColors[@model.get('show')] ? @pipColors['default']
    @renderFavicon(color)
  renderFavicon: (color) ->
    ctx = @canvas.getContext('2d')
    ctx.clearRect(0, 0, @canvas.width, @canvas.height)
    ctx.fillStyle = color
    ctx.beginPath()
    ctx.arc(7.5, 7.5, 5.5, 0, Math.PI * 2)
    ctx.fill()
    @el.href = @canvas.toDataURL()
  render: ->
    $('head').append(@el)
    @