# into stuff or to get out from under your finger.

  constructor: (@config) ->

    # config has:

    #   getTarget -> vec2 of current target position

    #   getSuggestedTargetOffset -> vec2 pixel offset from target

    #   observable -> ko.observable we will read and write

    #   getValueForPos(pos) -> what should we set to if the user

    #                          moves target to this coord?

  _getValue: () ->

    @config.observable()

    #   ctx

    #   getTargetPosForValue(value) -> getTarget result for value

    #   getValueForPos

    if not @config.ctx?

      throw new Error("missing ctx")

    @config.graph.runHandler(@_syncValue.bind(@), "adj sync #{@config.subj}")

class window.AdjustableFade extends Adjustable

  constructor: (@yForV, @i0, @i1, @note, offset, ctx) ->

    @config = {

      getSuggestedTargetOffset: -> offset

      getTarget: @getTarget.bind(@)

      ctx: ctx

    }

  getTarget: ->

    mid = @note.worldPts[@i0].x(.5).add(@note.worldPts[@i1].x(.5))