actor Painter
   let listener: Main
   var history:  Array[Ressource box] = Array[Ressource box]

   new create(listener': Main) =>
     listener = listener'

   be paint(res: Ressource iso) =>
     if res.level() > 0 then
       history.push(consume res)
       listener.notify(stats())
     else
       res.fill()
       paint(consume res)
     end

   fun stats(): String =>
     var msg: String = "the painter has consumed: "
     for x in Properties.list() do
       var sum: U64 = 0
       for y in history.values() do
         sum = sum + if y.name is x then y.level() else 0 end
       end
       msg = msg + Properties.name(x) + ": " + sum.string() + ";  "
     end
     msg