     @trigger "updateLayer", @getActiveCellId(), @currentLayer.getSmoothedContourList()
 
   finishLayer : ->
+
+    return if @handleModification()
 
     unless @currentLayer?
       return

    window.setSmoothLength = (v) -> Drawing.setSmoothLength(v)


  createCell : (id) ->

    unless id?
      id = @idCount++


  addToLayer : (pos) ->

    return if @handleModification()

    unless @currentLayer?
      return

