give private access to a figure in a class

Hello I am building a class that accesses a figure and than manipulates the data of the figure. My problem is that a plot outside of my figure could destroy all the data of the figure.

the class definition:

classdef theVectorscope < handle
    properties(access=protected)

          thefig
          theaxis
          pltlist

      end

      methods

          %-----------DRAW-----------k        

          function obj = Myspecialfigure()

              obj.thefig = figure();%Create a figure

              obj.theaxis = axes('Position', [0.1, 0.1, .8, .8],'Parent',obj.thefig);

              obj.pltlist = plot(rand(1,5,rand(1,5)),'Parent',obj.theaxis)%Making a simple plot
              set(obj.thefig ,'HitTest','off')

          end
end

I tryed protected but the figure can still be manipulated outside of my class. Is it possible to make a protected figure with matlab classes ?