# File vtk/gtk/GtkGLExtVTKRenderWindowInteractor.rb, line 111
  def OnRealize(wid, event)
    unless @Created
      # you can't get the xid without the window being realized.
      self.realize
      if Config::CONFIG["host_os"] =~ /win32/
        win_id = self.window.handle.to_s
      else
        win_id =self.window.xid.to_s
      end

      @RenderWindow.SetWindowInfo(win_id)
#      @Iren.Initialize
      @Created = true
    end
    return true
  end