# File vtk/gtk/GtkVTKRenderWindow.rb, line 138
  def OnRealize(wid, event)
    if @Created == 0
      # you can't get the xid without the window being realized.
      self.realize
      win_id = self.get_window.xid.to_s
      @RenderWindow.SetWindowInfo(win_id)
      @Created = true
    end
    return true
  end