code: private void updateDomainAxisRange()
      {
          int count = dataSet.getSeries(0).getItemCount();
          if (count < SHOW_FIXED_GENERATIONS)
          {
              domainAxis.setRangeWithMargins(0, SHOW_FIXED_GENERATIONS);
          }
          else if (allDataButton.isSelected())
          {
              domainAxis.setRangeWithMargins(0, Math.max(SHOW_FIXED_GENERATIONS, count));
          }
          else
          {
              domainAxis.setRangeWithMargins(count - SHOW_FIXED_GENERATIONS, count);
          }
      }
docs: If "all data" is selected, set the range of the domain axis to include all
  values.  Otherwise set it to show the most recent 200 generations.