code: @Override
      public void setProgressBarVisibility(boolean visible) {
          if (ActionBarSherlock.DEBUG) Log.d(TAG, "[setProgressBarVisibility] visible: " + visible);
  
          setFeatureInt(Window.FEATURE_PROGRESS, visible ? Window.PROGRESS_VISIBILITY_ON :
              Window.PROGRESS_VISIBILITY_OFF);
      }
docs: /////////////////////////////////////////////////////////////////////////