public void arrowUp() {
    if (currentPosition > 0) {
      currentPosition -= 1;
      showMode(currentPosition);
      showMode(currentPosition + 1);
      modeScreenView.refreshTerminal();
    }
  }
The presentation logic for the mode screen.
hbase-hbtop/src/main/java/org/apache/hadoop/hbase/hbtop/screen/mode/ModeScreenPresenter.java