public void pageUp() {
    if (currentPosition > 0 && !moveMode) {
      int previousPosition = currentPosition;
      currentPosition = 0;
      showField(previousPosition);
      showField(currentPosition);
      fieldScreenView.refreshTerminal();
    }
  }
The presentation logic for the field screen.
hbase-hbtop/src/main/java/org/apache/hadoop/hbase/hbtop/screen/field/FieldScreenPresenter.java