abstract sclass DynBigInputAndSections {
  S text;
  switchable int fontSize = 20;
  transient JPanel stack;
  transient Trigger trigger_makeSections = new(r makeSections);

  start { onChange(trigger_makeSections); }

  visual withComputing(trigger_makeSections,
    jvsplit(setFontSize(fontSize, dm_textArea('text)),
      jscroll_trackWidth(stack = customLayoutPanel(new StackLayouter))));
      
  void makeSections() q {
    if (stack == null || !trigger_makeSections.check()) ret;
    removeAllComponents(stack);
    makeSections_impl();
  }
  
  // override me. stack is already cleared. we're in the module queue
  void makeSections_impl {}
}