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

  start { onChange(trigger_makeSections); }

  visual withComputing(trigger_makeSections,
    jvsplit(wrapTextArea(setFontSize(fontSize, dm_textArea('text))),
      jscroll_verticalExtend(stack = customLayoutPanel_trackWidth(
        nu StackLayouter(maximizeIfSingleComponent := maximizeSingleSection)))));
        
  JComponent wrapTextArea(JTextArea textArea) { ret textArea; }
      
  void makeSections() q {
    if (stack == null || !trigger_makeSections.check()) ret;
    removeAllComponents(stack);
    makeSections_impl();
    print("Have sections: " + componentCount(stack));
    print("Stack parent=" + getParent(stack));
  }
  
  // override me. stack is already cleared. we're in the module queue
  void makeSections_impl {}
  
  // only call in makeSections_impl()
  void addSection(S name, Component contents) {
    addComponent(stack, jSection(name, contents));
  }
}

Began life as a copy of #1022759