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));

  }

}