static abstract class DynSingleFunction extends DynModule {
  transient S buttonText;
  
  *() {}
  *(S *buttonText) {}
  
  // call before visualize
  void setFunctionName(S name) { buttonText = name; }
  
  visualize {
    ret jfullcenter(jbutton(or2(buttonText, dm_moduleName()), rThread doItWithEnter));
  }
  
  abstract void doIt();
  
  void doItWithEnter() {
    temp enter();
    doIt();
  }
}