sclass HDivWithVerticalExpandButton {
  int initialHeight;
  S expandButtonText = "MORE";
  O contents;
  S btnID = aGlobalID();
  
  *(int *initialHeight, O *contents) {}
  *(int *initialHeight, O *contents, S *expandButtonText) {}
  
  S html() {
    ret hjs(expandVars("var pressed_$btnID = false;"))
      + div(contents, class := "expandable", 
      style := "max-height: " + initialHeight + "px; overflow: hidden;") + "\n"
      + hbuttonOnClick_noSubmit(expandButtonText, expandVars([[
        pressed_$btnID = true;
        $(this).prev('.expandable').css('max-height', 'none');
        $(this).hide();
      ]]), style := "display: none", id := btnID) + "\n"
      + hjs(expandVars([[
        {
          let btn = $('#$btnID');
          window.check_$btnID = function() {
            if (pressed_$btnID) return;
            $(btn).toggle($(btn).prev('.expandable').outerHeight() >= $initialHeight);
            setTimeout(check_$btnID, 5000);
          };
          check_$btnID(); setTimeout(check_$btnID, 1000);
        }
      ]]));
  }
  
  S expandVars(S js) { ret replaceDollarVars(js, +btnID, +initialHeight); }
  
  bool needsJQuery() { true; }
}