Dart - second time click event detect
===

    var modify = document.queryAll("#tab");
      
      for(var i=0; i<modify.length; i++)
      {
        modify[i].on.click.add((Event e) => show_content(i));
      }
    // code for hide_content()

i have two function show_content() and hide_content() that operates on the div's
i'm not able to detect second time click on a div to trigger hide_content(). i've tried with a semaphore and - no luck 
