window.addEventListener("load", function()
{
  if (navigator.appName != "Microsoft Internet Explorer") // Older IE gets Microsoft Internet Explorer, so works with newer that get Netscape
  {
    var pre = document.getElementsByTagName('pre'), pl = pre.length;
    for (var i = 0; i < pl; i++)
    {
      var num = pre[i].innerText.replace(/\s+$/g, "").split(/\n/).length;
      pre[i].innerHTML = '<span class="line-number"></span>' + pre[i].innerHTML + '<span class="cl"></span>';;
      for (var j = 0; j < num; j++)
      {
        var line_num = pre[i].getElementsByTagName('span')[0];
        line_num.innerHTML += '<span>' + (j + 1) + '</span>';
      }
    }
  }
})

window.addEventListener("click", function(e)
{
  function selectCode(e)
  {
    var sel = window.getSelection();
    if (sel)
    {
      sel.removeAllRanges();

      var range = document.createRange();

      try
      {
        var span = e.firstChild, s = span;
        if (span)
          if (span.tagName == "SPAN")
            if (span.className == "line-number")
              s = span.nextSibling;
        range.setStartBefore(s);
        range.setEndAfter(e.lastChild);
      }
      catch (er)
      {
        var span = e.firstChild;
        if (span)
          if (span.tagName == "SPAN")
            if (span.className == "line-number")
              span.style.display = "none";

        range.selectNodeContents(e);
      };
      sel.addRange(range);
    }
  }

  function copyToClipboard(e)
  {
    var sel = window.getSelection();
    if (sel)
    {
      selectCode(e);
      document.execCommand('copy');
      sel.removeAllRanges();
    }
  }

  var tag = e.target.tagName;
  if (tag)
  {
    if (e.offsetY < 8)
    {
      if (tag == "PRE") // select code
        selectCode(e.target);
    }
    else
      if (tag == "PRE")
        if (e.offsetY > e.target.clientHeight - 8) // copy
          copyToClipboard(e.target);
  }
})