intro.js 70 KB
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 379 380 381 382 383 384 385 386 387 388 389 390 391 392 393 394 395 396 397 398 399 400 401 402 403 404 405 406 407 408 409 410 411 412 413 414 415 416 417 418 419 420 421 422 423 424 425 426 427 428 429 430 431 432 433 434 435 436 437 438 439 440 441 442 443 444 445 446 447 448 449 450 451 452 453 454 455 456 457 458 459 460 461 462 463 464 465 466 467 468 469 470 471 472 473 474 475 476 477 478 479 480 481 482 483 484 485 486 487 488 489 490 491 492 493 494 495 496 497 498 499 500 501 502 503 504 505 506 507 508 509 510 511 512 513 514 515 516 517 518 519 520 521 522 523 524 525 526 527 528 529 530 531 532 533 534 535 536 537 538 539 540 541 542 543 544 545 546 547 548 549 550 551 552 553 554 555 556 557 558 559 560 561 562 563 564 565 566 567 568 569 570 571 572 573 574 575 576 577 578 579 580 581 582 583 584 585 586 587 588 589 590 591 592 593 594 595 596 597 598 599 600 601 602 603 604 605 606 607 608 609 610 611 612 613 614 615 616 617 618 619 620 621 622 623 624 625 626 627 628 629 630 631 632 633 634 635 636 637 638 639 640 641 642 643 644 645 646 647 648 649 650 651 652 653 654 655 656 657 658 659 660 661 662 663 664 665 666 667 668 669 670 671 672 673 674 675 676 677 678 679 680 681 682 683 684 685 686 687 688 689 690 691 692 693 694 695 696 697 698 699 700 701 702 703 704 705 706 707 708 709 710 711 712 713 714 715 716 717 718 719 720 721 722 723 724 725 726 727 728 729 730 731 732 733 734 735 736 737 738 739 740 741 742 743 744 745 746 747 748 749 750 751 752 753 754 755 756 757 758 759 760 761 762 763 764 765 766 767 768 769 770 771 772 773 774 775 776 777 778 779 780 781 782 783 784 785 786 787 788 789 790 791 792 793 794 795 796 797 798 799 800 801 802 803 804 805 806 807 808 809 810 811 812 813 814 815 816 817 818 819 820 821 822 823 824 825 826 827 828 829 830 831 832 833 834 835 836 837 838 839 840 841 842 843 844 845 846 847 848 849 850 851 852 853 854 855 856 857 858 859 860 861 862 863 864 865 866 867 868 869 870 871 872 873 874 875 876 877 878 879 880 881 882 883 884 885 886 887 888 889 890 891 892 893 894 895 896 897 898 899 900 901 902 903 904 905 906 907 908 909 910 911 912 913 914 915 916 917 918 919 920 921 922 923 924 925 926 927 928 929 930 931 932 933 934 935 936 937 938 939 940 941 942 943 944 945 946 947 948 949 950 951 952 953 954 955 956 957 958 959 960 961 962 963 964 965 966 967 968 969 970 971 972 973 974 975 976 977 978 979 980 981 982 983 984 985 986 987 988 989 990 991 992 993 994 995 996 997 998 999 1000 1001 1002 1003 1004 1005 1006 1007 1008 1009 1010 1011 1012 1013 1014 1015 1016 1017 1018 1019 1020 1021 1022 1023 1024 1025 1026 1027 1028 1029 1030 1031 1032 1033 1034 1035 1036 1037 1038 1039 1040 1041 1042 1043 1044 1045 1046 1047 1048 1049 1050 1051 1052 1053 1054 1055 1056 1057 1058 1059 1060 1061 1062 1063 1064 1065 1066 1067 1068 1069 1070 1071 1072 1073 1074 1075 1076 1077 1078 1079 1080 1081 1082 1083 1084 1085 1086 1087 1088 1089 1090 1091 1092 1093 1094 1095 1096 1097 1098 1099 1100 1101 1102 1103 1104 1105 1106 1107 1108 1109 1110 1111 1112 1113 1114 1115 1116 1117 1118 1119 1120 1121 1122 1123 1124 1125 1126 1127 1128 1129 1130 1131 1132 1133 1134 1135 1136 1137 1138 1139 1140 1141 1142 1143 1144 1145 1146 1147 1148 1149 1150 1151 1152 1153 1154 1155 1156 1157 1158 1159 1160 1161 1162 1163 1164 1165 1166 1167 1168 1169 1170 1171 1172 1173 1174 1175 1176 1177 1178 1179 1180 1181 1182 1183 1184 1185 1186 1187 1188 1189 1190 1191 1192 1193 1194 1195 1196 1197 1198 1199 1200 1201 1202 1203 1204 1205 1206 1207 1208 1209 1210 1211 1212 1213 1214 1215 1216 1217 1218 1219 1220 1221 1222 1223 1224 1225 1226 1227 1228 1229 1230 1231 1232 1233 1234 1235 1236 1237 1238 1239 1240 1241 1242 1243 1244 1245 1246 1247 1248 1249 1250 1251 1252 1253 1254 1255 1256 1257 1258 1259 1260 1261 1262 1263 1264 1265 1266 1267 1268 1269 1270 1271 1272 1273 1274 1275 1276 1277 1278 1279 1280 1281 1282 1283 1284 1285 1286 1287 1288 1289 1290 1291 1292 1293 1294 1295 1296 1297 1298 1299 1300 1301 1302 1303 1304 1305 1306 1307 1308 1309 1310 1311 1312 1313 1314 1315 1316 1317 1318 1319 1320 1321 1322 1323 1324 1325 1326 1327 1328 1329 1330 1331 1332 1333 1334 1335 1336 1337 1338 1339 1340 1341 1342 1343 1344 1345 1346 1347 1348 1349 1350 1351 1352 1353 1354 1355 1356 1357 1358 1359 1360 1361 1362 1363 1364 1365 1366 1367 1368 1369 1370 1371 1372 1373 1374 1375 1376 1377 1378 1379 1380 1381 1382 1383 1384 1385 1386 1387 1388 1389 1390 1391 1392 1393 1394 1395 1396 1397 1398 1399 1400 1401 1402 1403 1404 1405 1406 1407 1408 1409 1410 1411 1412 1413 1414 1415 1416 1417 1418 1419 1420 1421 1422 1423 1424 1425 1426 1427 1428 1429 1430 1431 1432 1433 1434 1435 1436 1437 1438 1439 1440 1441 1442 1443 1444 1445 1446 1447 1448 1449 1450 1451 1452 1453 1454 1455 1456 1457 1458 1459 1460 1461 1462 1463 1464 1465 1466 1467 1468 1469 1470 1471 1472 1473 1474 1475 1476 1477 1478 1479 1480 1481 1482 1483 1484 1485 1486 1487 1488 1489 1490 1491 1492 1493 1494 1495 1496 1497 1498 1499 1500 1501 1502 1503 1504 1505 1506 1507 1508 1509 1510 1511 1512 1513 1514 1515 1516 1517 1518 1519 1520 1521 1522 1523 1524 1525 1526 1527 1528 1529 1530 1531 1532 1533 1534 1535 1536 1537 1538 1539 1540 1541 1542 1543 1544 1545 1546 1547 1548 1549 1550 1551 1552 1553 1554 1555 1556 1557 1558 1559 1560 1561 1562 1563 1564 1565 1566 1567 1568 1569 1570 1571 1572 1573 1574 1575 1576 1577 1578 1579 1580 1581 1582 1583 1584 1585 1586 1587 1588 1589 1590 1591 1592 1593 1594 1595 1596 1597 1598 1599 1600 1601 1602 1603 1604 1605 1606 1607 1608 1609 1610 1611 1612 1613 1614 1615 1616 1617 1618 1619 1620 1621 1622 1623 1624 1625 1626 1627 1628 1629 1630 1631 1632 1633 1634 1635 1636 1637 1638 1639 1640 1641 1642 1643 1644 1645 1646 1647 1648 1649 1650 1651 1652 1653 1654 1655 1656 1657 1658 1659 1660 1661 1662 1663 1664 1665 1666 1667 1668 1669 1670 1671 1672 1673 1674 1675 1676 1677 1678 1679 1680 1681 1682 1683 1684 1685 1686 1687 1688 1689 1690 1691 1692 1693 1694 1695 1696 1697 1698 1699 1700 1701 1702 1703 1704 1705 1706 1707 1708 1709 1710 1711 1712 1713 1714 1715 1716 1717 1718 1719 1720 1721 1722 1723 1724 1725 1726 1727 1728 1729 1730 1731 1732 1733 1734 1735 1736 1737 1738 1739 1740 1741 1742 1743 1744 1745 1746 1747 1748 1749 1750 1751 1752 1753 1754 1755 1756 1757 1758 1759 1760 1761 1762 1763 1764 1765 1766 1767 1768 1769 1770 1771 1772 1773 1774 1775 1776 1777 1778 1779 1780 1781 1782 1783 1784 1785 1786 1787 1788 1789 1790 1791 1792 1793 1794 1795 1796 1797 1798 1799 1800 1801 1802 1803 1804 1805 1806 1807 1808 1809 1810 1811 1812 1813 1814 1815 1816 1817 1818 1819 1820 1821 1822 1823 1824 1825 1826 1827 1828 1829 1830 1831 1832 1833 1834 1835 1836 1837 1838 1839 1840 1841 1842 1843 1844 1845 1846 1847 1848 1849 1850 1851 1852 1853 1854 1855 1856 1857 1858 1859 1860 1861 1862 1863 1864 1865 1866 1867 1868 1869 1870 1871 1872 1873 1874 1875 1876 1877 1878 1879 1880 1881 1882 1883 1884 1885 1886 1887 1888 1889 1890 1891 1892 1893 1894 1895 1896 1897 1898 1899 1900 1901 1902 1903 1904 1905 1906 1907 1908 1909 1910 1911 1912 1913 1914 1915 1916 1917 1918 1919 1920 1921 1922 1923 1924 1925 1926 1927 1928 1929 1930 1931 1932 1933 1934 1935 1936 1937 1938 1939 1940 1941 1942 1943 1944 1945 1946 1947 1948 1949 1950 1951 1952 1953 1954 1955 1956 1957 1958 1959 1960 1961 1962 1963 1964 1965 1966 1967 1968 1969 1970 1971 1972 1973 1974 1975 1976 1977 1978 1979 1980 1981 1982 1983 1984 1985 1986 1987 1988 1989 1990 1991 1992 1993 1994 1995 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005 2006 2007 2008 2009 2010 2011 2012 2013 2014 2015 2016 2017 2018 2019 2020 2021 2022 2023 2024 2025 2026 2027 2028 2029 2030 2031 2032 2033 2034 2035 2036 2037 2038 2039 2040 2041 2042 2043 2044 2045 2046 2047 2048 2049 2050 2051 2052 2053 2054 2055 2056 2057 2058 2059 2060 2061 2062 2063 2064 2065 2066 2067 2068 2069 2070 2071 2072 2073 2074 2075 2076 2077 2078 2079 2080 2081 2082 2083 2084 2085 2086 2087 2088 2089 2090 2091 2092 2093 2094 2095 2096 2097 2098 2099 2100 2101 2102 2103 2104 2105 2106 2107 2108 2109 2110 2111 2112 2113 2114 2115 2116 2117 2118 2119 2120 2121 2122 2123 2124 2125 2126 2127 2128 2129 2130 2131 2132 2133 2134 2135 2136 2137 2138 2139
/**
 * Intro.js v2.7.0
 * https://github.com/usablica/intro.js
 *
 * Copyright (C) 2017 Afshin Mehrabani (@afshinmeh)
 */

(function (root, factory) {
  if (typeof exports === 'object') {
    // CommonJS
    factory(exports);
  } else if (typeof define === 'function' && define.amd) {
    // AMD. Register as an anonymous module.
    define(['exports'], factory);
  } else {
    // Browser globals
    factory(root);
  }
} (this, function (exports) {
  //Default config/variables
  var VERSION = '2.7.0';

  /**
   * IntroJs main class
   *
   * @class IntroJs
   */
  function IntroJs(obj) {
    this._targetElement = obj;
    this._introItems = [];

    this._options = {
      /* Next button label in tooltip box */
      nextLabel: 'Next →',
      /* Previous button label in tooltip box */
      prevLabel: '← Back',
      /* Skip button label in tooltip box */
      skipLabel: 'Skip',
      /* Done button label in tooltip box */
      doneLabel: 'Done',
      /* Hide previous button in the first step? Otherwise, it will be disabled button. */
      hidePrev: false,
      /* Hide next button in the last step? Otherwise, it will be disabled button. */
      hideNext: false,
      /* Default tooltip box position */
      tooltipPosition: 'bottom',
      /* Next CSS class for tooltip boxes */
      tooltipClass: '',
      /* CSS class that is added to the helperLayer */
      highlightClass: '',
      /* Close introduction when pressing Escape button? */
      exitOnEsc: true,
      /* Close introduction when clicking on overlay layer? */
      exitOnOverlayClick: true,
      /* Show step numbers in introduction? */
      showStepNumbers: true,
      /* Let user use keyboard to navigate the tour? */
      keyboardNavigation: true,
      /* Show tour control buttons? */
      showButtons: true,
      /* Show tour bullets? */
      showBullets: true,
      /* Show tour progress? */
      showProgress: false,
      /* Scroll to highlighted element? */
      scrollToElement: true,
      /*
       * Should we scroll the tooltip or target element?
       *
       * Options are: 'element' or 'tooltip'
       */
      scrollTo: 'element',
      /* Padding to add after scrolling when element is not in the viewport (in pixels) */
      scrollPadding: 30,
      /* Set the overlay opacity */
      overlayOpacity: 0.8,
      /* Precedence of positions, when auto is enabled */
      positionPrecedence: ["bottom", "top", "right", "left"],
      /* Disable an interaction with element? */
      disableInteraction: false,
      /* Default hint position */
      hintPosition: 'top-middle',
      /* Hint button label */
      hintButtonLabel: 'Got it',
      /* Adding animation to hints? */
      hintAnimation: true
    };
  }

  /**
   * Initiate a new introduction/guide from an element in the page
   *
   * @api private
   * @method _introForElement
   * @param {Object} targetElm
   * @returns {Boolean} Success or not?
   */
  function _introForElement(targetElm) {
    var introItems = [],
        self = this;

    if (this._options.steps) {
      //use steps passed programmatically
      for (var i = 0, stepsLength = this._options.steps.length; i < stepsLength; i++) {
        var currentItem = _cloneObject(this._options.steps[i]);

        //set the step
        currentItem.step = introItems.length + 1;

        //use querySelector function only when developer used CSS selector
        if (typeof (currentItem.element) === 'string') {
          //grab the element with given selector from the page
          currentItem.element = document.querySelector(currentItem.element);
        }

        //intro without element
        if (typeof (currentItem.element) === 'undefined' || currentItem.element == null) {
          var floatingElementQuery = document.querySelector(".introjsFloatingElement");

          if (floatingElementQuery == null) {
            floatingElementQuery = document.createElement('div');
            floatingElementQuery.className = 'introjsFloatingElement';

            document.body.appendChild(floatingElementQuery);
          }

          currentItem.element  = floatingElementQuery;
          currentItem.position = 'floating';
        }

        currentItem.scrollTo = currentItem.scrollTo || this._options.scrollTo;

        if (typeof (currentItem.disableInteraction) === 'undefined') {
          currentItem.disableInteraction = this._options.disableInteraction;
        }

        if (currentItem.element != null) {
          introItems.push(currentItem);
        }
      }

    } else {
      //use steps from data-* annotations
      var allIntroSteps = targetElm.querySelectorAll('*[data-intro]');
      //if there's no element to intro
      if (allIntroSteps.length < 1) {
        return false;
      }

      //first add intro items with data-step
      for (var i = 0, elmsLength = allIntroSteps.length; i < elmsLength; i++) {
        var currentElement = allIntroSteps[i];

        // skip hidden elements
        if (currentElement.style.display == 'none') {
          continue;
        }

        var step = parseInt(currentElement.getAttribute('data-step'), 10);

        var disableInteraction = this._options.disableInteraction;

        if (typeof (currentElement.getAttribute('data-disable-interaction')) != 'undefined') {
          disableInteraction = !!currentElement.getAttribute('data-disable-interaction');
        }

        if (step > 0) {
          introItems[step - 1] = {
            element: currentElement,
            intro: currentElement.getAttribute('data-intro'),
            step: parseInt(currentElement.getAttribute('data-step'), 10),
            tooltipClass: currentElement.getAttribute('data-tooltipClass'),
            highlightClass: currentElement.getAttribute('data-highlightClass'),
            position: currentElement.getAttribute('data-position') || this._options.tooltipPosition,
            scrollTo: currentElement.getAttribute('data-scrollTo') || this._options.scrollTo,
            disableInteraction: disableInteraction
          };
        }
      }

      //next add intro items without data-step
      //todo: we need a cleanup here, two loops are redundant
      var nextStep = 0;
      for (var i = 0, elmsLength = allIntroSteps.length; i < elmsLength; i++) {
        var currentElement = allIntroSteps[i];

        if (currentElement.getAttribute('data-step') == null) {

          while (true) {
            if (typeof introItems[nextStep] == 'undefined') {
              break;
            } else {
              nextStep++;
            }
          }

          var disableInteraction = this._options.disableInteraction;

          if (typeof (currentElement.getAttribute('data-disable-interaction')) != 'undefined') {
            disableInteraction = !!currentElement.getAttribute('data-disable-interaction');
          }

          introItems[nextStep] = {
            element: currentElement,
            intro: currentElement.getAttribute('data-intro'),
            step: nextStep + 1,
            tooltipClass: currentElement.getAttribute('data-tooltipClass'),
            highlightClass: currentElement.getAttribute('data-highlightClass'),
            position: currentElement.getAttribute('data-position') || this._options.tooltipPosition,
            scrollTo: currentElement.getAttribute('data-scrollTo') || this._options.scrollTo,
            disableInteraction: disableInteraction
          };
        }
      }
    }

    //removing undefined/null elements
    var tempIntroItems = [];
    for (var z = 0; z < introItems.length; z++) {
      introItems[z] && tempIntroItems.push(introItems[z]);  // copy non-empty values to the end of the array
    }

    introItems = tempIntroItems;

    //Ok, sort all items with given steps
    introItems.sort(function (a, b) {
      return a.step - b.step;
    });

    //set it to the introJs object
    self._introItems = introItems;

    //add overlay layer to the page
    if(_addOverlayLayer.call(self, targetElm)) {
      //then, start the show
      _nextStep.call(self);

      var skipButton     = targetElm.querySelector('.introjs-skipbutton'),
          nextStepButton = targetElm.querySelector('.introjs-nextbutton');

      self._onKeyDown = function(e) {
        if (e.keyCode === 27 && self._options.exitOnEsc == true) {
          //escape key pressed, exit the intro
          //check if exit callback is defined
          _exitIntro.call(self, targetElm);
        } else if(e.keyCode === 37) {
          //left arrow
          _previousStep.call(self);
        } else if (e.keyCode === 39) {
          //right arrow
          _nextStep.call(self);
        } else if (e.keyCode === 13) {
          //srcElement === ie
          var target = e.target || e.srcElement;
          if (target && target.className.indexOf('introjs-prevbutton') > 0) {
            //user hit enter while focusing on previous button
            _previousStep.call(self);
          } else if (target && target.className.indexOf('introjs-skipbutton') > 0) {
            //user hit enter while focusing on skip button
            if (self._introItems.length - 1 == self._currentStep && typeof (self._introCompleteCallback) === 'function') {
                self._introCompleteCallback.call(self);
            }

            _exitIntro.call(self, targetElm);
          } else {
            //default behavior for responding to enter
            _nextStep.call(self);
          }

          //prevent default behaviour on hitting Enter, to prevent steps being skipped in some browsers
          if(e.preventDefault) {
            e.preventDefault();
          } else {
            e.returnValue = false;
          }
        }
      };

      self._onResize = function(e) {
        self.refresh.call(self);
      };

      if (window.addEventListener) {
        if (this._options.keyboardNavigation) {
          window.addEventListener('keydown', self._onKeyDown, true);
        }
        //for window resize
        window.addEventListener('resize', self._onResize, true);
      } else if (document.attachEvent) { //IE
        if (this._options.keyboardNavigation) {
          document.attachEvent('onkeydown', self._onKeyDown);
        }
        //for window resize
        document.attachEvent('onresize', self._onResize);
      }
    }
    return false;
  }

 /*
   * makes a copy of the object
   * @api private
   * @method _cloneObject
  */
  function _cloneObject(object) {
      if (object == null || typeof (object) != 'object' || typeof (object.nodeType) != 'undefined') {
        return object;
      }
      var temp = {};
      for (var key in object) {
        if (typeof (jQuery) != 'undefined' && object[key] instanceof jQuery) {
          temp[key] = object[key];
        } else {
          temp[key] = _cloneObject(object[key]);
        }
      }
      return temp;
  }
  /**
   * Go to specific step of introduction
   *
   * @api private
   * @method _goToStep
   */
  function _goToStep(step) {
    //because steps starts with zero
    this._currentStep = step - 2;
    if (typeof (this._introItems) !== 'undefined') {
      _nextStep.call(this);
    }
  }

  /**
   * Go to the specific step of introduction with the explicit [data-step] number
   *
   * @api private
   * @method _goToStepNumber
   */
  function _goToStepNumber(step) {
    this._currentStepNumber = step;
    if (typeof (this._introItems) !== 'undefined') {
      _nextStep.call(this);
    }
  }

  /**
   * Go to next step on intro
   *
   * @api private
   * @method _nextStep
   */
  function _nextStep() {
    this._direction = 'forward';

    if (typeof (this._currentStepNumber) !== 'undefined') {
        for( var i = 0, len = this._introItems.length; i < len; i++ ) {
            var item = this._introItems[i];
            if( item.step === this._currentStepNumber ) {
                this._currentStep = i - 1;
                this._currentStepNumber = undefined;
            }
        }
    }

    if (typeof (this._currentStep) === 'undefined') {
      this._currentStep = 0;
    } else {
      ++this._currentStep;
    }

    if ((this._introItems.length) <= this._currentStep) {
      //end of the intro
      //check if any callback is defined
      if (typeof (this._introCompleteCallback) === 'function') {
        this._introCompleteCallback.call(this);
      }
      _exitIntro.call(this, this._targetElement);
      return;
    }

    var nextStep = this._introItems[this._currentStep];
    if (typeof (this._introBeforeChangeCallback) !== 'undefined') {
      this._introBeforeChangeCallback.call(this, nextStep.element);
    }

    _showElement.call(this, nextStep);
  }

  /**
   * Go to previous step on intro
   *
   * @api private
   * @method _previousStep
   */
  function _previousStep() {
    this._direction = 'backward';

    if (this._currentStep === 0) {
      return false;
    }

    var nextStep = this._introItems[--this._currentStep];
    if (typeof (this._introBeforeChangeCallback) !== 'undefined') {
      this._introBeforeChangeCallback.call(this, nextStep.element);
    }

    _showElement.call(this, nextStep);
  }

  /**
   * Update placement of the intro objects on the screen
   * @api private
   */
  function _refresh() {
    // re-align intros
    _setHelperLayerPosition.call(this, document.querySelector('.introjs-helperLayer'));
    _setHelperLayerPosition.call(this, document.querySelector('.introjs-tooltipReferenceLayer'));

    // re-align tooltip
    if(this._currentStep !== undefined && this._currentStep !== null) {
      var oldHelperNumberLayer = document.querySelector('.introjs-helperNumberLayer'),
        oldArrowLayer        = document.querySelector('.introjs-arrow'),
        oldtooltipContainer  = document.querySelector('.introjs-tooltip');
      _placeTooltip.call(this, this._introItems[this._currentStep].element, oldtooltipContainer, oldArrowLayer, oldHelperNumberLayer);
    }

    //re-align hints
    _reAlignHints.call(this);
    return this;
  }

  /**
   * Exit from intro
   *
   * @api private
   * @method _exitIntro
   * @param {Object} targetElement
   * @param {Boolean} force - Setting to `true` will skip the result of beforeExit callback
   */
  function _exitIntro(targetElement, force) {
    var continueExit = true;

    // calling onbeforeexit callback
    // 
    // If this callback return `false`, it would halt the process
    if (this._introBeforeExitCallback != undefined) {
      continueExit = this._introBeforeExitCallback.call(self);
    }

    // skip this check if `force` parameter is `true`
    // otherwise, if `onbeforeexit` returned `false`, don't exit the intro
    if (!force && continueExit === false) return;

    //remove overlay layers from the page
    var overlayLayers = targetElement.querySelectorAll('.introjs-overlay');

    if (overlayLayers && overlayLayers.length > 0) {
      for (var i = overlayLayers.length - 1; i >= 0; i--) {
        //for fade-out animation
        var overlayLayer = overlayLayers[i];
        overlayLayer.style.opacity = 0;
        setTimeout(function () {
          if (this.parentNode) {
            this.parentNode.removeChild(this);
          }
        }.bind(overlayLayer), 500);
      };
    }

    //remove all helper layers
    var helperLayer = targetElement.querySelector('.introjs-helperLayer');
    if (helperLayer) {
      helperLayer.parentNode.removeChild(helperLayer);
    }

    var referenceLayer = targetElement.querySelector('.introjs-tooltipReferenceLayer');
    if (referenceLayer) {
      referenceLayer.parentNode.removeChild(referenceLayer);
    }

    //remove disableInteractionLayer
    var disableInteractionLayer = targetElement.querySelector('.introjs-disableInteraction');
    if (disableInteractionLayer) {
      disableInteractionLayer.parentNode.removeChild(disableInteractionLayer);
    }

    //remove intro floating element
    var floatingElement = document.querySelector('.introjsFloatingElement');
    if (floatingElement) {
      floatingElement.parentNode.removeChild(floatingElement);
    }

    _removeShowElement();

    //remove `introjs-fixParent` class from the elements
    var fixParents = document.querySelectorAll('.introjs-fixParent');
    if (fixParents && fixParents.length > 0) {
      for (var i = fixParents.length - 1; i >= 0; i--) {
        fixParents[i].className = fixParents[i].className.replace(/introjs-fixParent/g, '').replace(/^\s+|\s+$/g, '');
      }
    }

    //clean listeners
    if (window.removeEventListener) {
      window.removeEventListener('keydown', this._onKeyDown, true);
    } else if (document.detachEvent) { //IE
      document.detachEvent('onkeydown', this._onKeyDown);
    }

    //check if any callback is defined
    if (this._introExitCallback != undefined) {
      this._introExitCallback.call(self);
    }

    //set the step to zero
    this._currentStep = undefined;
  }

  /**
   * Render tooltip box in the page
   *
   * @api private
   * @method _placeTooltip
   * @param {HTMLElement} targetElement
   * @param {HTMLElement} tooltipLayer
   * @param {HTMLElement} arrowLayer
   * @param {HTMLElement} helperNumberLayer
   * @param {Boolean} hintMode
   */
  function _placeTooltip(targetElement, tooltipLayer, arrowLayer, helperNumberLayer, hintMode) {
    var tooltipCssClass = '',
        currentStepObj,
        tooltipOffset,
        targetOffset,
        windowSize,
        currentTooltipPosition;

    hintMode = hintMode || false;

    //reset the old style
    tooltipLayer.style.top        = null;
    tooltipLayer.style.right      = null;
    tooltipLayer.style.bottom     = null;
    tooltipLayer.style.left       = null;
    tooltipLayer.style.marginLeft = null;
    tooltipLayer.style.marginTop  = null;

    arrowLayer.style.display = 'inherit';

    if (typeof(helperNumberLayer) != 'undefined' && helperNumberLayer != null) {
      helperNumberLayer.style.top  = null;
      helperNumberLayer.style.left = null;
    }

    //prevent error when `this._currentStep` is undefined
    if (!this._introItems[this._currentStep]) return;

    //if we have a custom css class for each step
    currentStepObj = this._introItems[this._currentStep];
    if (typeof (currentStepObj.tooltipClass) === 'string') {
      tooltipCssClass = currentStepObj.tooltipClass;
    } else {
      tooltipCssClass = this._options.tooltipClass;
    }

    tooltipLayer.className = ('introjs-tooltip ' + tooltipCssClass).replace(/^\s+|\s+$/g, '');

    currentTooltipPosition = this._introItems[this._currentStep].position;

    if (currentTooltipPosition != "floating") { // Floating is always valid, no point in calculating
      if (currentTooltipPosition === "auto") {
        currentTooltipPosition = _determineAutoPosition.call(this, targetElement, tooltipLayer);
      } else {
        currentTooltipPosition = _determineAutoPosition.call(this, targetElement, tooltipLayer, currentTooltipPosition);
      }
    }

    targetOffset  = _getOffset(targetElement);
    tooltipOffset = _getOffset(tooltipLayer);
    windowSize    = _getWinSize();

    switch (currentTooltipPosition) {
      case 'top':
        arrowLayer.className = 'introjs-arrow bottom';

        if (hintMode) {
          var tooltipLayerStyleLeft = 0;
        } else {
          var tooltipLayerStyleLeft = 15;
        }

        _checkRight(targetOffset, tooltipLayerStyleLeft, tooltipOffset, windowSize, tooltipLayer);
        tooltipLayer.style.bottom = (targetOffset.height +  20) + 'px';
        break;
      case 'right':
        tooltipLayer.style.left = (targetOffset.width + 20) + 'px';
        if (targetOffset.top + tooltipOffset.height > windowSize.height) {
          // In this case, right would have fallen below the bottom of the screen.
          // Modify so that the bottom of the tooltip connects with the target
          arrowLayer.className = "introjs-arrow left-bottom";
          tooltipLayer.style.top = "-" + (tooltipOffset.height - targetOffset.height - 20) + "px";
        } else {
          arrowLayer.className = 'introjs-arrow left';
        }
        break;
      case 'left':
        if (!hintMode && this._options.showStepNumbers == true) {
          tooltipLayer.style.top = '15px';
        }

        if (targetOffset.top + tooltipOffset.height > windowSize.height) {
          // In this case, left would have fallen below the bottom of the screen.
          // Modify so that the bottom of the tooltip connects with the target
          tooltipLayer.style.top = "-" + (tooltipOffset.height - targetOffset.height - 20) + "px";
          arrowLayer.className = 'introjs-arrow right-bottom';
        } else {
          arrowLayer.className = 'introjs-arrow right';
        }
        tooltipLayer.style.right = (targetOffset.width + 20) + 'px';

        break;
      case 'floating':
        arrowLayer.style.display = 'none';

        //we have to adjust the top and left of layer manually for intro items without element
        tooltipLayer.style.left   = '50%';
        tooltipLayer.style.top    = '50%';
        tooltipLayer.style.marginLeft = '-' + (tooltipOffset.width / 2)  + 'px';
        tooltipLayer.style.marginTop  = '-' + (tooltipOffset.height / 2) + 'px';

        if (typeof(helperNumberLayer) != 'undefined' && helperNumberLayer != null) {
          helperNumberLayer.style.left = '-' + ((tooltipOffset.width / 2) + 18) + 'px';
          helperNumberLayer.style.top  = '-' + ((tooltipOffset.height / 2) + 18) + 'px';
        }

        break;
      case 'bottom-right-aligned':
        arrowLayer.className      = 'introjs-arrow top-right';

        var tooltipLayerStyleRight = 0;
        _checkLeft(targetOffset, tooltipLayerStyleRight, tooltipOffset, tooltipLayer);
        tooltipLayer.style.top    = (targetOffset.height +  20) + 'px';
        break;

      case 'bottom-middle-aligned':
        arrowLayer.className      = 'introjs-arrow top-middle';

        var tooltipLayerStyleLeftRight = targetOffset.width / 2 - tooltipOffset.width / 2;

        // a fix for middle aligned hints
        if (hintMode) {
          tooltipLayerStyleLeftRight += 5;
        }

        if (_checkLeft(targetOffset, tooltipLayerStyleLeftRight, tooltipOffset, tooltipLayer)) {
          tooltipLayer.style.right = null;
          _checkRight(targetOffset, tooltipLayerStyleLeftRight, tooltipOffset, windowSize, tooltipLayer);
        }
        tooltipLayer.style.top = (targetOffset.height + 20) + 'px';
        break;

      case 'bottom-left-aligned':
      // Bottom-left-aligned is the same as the default bottom
      case 'bottom':
      // Bottom going to follow the default behavior
      default:
        arrowLayer.className = 'introjs-arrow top';

        var tooltipLayerStyleLeft = 0;
        _checkRight(targetOffset, tooltipLayerStyleLeft, tooltipOffset, windowSize, tooltipLayer);
        tooltipLayer.style.top    = (targetOffset.height +  20) + 'px';
        break;
    }
  }

  /**
   * Set tooltip left so it doesn't go off the right side of the window
   *
   * @return boolean true, if tooltipLayerStyleLeft is ok.  false, otherwise.
   */
  function _checkRight(targetOffset, tooltipLayerStyleLeft, tooltipOffset, windowSize, tooltipLayer) {
    if (targetOffset.left + tooltipLayerStyleLeft + tooltipOffset.width > windowSize.width) {
      // off the right side of the window
      tooltipLayer.style.left = (windowSize.width - tooltipOffset.width - targetOffset.left) + 'px';
      return false;
    }
    tooltipLayer.style.left = tooltipLayerStyleLeft + 'px';
    return true;
  }

  /**
   * Set tooltip right so it doesn't go off the left side of the window
   *
   * @return boolean true, if tooltipLayerStyleRight is ok.  false, otherwise.
   */
  function _checkLeft(targetOffset, tooltipLayerStyleRight, tooltipOffset, tooltipLayer) {
    if (targetOffset.left + targetOffset.width - tooltipLayerStyleRight - tooltipOffset.width < 0) {
      // off the left side of the window
      tooltipLayer.style.left = (-targetOffset.left) + 'px';
      return false;
    }
    tooltipLayer.style.right = tooltipLayerStyleRight + 'px';
    return true;
  }

  /**
   * Determines the position of the tooltip based on the position precedence and availability
   * of screen space.
   *
   * @param {Object} targetElement
   * @param {Object} tooltipLayer
   * @param {Object} desiredTooltipPosition
   *
   */
  function _determineAutoPosition(targetElement, tooltipLayer, desiredTooltipPosition) {

    // Take a clone of position precedence. These will be the available
    var possiblePositions = this._options.positionPrecedence.slice();

    var windowSize = _getWinSize();
    var tooltipHeight = _getOffset(tooltipLayer).height + 10;
    var tooltipWidth = _getOffset(tooltipLayer).width + 20;
    var targetOffset = _getOffset(targetElement);

    // If we check all the possible areas, and there are no valid places for the tooltip, the element
    // must take up most of the screen real estate. Show the tooltip floating in the middle of the screen.
    var calculatedPosition = "floating";

    // Check if the width of the tooltip + the starting point would spill off the right side of the screen
    // If no, neither bottom or top are valid
    if (targetOffset.left + tooltipWidth > windowSize.width || ((targetOffset.left + (targetOffset.width / 2)) - tooltipWidth) < 0) {
      _removeEntry(possiblePositions, "bottom");
      _removeEntry(possiblePositions, "top");
    } else {
      // Check for space below
      if ((targetOffset.height + targetOffset.top + tooltipHeight) > windowSize.height) {
        _removeEntry(possiblePositions, "bottom");
      }

      // Check for space above
      if (targetOffset.top - tooltipHeight < 0) {
        _removeEntry(possiblePositions, "top");
      }
    }

    // Check for space to the right
    if (targetOffset.width + targetOffset.left + tooltipWidth > windowSize.width) {
      _removeEntry(possiblePositions, "right");
    }

    // Check for space to the left
    if (targetOffset.left - tooltipWidth < 0) {
      _removeEntry(possiblePositions, "left");
    }

    // At this point, our array only has positions that are valid. Pick the first one, as it remains in order
    if (possiblePositions.length > 0) {
      calculatedPosition = possiblePositions[0];
    }

    // If the requested position is in the list, replace our calculated choice with that
    if (desiredTooltipPosition && desiredTooltipPosition != "auto") {
      if (possiblePositions.indexOf(desiredTooltipPosition) > -1) {
        calculatedPosition = desiredTooltipPosition;
      }
    }

    return calculatedPosition;
  }

  /**
   * Remove an entry from a string array if it's there, does nothing if it isn't there.
   *
   * @param {Array} stringArray
   * @param {String} stringToRemove
   */
  function _removeEntry(stringArray, stringToRemove) {
    if (stringArray.indexOf(stringToRemove) > -1) {
      stringArray.splice(stringArray.indexOf(stringToRemove), 1);
    }
  }

  /**
   * Update the position of the helper layer on the screen
   *
   * @api private
   * @method _setHelperLayerPosition
   * @param {Object} helperLayer
   */
  function _setHelperLayerPosition(helperLayer) {
    if (helperLayer) {
      //prevent error when `this._currentStep` in undefined
      if (!this._introItems[this._currentStep]) return;

      var currentElement  = this._introItems[this._currentStep],
          elementPosition = _getOffset(currentElement.element),
          widthHeightPadding = 10;

      // If the target element is fixed, the tooltip should be fixed as well.
      // Otherwise, remove a fixed class that may be left over from the previous
      // step.
      if (_isFixed(currentElement.element)) {
        helperLayer.className += ' introjs-fixedTooltip';
      } else {
        helperLayer.className = helperLayer.className.replace(' introjs-fixedTooltip', '');
      }

      if (currentElement.position == 'floating') {
        widthHeightPadding = 0;
      }

      //set new position to helper layer
      helperLayer.setAttribute('style', 'width: ' + (elementPosition.width  + widthHeightPadding)  + 'px; ' +
                                        'height:' + (elementPosition.height + widthHeightPadding)  + 'px; ' +
                                        'top:'    + (elementPosition.top    - 5)   + 'px;' +
                                        'left: '  + (elementPosition.left   - 5)   + 'px;');

    }
  }

  /**
   * Add disableinteraction layer and adjust the size and position of the layer
   *
   * @api private
   * @method _disableInteraction
   */
  function _disableInteraction() {
    var disableInteractionLayer = document.querySelector('.introjs-disableInteraction');

    if (disableInteractionLayer === null) {
      disableInteractionLayer = document.createElement('div');
      disableInteractionLayer.className = 'introjs-disableInteraction';
      this._targetElement.appendChild(disableInteractionLayer);
    }

    _setHelperLayerPosition.call(this, disableInteractionLayer);
  }

  /**
   * Setting anchors to behave like buttons
   *
   * @api private
   * @method _setAnchorAsButton
   */
  function _setAnchorAsButton(anchor){
    anchor.setAttribute('role', 'button');
    anchor.tabIndex = 0;
  }

  /**
   * Show an element on the page
   *
   * @api private
   * @method _showElement
   * @param {Object} targetElement
   */
  function _showElement(targetElement) {
    if (typeof (this._introChangeCallback) !== 'undefined') {
      this._introChangeCallback.call(this, targetElement.element);
    }

    var self = this,
        oldHelperLayer = document.querySelector('.introjs-helperLayer'),
        oldReferenceLayer = document.querySelector('.introjs-tooltipReferenceLayer'),
        highlightClass = 'introjs-helperLayer',
        elementPosition = _getOffset(targetElement.element);

    //check for a current step highlight class
    if (typeof (targetElement.highlightClass) === 'string') {
      highlightClass += (' ' + targetElement.highlightClass);
    }
    //check for options highlight class
    if (typeof (this._options.highlightClass) === 'string') {
      highlightClass += (' ' + this._options.highlightClass);
    }

    if (oldHelperLayer != null) {
      var oldHelperNumberLayer = oldReferenceLayer.querySelector('.introjs-helperNumberLayer'),
          oldtooltipLayer      = oldReferenceLayer.querySelector('.introjs-tooltiptext'),
          oldArrowLayer        = oldReferenceLayer.querySelector('.introjs-arrow'),
          oldtooltipContainer  = oldReferenceLayer.querySelector('.introjs-tooltip'),
          skipTooltipButton    = oldReferenceLayer.querySelector('.introjs-skipbutton'),
          prevTooltipButton    = oldReferenceLayer.querySelector('.introjs-prevbutton'),
          nextTooltipButton    = oldReferenceLayer.querySelector('.introjs-nextbutton');

      //update or reset the helper highlight class
      oldHelperLayer.className = highlightClass;
      //hide the tooltip
      oldtooltipContainer.style.opacity = 0;
      oldtooltipContainer.style.display = "none";

      if (oldHelperNumberLayer != null) {
        var lastIntroItem = this._introItems[(targetElement.step - 2 >= 0 ? targetElement.step - 2 : 0)];

        if (lastIntroItem != null && (this._direction == 'forward' && lastIntroItem.position == 'floating') || (this._direction == 'backward' && targetElement.position == 'floating')) {
          oldHelperNumberLayer.style.opacity = 0;
        }
      }

      //set new position to helper layer
      _setHelperLayerPosition.call(self, oldHelperLayer);
      _setHelperLayerPosition.call(self, oldReferenceLayer);

      //remove `introjs-fixParent` class from the elements
      var fixParents = document.querySelectorAll('.introjs-fixParent');
      if (fixParents && fixParents.length > 0) {
        for (var i = fixParents.length - 1; i >= 0; i--) {
          fixParents[i].className = fixParents[i].className.replace(/introjs-fixParent/g, '').replace(/^\s+|\s+$/g, '');
        };
      }

      //remove old classes if the element still exist
      _removeShowElement();

      //we should wait until the CSS3 transition is competed (it's 0.3 sec) to prevent incorrect `height` and `width` calculation
      if (self._lastShowElementTimer) {
        clearTimeout(self._lastShowElementTimer);
      }

      self._lastShowElementTimer = setTimeout(function() {
        //set current step to the label
        if (oldHelperNumberLayer != null) {
          oldHelperNumberLayer.innerHTML = targetElement.step;
        }
        //set current tooltip text
        oldtooltipLayer.innerHTML = targetElement.intro;
        //set the tooltip position
        oldtooltipContainer.style.display = "block";
        _placeTooltip.call(self, targetElement.element, oldtooltipContainer, oldArrowLayer, oldHelperNumberLayer);

        //change active bullet
        if (self._options.showBullets) {
            oldReferenceLayer.querySelector('.introjs-bullets li > a.active').className = '';
            oldReferenceLayer.querySelector('.introjs-bullets li > a[data-stepnumber="' + targetElement.step + '"]').className = 'active';
        }
        oldReferenceLayer.querySelector('.introjs-progress .introjs-progressbar').setAttribute('style', 'width:' + _getProgress.call(self) + '%;');

        //show the tooltip
        oldtooltipContainer.style.opacity = 1;
        if (oldHelperNumberLayer) oldHelperNumberLayer.style.opacity = 1;

        //reset button focus
        if (typeof skipTooltipButton !== "undefined" && skipTooltipButton != null && /introjs-donebutton/gi.test(skipTooltipButton.className)) {
          // skip button is now "done" button
          skipTooltipButton.focus();
        } else if (typeof nextTooltipButton !== "undefined" && nextTooltipButton != null) {
          //still in the tour, focus on next
          nextTooltipButton.focus();
        }

        // change the scroll of the window, if needed
        _scrollTo.call(self, targetElement.scrollTo, targetElement, oldtooltipLayer);
      }, 350);

      // end of old element if-else condition
    } else {
      var helperLayer       = document.createElement('div'),
          referenceLayer    = document.createElement('div'),
          arrowLayer        = document.createElement('div'),
          tooltipLayer      = document.createElement('div'),
          tooltipTextLayer  = document.createElement('div'),
          bulletsLayer      = document.createElement('div'),
          progressLayer     = document.createElement('div'),
          buttonsLayer      = document.createElement('div');

      helperLayer.className = highlightClass;
      referenceLayer.className = 'introjs-tooltipReferenceLayer';

      //set new position to helper layer
      _setHelperLayerPosition.call(self, helperLayer);
      _setHelperLayerPosition.call(self, referenceLayer);

      //add helper layer to target element
      this._targetElement.appendChild(helperLayer);
      this._targetElement.appendChild(referenceLayer);

      arrowLayer.className = 'introjs-arrow';

      tooltipTextLayer.className = 'introjs-tooltiptext';
      tooltipTextLayer.innerHTML = targetElement.intro;

      bulletsLayer.className = 'introjs-bullets';

      if (this._options.showBullets === false) {
        bulletsLayer.style.display = 'none';
      }

      var ulContainer = document.createElement('ul');

      for (var i = 0, stepsLength = this._introItems.length; i < stepsLength; i++) {
        var innerLi    = document.createElement('li');
        var anchorLink = document.createElement('a');

        anchorLink.onclick = function() {
          self.goToStep(this.getAttribute('data-stepnumber'));
        };

        if (i === (targetElement.step-1)) anchorLink.className = 'active';

        _setAnchorAsButton(anchorLink);
        anchorLink.innerHTML = "&nbsp;";
        anchorLink.setAttribute('data-stepnumber', this._introItems[i].step);

        innerLi.appendChild(anchorLink);
        ulContainer.appendChild(innerLi);
      }

      bulletsLayer.appendChild(ulContainer);

      progressLayer.className = 'introjs-progress';

      if (this._options.showProgress === false) {
        progressLayer.style.display = 'none';
      }
      var progressBar = document.createElement('div');
      progressBar.className = 'introjs-progressbar';
      progressBar.setAttribute('style', 'width:' + _getProgress.call(this) + '%;');

      progressLayer.appendChild(progressBar);

      buttonsLayer.className = 'introjs-tooltipbuttons';
      if (this._options.showButtons === false) {
        buttonsLayer.style.display = 'none';
      }

      tooltipLayer.className = 'introjs-tooltip';
      tooltipLayer.appendChild(tooltipTextLayer);
      tooltipLayer.appendChild(bulletsLayer);
      tooltipLayer.appendChild(progressLayer);

      //add helper layer number
      if (this._options.showStepNumbers == true) {
        var helperNumberLayer = document.createElement('span');
        helperNumberLayer.className = 'introjs-helperNumberLayer';
        helperNumberLayer.innerHTML = targetElement.step;
        referenceLayer.appendChild(helperNumberLayer);
      }

      tooltipLayer.appendChild(arrowLayer);
      referenceLayer.appendChild(tooltipLayer);

      //next button
      var nextTooltipButton = document.createElement('a');

      nextTooltipButton.onclick = function() {
        if (self._introItems.length - 1 != self._currentStep) {
          _nextStep.call(self);
        }
      };

      _setAnchorAsButton(nextTooltipButton);
      nextTooltipButton.innerHTML = this._options.nextLabel;

      //previous button
      var prevTooltipButton = document.createElement('a');

      prevTooltipButton.onclick = function() {
        if (self._currentStep != 0) {
          _previousStep.call(self);
        }
      };

      _setAnchorAsButton(prevTooltipButton);
      prevTooltipButton.innerHTML = this._options.prevLabel;

      //skip button
      var skipTooltipButton = document.createElement('a');
      skipTooltipButton.className = 'introjs-button introjs-skipbutton';
      _setAnchorAsButton(skipTooltipButton);
      skipTooltipButton.innerHTML = this._options.skipLabel;

      skipTooltipButton.onclick = function() {
        if (self._introItems.length - 1 == self._currentStep && typeof (self._introCompleteCallback) === 'function') {
          self._introCompleteCallback.call(self);
        }

        _exitIntro.call(self, self._targetElement);
      };

      buttonsLayer.appendChild(skipTooltipButton);

      //in order to prevent displaying next/previous button always
      if (this._introItems.length > 1) {
        buttonsLayer.appendChild(prevTooltipButton);
        buttonsLayer.appendChild(nextTooltipButton);
      }

      tooltipLayer.appendChild(buttonsLayer);

      //set proper position
      _placeTooltip.call(self, targetElement.element, tooltipLayer, arrowLayer, helperNumberLayer);

      // change the scroll of the window, if needed
      _scrollTo.call(this, targetElement.scrollTo, targetElement, tooltipLayer);

      //end of new element if-else condition
    }

    // removing previous disable interaction layer
    var disableInteractionLayer = self._targetElement.querySelector('.introjs-disableInteraction');
    if (disableInteractionLayer) {
      disableInteractionLayer.parentNode.removeChild(disableInteractionLayer);
    }

    //disable interaction
    if (targetElement.disableInteraction) {
      _disableInteraction.call(self);
    }

    if (typeof nextTooltipButton !== "undefined" && nextTooltipButton != null) {
      nextTooltipButton.removeAttribute('tabIndex');
    }
    if (typeof prevTooltipButton !== "undefined" && prevTooltipButton != null) {
      prevTooltipButton.removeAttribute('tabIndex');
    }

    // when it's the first step of tour
    if (this._currentStep == 0 && this._introItems.length > 1) {
      if (typeof skipTooltipButton !== "undefined" && skipTooltipButton != null) {
        skipTooltipButton.className = 'introjs-button introjs-skipbutton';
      }
      if (typeof nextTooltipButton !== "undefined" && nextTooltipButton != null) {
        nextTooltipButton.className = 'introjs-button introjs-nextbutton';
      }

      if (this._options.hidePrev == true) {
        if (typeof prevTooltipButton !== "undefined" && prevTooltipButton != null) {
          prevTooltipButton.className = 'introjs-button introjs-prevbutton introjs-hidden';
        }
        if (typeof nextTooltipButton !== "undefined" && nextTooltipButton != null) {
          nextTooltipButton.className += ' introjs-fullbutton';
        }
      } else {
        if (typeof prevTooltipButton !== "undefined" && prevTooltipButton != null) {
          prevTooltipButton.className = 'introjs-button introjs-prevbutton introjs-disabled';
        }
      }

      if (typeof prevTooltipButton !== "undefined" && prevTooltipButton != null) {
        prevTooltipButton.tabIndex = '-1';
      }
      if (typeof skipTooltipButton !== "undefined" && skipTooltipButton != null) {
        skipTooltipButton.innerHTML = this._options.skipLabel;
      }
    } else if (this._introItems.length - 1 == this._currentStep || this._introItems.length == 1) {
      // last step of tour
      if (typeof skipTooltipButton !== "undefined" && skipTooltipButton != null) {
        skipTooltipButton.innerHTML = this._options.doneLabel;
        // adding donebutton class in addition to skipbutton
        skipTooltipButton.className += ' introjs-donebutton';
      }
      if (typeof prevTooltipButton !== "undefined" && prevTooltipButton != null) {
        prevTooltipButton.className = 'introjs-button introjs-prevbutton';
      }

      if (this._options.hideNext == true) {
        if (typeof nextTooltipButton !== "undefined" && nextTooltipButton != null) {
          nextTooltipButton.className = 'introjs-button introjs-nextbutton introjs-hidden';
        }
        if (typeof prevTooltipButton !== "undefined" && prevTooltipButton != null) {
          prevTooltipButton.className += ' introjs-fullbutton';
        }
      } else {
        if (typeof nextTooltipButton !== "undefined" && nextTooltipButton != null) {
          nextTooltipButton.className = 'introjs-button introjs-nextbutton introjs-disabled';
        }
      }

      if (typeof nextTooltipButton !== "undefined" && nextTooltipButton != null) {
        nextTooltipButton.tabIndex = '-1';
      }
    } else {
      // steps between start and end
      if (typeof skipTooltipButton !== "undefined" && skipTooltipButton != null) {
        skipTooltipButton.className = 'introjs-button introjs-skipbutton';
      }
      if (typeof prevTooltipButton !== "undefined" && prevTooltipButton != null) {
        prevTooltipButton.className = 'introjs-button introjs-prevbutton';
      }
      if (typeof nextTooltipButton !== "undefined" && nextTooltipButton != null) {
        nextTooltipButton.className = 'introjs-button introjs-nextbutton';
      }
      if (typeof skipTooltipButton !== "undefined" && skipTooltipButton != null) {
        skipTooltipButton.innerHTML = this._options.skipLabel;
      }
    }

    //Set focus on "next" button, so that hitting Enter always moves you onto the next step
    if (typeof nextTooltipButton !== "undefined" && nextTooltipButton != null) {
      nextTooltipButton.focus();
    }

    _setShowElement(targetElement);

    if (typeof (this._introAfterChangeCallback) !== 'undefined') {
      this._introAfterChangeCallback.call(this, targetElement.element);
    }
  }

  /**
   * To change the scroll of `window` after highlighting an element
   *
   * @api private
   * @method _scrollTo
   * @param {String} scrollTo
   * @param {Object} targetElement
   * @param {Object} tooltipLayer
   */
  function _scrollTo(scrollTo, targetElement, tooltipLayer) {
    if (!this._options.scrollToElement) return;

    if (scrollTo === 'tooltip') {
      var rect = tooltipLayer.getBoundingClientRect();
    } else {
      var rect = targetElement.element.getBoundingClientRect();
    }

    if (!_elementInViewport(targetElement.element)) {
      var winHeight = _getWinSize().height;
      var top = rect.bottom - (rect.bottom - rect.top);
      var bottom = rect.bottom - winHeight;

      // TODO (afshinm): do we need scroll padding now?
      // I have changed the scroll option and now it scrolls the window to
      // the center of the target element or tooltip.

      if (top < 0 || targetElement.element.clientHeight > winHeight) {
        window.scrollBy(0, rect.top - ((winHeight / 2) -  (rect.height / 2)) - this._options.scrollPadding); // 30px padding from edge to look nice

      //Scroll down
      } else {
        window.scrollBy(0, rect.top - ((winHeight / 2) -  (rect.height / 2)) + this._options.scrollPadding); // 30px padding from edge to look nice
      }
    }
  }

  /**
   * To remove all show element(s)
   *
   * @api private
   * @method _removeShowElement
   */
  function _removeShowElement() {
    var elms = document.querySelectorAll('.introjs-showElement');

    for (var i = 0, l = elms.length; i < l; i++) {
      var elm = elms[i];
      _removeClass(elm, /introjs-[a-zA-Z]+/g);
    }
  }

  /**
   * To set the show element
   * This function set a relative (in most cases) position and changes the z-index
   *
   * @api private
   * @method _setShowElement
   * @param {Object} targetElement
   */
  function _setShowElement(targetElement) {
    // we need to add this show element class to the parent of SVG elements
    // because the SVG elements can't have independent z-index
    if (targetElement.element instanceof SVGElement) {
      var parentElm = targetElement.element.parentNode;

      while (targetElement.element.parentNode != null) {
        if (!parentElm.tagName || parentElm.tagName.toLowerCase() === 'body') break;

        if (parentElm.tagName.toLowerCase() === 'svg') {
          _setClass(parentElm, 'introjs-showElement introjs-relativePosition');
        }

        parentElm = parentElm.parentNode;
      }
    }

    _setClass(targetElement.element, 'introjs-showElement');

    var currentElementPosition = _getPropValue(targetElement.element, 'position');
    if (currentElementPosition !== 'absolute' &&
        currentElementPosition !== 'relative' &&
        currentElementPosition !== 'fixed') {
      //change to new intro item
      //targetElement.element.className += ' introjs-relativePosition';
      _setClass(targetElement.element, 'introjs-relativePosition')
    }

    var parentElm = targetElement.element.parentNode;
    while (parentElm != null) {
      if (!parentElm.tagName || parentElm.tagName.toLowerCase() === 'body') break;

      //fix The Stacking Context problem.
      //More detail: https://developer.mozilla.org/en-US/docs/Web/Guide/CSS/Understanding_z_index/The_stacking_context
      var zIndex = _getPropValue(parentElm, 'z-index');
      var opacity = parseFloat(_getPropValue(parentElm, 'opacity'));
      var transform = _getPropValue(parentElm, 'transform') || _getPropValue(parentElm, '-webkit-transform') || _getPropValue(parentElm, '-moz-transform') || _getPropValue(parentElm, '-ms-transform') || _getPropValue(parentElm, '-o-transform');
      if (/[0-9]+/.test(zIndex) || opacity < 1 || (transform !== 'none' && transform !== undefined)) {
        parentElm.className += ' introjs-fixParent';
      }

      parentElm = parentElm.parentNode;
    }
  }

  function _setClass(element, className) {
    if (element instanceof SVGElement) {
      var pre = element.getAttribute('class') || '';

      element.setAttribute('class', pre + ' ' + className);
    } else {
      element.className += ' ' + className;
    }
  }

  function _removeClass(element, classNameRegex) {
    if (element instanceof SVGElement) {
      var pre = element.getAttribute('class') || '';

      element.setAttribute('class', pre.replace(classNameRegex, '').replace(/^\s+|\s+$/g, ''));
    } else {
      element.className = element.className.replace(classNameRegex, '').replace(/^\s+|\s+$/g, '');
    }
  }

  /**
   * Get an element CSS property on the page
   * Thanks to JavaScript Kit: http://www.javascriptkit.com/dhtmltutors/dhtmlcascade4.shtml
   *
   * @api private
   * @method _getPropValue
   * @param {Object} element
   * @param {String} propName
   * @returns Element's property value
   */
  function _getPropValue (element, propName) {
    var propValue = '';
    if (element.currentStyle) { //IE
      propValue = element.currentStyle[propName];
    } else if (document.defaultView && document.defaultView.getComputedStyle) { //Others
      propValue = document.defaultView.getComputedStyle(element, null).getPropertyValue(propName);
    }

    //Prevent exception in IE
    if (propValue && propValue.toLowerCase) {
      return propValue.toLowerCase();
    } else {
      return propValue;
    }
  }

  /**
   * Checks to see if target element (or parents) position is fixed or not
   *
   * @api private
   * @method _isFixed
   * @param {Object} element
   * @returns Boolean
   */
  function _isFixed (element) {
    var p = element.parentNode;

    if (!p || p.nodeName === 'HTML') {
      return false;
    }

    if (_getPropValue(element, 'position') == 'fixed') {
      return true;
    }

    return _isFixed(p);
  }

  /**
   * Provides a cross-browser way to get the screen dimensions
   * via: http://stackoverflow.com/questions/5864467/internet-explorer-innerheight
   *
   * @api private
   * @method _getWinSize
   * @returns {Object} width and height attributes
   */
  function _getWinSize() {
    if (window.innerWidth != undefined) {
      return { width: window.innerWidth, height: window.innerHeight };
    } else {
      var D = document.documentElement;
      return { width: D.clientWidth, height: D.clientHeight };
    }
  }

  /**
   * Check to see if the element is in the viewport or not
   * http://stackoverflow.com/questions/123999/how-to-tell-if-a-dom-element-is-visible-in-the-current-viewport
   *
   * @api private
   * @method _elementInViewport
   * @param {Object} el
   */
  function _elementInViewport(el) {
    var rect = el.getBoundingClientRect();

    return (
      rect.top >= 0 &&
      rect.left >= 0 &&
      (rect.bottom+80) <= window.innerHeight && // add 80 to get the text right
      rect.right <= window.innerWidth
    );
  }

  /**
   * Add overlay layer to the page
   *
   * @api private
   * @method _addOverlayLayer
   * @param {Object} targetElm
   */
  function _addOverlayLayer(targetElm) {
    var overlayLayer = document.createElement('div'),
        styleText = '',
        self = this;

    //set css class name
    overlayLayer.className = 'introjs-overlay';

    //check if the target element is body, we should calculate the size of overlay layer in a better way
    if (!targetElm.tagName || targetElm.tagName.toLowerCase() === 'body') {
      styleText += 'top: 0;bottom: 0; left: 0;right: 0;position: fixed;';
      overlayLayer.setAttribute('style', styleText);
    } else {
      //set overlay layer position
      var elementPosition = _getOffset(targetElm);
      if (elementPosition) {
        styleText += 'width: ' + elementPosition.width + 'px; height:' + elementPosition.height + 'px; top:' + elementPosition.top + 'px;left: ' + elementPosition.left + 'px;';
        overlayLayer.setAttribute('style', styleText);
      }
    }

    targetElm.appendChild(overlayLayer);

    overlayLayer.onclick = function() {
      if (self._options.exitOnOverlayClick == true) {
        _exitIntro.call(self, targetElm);
      }
    };

    setTimeout(function() {
      styleText += 'opacity: ' + self._options.overlayOpacity.toString() + ';';
      overlayLayer.setAttribute('style', styleText);
    }, 10);

    return true;
  }

  /**
   * Removes open hint (tooltip hint)
   *
   * @api private
   * @method _removeHintTooltip
   */
  function _removeHintTooltip() {
    var tooltip = this._targetElement.querySelector('.introjs-hintReference');

    if (tooltip) {
      var step = tooltip.getAttribute('data-step');
      tooltip.parentNode.removeChild(tooltip);
      return step;
    }
  }

  /**
   * Start parsing hint items
   *
   * @api private
   * @param {Object} targetElm
   * @method _startHint
   */
  function _populateHints(targetElm) {
    var self = this;
    this._introItems = [];

    if (this._options.hints) {
      for (var i = 0, l = this._options.hints.length; i < l; i++) {
        var currentItem = _cloneObject(this._options.hints[i]);

        if (typeof(currentItem.element) === 'string') {
          //grab the element with given selector from the page
          currentItem.element = document.querySelector(currentItem.element);
        }

        currentItem.hintPosition = currentItem.hintPosition || this._options.hintPosition;
        currentItem.hintAnimation = currentItem.hintAnimation || this._options.hintAnimation;

        if (currentItem.element != null) {
          this._introItems.push(currentItem);
        }
      }
    } else {
      var hints = targetElm.querySelectorAll('*[data-hint]');

      if (hints.length < 1) {
        return false;
      }

      //first add intro items with data-step
      for (var i = 0, l = hints.length; i < l; i++) {
        var currentElement = hints[i];

        // hint animation
        var hintAnimation = currentElement.getAttribute('data-hintAnimation');

        if (hintAnimation) {
          hintAnimation = (hintAnimation == 'true');
        } else {
          hintAnimation = this._options.hintAnimation;
        }

        this._introItems.push({
          element: currentElement,
          hint: currentElement.getAttribute('data-hint'),
          hintPosition: currentElement.getAttribute('data-hintPosition') || this._options.hintPosition,
          hintAnimation: hintAnimation,
          tooltipClass: currentElement.getAttribute('data-tooltipClass'),
          position: currentElement.getAttribute('data-position') || this._options.tooltipPosition
        });
      }
    }

    _addHints.call(this);

    if (document.addEventListener) {
      document.addEventListener('click', _removeHintTooltip.bind(this), false);
      //for window resize
      window.addEventListener('resize', _reAlignHints.bind(this), true);
    } else if (document.attachEvent) { //IE
      //for window resize
      document.attachEvent('onclick', _removeHintTooltip.bind(this));
      document.attachEvent('onresize', _reAlignHints.bind(this));
    }
  }

  /**
   * Re-aligns all hint elements
   *
   * @api private
   * @method _reAlignHints
   */
  function _reAlignHints() {
    for (var i = 0, l = this._introItems.length; i < l; i++) {
      var item = this._introItems[i];

      if (typeof (item.targetElement) == 'undefined') continue;

      _alignHintPosition.call(this, item.hintPosition, item.element, item.targetElement)
    }
  }

  /**
   * Hide a hint
   *
   * @api private
   * @method _hideHint
   */
  function _hideHint(stepId) {
    _removeHintTooltip.call(this);
    var hint = this._targetElement.querySelector('.introjs-hint[data-step="' + stepId + '"]');

    if (hint) {
      hint.className += ' introjs-hidehint';
    }

    // call the callback function (if any)
    if (typeof (this._hintCloseCallback) !== 'undefined') {
      this._hintCloseCallback.call(this, stepId);
    }
  }

  /**
   * Hide all hints
   *
   * @api private
   * @method _hideHints
   */
  function _hideHints() {
    var hints = this._targetElement.querySelectorAll('.introjs-hint');

    if (hints && hints.length > 0) {
      for (var i = 0; i < hints.length; i++) {
        _hideHint.call(this, hints[i].getAttribute('data-step'));
      }
    }
  }

  /**
   * Show all hints
   *
   * @api private
   * @method _showHints
   */
  function _showHints() {
    var hints = this._targetElement.querySelectorAll('.introjs-hint');

    if (hints && hints.length > 0) {
      for (var i = 0; i < hints.length; i++) {
        _showHint.call(this, hints[i].getAttribute('data-step'));
      }
    } else {
      _populateHints.call(this, this._targetElement);
    }
  };

  /**
   * Show a hint
   *
   * @api private
   * @method _showHint
   */
  function _showHint(stepId) {
    var hint = this._targetElement.querySelector('.introjs-hint[data-step="' + stepId + '"]');

    if (hint) {
      hint.className = hint.className.replace(/introjs\-hidehint/g, '');
    }
  };

  /**
   * Removes all hint elements on the page
   * Useful when you want to destroy the elements and add them again (e.g. a modal or popup)
   *
   * @api private
   * @method _removeHints
   */
  function _removeHints() {
    var hints = this._targetElement.querySelectorAll('.introjs-hint');

    if (hints && hints.length > 0) {
      for (var i = 0; i < hints.length; i++) {
        _removeHint.call(this, hints[i].getAttribute('data-step'));
      }
    }
  };

  /**
   * Remove one single hint element from the page
   * Useful when you want to destroy the element and add them again (e.g. a modal or popup)
   * Use removeHints if you want to remove all elements.
   *
   * @api private
   * @method _removeHint
   */
  function _removeHint(stepId) {
    var hint = this._targetElement.querySelector('.introjs-hint[data-step="' + stepId + '"]');

    if (hint) {
      hint.parentNode.removeChild(hint);
    }
  };

  /**
   * Add all available hints to the page
   *
   * @api private
   * @method _addHints
   */
  function _addHints() {
    var self = this;

    var oldHintsWrapper = document.querySelector('.introjs-hints');

    if (oldHintsWrapper != null) {
      hintsWrapper = oldHintsWrapper;
    } else {
      var hintsWrapper = document.createElement('div');
      hintsWrapper.className = 'introjs-hints';
    }

    for (var i = 0, l = this._introItems.length; i < l; i++) {
      var item = this._introItems[i];

      // avoid append a hint twice
      if (document.querySelector('.introjs-hint[data-step="' + i + '"]'))
        continue;

      var hint = document.createElement('a');
      _setAnchorAsButton(hint);

      (function (hint, item, i) {
        // when user clicks on the hint element
        hint.onclick = function(e) {
          var evt = e ? e : window.event;
          if (evt.stopPropagation)    evt.stopPropagation();
          if (evt.cancelBubble != null) evt.cancelBubble = true;

          _showHintDialog.call(self, i);
        };
      }(hint, item, i));

      hint.className = 'introjs-hint';

      if (!item.hintAnimation) {
        hint.className += ' introjs-hint-no-anim';
      }

      // hint's position should be fixed if the target element's position is fixed
      if (_isFixed(item.element)) {
        hint.className += ' introjs-fixedhint';
      }

      var hintDot = document.createElement('div');
      hintDot.className = 'introjs-hint-dot';
      var hintPulse = document.createElement('div');
      hintPulse.className = 'introjs-hint-pulse';

      hint.appendChild(hintDot);
      hint.appendChild(hintPulse);
      hint.setAttribute('data-step', i);

      // we swap the hint element with target element
      // because _setHelperLayerPosition uses `element` property
      item.targetElement = item.element;
      item.element = hint;

      // align the hint position
      _alignHintPosition.call(this, item.hintPosition, hint, item.targetElement);

      hintsWrapper.appendChild(hint);
    }

    // adding the hints wrapper
    document.body.appendChild(hintsWrapper);

    // call the callback function (if any)
    if (typeof (this._hintsAddedCallback) !== 'undefined') {
      this._hintsAddedCallback.call(this);
    }
  }

  /**
   * Aligns hint position
   *
   * @api private
   * @method _alignHintPosition
   * @param {String} position
   * @param {Object} hint
   * @param {Object} element
   */
  function _alignHintPosition(position, hint, element) {
    // get/calculate offset of target element
    var offset = _getOffset.call(this, element);
    var iconWidth = 20;
    var iconHeight = 20;

    // align the hint element
    switch (position) {
      default:
      case 'top-left':
        hint.style.left = offset.left + 'px';
        hint.style.top = offset.top + 'px';
        break;
      case 'top-right':
        hint.style.left = (offset.left + offset.width - iconWidth) + 'px';
        hint.style.top = offset.top + 'px';
        break;
      case 'bottom-left':
        hint.style.left = offset.left + 'px';
        hint.style.top = (offset.top + offset.height - iconHeight) + 'px';
        break;
      case 'bottom-right':
        hint.style.left = (offset.left + offset.width - iconWidth) + 'px';
        hint.style.top = (offset.top + offset.height - iconHeight) + 'px';
        break;
      case 'middle-left':
        hint.style.left = offset.left + 'px';
        hint.style.top = (offset.top + (offset.height - iconHeight) / 2) + 'px';
        break;
      case 'middle-right':
        hint.style.left = (offset.left + offset.width - iconWidth) + 'px';
        hint.style.top = (offset.top + (offset.height - iconHeight) / 2) + 'px';
        break;
      case 'middle-middle':
        hint.style.left = (offset.left + (offset.width - iconWidth) / 2) + 'px';
        hint.style.top = (offset.top + (offset.height - iconHeight) / 2) + 'px';
        break;
      case 'bottom-middle':
        hint.style.left = (offset.left + (offset.width - iconWidth) / 2) + 'px';
        hint.style.top = (offset.top + offset.height - iconHeight) + 'px';
        break;
      case 'top-middle':
        hint.style.left = (offset.left + (offset.width - iconWidth) / 2) + 'px';
        hint.style.top = offset.top + 'px';
        break;
    }
  }

  /**
   * Triggers when user clicks on the hint element
   *
   * @api private
   * @method _showHintDialog
   * @param {Number} stepId
   */
  function _showHintDialog(stepId) {
    var hintElement = document.querySelector('.introjs-hint[data-step="' + stepId + '"]');
    var item = this._introItems[stepId];

    // call the callback function (if any)
    if (typeof (this._hintClickCallback) !== 'undefined') {
      this._hintClickCallback.call(this, hintElement, item, stepId);
    }

    // remove all open tooltips
    var removedStep = _removeHintTooltip.call(this);

    // to toggle the tooltip
    if (parseInt(removedStep, 10) == stepId) {
      return;
    }

    var tooltipLayer = document.createElement('div');
    var tooltipTextLayer = document.createElement('div');
    var arrowLayer = document.createElement('div');
    var referenceLayer = document.createElement('div');

    tooltipLayer.className = 'introjs-tooltip';

    tooltipLayer.onclick = function (e) {
      //IE9 & Other Browsers
      if (e.stopPropagation) {
        e.stopPropagation();
      }
      //IE8 and Lower
      else {
        e.cancelBubble = true;
      }
    };

    tooltipTextLayer.className = 'introjs-tooltiptext';

    var tooltipWrapper = document.createElement('p');
    tooltipWrapper.innerHTML = item.hint;

    var closeButton = document.createElement('a');
    closeButton.className = 'introjs-button';
    closeButton.innerHTML = this._options.hintButtonLabel;
    closeButton.onclick = _hideHint.bind(this, stepId);

    tooltipTextLayer.appendChild(tooltipWrapper);
    tooltipTextLayer.appendChild(closeButton);

    arrowLayer.className = 'introjs-arrow';
    tooltipLayer.appendChild(arrowLayer);

    tooltipLayer.appendChild(tooltipTextLayer);

    // set current step for _placeTooltip function
    this._currentStep = hintElement.getAttribute('data-step');

    // align reference layer position
    referenceLayer.className = 'introjs-tooltipReferenceLayer introjs-hintReference';
    referenceLayer.setAttribute('data-step', hintElement.getAttribute('data-step'));
    _setHelperLayerPosition.call(this, referenceLayer);

    referenceLayer.appendChild(tooltipLayer);
    document.body.appendChild(referenceLayer);

    //set proper position
    _placeTooltip.call(this, hintElement, tooltipLayer, arrowLayer, null, true);
  }

  /**
   * Get an element position on the page
   * Thanks to `meouw`: http://stackoverflow.com/a/442474/375966
   *
   * @api private
   * @method _getOffset
   * @param {Object} element
   * @returns Element's position info
   */
  function _getOffset(element) {
    var elementPosition = {};

    var body = document.body;
    var docEl = document.documentElement;

    var scrollTop = window.pageYOffset || docEl.scrollTop || body.scrollTop;
    var scrollLeft = window.pageXOffset || docEl.scrollLeft || body.scrollLeft;

    if (element instanceof SVGElement) {
      var x = element.getBoundingClientRect()
      elementPosition.top = x.top + scrollTop;
      elementPosition.width = x.width;
      elementPosition.height = x.height;
      elementPosition.left = x.left + scrollLeft;
    } else {
      //set width
      elementPosition.width = element.offsetWidth;

      //set height
      elementPosition.height = element.offsetHeight;

      //calculate element top and left
      var _x = 0;
      var _y = 0;
      while (element && !isNaN(element.offsetLeft) && !isNaN(element.offsetTop)) {
        _x += element.offsetLeft;
        _y += element.offsetTop;
        element = element.offsetParent;
      }
      //set top
      elementPosition.top = _y;
      //set left
      elementPosition.left = _x;
    }

    return elementPosition;
  }

  /**
   * Gets the current progress percentage
   *
   * @api private
   * @method _getProgress
   * @returns current progress percentage
   */
  function _getProgress() {
    // Steps are 0 indexed
    var currentStep = parseInt((this._currentStep + 1), 10);
    return ((currentStep / this._introItems.length) * 100);
  }

  /**
   * Overwrites obj1's values with obj2's and adds obj2's if non existent in obj1
   * via: http://stackoverflow.com/questions/171251/how-can-i-merge-properties-of-two-javascript-objects-dynamically
   *
   * @param obj1
   * @param obj2
   * @returns obj3 a new object based on obj1 and obj2
   */
  function _mergeOptions(obj1,obj2) {
    var obj3 = {};
    for (var attrname in obj1) { obj3[attrname] = obj1[attrname]; }
    for (var attrname in obj2) { obj3[attrname] = obj2[attrname]; }
    return obj3;
  }

  var introJs = function (targetElm) {
    if (typeof (targetElm) === 'object') {
      //Ok, create a new instance
      return new IntroJs(targetElm);

    } else if (typeof (targetElm) === 'string') {
      //select the target element with query selector
      var targetElement = document.querySelector(targetElm);

      if (targetElement) {
        return new IntroJs(targetElement);
      } else {
        throw new Error('There is no element with given selector.');
      }
    } else {
      return new IntroJs(document.body);
    }
  };

  /**
   * Current IntroJs version
   *
   * @property version
   * @type String
   */
  introJs.version = VERSION;

  //Prototype
  introJs.fn = IntroJs.prototype = {
    clone: function () {
      return new IntroJs(this);
    },
    setOption: function(option, value) {
      this._options[option] = value;
      return this;
    },
    setOptions: function(options) {
      this._options = _mergeOptions(this._options, options);
      return this;
    },
    start: function () {
      _introForElement.call(this, this._targetElement);
      return this;
    },
    goToStep: function(step) {
      _goToStep.call(this, step);
      return this;
    },
    addStep: function(options) {
      if (!this._options.steps) {
        this._options.steps = [];
      }

      this._options.steps.push(options);

      return this;
    },
    addSteps: function(steps) {
      if (!steps.length) return;

      for(var index = 0; index < steps.length; index++) {
        this.addStep(steps[index]);
      }

      return this;
    },
    goToStepNumber: function(step) {
      _goToStepNumber.call(this, step);

      return this;
    },
    nextStep: function() {
      _nextStep.call(this);
      return this;
    },
    previousStep: function() {
      _previousStep.call(this);
      return this;
    },
    exit: function(force) {
      _exitIntro.call(this, this._targetElement, force);
      return this;
    },
    refresh: function() {
      _refresh.call(this);
      return this;
    },
    onbeforechange: function(providedCallback) {
      if (typeof (providedCallback) === 'function') {
        this._introBeforeChangeCallback = providedCallback;
      } else {
        throw new Error('Provided callback for onbeforechange was not a function');
      }
      return this;
    },
    onchange: function(providedCallback) {
      if (typeof (providedCallback) === 'function') {
        this._introChangeCallback = providedCallback;
      } else {
        throw new Error('Provided callback for onchange was not a function.');
      }
      return this;
    },
    onafterchange: function(providedCallback) {
      if (typeof (providedCallback) === 'function') {
        this._introAfterChangeCallback = providedCallback;
      } else {
        throw new Error('Provided callback for onafterchange was not a function');
      }
      return this;
    },
    oncomplete: function(providedCallback) {
      if (typeof (providedCallback) === 'function') {
        this._introCompleteCallback = providedCallback;
      } else {
        throw new Error('Provided callback for oncomplete was not a function.');
      }
      return this;
    },
    onhintsadded: function(providedCallback) {
      if (typeof (providedCallback) === 'function') {
        this._hintsAddedCallback = providedCallback;
      } else {
        throw new Error('Provided callback for onhintsadded was not a function.');
      }
      return this;
    },
    onhintclick: function(providedCallback) {
      if (typeof (providedCallback) === 'function') {
        this._hintClickCallback = providedCallback;
      } else {
        throw new Error('Provided callback for onhintclick was not a function.');
      }
      return this;
    },
    onhintclose: function(providedCallback) {
      if (typeof (providedCallback) === 'function') {
        this._hintCloseCallback = providedCallback;
      } else {
        throw new Error('Provided callback for onhintclose was not a function.');
      }
      return this;
    },
    onexit: function(providedCallback) {
      if (typeof (providedCallback) === 'function') {
        this._introExitCallback = providedCallback;
      } else {
        throw new Error('Provided callback for onexit was not a function.');
      }
      return this;
    },
    onbeforeexit: function(providedCallback) {
      if (typeof (providedCallback) === 'function') {
        this._introBeforeExitCallback = providedCallback;
      } else {
        throw new Error('Provided callback for onbeforeexit was not a function.');
      }
      return this;
    },
    addHints: function() {
      _populateHints.call(this, this._targetElement);
      return this;
    },
    hideHint: function (stepId) {
      _hideHint.call(this, stepId);
      return this;
    },
    hideHints: function () {
      _hideHints.call(this);
      return this;
    },
    showHint: function (stepId) {
      _showHint.call(this, stepId);
      return this;
    },
    showHints: function () {
      _showHints.call(this);
      return this;
    },
    removeHints: function () {
      _removeHints.call(this);
      return this;
    },
    removeHint: function (stepId) {
      _removeHint.call(this, stepId);
      return this;
    },
    showHintDialog: function (stepId) {
      _showHintDialog.call(this, stepId);
      return this;
    }
  };

  exports.introJs = introJs;
  return introJs;
}));