568 lines
16 KiB
JavaScript
568 lines
16 KiB
JavaScript
(function (root, factory) {
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if ( typeof define === 'function' && define.amd ) {
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define([], function () {
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return factory(root);
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});
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} else if ( typeof exports === 'object' ) {
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module.exports = factory(root);
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} else {
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root.SmoothScroll = factory(root);
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}
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})(typeof global !== 'undefined' ? global : typeof window !== 'undefined' ? window : this, function (window) {
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'use strict';
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//
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// Feature Test
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//
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var supports =
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'querySelector' in document &&
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'addEventListener' in window &&
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'requestAnimationFrame' in window &&
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'closest' in window.Element.prototype;
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//
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// Default settings
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//
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var defaults = {
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// Selectors
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ignore: '[data-scroll-ignore]',
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header: null,
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// Speed & Easing
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speed: 500,
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offset: 0,
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easing: 'easeInOutCubic',
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customEasing: null,
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// Callback API
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before: function () {},
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after: function () {}
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};
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//
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// Utility Methods
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//
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/**
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* Merge two or more objects. Returns a new object.
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* @param {Object} objects The objects to merge together
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* @returns {Object} Merged values of defaults and options
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*/
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var extend = function () {
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// Variables
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var extended = {};
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var i = 0;
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var length = arguments.length;
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// Merge the object into the extended object
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var merge = function (obj) {
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for (var prop in obj) {
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if (obj.hasOwnProperty(prop)) {
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extended[prop] = obj[prop];
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}
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}
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};
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// Loop through each object and conduct a merge
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for ( ; i < length; i++ ) {
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var obj = arguments[i];
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merge(obj);
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}
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return extended;
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};
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/**
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* Get the height of an element.
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* @param {Node} elem The element to get the height of
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* @return {Number} The element's height in pixels
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*/
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var getHeight = function (elem) {
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return parseInt(window.getComputedStyle(elem).height, 10);
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};
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/**
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* Escape special characters for use with querySelector
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* @param {String} id The anchor ID to escape
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* @author Mathias Bynens
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* @link https://github.com/mathiasbynens/CSS.escape
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*/
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var escapeCharacters = function (id) {
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// Remove leading hash
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if (id.charAt(0) === '#') {
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id = id.substr(1);
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}
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var string = String(id);
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var length = string.length;
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var index = -1;
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var codeUnit;
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var result = '';
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var firstCodeUnit = string.charCodeAt(0);
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while (++index < length) {
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codeUnit = string.charCodeAt(index);
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// Note: there’s no need to special-case astral symbols, surrogate
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// pairs, or lone surrogates.
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// If the character is NULL (U+0000), then throw an
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// `InvalidCharacterError` exception and terminate these steps.
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if (codeUnit === 0x0000) {
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throw new InvalidCharacterError(
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'Invalid character: the input contains U+0000.'
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);
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}
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if (
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// If the character is in the range [\1-\1F] (U+0001 to U+001F) or is
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// U+007F, […]
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(codeUnit >= 0x0001 && codeUnit <= 0x001F) || codeUnit == 0x007F ||
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// If the character is the first character and is in the range [0-9]
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// (U+0030 to U+0039), […]
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(index === 0 && codeUnit >= 0x0030 && codeUnit <= 0x0039) ||
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// If the character is the second character and is in the range [0-9]
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// (U+0030 to U+0039) and the first character is a `-` (U+002D), […]
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(
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index === 1 &&
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codeUnit >= 0x0030 && codeUnit <= 0x0039 &&
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firstCodeUnit === 0x002D
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)
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) {
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// http://dev.w3.org/csswg/cssom/#escape-a-character-as-code-point
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result += '\\' + codeUnit.toString(16) + ' ';
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continue;
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}
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// If the character is not handled by one of the above rules and is
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// greater than or equal to U+0080, is `-` (U+002D) or `_` (U+005F), or
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// is in one of the ranges [0-9] (U+0030 to U+0039), [A-Z] (U+0041 to
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// U+005A), or [a-z] (U+0061 to U+007A), […]
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if (
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codeUnit >= 0x0080 ||
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codeUnit === 0x002D ||
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codeUnit === 0x005F ||
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codeUnit >= 0x0030 && codeUnit <= 0x0039 ||
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codeUnit >= 0x0041 && codeUnit <= 0x005A ||
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codeUnit >= 0x0061 && codeUnit <= 0x007A
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) {
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// the character itself
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result += string.charAt(index);
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continue;
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}
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// Otherwise, the escaped character.
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// http://dev.w3.org/csswg/cssom/#escape-a-character
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result += '\\' + string.charAt(index);
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}
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return '#' + result;
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};
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/**
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* Calculate the easing pattern
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* @link https://gist.github.com/gre/1650294
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* @param {String} type Easing pattern
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* @param {Number} time Time animation should take to complete
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* @returns {Number}
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*/
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var easingPattern = function (settings, time) {
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var pattern;
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// Default Easing Patterns
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if (settings.easing === 'easeInQuad') pattern = time * time; // accelerating from zero velocity
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if (settings.easing === 'easeOutQuad') pattern = time * (2 - time); // decelerating to zero velocity
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if (settings.easing === 'easeInOutQuad') pattern = time < 0.5 ? 2 * time * time : -1 + (4 - 2 * time) * time; // acceleration until halfway, then deceleration
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if (settings.easing === 'easeInCubic') pattern = time * time * time; // accelerating from zero velocity
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if (settings.easing === 'easeOutCubic') pattern = (--time) * time * time + 1; // decelerating to zero velocity
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if (settings.easing === 'easeInOutCubic') pattern = time < 0.5 ? 4 * time * time * time : (time - 1) * (2 * time - 2) * (2 * time - 2) + 1; // acceleration until halfway, then deceleration
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if (settings.easing === 'easeInQuart') pattern = time * time * time * time; // accelerating from zero velocity
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if (settings.easing === 'easeOutQuart') pattern = 1 - (--time) * time * time * time; // decelerating to zero velocity
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if (settings.easing === 'easeInOutQuart') pattern = time < 0.5 ? 8 * time * time * time * time : 1 - 8 * (--time) * time * time * time; // acceleration until halfway, then deceleration
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if (settings.easing === 'easeInQuint') pattern = time * time * time * time * time; // accelerating from zero velocity
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if (settings.easing === 'easeOutQuint') pattern = 1 + (--time) * time * time * time * time; // decelerating to zero velocity
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if (settings.easing === 'easeInOutQuint') pattern = time < 0.5 ? 16 * time * time * time * time * time : 1 + 16 * (--time) * time * time * time * time; // acceleration until halfway, then deceleration
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// Custom Easing Patterns
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if (!!settings.customEasing) pattern = settings.customEasing(time);
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return pattern || time; // no easing, no acceleration
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};
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/**
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* Determine the document's height
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* @returns {Number}
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*/
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var getDocumentHeight = function () {
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return Math.max(
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document.body.scrollHeight, document.documentElement.scrollHeight,
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document.body.offsetHeight, document.documentElement.offsetHeight,
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document.body.clientHeight, document.documentElement.clientHeight
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);
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};
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/**
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* Calculate how far to scroll
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* @param {Element} anchor The anchor element to scroll to
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* @param {Number} headerHeight Height of a fixed header, if any
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* @param {Number} offset Number of pixels by which to offset scroll
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* @returns {Number}
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*/
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var getEndLocation = function (anchor, headerHeight, offset) {
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var location = 0;
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if (anchor.offsetParent) {
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do {
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location += anchor.offsetTop;
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anchor = anchor.offsetParent;
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} while (anchor);
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}
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location = Math.max(location - headerHeight - offset, 0);
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return location;
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};
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/**
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* Get the height of the fixed header
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* @param {Node} header The header
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* @return {Number} The height of the header
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*/
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var getHeaderHeight = function (header) {
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return !header ? 0 : (getHeight(header) + header.offsetTop);
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};
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/**
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* Bring the anchored element into focus
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* @param {Node} anchor The anchor element
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* @param {Number} endLocation The end location to scroll to
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* @param {Boolean} isNum If true, scroll is to a position rather than an element
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*/
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var adjustFocus = function (anchor, endLocation, isNum) {
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// Don't run if scrolling to a number on the page
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if (isNum) return;
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// Otherwise, bring anchor element into focus
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anchor.focus();
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if (document.activeElement.id !== anchor.id) {
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anchor.setAttribute('tabindex', '-1');
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anchor.focus();
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anchor.style.outline = 'none';
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}
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window.scrollTo(0 , endLocation);
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};
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/**
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* Check to see if user prefers reduced motion
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* @param {Object} settings Script settings
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*/
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var reduceMotion = function (settings) {
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if ('matchMedia' in window && window.matchMedia('(prefers-reduced-motion)').matches) {
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return true;
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}
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return false;
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};
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//
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// SmoothScroll Constructor
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//
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var SmoothScroll = function (selector, options) {
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//
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// Variables
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//
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var smoothScroll = {}; // Object for public APIs
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var settings, anchor, toggle, fixedHeader, headerHeight, eventTimeout, animationInterval;
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//
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// Methods
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//
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/**
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* Cancel a scroll-in-progress
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*/
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smoothScroll.cancelScroll = function () {
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// clearInterval(animationInterval);
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cancelAnimationFrame(animationInterval);
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};
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/**
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* Start/stop the scrolling animation
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* @param {Node|Number} anchor The element or position to scroll to
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* @param {Element} toggle The element that toggled the scroll event
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* @param {Object} options
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*/
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smoothScroll.animateScroll = function (anchor, toggle, options) {
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// Local settings
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var animateSettings = extend(settings || defaults, options || {}); // Merge user options with defaults
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// Selectors and variables
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var isNum = Object.prototype.toString.call(anchor) === '[object Number]' ? true : false;
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var anchorElem = isNum || !anchor.tagName ? null : anchor;
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if (!isNum && !anchorElem) return;
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var startLocation = window.pageYOffset; // Current location on the page
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if (animateSettings.header && !fixedHeader) {
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// Get the fixed header if not already set
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fixedHeader = document.querySelector( animateSettings.header );
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}
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if (!headerHeight) {
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// Get the height of a fixed header if one exists and not already set
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headerHeight = getHeaderHeight(fixedHeader);
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}
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var endLocation = isNum ? anchor : getEndLocation(anchorElem, headerHeight, parseInt((typeof animateSettings.offset === 'function' ? animateSettings.offset() : animateSettings.offset), 10)); // Location to scroll to
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var distance = endLocation - startLocation; // distance to travel
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var documentHeight = getDocumentHeight();
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var timeLapsed = 0;
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var start, percentage, position;
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/**
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* Stop the scroll animation when it reaches its target (or the bottom/top of page)
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* @param {Number} position Current position on the page
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* @param {Number} endLocation Scroll to location
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* @param {Number} animationInterval How much to scroll on this loop
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*/
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var stopAnimateScroll = function (position, endLocation) {
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// Get the current location
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var currentLocation = window.pageYOffset;
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// Check if the end location has been reached yet (or we've hit the end of the document)
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if ( position == endLocation || currentLocation == endLocation || ((startLocation < endLocation && window.innerHeight + currentLocation) >= documentHeight )) {
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// Clear the animation timer
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smoothScroll.cancelScroll();
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// Bring the anchored element into focus
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adjustFocus(anchor, endLocation, isNum);
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// Run callback after animation complete
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animateSettings.after(anchor, toggle);
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// Reset start
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start = null;
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return true;
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}
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};
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/**
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* Loop scrolling animation
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*/
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var loopAnimateScroll = function (timestamp) {
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if (!start) { start = timestamp; }
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timeLapsed += timestamp - start;
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percentage = (timeLapsed / parseInt(animateSettings.speed, 10));
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percentage = (percentage > 1) ? 1 : percentage;
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position = startLocation + (distance * easingPattern(animateSettings, percentage));
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window.scrollTo(0, Math.floor(position));
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if (!stopAnimateScroll(position, endLocation)) {
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window.requestAnimationFrame(loopAnimateScroll);
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start = timestamp;
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}
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};
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/**
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* Reset position to fix weird iOS bug
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* @link https://github.com/cferdinandi/smooth-scroll/issues/45
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*/
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if (window.pageYOffset === 0) {
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window.scrollTo( 0, 0 );
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}
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// Run callback before animation starts
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animateSettings.before(anchor, toggle);
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// Start scrolling animation
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smoothScroll.cancelScroll();
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window.requestAnimationFrame(loopAnimateScroll);
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};
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/**
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* Handle has change event
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*/
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var hashChangeHandler = function (event) {
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// Only run if there's an anchor element to scroll to
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if (!anchor) return;
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// Reset the anchor element's ID
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anchor.id = anchor.getAttribute('data-scroll-id');
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// Scroll to the anchored content
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smoothScroll.animateScroll(anchor, toggle);
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// Reset anchor and toggle
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anchor = null;
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toggle = null;
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};
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/**
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* If smooth scroll element clicked, animate scroll
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*/
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var clickHandler = function (event) {
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// Don't run if the user prefers reduced motion
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if (reduceMotion(settings)) return;
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// Don't run if right-click or command/control + click
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if (event.button !== 0 || event.metaKey || event.ctrlKey) return;
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// Check if a smooth scroll link was clicked
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toggle = event.target.closest(selector);
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if (!toggle || toggle.tagName.toLowerCase() !== 'a' || event.target.closest(settings.ignore)) return;
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// Only run if link is an anchor and points to the current page
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if (toggle.hostname !== window.location.hostname || toggle.pathname !== window.location.pathname || !/#/.test(toggle.href)) return;
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// Get the sanitized hash
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var hash;
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try {
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hash = escapeCharacters(decodeURIComponent(toggle.hash));
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} catch(e) {
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hash = escapeCharacters(toggle.hash);
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}
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// If the hash is empty, scroll to the top of the page
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if (hash === '#') {
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// Prevent default link behavior
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event.preventDefault();
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// Set the anchored element
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anchor = document.body;
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// Save or create the ID as a data attribute and remove it (prevents scroll jump)
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var id = anchor.id ? anchor.id : 'smooth-scroll-top';
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anchor.setAttribute('data-scroll-id', id);
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anchor.id = '';
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// If no hash change event will happen, fire manually
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// Otherwise, update the hash
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if (window.location.hash.substring(1) === id) {
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hashChangeHandler();
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} else {
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window.location.hash = id;
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}
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return;
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}
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// Get the anchored element
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anchor = document.querySelector(hash);
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// If anchored element exists, save the ID as a data attribute and remove it (prevents scroll jump)
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if (!anchor) return;
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anchor.setAttribute('data-scroll-id', anchor.id);
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anchor.id = '';
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// If no hash change event will happen, fire manually
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if (toggle.hash === window.location.hash) {
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event.preventDefault();
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hashChangeHandler();
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}
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};
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/**
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* On window scroll and resize, only run events at a rate of 15fps for better performance
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*/
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var resizeThrottler = function (event) {
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if (!eventTimeout) {
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eventTimeout = setTimeout(function() {
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eventTimeout = null; // Reset timeout
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headerHeight = getHeaderHeight(fixedHeader); // Get the height of a fixed header if one exists
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}, 66);
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}
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};
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/**
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* Destroy the current initialization.
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*/
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smoothScroll.destroy = function () {
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// If plugin isn't already initialized, stop
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if (!settings) return;
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// Remove event listeners
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document.removeEventListener('click', clickHandler, false);
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window.removeEventListener('resize', resizeThrottler, false);
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// Cancel any scrolls-in-progress
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smoothScroll.cancelScroll();
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// Reset variables
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settings = null;
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anchor = null;
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toggle = null;
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fixedHeader = null;
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headerHeight = null;
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eventTimeout = null;
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animationInterval = null;
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};
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/**
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* Initialize Smooth Scroll
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* @param {Object} options User settings
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*/
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smoothScroll.init = function (options) {
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|
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// feature test
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if (!supports) return;
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// Destroy any existing initializations
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smoothScroll.destroy();
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// Selectors and variables
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settings = extend(defaults, options || {}); // Merge user options with defaults
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fixedHeader = settings.header ? document.querySelector(settings.header) : null; // Get the fixed header
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headerHeight = getHeaderHeight(fixedHeader);
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// When a toggle is clicked, run the click handler
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document.addEventListener('click', clickHandler, false);
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// Listen for hash changes
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window.addEventListener('hashchange', hashChangeHandler, false);
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// If window is resized and there's a fixed header, recalculate its size
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if (fixedHeader) {
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window.addEventListener('resize', resizeThrottler, false);
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}
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};
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//
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// Initialize plugin
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//
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||
|
||
smoothScroll.init(options);
|
||
|
||
|
||
//
|
||
// Public APIs
|
||
//
|
||
|
||
return smoothScroll;
|
||
|
||
};
|
||
|
||
return SmoothScroll;
|
||
|
||
}); |