633 lines
19 KiB
JavaScript
633 lines
19 KiB
JavaScript
/*!
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* smooth-scroll v15.2.1
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* Animate scrolling to anchor links
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* (c) 2019 Chris Ferdinandi
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* MIT License
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* http://github.com/cferdinandi/smooth-scroll
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*/
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(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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// 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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topOnEmptyHash: true,
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// Speed & Duration
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speed: 500,
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speedAsDuration: false,
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durationMax: null,
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durationMin: null,
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clip: true,
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offset: 0,
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// Easing
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easing: 'easeInOutCubic',
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customEasing: null,
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// History
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updateURL: true,
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popstate: true,
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// Custom Events
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emitEvents: true
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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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* Check if browser supports required methods
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* @return {Boolean} Returns true if all required methods are supported
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*/
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var supports = function () {
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return (
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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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};
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/**
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* Merge two or more objects together.
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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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var merged = {};
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Array.prototype.forEach.call(arguments, (function (obj) {
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for (var key in obj) {
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if (!obj.hasOwnProperty(key)) return;
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merged[key] = obj[key];
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}
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}));
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return merged;
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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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* 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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* @author Mathias Bynens
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* @link https://github.com/mathiasbynens/CSS.escape
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* @param {String} id The anchor ID to 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 sanitized hash
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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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* Clip support added by robjtede - https://github.com/cferdinandi/smooth-scroll/issues/405
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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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* @param {Boolean} clip If true, adjust scroll distance to prevent abrupt stops near the bottom of the page
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* @returns {Number}
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*/
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var getEndLocation = function (anchor, headerHeight, offset, clip) {
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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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if (clip) {
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location = Math.min(location, getDocumentHeight() - window.innerHeight);
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}
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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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* Calculate the speed to use for the animation
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* @param {Number} distance The distance to travel
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* @param {Object} settings The plugin settings
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* @return {Number} How fast to animate
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*/
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var getSpeed = function (distance, settings) {
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var speed = settings.speedAsDuration ? settings.speed : Math.abs(distance / 1000 * settings.speed);
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if (settings.durationMax && speed > settings.durationMax) return settings.durationMax;
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if (settings.durationMin && speed < settings.durationMin) return settings.durationMin;
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return parseInt(speed, 10);
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};
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var setHistory = function (options) {
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// Make sure this should run
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if (!history.replaceState || !options.updateURL || history.state) return;
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// Get the hash to use
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var hash = window.location.hash;
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hash = hash ? hash : '';
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// Set a default history
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history.replaceState(
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{
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smoothScroll: JSON.stringify(options),
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anchor: hash ? hash : window.pageYOffset
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},
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document.title,
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hash ? hash : window.location.href
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);
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};
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/**
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* Update the URL
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* @param {Node} anchor The anchor that was scrolled to
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* @param {Boolean} isNum If true, anchor is a number
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* @param {Object} options Settings for Smooth Scroll
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*/
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var updateURL = function (anchor, isNum, options) {
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// Bail if the anchor is a number
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if (isNum) return;
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// Verify that pushState is supported and the updateURL option is enabled
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if (!history.pushState || !options.updateURL) return;
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// Update URL
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history.pushState(
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{
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smoothScroll: JSON.stringify(options),
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anchor: anchor.id
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},
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document.title,
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anchor === document.documentElement ? '#top' : '#' + anchor.id
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);
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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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// Is scrolling to top of page, blur
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if (anchor === 0) {
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document.body.focus();
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}
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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 !== anchor) {
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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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* Emit a custom event
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* @param {String} type The event type
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* @param {Object} options The settings object
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* @param {Node} anchor The anchor element
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* @param {Node} toggle The toggle element
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*/
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var emitEvent = function (type, options, anchor, toggle) {
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if (!options.emitEvents || typeof window.CustomEvent !== 'function') return;
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var event = new CustomEvent(type, {
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bubbles: true,
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detail: {
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anchor: anchor,
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toggle: toggle
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}
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});
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document.dispatchEvent(event);
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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, 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 (noEvent) {
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cancelAnimationFrame(animationInterval);
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animationInterval = null;
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if (noEvent) return;
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emitEvent('scrollCancel', settings);
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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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// Cancel any in progress scrolls
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smoothScroll.cancelScroll();
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// Local settings
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var _settings = 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 (_settings.header && !fixedHeader) {
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// Get the fixed header if not already set
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fixedHeader = document.querySelector(_settings.header);
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}
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var headerHeight = getHeaderHeight(fixedHeader);
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var endLocation = isNum ? anchor : getEndLocation(anchorElem, headerHeight, parseInt((typeof _settings.offset === 'function' ? _settings.offset(anchor, toggle) : _settings.offset), 10), _settings.clip); // 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 speed = getSpeed(distance, _settings);
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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(true);
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// Bring the anchored element into focus
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adjustFocus(anchor, endLocation, isNum);
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// Emit a custom event
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emitEvent('scrollStop', _settings, anchor, toggle);
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// Reset start
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start = null;
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animationInterval = 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 = speed === 0 ? 0 : (timeLapsed / speed);
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percentage = (percentage > 1) ? 1 : percentage;
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position = startLocation + (distance * easingPattern(_settings, percentage));
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window.scrollTo(0, Math.floor(position));
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if (!stopAnimateScroll(position, endLocation)) {
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animationInterval = 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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// Update the URL
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updateURL(anchor, isNum, _settings);
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// Emit a custom event
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emitEvent('scrollStart', _settings, anchor, toggle);
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// Start scrolling animation
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smoothScroll.cancelScroll(true);
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window.requestAnimationFrame(loopAnimateScroll);
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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 event.target has closest() method
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// By @totegi - https://github.com/cferdinandi/smooth-scroll/pull/401/
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if(!('closest' in event.target))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 an escaped version of the hash
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var hash = escapeCharacters(toggle.hash);
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// Get the anchored element
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var anchor = settings.topOnEmptyHash && hash === '#' ? document.documentElement : document.querySelector(hash);
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anchor = !anchor && hash === '#top' ? document.documentElement : anchor;
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// If anchored element exists, scroll to it
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if (!anchor) return;
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event.preventDefault();
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setHistory(settings);
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smoothScroll.animateScroll(anchor, toggle);
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};
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/**
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* Animate scroll on popstate events
|
||
*/
|
||
var popstateHandler = function (event) {
|
||
|
||
// Stop if history.state doesn't exist (ex. if clicking on a broken anchor link).
|
||
// fixes `Cannot read property 'smoothScroll' of null` error getting thrown.
|
||
if (history.state === null) return;
|
||
|
||
// Only run if state is a popstate record for this instantiation
|
||
if (!history.state.smoothScroll || history.state.smoothScroll !== JSON.stringify(settings)) return;
|
||
|
||
// Only run if state includes an anchor
|
||
|
||
// if (!history.state.anchor && history.state.anchor !== 0) return;
|
||
|
||
// Get the anchor
|
||
var anchor = history.state.anchor;
|
||
if (typeof anchor === 'string' && anchor) {
|
||
anchor = document.querySelector(escapeCharacters(history.state.anchor));
|
||
if (!anchor) return;
|
||
}
|
||
|
||
// Animate scroll to anchor link
|
||
smoothScroll.animateScroll(anchor, null, {updateURL: false});
|
||
|
||
};
|
||
|
||
/**
|
||
* Destroy the current initialization.
|
||
*/
|
||
smoothScroll.destroy = function () {
|
||
|
||
// If plugin isn't already initialized, stop
|
||
if (!settings) return;
|
||
|
||
// Remove event listeners
|
||
document.removeEventListener('click', clickHandler, false);
|
||
window.removeEventListener('popstate', popstateHandler, false);
|
||
|
||
// Cancel any scrolls-in-progress
|
||
smoothScroll.cancelScroll();
|
||
|
||
// Reset variables
|
||
settings = null;
|
||
anchor = null;
|
||
toggle = null;
|
||
fixedHeader = null;
|
||
eventTimeout = null;
|
||
animationInterval = null;
|
||
|
||
};
|
||
|
||
/**
|
||
* Initialize Smooth Scroll
|
||
* @param {Object} options User settings
|
||
*/
|
||
smoothScroll.init = function (options) {
|
||
|
||
// feature test
|
||
if (!supports()) throw 'Smooth Scroll: This browser does not support the required JavaScript methods and browser APIs.';
|
||
|
||
// Destroy any existing initializations
|
||
smoothScroll.destroy();
|
||
|
||
// Selectors and variables
|
||
settings = extend(defaults, options || {}); // Merge user options with defaults
|
||
fixedHeader = settings.header ? document.querySelector(settings.header) : null; // Get the fixed header
|
||
|
||
// When a toggle is clicked, run the click handler
|
||
document.addEventListener('click', clickHandler, false);
|
||
|
||
// If updateURL and popState are enabled, listen for pop events
|
||
if (settings.updateURL && settings.popstate) {
|
||
window.addEventListener('popstate', popstateHandler, false);
|
||
}
|
||
|
||
};
|
||
|
||
|
||
//
|
||
// Initialize plugin
|
||
//
|
||
|
||
smoothScroll.init(options);
|
||
|
||
|
||
//
|
||
// Public APIs
|
||
//
|
||
|
||
return smoothScroll;
|
||
|
||
};
|
||
|
||
return SmoothScroll;
|
||
|
||
}));
|