source/js/_files/smooth-scroll.js
/*!
* smooth-scroll v15.2.0
* Animate scrolling to anchor links
* (c) 2019 Chris Ferdinandi
* MIT License
* http://github.com/cferdinandi/smooth-scroll
*/
/**
* closest() polyfill
* @link https://developer.mozilla.org/en-US/docs/Web/API/Element/closest#Polyfill
*/
if (window.Element && !Element.prototype.closest) {
Element.prototype.closest = function(s) {
var matches = (this.document || this.ownerDocument).querySelectorAll(s),
i,
el = this;
do {
i = matches.length;
while (--i >= 0 && matches.item(i) !== el) {}
} while ((i < 0) && (el = el.parentElement));
return el;
};
}
/**
* CustomEvent() polyfill
* https://developer.mozilla.org/en-US/docs/Web/API/CustomEvent/CustomEvent#Polyfill
*/
(function () {
if (typeof window.CustomEvent === "function") return false;
function CustomEvent(event, params) {
params = params || { bubbles: false, cancelable: false, detail: undefined };
var evt = document.createEvent('CustomEvent');
evt.initCustomEvent(event, params.bubbles, params.cancelable, params.detail);
return evt;
}
CustomEvent.prototype = window.Event.prototype;
window.CustomEvent = CustomEvent;
})();
/**
* requestAnimationFrame() polyfill
* By Erik Möller. Fixes from Paul Irish and Tino Zijdel.
* @link http://paulirish.com/2011/requestanimationframe-for-smart-animating/
* @link http://my.opera.com/emoller/blog/2011/12/20/requestanimationframe-for-smart-er-animating
* @license MIT
*/
(function() {
var lastTime = 0;
var vendors = ['ms', 'moz', 'webkit', 'o'];
for(var x = 0; x < vendors.length && !window.requestAnimationFrame; ++x) {
window.requestAnimationFrame = window[vendors[x]+'RequestAnimationFrame'];
window.cancelAnimationFrame = window[vendors[x]+'CancelAnimationFrame'] ||
window[vendors[x]+'CancelRequestAnimationFrame'];
}
if (!window.requestAnimationFrame) {
window.requestAnimationFrame = function(callback, element) {
var currTime = new Date().getTime();
var timeToCall = Math.max(0, 16 - (currTime - lastTime));
var id = window.setTimeout((function() { callback(currTime + timeToCall); }),
timeToCall);
lastTime = currTime + timeToCall;
return id;
};
}
if (!window.cancelAnimationFrame) {
window.cancelAnimationFrame = function(id) {
clearTimeout(id);
};
}
}());
(function (root, factory) {
if (typeof define === 'function' && define.amd) {
define([], (function () {
return factory(root);
}));
} else if (typeof exports === 'object') {
module.exports = factory(root);
} else {
root.SmoothScroll = factory(root);
}
})(typeof global !== 'undefined' ? global : typeof window !== 'undefined' ? window : this, (function (window) {
'use strict';
//
// Default settings
//
var defaults = {
// Selectors
ignore: '[data-scroll-ignore]',
header: null,
topOnEmptyHash: true,
// Speed & Duration
speed: 500,
speedAsDuration: false,
durationMax: null,
durationMin: null,
clip: true,
offset: 0,
// Easing
easing: 'easeInOutCubic',
customEasing: null,
// History
updateURL: true,
popstate: true,
// Custom Events
emitEvents: true
};
//
// Utility Methods
//
/**
* Check if browser supports required methods
* @return {Boolean} Returns true if all required methods are supported
*/
var supports = function () {
return (
'querySelector' in document &&
'addEventListener' in window &&
'requestAnimationFrame' in window &&
'closest' in window.Element.prototype
);
};
/**
* Merge two or more objects together.
* @param {Object} objects The objects to merge together
* @returns {Object} Merged values of defaults and options
*/
var extend = function () {
var merged = {};
Array.prototype.forEach.call(arguments, (function (obj) {
for (var key in obj) {
if (!obj.hasOwnProperty(key)) return;
merged[key] = obj[key];
}
}));
return merged;
};
/**
* Check to see if user prefers reduced motion
* @param {Object} settings Script settings
*/
var reduceMotion = function (settings) {
if ('matchMedia' in window && window.matchMedia('(prefers-reduced-motion)').matches) {
return true;
}
return false;
};
/**
* Get the height of an element.
* @param {Node} elem The element to get the height of
* @return {Number} The element's height in pixels
*/
var getHeight = function (elem) {
return parseInt(window.getComputedStyle(elem).height, 10);
};
/**
* Escape special characters for use with querySelector
* @author Mathias Bynens
* @link https://github.com/mathiasbynens/CSS.escape
* @param {String} id The anchor ID to escape
*/
var escapeCharacters = function (id) {
// Remove leading hash
if (id.charAt(0) === '#') {
id = id.substr(1);
}
var string = String(id);
var length = string.length;
var index = -1;
var codeUnit;
var result = '';
var firstCodeUnit = string.charCodeAt(0);
while (++index < length) {
codeUnit = string.charCodeAt(index);
// Note: there’s no need to special-case astral symbols, surrogate
// pairs, or lone surrogates.
// If the character is NULL (U+0000), then throw an
// `InvalidCharacterError` exception and terminate these steps.
if (codeUnit === 0x0000) {
throw new InvalidCharacterError(
'Invalid character: the input contains U+0000.'
);
}
if (
// If the character is in the range [\1-\1F] (U+0001 to U+001F) or is
// U+007F, […]
(codeUnit >= 0x0001 && codeUnit <= 0x001F) || codeUnit == 0x007F ||
// If the character is the first character and is in the range [0-9]
// (U+0030 to U+0039), […]
(index === 0 && codeUnit >= 0x0030 && codeUnit <= 0x0039) ||
// If the character is the second character and is in the range [0-9]
// (U+0030 to U+0039) and the first character is a `-` (U+002D), […]
(
index === 1 &&
codeUnit >= 0x0030 && codeUnit <= 0x0039 &&
firstCodeUnit === 0x002D
)
) {
// http://dev.w3.org/csswg/cssom/#escape-a-character-as-code-point
result += '\\' + codeUnit.toString(16) + ' ';
continue;
}
// If the character is not handled by one of the above rules and is
// greater than or equal to U+0080, is `-` (U+002D) or `_` (U+005F), or
// is in one of the ranges [0-9] (U+0030 to U+0039), [A-Z] (U+0041 to
// U+005A), or [a-z] (U+0061 to U+007A), […]
if (
codeUnit >= 0x0080 ||
codeUnit === 0x002D ||
codeUnit === 0x005F ||
codeUnit >= 0x0030 && codeUnit <= 0x0039 ||
codeUnit >= 0x0041 && codeUnit <= 0x005A ||
codeUnit >= 0x0061 && codeUnit <= 0x007A
) {
// the character itself
result += string.charAt(index);
continue;
}
// Otherwise, the escaped character.
// http://dev.w3.org/csswg/cssom/#escape-a-character
result += '\\' + string.charAt(index);
}
// Return sanitized hash
return '#' + result;
};
/**
* Calculate the easing pattern
* @link https://gist.github.com/gre/1650294
* @param {String} type Easing pattern
* @param {Number} time Time animation should take to complete
* @returns {Number}
*/
var easingPattern = function (settings, time) {
var pattern;
// Default Easing Patterns
if (settings.easing === 'easeInQuad') pattern = time * time; // accelerating from zero velocity
if (settings.easing === 'easeOutQuad') pattern = time * (2 - time); // decelerating to zero velocity
if (settings.easing === 'easeInOutQuad') pattern = time < 0.5 ? 2 * time * time : -1 + (4 - 2 * time) * time; // acceleration until halfway, then deceleration
if (settings.easing === 'easeInCubic') pattern = time * time * time; // accelerating from zero velocity
if (settings.easing === 'easeOutCubic') pattern = (--time) * time * time + 1; // decelerating to zero velocity
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
if (settings.easing === 'easeInQuart') pattern = time * time * time * time; // accelerating from zero velocity
if (settings.easing === 'easeOutQuart') pattern = 1 - (--time) * time * time * time; // decelerating to zero velocity
if (settings.easing === 'easeInOutQuart') pattern = time < 0.5 ? 8 * time * time * time * time : 1 - 8 * (--time) * time * time * time; // acceleration until halfway, then deceleration
if (settings.easing === 'easeInQuint') pattern = time * time * time * time * time; // accelerating from zero velocity
if (settings.easing === 'easeOutQuint') pattern = 1 + (--time) * time * time * time * time; // decelerating to zero velocity
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
// Custom Easing Patterns
if (!!settings.customEasing) pattern = settings.customEasing(time);
return pattern || time; // no easing, no acceleration
};
/**
* Determine the document's height
* @returns {Number}
*/
var getDocumentHeight = function () {
return Math.max(
document.body.scrollHeight, document.documentElement.scrollHeight,
document.body.offsetHeight, document.documentElement.offsetHeight,
document.body.clientHeight, document.documentElement.clientHeight
);
};
/**
* Calculate how far to scroll
* Clip support added by robjtede - https://github.com/cferdinandi/smooth-scroll/issues/405
* @param {Element} anchor The anchor element to scroll to
* @param {Number} headerHeight Height of a fixed header, if any
* @param {Number} offset Number of pixels by which to offset scroll
* @param {Boolean} clip If true, adjust scroll distance to prevent abrupt stops near the bottom of the page
* @returns {Number}
*/
var getEndLocation = function (anchor, headerHeight, offset, clip) {
var location = 0;
if (anchor.offsetParent) {
do {
location += anchor.offsetTop;
anchor = anchor.offsetParent;
} while (anchor);
}
location = Math.max(location - headerHeight - offset, 0);
if (clip) {
location = Math.min(location, getDocumentHeight() - window.innerHeight);
}
return location;
};
/**
* Get the height of the fixed header
* @param {Node} header The header
* @return {Number} The height of the header
*/
var getHeaderHeight = function (header) {
return !header ? 0 : (getHeight(header) + header.offsetTop);
};
/**
* Calculate the speed to use for the animation
* @param {Number} distance The distance to travel
* @param {Object} settings The plugin settings
* @return {Number} How fast to animate
*/
var getSpeed = function (distance, settings) {
var speed = settings.speedAsDuration ? settings.speed : Math.abs(distance / 1000 * settings.speed);
if (settings.durationMax && speed > settings.durationMax) return settings.durationMax;
if (settings.durationMin && speed < settings.durationMin) return settings.durationMin;
return parseInt(speed, 10);
};
var setHistory = function (options) {
// Make sure this should run
if (!history.replaceState || !options.updateURL || history.state) return;
// Get the hash to use
var hash = window.location.hash;
hash = hash ? hash : window.pageYOffset;
// Set a default history
history.replaceState(
{
smoothScroll: JSON.stringify(options),
anchor: hash ? hash : window.pageYOffset
},
document.title,
hash ? hash : window.location.href
);
};
/**
* Update the URL
* @param {Node} anchor The anchor that was scrolled to
* @param {Boolean} isNum If true, anchor is a number
* @param {Object} options Settings for Smooth Scroll
*/
var updateURL = function (anchor, isNum, options) {
// Bail if the anchor is a number
if (isNum) return;
// Verify that pushState is supported and the updateURL option is enabled
if (!history.pushState || !options.updateURL) return;
// Update URL
history.pushState(
{
smoothScroll: JSON.stringify(options),
anchor: anchor.id
},
document.title,
anchor === document.documentElement ? '#top' : '#' + anchor.id
);
};
/**
* Bring the anchored element into focus
* @param {Node} anchor The anchor element
* @param {Number} endLocation The end location to scroll to
* @param {Boolean} isNum If true, scroll is to a position rather than an element
*/
var adjustFocus = function (anchor, endLocation, isNum) {
// Is scrolling to top of page, blur
if (anchor === 0) {
document.body.focus();
}
// Don't run if scrolling to a number on the page
if (isNum) return;
// Otherwise, bring anchor element into focus
anchor.focus();
if (document.activeElement !== anchor) {
anchor.setAttribute('tabindex', '-1');
anchor.focus();
anchor.style.outline = 'none';
}
window.scrollTo(0 , endLocation);
};
/**
* Emit a custom event
* @param {String} type The event type
* @param {Object} options The settings object
* @param {Node} anchor The anchor element
* @param {Node} toggle The toggle element
*/
var emitEvent = function (type, options, anchor, toggle) {
if (!options.emitEvents || typeof window.CustomEvent !== 'function') return;
var event = new CustomEvent(type, {
bubbles: true,
detail: {
anchor: anchor,
toggle: toggle
}
});
document.dispatchEvent(event);
};
//
// SmoothScroll Constructor
//
var SmoothScroll = function (selector, options) {
//
// Variables
//
var smoothScroll = {}; // Object for public APIs
var settings, anchor, toggle, fixedHeader, eventTimeout, animationInterval;
//
// Methods
//
/**
* Cancel a scroll-in-progress
*/
smoothScroll.cancelScroll = function (noEvent) {
cancelAnimationFrame(animationInterval);
animationInterval = null;
if (noEvent) return;
emitEvent('scrollCancel', settings);
};
/**
* Start/stop the scrolling animation
* @param {Node|Number} anchor The element or position to scroll to
* @param {Element} toggle The element that toggled the scroll event
* @param {Object} options
*/
smoothScroll.animateScroll = function (anchor, toggle, options) {
// Cancel any in progress scrolls
smoothScroll.cancelScroll();
// Local settings
var _settings = extend(settings || defaults, options || {}); // Merge user options with defaults
// Selectors and variables
var isNum = Object.prototype.toString.call(anchor) === '[object Number]' ? true : false;
var anchorElem = isNum || !anchor.tagName ? null : anchor;
if (!isNum && !anchorElem) return;
var startLocation = window.pageYOffset; // Current location on the page
if (_settings.header && !fixedHeader) {
// Get the fixed header if not already set
fixedHeader = document.querySelector(_settings.header);
}
var headerHeight = getHeaderHeight(fixedHeader);
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
var distance = endLocation - startLocation; // distance to travel
var documentHeight = getDocumentHeight();
var timeLapsed = 0;
var speed = getSpeed(distance, _settings);
var start, percentage, position;
/**
* Stop the scroll animation when it reaches its target (or the bottom/top of page)
* @param {Number} position Current position on the page
* @param {Number} endLocation Scroll to location
* @param {Number} animationInterval How much to scroll on this loop
*/
var stopAnimateScroll = function (position, endLocation) {
// Get the current location
var currentLocation = window.pageYOffset;
// Check if the end location has been reached yet (or we've hit the end of the document)
if (position == endLocation || currentLocation == endLocation || ((startLocation < endLocation && window.innerHeight + currentLocation) >= documentHeight)) {
// Clear the animation timer
smoothScroll.cancelScroll(true);
// Bring the anchored element into focus
adjustFocus(anchor, endLocation, isNum);
// Emit a custom event
emitEvent('scrollStop', _settings, anchor, toggle);
// Reset start
start = null;
animationInterval = null;
return true;
}
};
/**
* Loop scrolling animation
*/
var loopAnimateScroll = function (timestamp) {
if (!start) { start = timestamp; }
timeLapsed += timestamp - start;
percentage = speed === 0 ? 0 : (timeLapsed / speed);
percentage = (percentage > 1) ? 1 : percentage;
position = startLocation + (distance * easingPattern(_settings, percentage));
window.scrollTo(0, Math.floor(position));
if (!stopAnimateScroll(position, endLocation)) {
animationInterval = window.requestAnimationFrame(loopAnimateScroll);
start = timestamp;
}
};
/**
* Reset position to fix weird iOS bug
* @link https://github.com/cferdinandi/smooth-scroll/issues/45
*/
if (window.pageYOffset === 0) {
window.scrollTo(0, 0);
}
// Update the URL
updateURL(anchor, isNum, _settings);
// Emit a custom event
emitEvent('scrollStart', _settings, anchor, toggle);
// Start scrolling animation
smoothScroll.cancelScroll(true);
window.requestAnimationFrame(loopAnimateScroll);
};
/**
* If smooth scroll element clicked, animate scroll
*/
var clickHandler = function (event) {
// Don't run if the user prefers reduced motion
if (reduceMotion(settings)) return;
// Don't run if right-click or command/control + click
if (event.button !== 0 || event.metaKey || event.ctrlKey) return;
// Check if event.target has closest() method
// By @totegi - https://github.com/cferdinandi/smooth-scroll/pull/401/
if(!('closest' in event.target))return;
// Check if a smooth scroll link was clicked
toggle = event.target.closest(selector);
if (!toggle || toggle.tagName.toLowerCase() !== 'a' || event.target.closest(settings.ignore)) return;
// Only run if link is an anchor and points to the current page
if (toggle.hostname !== window.location.hostname || toggle.pathname !== window.location.pathname || !/#/.test(toggle.href)) return;
// Get an escaped version of the hash
var hash = escapeCharacters(toggle.hash);
// Get the anchored element
var anchor = settings.topOnEmptyHash && hash === '#' ? document.documentElement : document.querySelector(hash);
anchor = !anchor && hash === '#top' ? document.documentElement : anchor;
// If anchored element exists, scroll to it
if (!anchor) return;
event.preventDefault();
setHistory(settings);
smoothScroll.animateScroll(anchor, toggle);
};
/**
* 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 (anchor && anchor !== 0) {
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;
}));