Team:Aix-Marseille/js/smooth-scroll.js
From 2014.igem.org
/**
* smooth-scroll v5.0.1 * Animate scrolling to anchor links, by Chris Ferdinandi. * http://github.com/cferdinandi/smooth-scroll * * Free to use under the MIT License. * http://gomakethings.com/mit/ */
(function (root, factory) { if ( typeof define === 'function' && define.amd ) { define('smoothScroll', factory(root)); } else if ( typeof exports === 'object' ) { module.smoothScroll = factory(root); } else { root.smoothScroll = factory(root); } })(this, function (root) {
'use strict';
// // Variables //
var exports = {}; // Object for public APIs var supports = !!document.querySelector && !!root.addEventListener; // Feature test var settings;
// Default settings var defaults = { speed: 500, easing: 'easeInOutCubic', offset: 0, updateURL: true, callbackBefore: function () {}, callbackAfter: function () {} };
//
// Methods
//
/** * A simple forEach() implementation for Arrays, Objects and NodeLists * @private * @param {Array|Object|NodeList} collection Collection of items to iterate * @param {Function} callback Callback function for each iteration * @param {Array|Object|NodeList} scope Object/NodeList/Array that forEach is iterating over (aka `this`) */ var forEach = function (collection, callback, scope) { if (Object.prototype.toString.call(collection) === '[object Object]') { for (var prop in collection) { if (Object.prototype.hasOwnProperty.call(collection, prop)) { callback.call(scope, collection[prop], prop, collection); } } } else { for (var i = 0, len = collection.length; i < len; i++) { callback.call(scope, collection[i], i, collection); } } };
/** * Merge defaults with user options * @private * @param {Object} defaults Default settings * @param {Object} options User options * @returns {Object} Merged values of defaults and options */ var extend = function ( defaults, options ) { var extended = {}; forEach(defaults, function (value, prop) { extended[prop] = defaults[prop]; }); forEach(options, function (value, prop) { extended[prop] = options[prop]; }); return extended; };
/** * Calculate the easing pattern * @private * @param {String} type Easing pattern * @param {Number} time Time animation should take to complete * @returns {Number} */ var easingPattern = function ( type, time ) { var pattern; if ( type === 'easeInQuad' ) pattern = time * time; // accelerating from zero velocity if ( type === 'easeOutQuad' ) pattern = time * (2 - time); // decelerating to zero velocity if ( type === 'easeInOutQuad' ) pattern = time < 0.5 ? 2 * time * time : -1 + (4 - 2 * time) * time; // acceleration until halfway, then deceleration if ( type === 'easeInCubic' ) pattern = time * time * time; // accelerating from zero velocity if ( type === 'easeOutCubic' ) pattern = (--time) * time * time + 1; // decelerating to zero velocity if ( type === 'easeInOutCubic' ) pattern = time < 0.5 ? 4 * time * time * time : (time - 1) * (2 * time - 2) * (2 * time - 2) + 1; // acceleration until halfway, then deceleration if ( type === 'easeInQuart' ) pattern = time * time * time * time; // accelerating from zero velocity if ( type === 'easeOutQuart' ) pattern = 1 - (--time) * time * time * time; // decelerating to zero velocity if ( type === 'easeInOutQuart' ) pattern = time < 0.5 ? 8 * time * time * time * time : 1 - 8 * (--time) * time * time * time; // acceleration until halfway, then deceleration if ( type === 'easeInQuint' ) pattern = time * time * time * time * time; // accelerating from zero velocity if ( type === 'easeOutQuint' ) pattern = 1 + (--time) * time * time * time * time; // decelerating to zero velocity if ( type === 'easeInOutQuint' ) pattern = time < 0.5 ? 16 * time * time * time * time * time : 1 + 16 * (--time) * time * time * time * time; // acceleration until halfway, then deceleration return pattern || time; // no easing, no acceleration };
/** * Calculate how far to scroll * @private * @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 * @returns {Number} */ var getEndLocation = function ( anchor, headerHeight, offset ) { var location = 0; if (anchor.offsetParent) { do { location += anchor.offsetTop; anchor = anchor.offsetParent; } while (anchor); } location = location - headerHeight - offset; return location >= 0 ? location : 0; };
/** * Determine the document's height * @private * @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 ); };
/** * Convert data-options attribute into an object of key/value pairs * @private * @param {String} options Link-specific options as a data attribute string * @returns {Object} */ var getDataOptions = function ( options ) { return !options || !(typeof JSON === 'object' && typeof JSON.parse === 'function') ? {} : JSON.parse( options ); };
/** * Update the URL * @private * @param {Element} anchor The element to scroll to * @param {Boolean} url Whether or not to update the URL history */ var updateUrl = function ( anchor, url ) { if ( history.pushState && (url || url === 'true') ) { history.pushState( { pos: anchor.id }, , window.location.pathname + anchor ); } };
/** * Start/stop the scrolling animation * @public * @param {Element} toggle The element that toggled the scroll event * @param {Element} anchor The element to scroll to * @param {Object} settings * @param {Event} event */ exports.animateScroll = function ( toggle, anchor, options, event ) {
// Options and overrides var settings = extend( settings || defaults, options || {} ); // Merge user options with defaults var overrides = getDataOptions( toggle ? toggle.getAttribute('data-options') : null ); settings = extend( settings, overrides );
// Selectors and variables var fixedHeader = document.querySelector('[data-scroll-header]'); // Get the fixed header var headerHeight = fixedHeader === null ? 0 : (fixedHeader.offsetHeight + fixedHeader.offsetTop); // Get the height of a fixed header if one exists var startLocation = root.pageYOffset; // Current location on the page var endLocation = getEndLocation( document.querySelector(anchor), headerHeight, parseInt(settings.offset, 10) ); // Scroll to location var animationInterval; // interval timer var distance = endLocation - startLocation; // distance to travel var documentHeight = getDocumentHeight(); var timeLapsed = 0; var percentage, position;
// Prevent default click event if ( toggle && toggle.tagName.toLowerCase() === 'a' && event ) { event.preventDefault(); }
// Update URL updateUrl(anchor, settings.updateURL);
/** * Stop the scroll animation when it reaches its target (or the bottom/top of page) * @private * @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, animationInterval) { var currentLocation = root.pageYOffset; if ( position == endLocation || currentLocation == endLocation || ( (root.innerHeight + currentLocation) >= documentHeight ) ) { clearInterval(animationInterval); settings.callbackAfter( toggle, anchor ); // Run callbacks after animation complete } };
/** * Loop scrolling animation * @private */ var loopAnimateScroll = function () { timeLapsed += 16; percentage = ( timeLapsed / parseInt(settings.speed, 10) ); percentage = ( percentage > 1 ) ? 1 : percentage; position = startLocation + ( distance * easingPattern(settings.easing, percentage) ); root.scrollTo( 0, Math.floor(position) ); stopAnimateScroll(position, endLocation, animationInterval); };
/** * Set interval timer * @private */ var startAnimateScroll = function () { settings.callbackBefore( toggle, anchor ); // Run callbacks before animating scroll animationInterval = setInterval(loopAnimateScroll, 16); };
/** * Reset position to fix weird iOS bug * @link https://github.com/cferdinandi/smooth-scroll/issues/45 */ if ( root.pageYOffset === 0 ) { root.scrollTo( 0, 0 ); }
// Start scrolling animation startAnimateScroll();
};
/** * Initialize Smooth Scroll * @public * @param {Object} options User settings */ exports.init = function ( options ) {
// feature test if ( !supports ) return;
// Selectors and variables settings = extend( defaults, options || {} ); // Merge user options with defaults var toggles = document.querySelectorAll('[data-scroll]'); // Get smooth scroll toggles
// When a toggle is clicked, run the click handler forEach(toggles, function (toggle) { toggle.addEventListener('click', exports.animateScroll.bind( null, toggle, toggle.hash, settings ), false); });
};
//
// Public APIs
//
return exports;
});