Team:Tokyo Tech/mobirise/smoothscroll/smooth-scroll-js
// // SmoothScroll for websites v1.4.5 (Balazs Galambosi) // http://www.smoothscroll.net/ // // Licensed under the terms of the MIT license. // // You may use it in your theme if you credit me. // It is also free to use on any individual website. // // Exception: // The only restriction is to not publish any // extension for browsers or native application // without getting a written permission first. //
(function () {
// Scroll Variables (tweakable) var defaultOptions = {
// Scrolling Core frameRate : 150, // [Hz] animationTime : 400, // [ms] stepSize : 100, // [px]
// Pulse (less tweakable) // ratio of "tail" to "acceleration" pulseAlgorithm : true, pulseScale : 4, pulseNormalize : 1,
// Acceleration accelerationDelta : 50, // 50 accelerationMax : 3, // 3
// Keyboard Settings keyboardSupport : true, // option arrowScroll : 50, // [px]
// Other touchpadSupport : false, // ignore touchpad by default fixedBackground : true, excluded :
};
var options = defaultOptions;
// Other Variables
var isExcluded = false;
var isFrame = false;
var direction = { x: 0, y: 0 };
var initDone = false;
var root = document.documentElement;
var activeElement;
var observer;
var refreshSize;
var deltaBuffer = [];
var isMac = /^Mac/.test(navigator.platform);
var key = { left: 37, up: 38, right: 39, down: 40, spacebar: 32,
pageup: 33, pagedown: 34, end: 35, home: 36 };
var arrowKeys = { 37: 1, 38: 1, 39: 1, 40: 1 };
/***********************************************
* INITIALIZE ***********************************************/
/**
* Tests if smooth scrolling is allowed. Shuts down everything if not. */
function initTest() {
if (options.keyboardSupport) {
addEvent('keydown', keydown);
}
}
/**
* Sets up scrolls array, determines if frames are involved. */
function init() {
if (initDone || !document.body) return;
initDone = true;
var body = document.body; var html = document.documentElement; var windowHeight = window.innerHeight; var scrollHeight = body.scrollHeight;
// check compat mode for root element
root = (document.compatMode.indexOf('CSS') >= 0) ? html : body;
activeElement = body;
initTest();
// Checks if this script is running in a frame
if (top != self) {
isFrame = true;
}
/**
* Safari 10 fixed it, Chrome fixed it in v45:
* This fixes a bug where the areas left and right to
* the content does not trigger the onmousewheel event
* on some pages. e.g.: html, body { height: 100% }
*/
else if (isOldSafari &&
scrollHeight > windowHeight &&
(body.offsetHeight <= windowHeight ||
html.offsetHeight <= windowHeight)) {
var fullPageElem = document.createElement('div');
fullPageElem.style.cssText = 'position:absolute; z-index:-10000; ' +
'top:0; left:0; right:0; height:' +
root.scrollHeight + 'px';
document.body.appendChild(fullPageElem);
// DOM changed (throttled) to fix height
var pendingRefresh;
refreshSize = function () {
if (pendingRefresh) return; // could also be: clearTimeout(pendingRefresh);
pendingRefresh = setTimeout(function () {
if (isExcluded) return; // could be running after cleanup
fullPageElem.style.height = '0';
fullPageElem.style.height = root.scrollHeight + 'px';
pendingRefresh = null;
}, 500); // act rarely to stay fast
};
setTimeout(refreshSize, 10);
addEvent('resize', refreshSize);
// TODO: attributeFilter?
var config = {
attributes: true,
childList: true,
characterData: false
// subtree: true
};
observer = new MutationObserver(refreshSize);
observer.observe(body, config);
if (root.offsetHeight <= windowHeight) {
var clearfix = document.createElement('div');
clearfix.style.clear = 'both';
body.appendChild(clearfix);
}
}
// disable fixed background
if (!options.fixedBackground && !isExcluded) {
body.style.backgroundAttachment = 'scroll';
html.style.backgroundAttachment = 'scroll';
}
}
/**
* Removes event listeners and other traces left on the page. */
function cleanup() {
observer && observer.disconnect();
removeEvent(wheelEvent, wheel);
removeEvent('mousedown', mousedown);
removeEvent('keydown', keydown);
removeEvent('resize', refreshSize);
removeEvent('load', init);
}
/************************************************
* SCROLLING ************************************************/
var que = []; var pending = false; var lastScroll = Date.now();
/**
* Pushes scroll actions to the scrolling queue. */
function scrollArray(elem, left, top) {
directionCheck(left, top);
if (options.accelerationMax != 1) {
var now = Date.now();
var elapsed = now - lastScroll;
if (elapsed < options.accelerationDelta) {
var factor = (1 + (50 / elapsed)) / 2;
if (factor > 1) {
factor = Math.min(factor, options.accelerationMax);
left *= factor;
top *= factor;
}
}
lastScroll = Date.now();
}
// push a scroll command
que.push({
x: left,
y: top,
lastX: (left < 0) ? 0.99 : -0.99,
lastY: (top < 0) ? 0.99 : -0.99,
start: Date.now()
});
// don't act if there's a pending queue
if (pending) {
return;
}
var scrollWindow = (elem === document.body);
var step = function (time) {
var now = Date.now();
var scrollX = 0;
var scrollY = 0;
for (var i = 0; i < que.length; i++) {
var item = que[i];
var elapsed = now - item.start;
var finished = (elapsed >= options.animationTime);
// scroll position: [0, 1]
var position = (finished) ? 1 : elapsed / options.animationTime;
// easing [optional]
if (options.pulseAlgorithm) {
position = pulse(position);
}
// only need the difference
var x = (item.x * position - item.lastX) >> 0;
var y = (item.y * position - item.lastY) >> 0;
// add this to the total scrolling
scrollX += x;
scrollY += y;
// update last values
item.lastX += x;
item.lastY += y;
// delete and step back if it's over
if (finished) {
que.splice(i, 1); i--;
}
}
// scroll left and top
if (scrollWindow) {
window.scrollBy(scrollX, scrollY);
}
else {
if (scrollX) elem.scrollLeft += scrollX;
if (scrollY) elem.scrollTop += scrollY;
}
// clean up if there's nothing left to do
if (!left && !top) {
que = [];
}
if (que.length) {
requestFrame(step, elem, (1000 / options.frameRate + 1));
} else {
pending = false;
}
};
// start a new queue of actions requestFrame(step, elem, 0); pending = true;
}
/***********************************************
* EVENTS ***********************************************/
/**
* Mouse wheel handler.
* @param {Object} event
*/
function wheel(event) {
if (!initDone) {
init();
}
var target = event.target;
// leave early if default action is prevented
// or it's a zooming event with CTRL
if (event.defaultPrevented || event.ctrlKey) {
return true;
}
// leave embedded content alone (flash & pdf)
if (isNodeName(activeElement, 'embed') ||
(isNodeName(target, 'embed') && /\.pdf/i.test(target.src)) ||
isNodeName(activeElement, 'object') ||
target.shadowRoot) {
return true;
}
var deltaX = -event.wheelDeltaX || event.deltaX || 0; var deltaY = -event.wheelDeltaY || event.deltaY || 0;
if (isMac) {
if (event.wheelDeltaX && isDivisible(event.wheelDeltaX, 120)) {
deltaX = -120 * (event.wheelDeltaX / Math.abs(event.wheelDeltaX));
}
if (event.wheelDeltaY && isDivisible(event.wheelDeltaY, 120)) {
deltaY = -120 * (event.wheelDeltaY / Math.abs(event.wheelDeltaY));
}
}
// use wheelDelta if deltaX/Y is not available
if (!deltaX && !deltaY) {
deltaY = -event.wheelDelta || 0;
}
// line based scrolling (Firefox mostly)
if (event.deltaMode === 1) {
deltaX *= 40;
deltaY *= 40;
}
var overflowing = overflowingAncestor(target);
// nothing to do if there's no element that's scrollable
if (!overflowing) {
// except Chrome iframes seem to eat wheel events, which we need to
// propagate up, if the iframe has nothing overflowing to scroll
if (isFrame && isChrome) {
// change target to iframe element itself for the parent frame
Object.defineProperty(event, "target", {value: window.frameElement});
event = new event.constructor(event.type, event); // redefine event because already dispatched
return parent.dispatchEvent(event);
}
return true;
}
// check if it's a touchpad scroll that should be ignored
if (!options.touchpadSupport && isTouchpad(deltaY)) {
return true;
}
// scale by step size
// delta is 120 most of the time
// synaptics seems to send 1 sometimes
if (Math.abs(deltaX) > 1.2) {
deltaX *= options.stepSize / 120;
}
if (Math.abs(deltaY) > 1.2) {
deltaY *= options.stepSize / 120;
}
scrollArray(overflowing, deltaX, deltaY); event.preventDefault(); scheduleClearCache();
}
/**
* Keydown event handler.
* @param {Object} event
*/
function keydown(event) {
var target = event.target;
var modifier = event.ctrlKey || event.altKey || event.metaKey ||
(event.shiftKey && event.keyCode !== key.spacebar);
// our own tracked active element could've been removed from the DOM
if (!document.body.contains(activeElement)) {
activeElement = document.activeElement;
}
// do nothing if user is editing text
// or using a modifier key (except shift)
// or in a dropdown
// or inside interactive elements
var inputNodeNames = /^(textarea|select|embed|object)$/i;
var buttonTypes = /^(button|submit|radio|checkbox|file|color|image)$/i;
if ( event.defaultPrevented ||
inputNodeNames.test(target.nodeName) ||
isNodeName(target, 'input') && !buttonTypes.test(target.type) ||
isNodeName(activeElement, 'video') ||
isInsideYoutubeVideo(event) ||
target.isContentEditable ||
modifier ) {
return true;
}
// [spacebar] should trigger button press, leave it alone
if ((isNodeName(target, 'button') ||
isNodeName(target, 'input') && buttonTypes.test(target.type)) &&
event.keyCode === key.spacebar) {
return true;
}
// [arrwow keys] on radio buttons should be left alone
if (isNodeName(target, 'input') && target.type == 'radio' &&
arrowKeys[event.keyCode]) {
return true;
}
var shift, x = 0, y = 0; var overflowing = overflowingAncestor(activeElement);
if (!overflowing) {
// Chrome iframes seem to eat key events, which we need to
// propagate up, if the iframe has nothing overflowing to scroll
return (isFrame && isChrome) ? parent.keydown(event) : true;
}
var clientHeight = overflowing.clientHeight;
if (overflowing == document.body) {
clientHeight = window.innerHeight;
}
switch (event.keyCode) {
case key.up:
y = -options.arrowScroll;
break;
case key.down:
y = options.arrowScroll;
break;
case key.spacebar: // (+ shift)
shift = event.shiftKey ? 1 : -1;
y = -shift * clientHeight * 0.9;
break;
case key.pageup:
y = -clientHeight * 0.9;
break;
case key.pagedown:
y = clientHeight * 0.9;
break;
case key.home:
y = -overflowing.scrollTop;
break;
case key.end:
var scroll = overflowing.scrollHeight - overflowing.scrollTop;
var scrollRemaining = scroll - clientHeight;
y = (scrollRemaining > 0) ? scrollRemaining + 10 : 0;
break;
case key.left:
x = -options.arrowScroll;
break;
case key.right:
x = options.arrowScroll;
break;
default:
return true; // a key we don't care about
}
scrollArray(overflowing, x, y); event.preventDefault(); scheduleClearCache();
}
/**
* Mousedown event only for updating activeElement */
function mousedown(event) {
activeElement = event.target;
}
/***********************************************
* OVERFLOW ***********************************************/
var uniqueID = (function () {
var i = 0;
return function (el) {
return el.uniqueID || (el.uniqueID = i++);
};
})();
var cache = {}; // cleared out after a scrolling session var clearCacheTimer;
//setInterval(function () { cache = {}; }, 10 * 1000);
function scheduleClearCache() {
clearTimeout(clearCacheTimer);
clearCacheTimer = setInterval(function () { cache = {}; }, 1*1000);
}
function setCache(elems, overflowing) {
for (var i = elems.length; i--;)
cache[uniqueID(elems[i])] = overflowing;
return overflowing;
}
// (body) (root) // | hidden | visible | scroll | auto | // hidden | no | no | YES | YES | // visible | no | YES | YES | YES | // scroll | no | YES | YES | YES | // auto | no | YES | YES | YES |
function overflowingAncestor(el) {
var elems = [];
var body = document.body;
var rootScrollHeight = root.scrollHeight;
do {
var cached = cache[uniqueID(el)];
if (cached) {
return setCache(elems, cached);
}
elems.push(el);
if (rootScrollHeight === el.scrollHeight) {
var topOverflowsNotHidden = overflowNotHidden(root) && overflowNotHidden(body);
var isOverflowCSS = topOverflowsNotHidden || overflowAutoOrScroll(root);
if (isFrame && isContentOverflowing(root) ||
!isFrame && isOverflowCSS) {
return setCache(elems, getScrollRoot());
}
} else if (isContentOverflowing(el) && overflowAutoOrScroll(el)) {
return setCache(elems, el);
}
} while (el = el.parentElement);
}
function isContentOverflowing(el) {
return (el.clientHeight + 10 < el.scrollHeight);
}
// typically for <body> and function overflowNotHidden(el) { var overflow = getComputedStyle(el, '').getPropertyValue('overflow-y'); return (overflow !== 'hidden'); } // for all other elements function overflowAutoOrScroll(el) { var overflow = getComputedStyle(el, '').getPropertyValue('overflow-y'); return (overflow === 'scroll' || overflow === 'auto'); } /*********************************************** * HELPERS ***********************************************/ function addEvent(type, fn) { window.addEventListener(type, fn, false); } function removeEvent(type, fn) { window.removeEventListener(type, fn, false); } function isNodeName(el, tag) { return (el.nodeName||'').toLowerCase() === tag.toLowerCase(); } function directionCheck(x, y) { x = (x > 0) ? 1 : -1; y = (y > 0) ? 1 : -1; if (direction.x !== x || direction.y !== y) { direction.x = x; direction.y = y; que = []; lastScroll = 0; } } var deltaBufferTimer; if (window.localStorage && localStorage.SS_deltaBuffer) { try { // #46 Safari throws in private browsing for localStorage deltaBuffer = localStorage.SS_deltaBuffer.split(','); } catch (e) { } } function isTouchpad(deltaY) { if (!deltaY) return; if (!deltaBuffer.length) { deltaBuffer = [deltaY, deltaY, deltaY]; } deltaY = Math.abs(deltaY); deltaBuffer.push(deltaY); deltaBuffer.shift(); clearTimeout(deltaBufferTimer); deltaBufferTimer = setTimeout(function () { try { // #46 Safari throws in private browsing for localStorage localStorage.SS_deltaBuffer = deltaBuffer.join(','); } catch (e) { } }, 1000); return !allDeltasDivisableBy(120) && !allDeltasDivisableBy(100); } function isDivisible(n, divisor) { return (Math.floor(n / divisor) == n / divisor); } function allDeltasDivisableBy(divisor) { return (isDivisible(deltaBuffer[0], divisor) && isDivisible(deltaBuffer[1], divisor) && isDivisible(deltaBuffer[2], divisor)); } function isInsideYoutubeVideo(event) { var elem = event.target; var isControl = false; if (document.URL.indexOf ('www.youtube.com/watch') != -1) { do { isControl = (elem.classList && elem.classList.contains('html5-video-controls')); if (isControl) break; } while (elem = elem.parentNode); } return isControl; } var requestFrame = (function () { return (window.requestAnimationFrame || window.webkitRequestAnimationFrame || window.mozRequestAnimationFrame || function (callback, element, delay) { window.setTimeout(callback, delay || (1000/60)); }); })(); var MutationObserver = (window.MutationObserver || window.WebKitMutationObserver || window.MozMutationObserver); var getScrollRoot = (function() { var SCROLL_ROOT; return function() { if (!SCROLL_ROOT) { var dummy = document.createElement('div'); dummy.style.cssText = 'height:10000px;width:1px;'; document.body.appendChild(dummy); var bodyScrollTop = document.body.scrollTop; var docElScrollTop = document.documentElement.scrollTop; window.scrollBy(0, 3); if (document.body.scrollTop != bodyScrollTop) (SCROLL_ROOT = document.body); else (SCROLL_ROOT = document.documentElement); window.scrollBy(0, -3); document.body.removeChild(dummy); } return SCROLL_ROOT; }; })(); /*********************************************** * PULSE (by Michael Herf) ***********************************************/ /** * Viscous fluid with a pulse for part and decay for the rest. * - Applies a fixed force over an interval (a damped acceleration), and * - Lets the exponential bleed away the velocity over a longer interval * - Michael Herf, http://stereopsis.com/stopping/ */ function pulse_(x) { var val, start, expx; // test x = x * options.pulseScale; if (x < 1) { // acceleartion val = x - (1 - Math.exp(-x)); } else { // tail // the previous animation ended here: start = Math.exp(-1); // simple viscous drag x -= 1; expx = 1 - Math.exp(-x); val = start + (expx * (1 - start)); } return val * options.pulseNormalize; } function pulse(x) { if (x >= 1) return 1; if (x <= 0) return 0; if (options.pulseNormalize == 1) { options.pulseNormalize /= pulse_(1); } return pulse_(x); } /*********************************************** * FIRST RUN ***********************************************/ var userAgent = window.navigator.userAgent; var isEdge = /Edge/.test(userAgent); // thank you MS var isChrome = /chrome/i.test(userAgent) && !isEdge; var isSafari = /safari/i.test(userAgent) && !isEdge; var isMobile = /mobile/i.test(userAgent); var isIEWin7 = /Windows NT 6.1/i.test(userAgent) && /rv:11/i.test(userAgent); var isOldSafari = isSafari && (/Version\/8/i.test(userAgent) || /Version\/9/i.test(userAgent)); var isEnabledForBrowser = (isChrome || isSafari || isIEWin7) && !isMobile; var wheelEvent; if ('onwheel' in document.createElement('div')) wheelEvent = 'wheel'; else if ('onmousewheel' in document.createElement('div')) wheelEvent = 'mousewheel'; if (wheelEvent && isEnabledForBrowser) { addEvent(wheelEvent, wheel); addEvent('mousedown', mousedown); addEvent('load', init); } /*********************************************** * PUBLIC INTERFACE ***********************************************/ function SmoothScroll(optionsToSet) { for (var key in optionsToSet) if (defaultOptions.hasOwnProperty(key)) options[key] = optionsToSet[key]; } SmoothScroll.destroy = cleanup; if (window.SmoothScrollOptions) // async API SmoothScroll(window.SmoothScrollOptions); if (typeof define === 'function' && define.amd) define(function() { return SmoothScroll; }); else if ('object' == typeof exports) module.exports = SmoothScroll; else window.SmoothScroll = SmoothScroll; })();