Last active

Embed URL

HTTPS clone URL

SSH clone URL

You can clone with HTTPS or SSH.

Download Gist
View SmoothScroll.js
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 379 380 381 382 383 384 385 386 387 388 389 390 391 392 393 394 395 396 397 398 399 400 401 402 403 404 405 406 407 408 409 410 411 412 413 414 415 416 417 418 419 420 421 422 423 424 425 426 427 428 429 430 431 432 433 434 435 436 437 438 439 440 441 442 443 444 445 446 447 448 449 450 451 452 453 454 455 456 457 458 459 460 461 462 463 464 465 466 467 468 469 470 471 472 473 474 475 476 477 478 479 480 481 482 483 484 485 486 487 488 489 490 491 492 493 494 495 496 497 498 499 500 501 502 503 504 505 506 507 508 509 510 511 512 513 514 515 516 517 518 519 520 521 522 523 524 525 526 527 528 529 530 531 532 533 534 535 536 537 538 539 540 541 542 543 544 545
//
// SmoothScroll for websites v1.2.1
// 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 would be not to publish any
// extension for browsers or native application
// without getting a permission first.
//
 
// People involved
// - Balazs Galambosi (maintainer)
// - Michael Herf (Pulse Algorithm)
 
(function(){
// Scroll Variables (tweakable)
var defaultOptions = {
 
// Scrolling Core
frameRate : 150, // [Hz]
animationTime : 400, // [px]
stepSize : 120, // [px]
 
// Pulse (less tweakable)
// ratio of "tail" to "acceleration"
pulseAlgorithm : true,
pulseScale : 8,
pulseNormalize : 1,
 
// Acceleration
accelerationDelta : 20, // 20
accelerationMax : 1, // 1
 
// Keyboard Settings
keyboardSupport : true, // option
arrowScroll : 50, // [px]
 
// Other
touchpadSupport : true,
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 deltaBuffer = [ 120, 120, 120 ];
 
var key = { left: 37, up: 38, right: 39, down: 40, spacebar: 32,
pageup: 33, pagedown: 34, end: 35, home: 36 };
 
 
/***********************************************
* SETTINGS
***********************************************/
 
var options = defaultOptions;
 
 
/***********************************************
* INITIALIZE
***********************************************/
 
/**
* Tests if smooth scrolling is allowed. Shuts down everything if not.
*/
function initTest() {
 
var disableKeyboard = false;
// disable keyboard support if anything above requested it
if (disableKeyboard) {
removeEvent("keydown", keydown);
}
 
if (options.keyboardSupport && !disableKeyboard) {
addEvent("keydown", keydown);
}
}
 
/**
* Sets up scrolls array, determines if frames are involved.
*/
function init() {
if (!document.body) return;
 
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();
initDone = true;
 
// Checks if this script is running in a frame
if (top != self) {
isFrame = true;
}
 
/**
* 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 (scrollHeight > windowHeight &&
(body.offsetHeight <= windowHeight ||
html.offsetHeight <= windowHeight)) {
 
// DOMChange (throttle): fix height
var pending = false;
var refresh = function () {
if (!pending && html.scrollHeight != document.height) {
pending = true; // add a new pending action
setTimeout(function () {
html.style.height = document.height + 'px';
pending = false;
}, 500); // act rarely to stay fast
}
};
html.style.height = 'auto';
setTimeout(refresh, 10);
 
// clearfix
if (root.offsetHeight <= windowHeight) {
var underlay = document.createElement("div");
underlay.style.clear = "both";
body.appendChild(underlay);
}
}
 
// disable fixed background
if (!options.fixedBackground && !isExcluded) {
body.style.backgroundAttachment = "scroll";
html.style.backgroundAttachment = "scroll";
}
}
 
 
/************************************************
* SCROLLING
************************************************/
var que = [];
var pending = false;
var lastScroll = +new Date;
 
/**
* Pushes scroll actions to the scrolling queue.
*/
function scrollArray(elem, left, top, delay) {
delay || (delay = 1000);
directionCheck(left, top);
 
if (options.accelerationMax != 1) {
var now = +new Date;
var elapsed = now - lastScroll;
if (elapsed < options.accelerationDelta) {
var factor = (1 + (30 / elapsed)) / 2;
if (factor > 1) {
factor = Math.min(factor, options.accelerationMax);
left *= factor;
top *= factor;
}
}
lastScroll = +new Date;
}
// 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: +new Date
});
// don't act if there's a pending queue
if (pending) {
return;
}
 
var scrollWindow = (elem === document.body);
var step = function (time) {
var now = +new Date;
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, (delay / 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;
var overflowing = overflowingAncestor(target);
// use default if there's no overflowing
// element or default action is prevented
if (!overflowing || event.defaultPrevented ||
isNodeName(activeElement, "embed") ||
(isNodeName(target, "embed") && /\.pdf/i.test(target.src))) {
return true;
}
 
var deltaX = event.wheelDeltaX || 0;
var deltaY = event.wheelDeltaY || 0;
// use wheelDelta if deltaX/Y is not available
if (!deltaX && !deltaY) {
deltaY = event.wheelDelta || 0;
}
 
// 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();
}
 
/**
* 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);
// do nothing if user is editing text
// or using a modifier key (except shift)
// or in a dropdown
if ( /input|textarea|select|embed/i.test(target.nodeName) ||
target.isContentEditable ||
event.defaultPrevented ||
modifier ) {
return true;
}
// spacebar should trigger button press
if (isNodeName(target, "button") &&
event.keyCode === key.spacebar) {
return true;
}
var shift, x = 0, y = 0;
var elem = overflowingAncestor(activeElement);
var clientHeight = elem.clientHeight;
 
if (elem == 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 = -elem.scrollTop;
break;
case key.end:
var damt = elem.scrollHeight - elem.scrollTop - clientHeight;
y = (damt > 0) ? damt+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(elem, x, y);
event.preventDefault();
}
 
/**
* Mousedown event only for updating activeElement
*/
function mousedown(event) {
activeElement = event.target;
}
 
 
/***********************************************
* OVERFLOW
***********************************************/
var cache = {}; // cleared out every once in while
setInterval(function () { cache = {}; }, 10 * 1000);
 
var uniqueID = (function () {
var i = 0;
return function (el) {
return el.uniqueID || (el.uniqueID = i++);
};
})();
 
function setCache(elems, overflowing) {
for (var i = elems.length; i--;)
cache[uniqueID(elems[i])] = overflowing;
return overflowing;
}
 
function overflowingAncestor(el) {
var elems = [];
var rootScrollHeight = root.scrollHeight;
do {
var cached = cache[uniqueID(el)];
if (cached) {
return setCache(elems, cached);
}
elems.push(el);
if (rootScrollHeight === el.scrollHeight) {
if (!isFrame || root.clientHeight + 10 < rootScrollHeight) {
return setCache(elems, document.body); // scrolling root in WebKit
}
} else if (el.clientHeight + 10 < el.scrollHeight) {
overflow = getComputedStyle(el, "").getPropertyValue("overflow-y");
if (overflow === "scroll" || overflow === "auto") {
return setCache(elems, el);
}
}
} while (el = el.parentNode);
}
 
 
/***********************************************
* HELPERS
***********************************************/
 
function addEvent(type, fn, bubble) {
window.addEventListener(type, fn, (bubble||false));
}
 
function removeEvent(type, fn, bubble) {
window.removeEventListener(type, fn, (bubble||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;
 
function isTouchpad(deltaY) {
if (!deltaY) return;
deltaY = Math.abs(deltaY)
deltaBuffer.push(deltaY);
deltaBuffer.shift();
clearTimeout(deltaBufferTimer);
var allDivisable = (isDivisible(deltaBuffer[0], 120) &&
isDivisible(deltaBuffer[1], 120) &&
isDivisible(deltaBuffer[2], 120));
return !allDivisable;
}
 
function isDivisible(n, divisor) {
return (Math.floor(n / divisor) == n / divisor);
}
 
var requestFrame = (function () {
return window.requestAnimationFrame ||
window.webkitRequestAnimationFrame ||
function (callback, element, delay) {
window.setTimeout(callback, delay || (1000/60));
};
})();
 
 
/***********************************************
* PULSE
***********************************************/
/**
* 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);
}
 
var isChrome = /chrome/i.test(window.navigator.userAgent);
var wheelEvent = null;
if ("onwheel" in document.createElement("div"))
wheelEvent = "wheel";
else if ("onmousewheel" in document.createElement("div"))
wheelEvent = "mousewheel";
 
if (wheelEvent && isChrome) {
addEvent(wheelEvent, wheel);
addEvent("mousedown", mousedown);
addEvent("load", init);
}
 
})();

Hi Balazs, very handy and nice works! I have a question, in line 117 you called a function named refresh, but I don't see it defined anywhere in the codes, therefore it's causing error. Can you advise on this? Thanks again!

Owner

yes there was a part missing. Updated the code. Thanks

Thank You, That is Awesome effect!!!

eboyer commented

What's wrong with the default scroll behavior of a browser?

Great job, man. Thank you for sharing it! :)

Any reason why a random link to a local element id like < a href="#myid" > my link < / a> (without spaces) wouldn't smooth scroll?

hi, how can i make an anchor link to use that scroller when clicked and scroll to a different position (a top of a div) ?

You done a great job! Your script is awesome & I love to use it on my website.

But there is a small issue, which should be fixed. When I set background image fixed for particular section, the image gets lifted to upside while I am scrolling the page.

Please help us to fixing this issue ASAP. Thanks in advance.

awesome

How do I use it in JS instead of href="#

@nadavb

Here are two ways that I call it in JS:
$.smoothScroll({scrollTarget: '#mydiv',speed: 1200});
or
$('ul.navigation li a[href="#mydiv"]').trigger('click');

Hope that helps

Great Job. Thanks for sharing it.

Very nice work, and ...can I use it in themes I make and sell on ThemeForest ? I will credit you in my item.

Can anyone provide a minified version. Tried to minify the script with jscompress. but the script breaks.

Thanks

@towfiqi here you go! (scroll all the way down for the minified js file!)

https://gist.github.com/theroyalstudent/4e6ec834be19bf077298

Anyone have problems with IE with this scrip? Seems it doesn't work. In IE10 and IE9.
Thanks!

Hmm.. Holding CTRL key will not resize the page in Chrome, but it will resize the page in FireFox. It seems to work well with the chrome extension though..
Chrome Version 40.0.2214.93 m (64-bit)

Nice and useful script! Thanks.
You should definately turn it into bower and npm module

missing semicolon in Helpers section on line 462 after;
deltaY = Math.abs(deltaY)

should be deltaY = Math.abs(deltaY);

Owner

@Margox yes you may use it in your theme if you credit me. It is also free to use on any individual website.

I'd appreciate if you sent me an email with a link to your Theme to the email address found on my Github profile :) https://github.com/galambalazs

The only restriction would be not to publish any extension for browsers or native application with this code.

I have a Mac OS version in the works which works system wide.

@z3nix it is not meant to work with anchor links. There are tons of other plugins for that. This code smoothes out your mouse wheel scrolling.

Great plugin!

@galambalazs, I would like to make it work in my WordPress theme under Opera 12.6 or higher. I installed the polyfill for the requestAnimationFrame (rAF), but it didn't work.

(The case is that I have a sticky menu at top: 34px, and it looks really better when the user scrolls down with a smooth scroll effect. I would like to have this effect cross-browser).

Sign up for free to join this conversation on GitHub. Already have an account? Sign in to comment
Something went wrong with that request. Please try again.