natural scroll

Objects in real life never stop or start moving instantly. Having this in mind, natural scroll performs scrolling smoothly and naturally: it starts and finishes the movement with zero speed and acceleration. If another scrolling target is specified during an animation still running, natural scroll recalculates the remaining animation frames, so that the scrolling continues smoothly and reaches the new destination. The slowdowns and accelerations do not make the animation look slower. The scrolling just feels better. A user may not even notice the magic at all, but a good design should not be noticed. For him the scrolling becomes natural, comfortable and predictable.

You can see how natural scroll works on the following web-pages (click the menu items there and carefully watch how the page is scrolled):

• Home page of the intence project

• Demo page for the viewport.js library

natural scroll has flexible FPS. Which means if a system is too slow (or a web-page is too overdesigned), natural scroll skips some of the frames, preserving the total time of animation. Therefore the destination scrolling position is reached on time and users do not have to wait any longer. Of course on faster systems the animation is more fluent.

natural scroll does not have any dependencies, it is written in vanilla javascript which means it works anywhere. And it only costs 748 bytes of minified code including the UMD-headers!

Usage

Using natural scroll is very simple. Download and unpack the distribution, or install it using Bower:

$ bower install natural-scroll

Load the naturalScroll.js module in a preferable way:

<script src="naturalScroll.js"></script>

Invoke the following methods to scroll a viewport to the desired position:

// element to scroll, can be document.body
var viewport = document.getElementById('myViewport');
var positionTop = 1000;
var positionLeft = 500;

naturalScroll.scrollTop(viewport, positionTop);
naturalScroll.scrollLeft(viewport, positionLeft);

You can also provide the third argument which is an animation time (in msec, 600 by default), but I would not change it.

Have fun!

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