virtual-scroll

Custom scroll event with inertia/momentum, touch (works on <=iOS7) and keyboard compatible. This is a fork of Bartek Drozdz VirtualScroll util. See his article) for a complete description.

Goals of the fork

Easier to add in a CommonJS / require environment
Enable to create several distinct instances by using a prototype rather than a singleton
Add some extra features
modules (using a dedicated Emitter for instance)

Installation

npm i virtual-scroll -S

Usage & API

For in-depth usage and tutorial, you can check Bartek's article (link above).

new VirtualScroll(options) Return a new instance of VirtualScroll. See the options below.
instance.on(fn, context) Listen to the scroll event using the specified function (fn) and optional context.
instance.off(fn, context) Remove the listener.
instance.destroy() Will remove all events and unbind the DOM listeners.

Events note: Each instance will listen only once to any DOM listener. These listener are enabled/disabled automatically. However, it's a good practice to always call destroy() on your VirtualScroll instance, especially if you are working with a SPA.

Options

mouseMultiplier: General multiplier for all mousewheel (including Firefox). Default to 1.
touchMultiplier: Mutiply the touch action by two making the scroll a bit faster than finger movement. Default is 2.
firefoxMultiplier: Firefox on Windows needs a boost, since scrolling is very slow. Default is 15.
keyStep: How many pixels to move with each key press. Default is 120.
preventTouch: If true, automatically call e.preventDefault on touchMove. Default is false.
unpreventTouchClass: Elements with this class won't preventDefault on touchMove. For instance, useful for a scrolling text inside a VirtualScroll-controled element. Default is vs-touchmove-allowed.
limitInertia: if true, will leverage Lethargy to avoid everlasting scroll events (mostly on Apple Mouse, Trackpad, and free-wheel mouse). Default is false.

Todo