virtual-scroll

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

• In-depth tests
• Possibility to pass a 'keys' options (bind other keyboard keys)
• Add a "direction" option to force a single direction?