Custom scroll events for smooth, fake scroll
npm install virtual-scrollvirtual-scroll
=====
A 2kb gzipped low-level library to create custom scrollers with touch and keyboard support.
This is heavily inspired by Bartek Drozdz VirtualScroll util. See his article for reference.
For high-level libraries based off virtual-scroll, check locomotive-scroll or smooth-scrolling.
npm i virtual-scroll -S
`$3
#### Constructor
- new VirtualScroll(options)
- el: the target element for mobile touch events. Defaults to window.
- mouseMultiplier: General multiplier for all mousewheel (including Firefox). Default to 1.
- touchMultiplier: Mutiply the touch action by this modifier to make scroll faster than finger movement. Defaults to 2.
- firefoxMultiplier: Firefox on Windows needs a boost, since scrolling is very slow. Defaults to 15.
- keyStep: How many pixels to move with each key press. Defaults to 120.
- preventTouch: If true, automatically call e.preventDefault on touchMove. Defaults to false.
- unpreventTouchClass: Elements with this class won't preventDefault on touchMove. For instance, useful for a scrolling text inside a VirtualScroll-controled element. Defaults to vs-touchmove-allowed.
- passive: if used, will use passive events declaration for the wheel and touch listeners. Can be true or false. Defaults to undefined.
- useKeyboard: if true, allows to use arrows to navigate, and space to jump from one screen. Defaults to true
- useTouch: if true, uses touch events to simulate scrolling. Defaults to true#### Methods
-
instance.on(callback, context)
Listen to the scroll event using the specified callback and optional context.-
instance.off(callback, context)
Remove the listener.-
instance.destroy()
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.#### Event
When a scroll event happens, all the listeners attached with instance.on(callback, context) will get triggered with the following event:
`js
{
x, // total distance scrolled on the x axis
y, // total distance scrolled on the y axis
deltaX, // distance scrolled since the last event on the x axis
deltaY, // distance scrolled since the last event on the y axis
originalEvent // the native event triggered by the pointer device or keyboard
}
`$3
`js
import VirtualScroll from 'virtual-scroll'const scroller = new VirtualScroll()
scroller.on(event => {
wrapper.style.transform =
translateY(${event.y}px)
})``