virtual-scroll-pointer
v2.2.3
Published
Enhanced Custom scroll events for smooth, fake scroll, with mouse pointer support.
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Readme
virtual-scroll-pointer
This fork supports
PointerEvent
for mouse or other pointer devices. SeeUsage & API
Section below
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.
Features
- Can create multiple instances with different elements as targets
- Let you do the actual scrolling logic: use CSS Transforms, WebGL animation or anything you like
- Native arrow keys support and shift/space support mimicking default browser behaviour
For high-level libraries based off virtual-scroll, check locomotive-scroll or smooth-scrolling.
Installation
npm i virtual-scroll-pointer -S
Usage & API
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 calle.preventDefault
on touchMove. Defaults to false.unpreventTouchClass
: Elements with this class won'tpreventDefault
on touchMove. For instance, useful for a scrolling text inside a VirtualScroll-controled element. Defaults tovs-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 trueuseTouch
: if true, uses touch events to simulate scrolling. Defaults to trueusePointer
: if true, uses pointer events to simulate scrolling if is not a touch screen device, e.g. desktop with a mouse, Defaults to truepointerClickDelta
: whenusePointer
is true, the minimum scroll delta pervent a click event being fired afterpointerup
, Defaults1 * window.devicePixelRatio,
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:
{
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
}
Example
import VirtualScroll from "virtual-scroll";
const scroller = new VirtualScroll();
scroller.on((event) => {
wrapper.style.transform = `translateY(${event.y}px)`;
});
License
MIT.