vanillajs-browser-helpers/scrollInfo.mjs

Collection of convenience code snippets (helpers) that aims to make it a little easier to work with vanilla JS in the browser

import viewport from './viewport';
import isWindow from './isWindow';
/**
 * Gather the current scroll position information of a DOM element or the window
 *
 * @param elm - The element to find the scrolling position from
 * @return The scroll information
 */
export default function scrollInfo(elm = window) {
    const _elm = isWindow(elm)
        ? viewport(elm)
        : elm;
    const info = { x: 0, y: 0, xMax: 0, yMax: 0, xPct: 0, yPct: 0 };
    if (!_elm) {
        return info;
    }
    info.x = _elm.scrollLeft;
    info.y = _elm.scrollTop;
    info.xMax = Math.max(_elm.scrollWidth - _elm.clientWidth, 0);
    info.yMax = Math.max(_elm.scrollHeight - _elm.clientHeight, 0);
    if (info.xMax) {
        info.xPct = info.x / info.xMax;
    }
    if (info.yMax) {
        info.yPct = info.y / info.yMax;
    }
    return info;
}