obsize/dist/obsize.mjs

🧐 Element size observer based on ResizeObserver

import { randomFillSync } from 'crypto';

var urlAlphabet = 'useandom-26T198340PX75pxJACKVERYMINDBUSHWOLF_GQZbfghjklqvwyzrict';

var POOL_SIZE_MULTIPLIER = 128;
var pool, poolOffset;

var fillPool = function fillPool(bytes) {
  if (!pool || pool.length < bytes) {
    pool = Buffer.allocUnsafe(bytes * POOL_SIZE_MULTIPLIER);
    randomFillSync(pool);
    poolOffset = 0;
  } else if (poolOffset + bytes > pool.length) {
    randomFillSync(pool);
    poolOffset = 0;
  }

  poolOffset += bytes;
};
var nanoid = function nanoid() {
  var size = arguments.length > 0 && arguments[0] !== undefined ? arguments[0] : 21;
  fillPool(size -= 0);
  var id = '';

  for (var i = poolOffset - size; i < poolOffset; i++) {
    id += urlAlphabet[pool[i] & 63];
  }

  return id;
};

const map = new Map();
const obs = new ResizeObserver((entries) => {
    entries.forEach((entry) => {
        const { target } = entry;
        const fns = map.get(target);
        if (fns?.length) {
            const newFns = [];
            fns.forEach((item) => {
                const { fn, once } = item;
                fn();
                if (!once) {
                    newFns.push(item);
                }
            });
            map.set(target, newFns);
        }
    });
});
function observe(element, fn, options = { once: false }) {
    const isElementObserver = map.has(element);
    const elementFns = isElementObserver ? map.get(element) : [];
    const key = nanoid();
    const { once } = options;
    elementFns.push({ key, once, fn });
    if (!isElementObserver) {
        obs.observe(element);
        map.set(element, elementFns);
    }
    return () => {
        if (map.has(element)) {
            const fns = map.get(element).filter((item) => {
                return item.key !== key;
            });
            if (fns.length === 0) {
                map.delete(element);
                obs.unobserve(element);
            }
            else {
                map.set(element, fns);
            }
        }
    };
}
function clear() {
    map.clear();
    obs.disconnect();
}

export { clear, observe };