ant-design-vue/components/_util/hooks/useScrollLocker.ts

import type { Ref } from 'vue';
import { computed, watchEffect } from 'vue';
import { updateCSS, removeCSS } from '../../vc-util/Dom/dynamicCSS';
import getScrollBarSize from '../../_util/getScrollBarSize';

const UNIQUE_ID = `vc-util-locker-${Date.now()}`;

let uuid = 0;

/**../vc-util/Dom/dynam
 * Test usage export. Do not use in your production
 */
export function isBodyOverflowing() {
  return (
    document.body.scrollHeight > (window.innerHeight || document.documentElement.clientHeight) &&
    window.innerWidth > document.body.offsetWidth
  );
}

export default function useScrollLocker(lock?: Ref<boolean>) {
  const mergedLock = computed(() => !!lock && !!lock.value);
  uuid += 1;
  const id = `${UNIQUE_ID}_${uuid}`;

  watchEffect(
    onClear => {
      if (mergedLock.value) {
        const scrollbarSize = getScrollBarSize();
        const isOverflow = isBodyOverflowing();

        updateCSS(
          `
html body {
  overflow-y: hidden;
  ${isOverflow ? `width: calc(100% - ${scrollbarSize}px);` : ''}
}`,
          id,
        );
      } else {
        removeCSS(id);
      }
      onClear(() => {
        removeCSS(id);
      });
    },
    { flush: 'post' },
  );
}