shu-c-view/packages/cascader/mixins/resize-event.js

rollup 打包vue@2.7组件库框架

// eslint-disable-next-line import/no-extraneous-dependencies
import ResizeObserver from 'resize-observer-polyfill';

const isServer = typeof window === 'undefined';

/* istanbul ignore next */
const resizeHandler = function(entries) {
  for (const entry of entries) {
    const listeners = entry.target.__resizeListeners__ || [];
    if (listeners.length) {
      listeners.forEach(fn => {
        fn();
      });
    }
  }
};

/* istanbul ignore next */
// eslint-disable-next-line import/group-exports
export const addResizeListener = function(element, fn) {
  if (isServer) {
    return;
  }
  if (!element.__resizeListeners__) {
    element.__resizeListeners__ = [];
    element.__ro__ = new ResizeObserver(resizeHandler);
    element.__ro__.observe(element);
  }
  element.__resizeListeners__.push(fn);
};

/* istanbul ignore next */
// eslint-disable-next-line import/group-exports
export const removeResizeListener = function(element, fn) {
  if (!element || !element.__resizeListeners__) {
    return;
  }
  element.__resizeListeners__.splice(
    element.__resizeListeners__.indexOf(fn),
    1
  );
  if (!element.__resizeListeners__.length) {
    element.__ro__.disconnect();
  }
};