weex-nuke/lib/node_modules/nuke-helper/src/rem.js

基于 Rax 、Weex 的高性能组件体系 ~~

import { isWeex } from 'nuke-env';
/**
 * @description parse rem to even px to solve andoird float px issue.
 */
export function caculateRemToPx(rem, defaultWidth = 750) {
  // Default 1 rem to 1 px
  if (typeof rem === 'object' && 'raw' in rem) {
    rem = rem.raw;
  }
  if (isWeex) return rem;
  rem = exports.removeRemUnit(rem);
  const defaultPixUnit = document.documentElement.clientWidth / defaultWidth;
  const num = Math.round(parseFloat(rem) * defaultPixUnit);
  if (num % 2 === 0) {
    return `${num}px`;
  }
  return `${num - 1}px`;
}
/**
 * @description remove rem unit for string like 12rem => 12
 * @param {string or number} rem
 */
export function removeRemUnit(rem) {
  rem = String(rem);
  return rem.replace('rem', '');
}