element/examples/components/theme-configurator/utils/boxShadow.js

60 lines
1.3 KiB
JavaScript

const VALUES_REG = /,(?![^\(]*\))/;
const PARTS_REG = /\s(?![^(]*\))/;
const LENGTH_REG = /^[0-9]+[a-zA-Z%]+?$/;
const parseValue = str => {
const parts = str.split(PARTS_REG);
const inset = parts.includes('inset');
const last = parts.slice(-1)[0];
const color = !isLength(last) ? last : undefined;
const nums = parts
.filter(n => n !== 'inset')
.filter(n => n !== color)
.map(toNum);
const [ offsetX, offsetY, blurRadius, spreadRadius ] = nums;
return {
inset,
offsetX,
offsetY,
blurRadius,
spreadRadius,
color
};
};
const stringifyValue = obj => {
const {
inset,
offsetX = 0,
offsetY = 0,
blurRadius = 0,
spreadRadius,
color
} = obj || {};
return [
(inset ? 'inset' : null),
offsetX,
offsetY,
blurRadius,
spreadRadius,
color
].filter(v => v !== null && v !== undefined)
.map(toPx)
.map(s => ('' + s).trim())
.join(' ');
};
const isLength = v => v === '0' || LENGTH_REG.test(v);
const toNum = v => {
if (!/px$/.test(v) && v !== '0') return v;
const n = parseFloat(v);
return !isNaN(n) ? n : v;
};
const toPx = n => typeof n === 'number' && n !== 0 ? (n + 'px') : n;
export const parse = str => str.split(VALUES_REG).map(s => s.trim()).map(parseValue);
export const stringify = arr => arr.map(stringifyValue).join(', ');