70 lines
1.7 KiB
TypeScript

import { isString, hyphenate, capitalize } from '@vue/shared'
import { camelize } from '@vue/runtime-core'
type Style = string | Partial<CSSStyleDeclaration> | null
export function patchStyle(el: Element, prev: Style, next: Style) {
const style = (el as HTMLElement).style
if (!next) {
el.removeAttribute('style')
} else if (isString(next)) {
if (prev !== next) {
style.cssText = next
}
} else {
for (const key in next) {
setStyle(style, key, next[key] as string)
}
if (prev && !isString(prev)) {
for (const key in prev) {
if (!next[key]) {
setStyle(style, key, '')
}
}
}
}
}
const importantRE = /\s*!important$/
function setStyle(style: CSSStyleDeclaration, name: string, val: string) {
if (name.startsWith('--')) {
// custom property definition
style.setProperty(name, val)
} else {
const prefixed = autoPrefix(style, name)
if (importantRE.test(val)) {
// !important
style.setProperty(
hyphenate(prefixed),
val.replace(importantRE, ''),
'important'
)
} else {
style[prefixed as any] = val
}
}
}
const prefixes = ['Webkit', 'Moz', 'ms']
const prefixCache: Record<string, string> = {}
function autoPrefix(style: CSSStyleDeclaration, rawName: string): string {
const cached = prefixCache[rawName]
if (cached) {
return cached
}
let name = camelize(rawName)
if (name !== 'filter' && name in style) {
return (prefixCache[rawName] = name)
}
name = capitalize(name)
for (let i = 0; i < prefixes.length; i++) {
const prefixed = prefixes[i] + name
if (prefixed in style) {
return (prefixCache[rawName] = prefixed)
}
}
return rawName
}