Files
yjs/src/Util/NamedEventHandler.js
2017-11-07 18:31:04 -08:00

47 lines
1.1 KiB
JavaScript

export default class NamedEventHandler {
constructor () {
this._eventListener = new Map()
}
_getListener (name) {
let listeners = this._eventListener.get(name)
if (listeners === undefined) {
listeners = {
once: new Set(),
on: new Set()
}
this._eventListener.set(name, listeners)
}
return listeners
}
once (name, f) {
let listeners = this._getListener(name)
listeners.once.add(f)
}
on (name, f) {
let listeners = this._getListener(name)
listeners.on.add(f)
}
off (name, f) {
if (name == null || f == null) {
throw new Error('You must specify event name and function!')
}
const listener = this._eventListener.get(name)
if (listener !== undefined) {
listener.remove(f)
}
}
emit (name, ...args) {
const listener = this._eventListener.get(name)
if (listener !== undefined) {
listener.on.forEach(f => f.apply(null, args))
listener.once.forEach(f => f.apply(null, args))
listener.once = new Set()
} else if (name === 'error') {
console.error(args[0])
}
}
destroy () {
this._eventListener = null
}
}