/**
|
* @Author: Caven
|
* @Date: 2020-01-02 15:24:38
|
*/
|
|
class Event {
|
constructor() {
|
this._cache = {}
|
this._registerEvent()
|
}
|
|
/**
|
* Event registration
|
* Subclasses need to override
|
* @private
|
*/
|
_registerEvent () { }
|
|
/**
|
* @param type
|
* @param callback
|
* @param context
|
* @returns {any}
|
* @private
|
*/
|
_on (type, callback, context) {
|
let event = this.getEvent(type)
|
let removeCallback = undefined
|
if (event && callback) {
|
removeCallback = event.addEventListener(callback, context || this)
|
}
|
return removeCallback
|
}
|
|
/**
|
* @param type
|
* @param callback
|
* @param context
|
* @returns {boolean}
|
* @private
|
*/
|
_off (type, callback, context) {
|
let event = this.getEvent(type)
|
let removed = false
|
if (event && callback) {
|
removed = event.removeEventListener(callback, context || this)
|
}
|
return removed
|
}
|
|
/**
|
* @param type
|
* @param params
|
* @private
|
*/
|
_fire (type, params) {
|
let event = this.getEvent(type)
|
if (event) {
|
event.raiseEvent(params)
|
}
|
}
|
|
/**
|
* Subscribe event
|
* @param type
|
* @param callback
|
* @param context
|
* @returns remove callback function
|
*/
|
on (type, callback, context) {
|
return this._on(type, callback, context)
|
}
|
|
/**
|
* Subscribe once event
|
* @param type
|
* @param callback
|
* @param context
|
*/
|
once (type, callback, context) {
|
let removeCallback = this._on(
|
type,
|
e => {
|
callback(e)
|
removeCallback && removeCallback()
|
},
|
context
|
)
|
}
|
|
/**
|
* Unsubscribe event
|
* @param type
|
* @param callback
|
* @param context
|
* @returns Boolean
|
*/
|
off (type, callback, context) {
|
return this._off(type, callback, context)
|
}
|
|
/**
|
* Trigger subscription event
|
* @param type
|
* @param params
|
*/
|
fire (type, params) {
|
this._fire(type, params)
|
}
|
|
/**
|
* Returns events by type
|
* @param type
|
* @returns Event
|
*/
|
getEvent (type) {
|
return this._cache[type] || undefined
|
}
|
}
|
|
export default Event
|
