/**
* Copyright (c) 2018-present clchart Contributors.
*
* This source code is licensed under the MIT license found in the
* LICENSE file in the root directory of this source tree.
*
*/
/**
* Class representing a event
* @export
* @class EV
*/
export default class EV {
constructor () {
this.handlers = {}
}
/**
* emit an event
* @param {String} event event name
* @param {any} args event params
* @memberof EV
*/
emit (event, ...args) {
if (this.handlers[event]) {
this
.handlers[event]
.forEach((handler) => handler.apply(this, args))
}
}
/**
* emit with special scope
* @param {any} event event name
* @param {any} scope scope
* @param {any} args event params
* @memberof EV
*/
emitWithScope (event, scope, ...args) {
if (this.handlers[event]) {
this
.handlers[event]
.forEach((handler) => handler.apply(scope, args))
}
}
/**
* listen event
* @param {any} event event name
* @param {any} callback listen callback
* @memberof EV
*/
addEventListener (event, callback) {
if (!this.handlers[event]) {
this.handlers[event] = []
}
this
.handlers[event]
.push(callback)
}
/**
* listen only once
* @param {any} event event name
* @param {any} callback event listener callback function
* @memberof EV
*/
once (event, callback) {
const self = this
self.on(event, function onetimeCallback () {
callback.apply(this, arguments)
self.removeListener(event, onetimeCallback)
})
}
/**
* remove special event listener by callback function
* @param {any} event event name
* @param {any} callback event listener callback function
* @memberof EV
*/
removeEventListener (event, callback) {
if (this.handlers[event]) {
const index = this
.handlers[event]
.indexOf(callback)
if (index > -1) {
this
.handlers[event]
.splice(index, 1)
}
}
}
/**
* remove all listeners for events
* @param {any} event event name
* @memberof EV
*/
removeAllListeners (event) {
this.handlers[event] = undefined
}
};