82 lines
2.2 KiB
TypeScript
82 lines
2.2 KiB
TypeScript
|
// tslint:disable no-default-export
|
||
|
|
|
||
|
|
/*
|
||
|
|
* Implements EventTarget
|
||
|
|
* https://developer.mozilla.org/en-US/docs/Web/API/EventTarget
|
||
|
|
*/
|
||
|
|
|
||
|
|
export default class EventTarget {
|
||
|
|
listeners?: { [type: string]: Array<Function> };
|
||
|
|
|
||
|
|
dispatchEvent(ev: Event) {
|
||
|
|
if (!(ev instanceof Event)) {
|
||
|
|
throw new Error('Expects an event');
|
||
|
|
}
|
||
|
|
if (this.listeners === null || typeof this.listeners !== 'object') {
|
||
|
|
this.listeners = {};
|
||
|
|
}
|
||
|
|
const listeners = this.listeners[ev.type];
|
||
|
|
const results = [];
|
||
|
|
if (typeof listeners === 'object') {
|
||
|
|
const max = listeners.length;
|
||
|
|
for (let i = 0; i < max; i += 1) {
|
||
|
|
const listener = listeners[i];
|
||
|
|
if (typeof listener === 'function') {
|
||
|
|
results.push(listener.call(null, ev));
|
||
|
|
}
|
||
|
|
}
|
||
|
|
}
|
||
|
|
return results;
|
||
|
|
}
|
||
|
|
|
||
|
|
addEventListener(eventName: string, callback: Function) {
|
||
|
|
if (typeof eventName !== 'string') {
|
||
|
|
throw new Error('First argument expects a string');
|
||
|
|
}
|
||
|
|
if (typeof callback !== 'function') {
|
||
|
|
throw new Error('Second argument expects a function');
|
||
|
|
}
|
||
|
|
if (this.listeners === null || typeof this.listeners !== 'object') {
|
||
|
|
this.listeners = {};
|
||
|
|
}
|
||
|
|
let listeners = this.listeners[eventName];
|
||
|
|
if (typeof listeners !== 'object') {
|
||
|
|
listeners = [];
|
||
|
|
}
|
||
|
|
listeners.push(callback);
|
||
|
|
this.listeners[eventName] = listeners;
|
||
|
|
}
|
||
|
|
|
||
|
|
removeEventListener(eventName: string, callback: Function) {
|
||
|
|
if (typeof eventName !== 'string') {
|
||
|
|
throw new Error('First argument expects a string');
|
||
|
|
}
|
||
|
|
if (typeof callback !== 'function') {
|
||
|
|
throw new Error('Second argument expects a function');
|
||
|
|
}
|
||
|
|
if (this.listeners === null || typeof this.listeners !== 'object') {
|
||
|
|
this.listeners = {};
|
||
|
|
}
|
||
|
|
const listeners = this.listeners[eventName];
|
||
|
|
if (typeof listeners === 'object') {
|
||
|
|
for (let i = 0; i < listeners.length; i += 1) {
|
||
|
|
if (listeners[i] === callback) {
|
||
|
|
listeners.splice(i, 1);
|
||
|
|
return;
|
||
|
|
}
|
||
|
|
}
|
||
|
|
}
|
||
|
|
this.listeners[eventName] = listeners;
|
||
|
|
}
|
||
|
|
|
||
|
|
extend(source: any) {
|
||
|
|
const target = this as any;
|
||
|
|
|
||
|
|
// tslint:disable-next-line forin no-for-in no-default-export
|
||
|
|
for (const prop in source) {
|
||
|
|
target[prop] = source[prop];
|
||
|
|
}
|
||
|
|
return target;
|
||
|
|
}
|
||
|
|
}
|