export default class Bus {
|
constructor() {
|
this.listeners = new Map();
|
this.emitted = new Set();
|
}
|
on(evtName, listener) {
|
if (this.emitted.has(evtName)) {
|
listener();
|
return;
|
}
|
const target = this.listeners.get(evtName) || [];
|
target.push(listener);
|
this.listeners.set(evtName, target);
|
}
|
emit(evtName) {
|
const listeners = this.listeners.get(evtName);
|
if (listeners) {
|
listeners.forEach((func) => func());
|
}
|
this.emitted.add(evtName);
|
}
|
}
|
