code-server/packages/events/src/events.ts

100 lines
2.6 KiB
TypeScript

import { IDisposable } from "@coder/disposable";
export interface Event<T> {
(listener: (value: T) => void): IDisposable;
(id: number | string, listener: (value: T) => void): IDisposable;
}
/**
* Emitter typecasts for a single event type. You can optionally use IDs, but
* using undefined with IDs will not work. If you emit without an ID, *all*
* listeners regardless of their ID (or lack thereof) will receive the event.
* Similarly, if you listen without an ID you will get *all* events for any or
* no ID.
*/
export class Emitter<T> {
private listeners = <Array<(value: T) => void>>[];
private readonly idListeners = new Map<number | string, Array<(value: T) => void>>();
public get event(): Event<T> {
return (id: number | string | ((value: T) => void), cb?: (value: T) => void): IDisposable => {
if (typeof id !== "function") {
if (this.idListeners.has(id)) {
this.idListeners.get(id)!.push(cb!);
} else {
this.idListeners.set(id, [cb!]);
}
return {
dispose: (): void => {
if (this.idListeners.has(id)) {
const cbs = this.idListeners.get(id)!;
const i = cbs.indexOf(cb!);
if (i !== -1) {
cbs.splice(i, 1);
}
}
},
};
}
cb = id;
this.listeners.push(cb);
return {
dispose: (): void => {
const i = this.listeners.indexOf(cb!);
if (i !== -1) {
this.listeners.splice(i, 1);
}
},
};
};
}
/**
* Emit an event with a value.
*/
public emit(value: T): void;
public emit(id: number | string, value: T): void;
public emit(id: number | string | T, value?: T): void {
if ((typeof id === "number" || typeof id === "string") && typeof value !== "undefined") {
if (this.idListeners.has(id)) {
this.idListeners.get(id)!.forEach((cb) => cb(value!));
}
this.listeners.forEach((cb) => cb(value!));
} else {
this.idListeners.forEach((cbs) => cbs.forEach((cb) => cb((id as T)!)));
this.listeners.forEach((cb) => cb((id as T)!));
}
}
/**
* Dispose the current events.
*/
public dispose(): void;
public dispose(id: number | string): void;
public dispose(id?: number | string): void {
if (typeof id !== "undefined") {
this.idListeners.delete(id);
} else {
this.listeners = [];
this.idListeners.clear();
}
}
public get counts(): { [key: string]: number } {
const counts = <{ [key: string]: number }>{};
if (this.listeners.length > 0) {
counts["n/a"] = this.listeners.length;
}
this.idListeners.forEach((cbs, id) => {
if (cbs.length > 0) {
counts[`${id}`] = cbs.length;
}
});
return counts;
}
}