Files
xterm.js/src/common/Event.ts
T

107 lines
3.0 KiB
TypeScript

/**
* Copyright (c) 2024-2026 The xterm.js authors. All rights reserved.
* @license MIT
*
* Minimal event utilities for xterm.js core.
* Simplified from VS Code's event.ts - no leak detection/profiling.
*/
import { IDisposable, DisposableStore, toDisposable } from 'common/Lifecycle';
export interface IEvent<T> {
(listener: (e: T) => any, thisArgs?: any, disposables?: IDisposable[] | DisposableStore): IDisposable;
}
export class Emitter<T> {
private _listeners: { fn: (e: T) => any, thisArgs: any }[] = [];
private _disposed = false;
private _event: IEvent<T> | undefined;
public get event(): IEvent<T> {
if (this._event) {
return this._event;
}
this._event = (listener: (e: T) => any, thisArgs?: any, disposables?: IDisposable[] | DisposableStore) => {
if (this._disposed) {
return toDisposable(() => {});
}
const entry = { fn: listener, thisArgs };
this._listeners.push(entry);
const result = toDisposable(() => {
const idx = this._listeners.indexOf(entry);
if (idx !== -1) {
this._listeners.splice(idx, 1);
}
});
if (disposables) {
if (Array.isArray(disposables)) {
disposables.push(result);
} else {
disposables.add(result);
}
}
return result;
};
return this._event;
}
public fire(event: T): void {
if (this._disposed) {
return;
}
// Snapshot listeners to allow modifications during iteration
const listeners = this._listeners.slice();
for (const { fn, thisArgs } of listeners) {
fn.call(thisArgs, event);
}
}
public dispose(): void {
if (this._disposed) {
return;
}
this._disposed = true;
this._listeners.length = 0;
}
}
export namespace EventUtils {
export function forward<T>(from: IEvent<T>, to: Emitter<T>): IDisposable {
return from(e => to.fire(e));
}
export function map<I, O>(event: IEvent<I>, map: (i: I) => O): IEvent<O> {
return (listener: (e: O) => any, thisArgs?: any, disposables?: IDisposable[] | DisposableStore) => {
return event(i => listener.call(thisArgs, map(i)), undefined, disposables);
};
}
export function any<T>(...events: IEvent<T>[]): IEvent<T>;
export function any(...events: IEvent<any>[]): IEvent<void>;
export function any<T>(...events: IEvent<T>[]): IEvent<T> {
return (listener: (e: T) => any, thisArgs?: any, disposables?: IDisposable[] | DisposableStore) => {
const store = new DisposableStore();
for (const event of events) {
store.add(event(e => listener.call(thisArgs, e)));
}
if (disposables) {
if (Array.isArray(disposables)) {
disposables.push(store);
} else {
disposables.add(store);
}
}
return store;
};
}
export function runAndSubscribe<T>(event: IEvent<T>, handler: (e: T | undefined) => void): IDisposable {
handler(undefined);
return event(e => handler(e));
}
}