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xterm.js/addons/addon-attach/src/AttachAddon.ts
T

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TypeScript

/**
* Copyright (c) 2014, 2019 The xterm.js authors. All rights reserved.
* @license MIT
*
* Implements the attach method, that attaches the terminal to a WebSocket stream.
*/
import type { Terminal, IDisposable, ITerminalAddon } from '@xterm/xterm';
import type { AttachAddon as IAttachApi } from '@xterm/addon-attach';
interface IAttachOptions {
bidirectional?: boolean;
}
export class AttachAddon implements ITerminalAddon , IAttachApi {
private _socket: WebSocket;
private _bidirectional: boolean;
private _disposables: IDisposable[] = [];
constructor(socket: WebSocket, options?: IAttachOptions) {
this._socket = socket;
// always set binary type to arraybuffer, we do not handle blobs
this._socket.binaryType = 'arraybuffer';
this._bidirectional = !(options && options.bidirectional === false);
}
public activate(terminal: Terminal): void {
this._disposables.push(
addSocketListener(this._socket, 'message', ev => {
const data: ArrayBuffer | string = ev.data;
terminal.write(typeof data === 'string' ? data : new Uint8Array(data));
})
);
if (this._bidirectional) {
this._disposables.push(terminal.onData(data => this._sendData(data)));
this._disposables.push(terminal.onBinary(data => this._sendBinary(data)));
}
this._disposables.push(addSocketListener(this._socket, 'close', () => this.dispose()));
this._disposables.push(addSocketListener(this._socket, 'error', () => this.dispose()));
}
public dispose(): void {
for (const d of this._disposables) {
d.dispose();
}
}
private _sendData(data: string): void {
if (!this._checkOpenSocket()) {
return;
}
this._socket.send(data);
}
private _sendBinary(data: string): void {
if (!this._checkOpenSocket()) {
return;
}
const buffer = new Uint8Array(data.length);
for (let i = 0; i < data.length; ++i) {
buffer[i] = data.charCodeAt(i) & 255;
}
this._socket.send(buffer);
}
private _checkOpenSocket(): boolean {
switch (this._socket.readyState) {
case WebSocket.OPEN:
return true;
case WebSocket.CONNECTING:
throw new Error('Attach addon was loaded before socket was open');
case WebSocket.CLOSING:
console.warn('Attach addon socket is closing');
return false;
case WebSocket.CLOSED:
throw new Error('Attach addon socket is closed');
default:
throw new Error('Unexpected socket state');
}
}
}
function addSocketListener<K extends keyof WebSocketEventMap>(socket: WebSocket, type: K, handler: (this: WebSocket, ev: WebSocketEventMap[K]) => any): IDisposable {
socket.addEventListener(type, handler);
return {
dispose: () => {
if (!handler) {
// Already disposed
return;
}
socket.removeEventListener(type, handler);
}
};
}