Adding upstream version 1.7.4.upstream/1.7.4

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

7 files changed, 946 insertions, 0 deletions

diff --git a/html/src/components/app.tsx b/html/src/components/app.tsx
new file mode 100644
index 0000000..1ad5fd3
--- /dev/null
+++ b/html/src/components/app.tsx
@@ -0,0 +1,65 @@
+import { h, Component } from 'preact';
+
+import { ITerminalOptions, ITheme } from 'xterm';
+import { ClientOptions, FlowControl } from './terminal/xterm';
+import { Terminal } from './terminal';
+
+const protocol = window.location.protocol === 'https:' ? 'wss:' : 'ws:';
+const path = window.location.pathname.replace(/[/]+$/, '');
+const wsUrl = [protocol, '//', window.location.host, path, '/ws', window.location.search].join('');
+const tokenUrl = [window.location.protocol, '//', window.location.host, path, '/token'].join('');
+const clientOptions = {
+    rendererType: 'webgl',
+    disableLeaveAlert: false,
+    disableResizeOverlay: false,
+    enableZmodem: false,
+    enableTrzsz: false,
+    enableSixel: false,
+    isWindows: false,
+} as ClientOptions;
+const termOptions = {
+    fontSize: 13,
+    fontFamily: 'Consolas,Liberation Mono,Menlo,Courier,monospace',
+    theme: {
+        foreground: '#d2d2d2',
+        background: '#2b2b2b',
+        cursor: '#adadad',
+        black: '#000000',
+        red: '#d81e00',
+        green: '#5ea702',
+        yellow: '#cfae00',
+        blue: '#427ab3',
+        magenta: '#89658e',
+        cyan: '#00a7aa',
+        white: '#dbded8',
+        brightBlack: '#686a66',
+        brightRed: '#f54235',
+        brightGreen: '#99e343',
+        brightYellow: '#fdeb61',
+        brightBlue: '#84b0d8',
+        brightMagenta: '#bc94b7',
+        brightCyan: '#37e6e8',
+        brightWhite: '#f1f1f0',
+    } as ITheme,
+    allowProposedApi: true,
+} as ITerminalOptions;
+const flowControl = {
+    limit: 100000,
+    highWater: 10,
+    lowWater: 4,
+} as FlowControl;
+
+export class App extends Component {
+    render() {
+        return (
+            <Terminal
+                id="terminal-container"
+                wsUrl={wsUrl}
+                tokenUrl={tokenUrl}
+                clientOptions={clientOptions}
+                termOptions={termOptions}
+                flowControl={flowControl}
+            />
+        );
+    }
+}
diff --git a/html/src/components/modal/index.tsx b/html/src/components/modal/index.tsx
new file mode 100644
index 0000000..558a218
--- /dev/null
+++ b/html/src/components/modal/index.tsx
@@ -0,0 +1,27 @@
+import { h, Component, ComponentChildren } from 'preact';
+
+import './modal.scss';
+
+interface Props {
+    show: boolean;
+    children: ComponentChildren;
+}
+
+export class Modal extends Component<Props> {
+    constructor(props: Props) {
+        super(props);
+    }
+
+    render({ show, children }: Props) {
+        return (
+            show && (
+                <div className="modal">
+                    <div className="modal-background" />
+                    <div className="modal-content">
+                        <div className="box">{children}</div>
+                    </div>
+                </div>
+            )
+        );
+    }
+}
diff --git a/html/src/components/modal/modal.scss b/html/src/components/modal/modal.scss
new file mode 100644
index 0000000..a99873b
--- /dev/null
+++ b/html/src/components/modal/modal.scss
@@ -0,0 +1,81 @@
+.modal {
+  bottom: 0;
+  left: 0;
+  right: 0;
+  top: 0;
+  align-items: center;
+  display: flex;
+  overflow: hidden;
+  position: fixed;
+  z-index: 40;
+}
+
+.modal-background {
+  bottom: 0;
+  left: 0;
+  position: absolute;
+  right: 0;
+  top: 0;
+  background-color: #4a4a4acc;
+}
+
+.modal-content {
+  margin: 0 20px;
+  max-height: calc(100vh - 160px);
+  overflow: auto;
+  position: relative;
+  width: 100%;
+
+  .box {
+    background-color: #fff;
+    color: #4a4a4a;
+    display: block;
+    padding: 1.25rem;
+  }
+
+  header {
+    font-weight: bold;
+    text-align: center;
+    padding-bottom: 10px;
+    margin-bottom: 10px;
+    border-bottom: 1px solid #ddd;
+  }
+
+  .file-input {
+    height: .01em;
+    left: 0;
+    outline: none;
+    position: absolute;
+    top: 0;
+    width: .01em;
+  }
+
+  .file-cta {
+    cursor: pointer;
+    background-color: #f5f5f5;
+    color: #6200ee;
+    outline: none;
+    align-items: center;
+    box-shadow: none;
+    display: inline-flex;
+    height: 2.25em;
+    justify-content: flex-start;
+    line-height: 1.5;
+    position: relative;
+    vertical-align: top;
+    border-color: #dbdbdb;
+    border-radius: 3px;
+    font-size: 1em;
+    font-weight: 500;
+    padding: calc(.375em - 1px) 1em;
+    white-space: nowrap;
+  }
+}
+
+@media print, screen and (min-width: 769px) {
+  .modal-content {
+    margin: 0 auto;
+    max-height: calc(100vh - 40px);
+    width: 640px;
+  }
+}
diff --git a/html/src/components/terminal/index.tsx b/html/src/components/terminal/index.tsx
new file mode 100644
index 0000000..a7349fd
--- /dev/null
+++ b/html/src/components/terminal/index.tsx
@@ -0,0 +1,59 @@
+import { bind } from 'decko';
+import { Component, h } from 'preact';
+import { Xterm, XtermOptions } from './xterm';
+
+import 'xterm/css/xterm.css';
+import { Modal } from '../modal';
+
+interface Props extends XtermOptions {
+    id: string;
+}
+
+interface State {
+    modal: boolean;
+}
+
+export class Terminal extends Component<Props, State> {
+    private container: HTMLElement;
+    private xterm: Xterm;
+
+    constructor(props: Props) {
+        super();
+        this.xterm = new Xterm(props, this.showModal);
+    }
+
+    async componentDidMount() {
+        await this.xterm.refreshToken();
+        this.xterm.open(this.container);
+        this.xterm.connect();
+    }
+
+    componentWillUnmount() {
+        this.xterm.dispose();
+    }
+
+    render({ id }: Props, { modal }: State) {
+        return (
+            <div id={id} ref={c => (this.container = c as HTMLElement)}>
+                <Modal show={modal}>
+                    <label class="file-label">
+                        <input onChange={this.sendFile} class="file-input" type="file" multiple />
+                        <span class="file-cta">Choose files…</span>
+                    </label>
+                </Modal>
+            </div>
+        );
+    }
+
+    @bind
+    showModal() {
+        this.setState({ modal: true });
+    }
+
+    @bind
+    sendFile(event: Event) {
+        this.setState({ modal: false });
+        const files = (event.target as HTMLInputElement).files;
+        if (files) this.xterm.sendFile(files);
+    }
+}
diff --git a/html/src/components/terminal/xterm/addons/overlay.ts b/html/src/components/terminal/xterm/addons/overlay.ts
new file mode 100644
index 0000000..6fa5a92
--- /dev/null
+++ b/html/src/components/terminal/xterm/addons/overlay.ts
@@ -0,0 +1,73 @@
+// ported from hterm.Terminal.prototype.showOverlay
+// https://chromium.googlesource.com/apps/libapps/+/master/hterm/js/hterm_terminal.js
+import { bind } from 'decko';
+import { ITerminalAddon, Terminal } from 'xterm';
+
+export class OverlayAddon implements ITerminalAddon {
+    private terminal: Terminal;
+    private overlayNode: HTMLElement;
+    private overlayTimeout?: number;
+
+    constructor() {
+        this.overlayNode = document.createElement('div');
+        this.overlayNode.style.cssText = `border-radius: 15px;
+font-size: xx-large;
+opacity: 0.75;
+padding: 0.2em 0.5em 0.2em 0.5em;
+position: absolute;
+-webkit-user-select: none;
+-webkit-transition: opacity 180ms ease-in;
+-moz-user-select: none;
+-moz-transition: opacity 180ms ease-in;`;
+
+        this.overlayNode.addEventListener(
+            'mousedown',
+            e => {
+                e.preventDefault();
+                e.stopPropagation();
+            },
+            true
+        );
+    }
+
+    activate(terminal: Terminal): void {
+        this.terminal = terminal;
+    }
+
+    dispose(): void {}
+
+    @bind
+    showOverlay(msg: string, timeout?: number): void {
+        const { terminal, overlayNode } = this;
+        if (!terminal.element) return;
+
+        overlayNode.style.color = '#101010';
+        overlayNode.style.backgroundColor = '#f0f0f0';
+        overlayNode.textContent = msg;
+        overlayNode.style.opacity = '0.75';
+
+        if (!overlayNode.parentNode) {
+            terminal.element.appendChild(overlayNode);
+        }
+
+        const divSize = terminal.element.getBoundingClientRect();
+        const overlaySize = overlayNode.getBoundingClientRect();
+
+        overlayNode.style.top = (divSize.height - overlaySize.height) / 2 + 'px';
+        overlayNode.style.left = (divSize.width - overlaySize.width) / 2 + 'px';
+
+        if (this.overlayTimeout) clearTimeout(this.overlayTimeout);
+        if (!timeout) return;
+
+        this.overlayTimeout = window.setTimeout(() => {
+            overlayNode.style.opacity = '0';
+            this.overlayTimeout = window.setTimeout(() => {
+                if (overlayNode.parentNode) {
+                    overlayNode.parentNode.removeChild(overlayNode);
+                }
+                this.overlayTimeout = undefined;
+                overlayNode.style.opacity = '0.75';
+            }, 200);
+        }, timeout || 1500);
+    }
+}
diff --git a/html/src/components/terminal/xterm/addons/zmodem.ts b/html/src/components/terminal/xterm/addons/zmodem.ts
new file mode 100644
index 0000000..8571f68
--- /dev/null
+++ b/html/src/components/terminal/xterm/addons/zmodem.ts
@@ -0,0 +1,180 @@
+import { bind } from 'decko';
+import { saveAs } from 'file-saver';
+import { IDisposable, ITerminalAddon, Terminal } from 'xterm';
+import * as Zmodem from 'zmodem.js/src/zmodem_browser';
+import { TrzszFilter } from 'trzsz';
+
+export interface ZmodeOptions {
+    zmodem: boolean;
+    trzsz: boolean;
+    windows: boolean;
+    onSend: () => void;
+    sender: (data: string | Uint8Array) => void;
+    writer: (data: string | Uint8Array) => void;
+}
+
+export class ZmodemAddon implements ITerminalAddon {
+    private disposables: IDisposable[] = [];
+    private terminal: Terminal;
+    private sentry: Zmodem.Sentry;
+    private session: Zmodem.Session;
+    private denier: () => void;
+    private trzszFilter: TrzszFilter;
+
+    constructor(private options: ZmodeOptions) {}
+
+    activate(terminal: Terminal) {
+        this.terminal = terminal;
+        if (this.options.zmodem) this.zmodemInit();
+        if (this.options.trzsz) this.trzszInit();
+    }
+
+    dispose() {
+        for (const d of this.disposables) {
+            d.dispose();
+        }
+        this.disposables.length = 0;
+    }
+
+    consume(data: ArrayBuffer) {
+        try {
+            if (this.options.trzsz) {
+                this.trzszFilter.processServerOutput(data);
+            } else {
+                this.sentry.consume(data);
+            }
+        } catch (e) {
+            console.error('[ttyd] zmodem consume: ', e);
+            this.reset();
+        }
+    }
+
+    @bind
+    private reset() {
+        this.terminal.options.disableStdin = false;
+        this.terminal.focus();
+    }
+
+    private addDisposableListener(target: EventTarget, type: string, listener: EventListener) {
+        target.addEventListener(type, listener);
+        this.disposables.push({ dispose: () => target.removeEventListener(type, listener) });
+    }
+
+    @bind
+    private trzszInit() {
+        const { terminal } = this;
+        const { sender, writer, zmodem } = this.options;
+        this.trzszFilter = new TrzszFilter({
+            writeToTerminal: data => {
+                if (!this.trzszFilter.isTransferringFiles() && zmodem) {
+                    this.sentry.consume(data);
+                } else {
+                    writer(typeof data === 'string' ? data : new Uint8Array(data as ArrayBuffer));
+                }
+            },
+            sendToServer: data => sender(data),
+            terminalColumns: terminal.cols,
+            isWindowsShell: this.options.windows,
+        });
+        const element = terminal.element as EventTarget;
+        this.addDisposableListener(element, 'dragover', event => event.preventDefault());
+        this.addDisposableListener(element, 'drop', event => {
+            event.preventDefault();
+            this.trzszFilter
+                .uploadFiles((event as DragEvent).dataTransfer?.items as DataTransferItemList)
+                .then(() => console.log('[ttyd] upload success'))
+                .catch(err => console.log('[ttyd] upload failed: ' + err));
+        });
+        this.disposables.push(terminal.onResize(size => this.trzszFilter.setTerminalColumns(size.cols)));
+    }
+
+    @bind
+    private zmodemInit() {
+        const { sender, writer } = this.options;
+        const { terminal, reset, zmodemDetect } = this;
+        this.session = null;
+        this.sentry = new Zmodem.Sentry({
+            to_terminal: octets => writer(new Uint8Array(octets)),
+            sender: octets => sender(new Uint8Array(octets)),
+            on_retract: () => reset(),
+            on_detect: detection => zmodemDetect(detection),
+        });
+        this.disposables.push(
+            terminal.onKey(e => {
+                const event = e.domEvent;
+                if (event.ctrlKey && event.key === 'c') {
+                    if (this.denier) this.denier();
+                }
+            })
+        );
+    }
+
+    @bind
+    private zmodemDetect(detection: Zmodem.Detection): void {
+        const { terminal, receiveFile } = this;
+        terminal.options.disableStdin = true;
+
+        this.denier = () => detection.deny();
+        this.session = detection.confirm();
+        this.session.on('session_end', () => this.reset());
+
+        if (this.session.type === 'send') {
+            this.options.onSend();
+        } else {
+            receiveFile();
+        }
+    }
+
+    @bind
+    public sendFile(files: FileList) {
+        const { session, writeProgress } = this;
+        Zmodem.Browser.send_files(session, files, {
+            on_progress: (_, offer) => writeProgress(offer),
+        })
+            .then(() => session.close())
+            .catch(() => this.reset());
+    }
+
+    @bind
+    private receiveFile() {
+        const { session, writeProgress } = this;
+
+        session.on('offer', offer => {
+            offer.on('input', () => writeProgress(offer));
+            offer
+                .accept()
+                .then(payloads => {
+                    const blob = new Blob(payloads, { type: 'application/octet-stream' });
+                    saveAs(blob, offer.get_details().name);
+                })
+                .catch(() => this.reset());
+        });
+
+        session.start();
+    }
+
+    @bind
+    private writeProgress(offer: Zmodem.Offer) {
+        const { bytesHuman } = this;
+        const file = offer.get_details();
+        const name = file.name;
+        const size = file.size;
+        const offset = offer.get_offset();
+        const percent = ((100 * offset) / size).toFixed(2);
+
+        this.options.writer(`${name} ${percent}% ${bytesHuman(offset, 2)}/${bytesHuman(size, 2)}\r`);
+    }
+
+    // eslint-disable-next-line @typescript-eslint/no-explicit-any
+    private bytesHuman(bytes: any, precision: number): string {
+        if (!/^([-+])?|(\.\d+)(\d+(\.\d+)?|(\d+\.)|Infinity)$/.test(bytes)) {
+            return '-';
+        }
+        if (bytes === 0) return '0';
+        if (typeof precision === 'undefined') precision = 1;
+        const units = ['bytes', 'KB', 'MB', 'GB', 'TB', 'PB'];
+        const num = Math.floor(Math.log(bytes) / Math.log(1024));
+        const value = (bytes / Math.pow(1024, Math.floor(num))).toFixed(precision);
+        return `${value} ${units[num]}`;
+    }
+}
diff --git a/html/src/components/terminal/xterm/index.ts b/html/src/components/terminal/xterm/index.ts
new file mode 100644
index 0000000..06d97ee
--- /dev/null
+++ b/html/src/components/terminal/xterm/index.ts
@@ -0,0 +1,461 @@
+import { bind } from 'decko';
+import { IDisposable, ITerminalOptions, Terminal } from 'xterm';
+import { CanvasAddon } from 'xterm-addon-canvas';
+import { WebglAddon } from 'xterm-addon-webgl';
+import { FitAddon } from 'xterm-addon-fit';
+import { WebLinksAddon } from 'xterm-addon-web-links';
+import { ImageAddon } from 'xterm-addon-image';
+import { OverlayAddon } from './addons/overlay';
+import { ZmodemAddon } from './addons/zmodem';
+
+import 'xterm/css/xterm.css';
+
+interface TtydTerminal extends Terminal {
+    fit(): void;
+}
+
+declare global {
+    interface Window {
+        term: TtydTerminal;
+    }
+}
+
+const enum Command {
+    // server side
+    OUTPUT = '0',
+    SET_WINDOW_TITLE = '1',
+    SET_PREFERENCES = '2',
+
+    // client side
+    INPUT = '0',
+    RESIZE_TERMINAL = '1',
+    PAUSE = '2',
+    RESUME = '3',
+}
+type Preferences = ITerminalOptions & ClientOptions;
+
+export type RendererType = 'dom' | 'canvas' | 'webgl';
+
+export interface ClientOptions {
+    rendererType: RendererType;
+    disableLeaveAlert: boolean;
+    disableResizeOverlay: boolean;
+    enableZmodem: boolean;
+    enableTrzsz: boolean;
+    enableSixel: boolean;
+    titleFixed?: string;
+    isWindows: boolean;
+}
+
+export interface FlowControl {
+    limit: number;
+    highWater: number;
+    lowWater: number;
+}
+
+export interface XtermOptions {
+    wsUrl: string;
+    tokenUrl: string;
+    flowControl: FlowControl;
+    clientOptions: ClientOptions;
+    termOptions: ITerminalOptions;
+}
+
+function toDisposable(f: () => void): IDisposable {
+    return { dispose: f };
+}
+
+function addEventListener(target: EventTarget, type: string, listener: EventListener): IDisposable {
+    target.addEventListener(type, listener);
+    return toDisposable(() => target.removeEventListener(type, listener));
+}
+
+export class Xterm {
+    private disposables: IDisposable[] = [];
+    private textEncoder = new TextEncoder();
+    private textDecoder = new TextDecoder();
+    private written = 0;
+    private pending = 0;
+
+    private terminal: Terminal;
+    private fitAddon = new FitAddon();
+    private overlayAddon = new OverlayAddon();
+    private webglAddon?: WebglAddon;
+    private canvasAddon?: CanvasAddon;
+    private zmodemAddon?: ZmodemAddon;
+
+    private socket?: WebSocket;
+    private token: string;
+    private opened = false;
+    private title?: string;
+    private titleFixed?: string;
+    private resizeOverlay = true;
+    private reconnect = true;
+    private doReconnect = true;
+
+    private writeFunc = (data: ArrayBuffer) => this.writeData(new Uint8Array(data));
+
+    constructor(
+        private options: XtermOptions,
+        private sendCb: () => void
+    ) {}
+
+    dispose() {
+        for (const d of this.disposables) {
+            d.dispose();
+        }
+        this.disposables.length = 0;
+    }
+
+    @bind
+    private register<T extends IDisposable>(d: T): T {
+        this.disposables.push(d);
+        return d;
+    }
+
+    @bind
+    public sendFile(files: FileList) {
+        this.zmodemAddon?.sendFile(files);
+    }
+
+    @bind
+    public async refreshToken() {
+        try {
+            const resp = await fetch(this.options.tokenUrl);
+            if (resp.ok) {
+                const json = await resp.json();
+                this.token = json.token;
+            }
+        } catch (e) {
+            console.error(`[ttyd] fetch ${this.options.tokenUrl}: `, e);
+        }
+    }
+
+    @bind
+    private onWindowUnload(event: BeforeUnloadEvent) {
+        event.preventDefault();
+        if (this.socket?.readyState === WebSocket.OPEN) {
+            const message = 'Close terminal? this will also terminate the command.';
+            event.returnValue = message;
+            return message;
+        }
+        return undefined;
+    }
+
+    @bind
+    public open(parent: HTMLElement) {
+        this.terminal = new Terminal(this.options.termOptions);
+        const { terminal, fitAddon, overlayAddon } = this;
+        window.term = terminal as TtydTerminal;
+        window.term.fit = () => {
+            this.fitAddon.fit();
+        };
+
+        terminal.loadAddon(fitAddon);
+        terminal.loadAddon(overlayAddon);
+        terminal.loadAddon(new WebLinksAddon());
+
+        terminal.open(parent);
+        fitAddon.fit();
+    }
+
+    @bind
+    private initListeners() {
+        const { terminal, fitAddon, overlayAddon, register, sendData } = this;
+        register(
+            terminal.onTitleChange(data => {
+                if (data && data !== '' && !this.titleFixed) {
+                    document.title = data + ' | ' + this.title;
+                }
+            })
+        );
+        register(terminal.onData(data => sendData(data)));
+        register(terminal.onBinary(data => sendData(Uint8Array.from(data, v => v.charCodeAt(0)))));
+        register(
+            terminal.onResize(({ cols, rows }) => {
+                const msg = JSON.stringify({ columns: cols, rows: rows });
+                this.socket?.send(this.textEncoder.encode(Command.RESIZE_TERMINAL + msg));
+                if (this.resizeOverlay) overlayAddon.showOverlay(`${cols}x${rows}`, 300);
+            })
+        );
+        register(
+            terminal.onSelectionChange(() => {
+                if (this.terminal.getSelection() === '') return;
+                try {
+                    document.execCommand('copy');
+                } catch (e) {
+                    return;
+                }
+                this.overlayAddon?.showOverlay('\u2702', 200);
+            })
+        );
+        register(addEventListener(window, 'resize', () => fitAddon.fit()));
+        register(addEventListener(window, 'beforeunload', this.onWindowUnload));
+    }
+
+    @bind
+    public writeData(data: string | Uint8Array) {
+        const { terminal, textEncoder } = this;
+        const { limit, highWater, lowWater } = this.options.flowControl;
+
+        this.written += data.length;
+        if (this.written > limit) {
+            terminal.write(data, () => {
+                this.pending = Math.max(this.pending - 1, 0);
+                if (this.pending < lowWater) {
+                    this.socket?.send(textEncoder.encode(Command.RESUME));
+                }
+            });
+            this.pending++;
+            this.written = 0;
+            if (this.pending > highWater) {
+                this.socket?.send(textEncoder.encode(Command.PAUSE));
+            }
+        } else {
+            terminal.write(data);
+        }
+    }
+
+    @bind
+    public sendData(data: string | Uint8Array) {
+        const { socket, textEncoder } = this;
+        if (socket?.readyState !== WebSocket.OPEN) return;
+
+        if (typeof data === 'string') {
+            const payload = new Uint8Array(data.length * 3 + 1);
+            payload[0] = Command.INPUT.charCodeAt(0);
+            const stats = textEncoder.encodeInto(data, payload.subarray(1));
+            socket.send(payload.subarray(0, (stats.written as number) + 1));
+        } else {
+            const payload = new Uint8Array(data.length + 1);
+            payload[0] = Command.INPUT.charCodeAt(0);
+            payload.set(data, 1);
+            socket.send(payload);
+        }
+    }
+
+    @bind
+    public connect() {
+        this.socket = new WebSocket(this.options.wsUrl, ['tty']);
+        const { socket, register } = this;
+
+        socket.binaryType = 'arraybuffer';
+        register(addEventListener(socket, 'open', this.onSocketOpen));
+        register(addEventListener(socket, 'message', this.onSocketData as EventListener));
+        register(addEventListener(socket, 'close', this.onSocketClose as EventListener));
+        register(addEventListener(socket, 'error', () => (this.doReconnect = false)));
+    }
+
+    @bind
+    private onSocketOpen() {
+        console.log('[ttyd] websocket connection opened');
+
+        const { textEncoder, terminal, overlayAddon } = this;
+        const msg = JSON.stringify({ AuthToken: this.token, columns: terminal.cols, rows: terminal.rows });
+        this.socket?.send(textEncoder.encode(msg));
+
+        if (this.opened) {
+            terminal.reset();
+            terminal.options.disableStdin = false;
+            overlayAddon.showOverlay('Reconnected', 300);
+        } else {
+            this.opened = true;
+        }
+
+        this.doReconnect = this.reconnect;
+        this.initListeners();
+        terminal.focus();
+    }
+
+    @bind
+    private onSocketClose(event: CloseEvent) {
+        console.log(`[ttyd] websocket connection closed with code: ${event.code}`);
+
+        const { refreshToken, connect, doReconnect, overlayAddon } = this;
+        overlayAddon.showOverlay('Connection Closed');
+        this.dispose();
+
+        // 1000: CLOSE_NORMAL
+        if (event.code !== 1000 && doReconnect) {
+            overlayAddon.showOverlay('Reconnecting...');
+            refreshToken().then(connect);
+        } else {
+            const { terminal } = this;
+            const keyDispose = terminal.onKey(e => {
+                const event = e.domEvent;
+                if (event.key === 'Enter') {
+                    keyDispose.dispose();
+                    overlayAddon.showOverlay('Reconnecting...');
+                    refreshToken().then(connect);
+                }
+            });
+            overlayAddon.showOverlay('Press ⏎ to Reconnect');
+        }
+    }
+
+    @bind
+    private onSocketData(event: MessageEvent) {
+        const { textDecoder } = this;
+        const rawData = event.data as ArrayBuffer;
+        const cmd = String.fromCharCode(new Uint8Array(rawData)[0]);
+        const data = rawData.slice(1);
+
+        switch (cmd) {
+            case Command.OUTPUT:
+                this.writeFunc(data);
+                break;
+            case Command.SET_WINDOW_TITLE:
+                this.title = textDecoder.decode(data);
+                document.title = this.title;
+                break;
+            case Command.SET_PREFERENCES:
+                this.applyPreferences({
+                    ...this.options.clientOptions,
+                    ...JSON.parse(textDecoder.decode(data)),
+                } as Preferences);
+                break;
+            default:
+                console.warn(`[ttyd] unknown command: ${cmd}`);
+                break;
+        }
+    }
+
+    @bind
+    private applyPreferences(prefs: Preferences) {
+        const { terminal, fitAddon, register } = this;
+        if (prefs.enableZmodem || prefs.enableTrzsz) {
+            this.zmodemAddon = new ZmodemAddon({
+                zmodem: prefs.enableZmodem,
+                trzsz: prefs.enableTrzsz,
+                windows: prefs.isWindows,
+                onSend: this.sendCb,
+                sender: this.sendData,
+                writer: this.writeData,
+            });
+            this.writeFunc = data => this.zmodemAddon?.consume(data);
+            terminal.loadAddon(register(this.zmodemAddon));
+        }
+        Object.keys(prefs).forEach(key => {
+            const value = prefs[key];
+            switch (key) {
+                case 'rendererType':
+                    this.setRendererType(value);
+                    break;
+                case 'disableLeaveAlert':
+                    if (value) {
+                        window.removeEventListener('beforeunload', this.onWindowUnload);
+                        console.log('[ttyd] Leave site alert disabled');
+                    }
+                    break;
+                case 'disableResizeOverlay':
+                    if (value) {
+                        console.log('[ttyd] Resize overlay disabled');
+                        this.resizeOverlay = false;
+                    }
+                    break;
+                case 'disableReconnect':
+                    if (value) {
+                        console.log('[ttyd] Reconnect disabled');
+                        this.reconnect = false;
+                        this.doReconnect = false;
+                    }
+                    break;
+                case 'enableZmodem':
+                    if (value) console.log('[ttyd] Zmodem enabled');
+                    break;
+                case 'enableTrzsz':
+                    if (value) console.log('[ttyd] trzsz enabled');
+                    break;
+                case 'enableSixel':
+                    if (value) {
+                        terminal.loadAddon(register(new ImageAddon()));
+                        console.log('[ttyd] Sixel enabled');
+                    }
+                    break;
+                case 'titleFixed':
+                    if (!value || value === '') return;
+                    console.log(`[ttyd] setting fixed title: ${value}`);
+                    this.titleFixed = value;
+                    document.title = value;
+                    break;
+                case 'isWindows':
+                    if (value) console.log('[ttyd] is windows');
+                    break;
+                default:
+                    console.log(`[ttyd] option: ${key}=${JSON.stringify(value)}`);
+                    if (terminal.options[key] instanceof Object) {
+                        terminal.options[key] = Object.assign({}, terminal.options[key], value);
+                    } else {
+                        terminal.options[key] = value;
+                    }
+                    if (key.indexOf('font') === 0) fitAddon.fit();
+                    break;
+            }
+        });
+    }
+
+    @bind
+    private setRendererType(value: RendererType) {
+        const { terminal } = this;
+        const disposeCanvasRenderer = () => {
+            try {
+                this.canvasAddon?.dispose();
+            } catch {
+                // ignore
+            }
+            this.canvasAddon = undefined;
+        };
+        const disposeWebglRenderer = () => {
+            try {
+                this.webglAddon?.dispose();
+            } catch {
+                // ignore
+            }
+            this.webglAddon = undefined;
+        };
+        const enableCanvasRenderer = () => {
+            if (this.canvasAddon) return;
+            this.canvasAddon = new CanvasAddon();
+            disposeWebglRenderer();
+            try {
+                this.terminal.loadAddon(this.canvasAddon);
+                console.log('[ttyd] canvas renderer loaded');
+            } catch (e) {
+                console.log('[ttyd] canvas renderer could not be loaded, falling back to dom renderer', e);
+                disposeCanvasRenderer();
+            }
+        };
+        const enableWebglRenderer = () => {
+            if (this.webglAddon) return;
+            this.webglAddon = new WebglAddon();
+            disposeCanvasRenderer();
+            try {
+                this.webglAddon.onContextLoss(() => {
+                    this.webglAddon?.dispose();
+                });
+                terminal.loadAddon(this.webglAddon);
+                console.log('[ttyd] WebGL renderer loaded');
+            } catch (e) {
+                console.log('[ttyd] WebGL renderer could not be loaded, falling back to canvas renderer', e);
+                disposeWebglRenderer();
+                enableCanvasRenderer();
+            }
+        };
+
+        switch (value) {
+            case 'canvas':
+                enableCanvasRenderer();
+                break;
+            case 'webgl':
+                enableWebglRenderer();
+                break;
+            case 'dom':
+                disposeWebglRenderer();
+                disposeCanvasRenderer();
+                console.log('[ttyd] dom renderer loaded');
+                break;
+            default:
+                break;
+        }
+    }
+}