Skip to main content

node-x11

node-x11 is a pure-JavaScript X Window System protocol client for Node.js. There is no native code and no runtime dependency: the library speaks the X11 wire protocol directly over a unix socket or TCP connection. It implements all 120 requests and 34 events of the core protocol, plus a long list of extensions — RENDER, RANDR, XFIXES, Composite, Damage, SHAPE, XTEST, XKB, XInput, MIT-SHM, GLX and more.

Install​

npm install x11

Hello, X server​

The smallest possible program — connect to the server named by $DISPLAY, print its vendor string, and disconnect:

const x11 = require('x11');

x11.createClient((err, display) => {
  console.log(`succesfully connected to "${display.vendor}" server`);
  display.client.terminate();
});

A more typical program creates a window, selects events and draws into it:

const x11 = require('x11');

const { Exposure, PointerMotion } = x11.eventMask;

x11.createClient((err, display) => {
  if (err) {
    console.log(err);
    return;
  }
  const X = display.client;
  const root = display.screen[0].root;
  const wid = X.AllocID();
  X.CreateWindow(
    wid,
    root, // new window id, parent
    0, 0, 500, 500, // x, y, w, h
    0, 0, 0, 0, // border, depth, class, visual
    { eventMask: Exposure | PointerMotion } // other parameters
  );
  X.MapWindow(wid);
  const white = display.screen[0].white_pixel;
  const black = display.screen[0].black_pixel;
  const cidBlack = X.AllocID();
  const cidWhite = X.AllocID();
  X.CreateGC(cidBlack, wid, { foreground: black, background: white });
  X.CreateGC(cidWhite, wid, { foreground: white, background: black });
  X.on('event', ev => {
    if (ev.type === 12) { // Expose
      X.PolyFillRectangle(wid, cidWhite, [0, 0, 500, 500]);
      X.PolyText8(wid, cidBlack, 50, 50, ['Hello, Node.JS!']);
    }
  });
  X.on('error', e => {
    console.log(e);
  });
});

Where to go next​