antosdk-apps/release/libwvnc.md

libwvnc

Overview about WVNC: https://blog.lxsang.me/r/id/23

libwvnc is the client side protocol API for my Antd's wvnc server side plugin. It allows to acess VNC server from the web using websocket (via the wvnc server plugin).

Since the wvnc plugin offers data compression using JPEG, wvnc.js depends on the libjpeg package and web worker to speed up the data decoding process, thus speed up the screen rendering on HTML canvas.

Example

It is straight forward to use the api:

Html code:

    ...
    <canvas id = "screen"></canvas>

Javascript:

  var args, client;
  args = {
    // the canvas element
    element: 'screen',
    // The websocket uri to the wvnc server side plugin
    ws: 'wss://localhost/wvnc',
    // the decoder worker
    libjpeg: 'path/to/jpg.js'
  };
  client = new WVNC(args);
  
  // This function responds to a VNC server password request
  // should return a promise
  client.onpassword = function() {
    return new Promise(function(r, e) {
      return r('password');
    });
  };
  
  // this function responds to the remote OS username and password request
  // should return a promise
  client.oncredential = function() {
    return new Promise(function(r, e) {
      return r('username', 'password');
    });
  };
  // event fired when a text is copied on
  // the remote computer
  client.oncopy = function(text) {
    console.log(text);
  };
  // init the WVNC client
  client.init()
    .then(function() {
        client.connect(
          // VNC server
          "192.168.1.20:5901", 
          {
            // bits per pixel
            bbp: 32,
            // data compression flag
            // 1 is for both JPEG
            // 0 is for raw data
            flag: 1,
            // JPEG quality %
            quality: 50
          });
    })
    .catch(function(m, s) {
      return console.error(m, s);
    });