electron/docs/api/desktop-capturer.md

desktop-capturer

The desktop-capturer is a renderer module used to capture the content of screen and individual app windows.

// In the renderer process.
var desktopCapturer = require('desktop-capturer');

desktopCapturer.getSources({types: ['window', 'screen']}, function(error, sources) {
  if (error) throw error;
  for (var i = 0; i < sources.length; ++i) {
    if (sources[i].name == "Electron") {
      navigator.webkitGetUserMedia({
        audio: false,
        video: {
          mandatory: {
            chromeMediaSource: 'desktop',
            chromeMediaSourceId: sources[i].id,
            minWidth: 1280,
            maxWidth: 1280,
            minHeight: 720,
            maxHeight: 720
          }
        }
      }, gotStream, getUserMediaError);
      return;
    }
  }
});

function gotStream(stream) {
  document.querySelector('video').src = URL.createObjectURL(stream);
}

function getUserMediaError(e) {
  console.log('getUserMediaError');
}

Methods

The desktopCapturer module has the following methods:

desktopCapturer.getSources(options, callback)

options Object, properties:

• types Array - An array of String that enums the types of desktop sources.
  • screen String - Screen
  • window String - Individual window
• thumbnailSize Object (optional) - The suggested size that thumbnail should be scaled.
  • width Integer - The width of thumbnail. By default, it is 150px.
  • height Integer - The height of thumbnail. By default, it is 150px.

callback Function - function(error, sources) {}

• error Error
• sources Array - An array of Source

Gets all desktop sources.

Note: There is no garuantee that the size of source.thumbnail is always the same as the thumnbailSize in options. It also depends on the scale of the screen or window.

Source

Source is an object represents a captured screen or individual window. It has following properties:

• id String - The id of the captured window or screen used in navigator.webkitGetUserMedia. The format looks like 'window:XX' or 'screen:XX' where XX is a random generated number.
• name String - The descriped name of the capturing screen or window. If the source is a screen, the name will be 'Entire Screen' or 'Screen '; if it is a window, the name will be the window's title.
• thumbnail NativeImage - A thumbnail image.