electron/docs/api/screen.md

screen

The screen module retrieves information about screen size, displays, cursor position, etc. You can not use this module until the ready event of the app module is emitted (by invoking or requiring it).

screen is an EventEmitter.

Note: In the renderer / DevTools, window.screen is a reserved DOM property, so writing var screen = require('electron').screen will not work. In our examples below, we use electronScreen as the variable name instead. An example of creating a window that fills the whole screen:

const electron = require('electron');
const app = electron.app;
const BrowserWindow = electron.BrowserWindow;

var mainWindow;

app.on('ready', function() {
  var electronScreen = electron.screen;
  var size = electronScreen.getPrimaryDisplay().workAreaSize;
  mainWindow = new BrowserWindow({ width: size.width, height: size.height });
});

Another example of creating a window in the external display:

const electron = require('electron');
const app = electron.app;
const BrowserWindow = electron.BrowserWindow;

var mainWindow;

app.on('ready', function() {
  var electronScreen = electron.screen;
  var displays = electronScreen.getAllDisplays();
  var externalDisplay = null;
  for (var i in displays) {
    if (displays[i].bounds.x != 0 || displays[i].bounds.y != 0) {
      externalDisplay = displays[i];
      break;
    }
  }

  if (externalDisplay) {
    mainWindow = new BrowserWindow({
      x: externalDisplay.bounds.x + 50,
      y: externalDisplay.bounds.y + 50
    });
  }
});

The Display object

The Display object represents a physical display connected to the system. A fake Display may exist on a headless system, or a Display may correspond to a remote, virtual display.

• display object
  • id Integer - Unique identifier associated with the display.
  • rotation Integer - Can be 0, 1, 2, 3, each represents screen rotation in clock-wise degrees of 0, 90, 180, 270.
  • scaleFactor Number - Output device's pixel scale factor.
  • touchSupport String - Can be available, unavailable, unknown.
  • bounds Object
  • size Object
  • workArea Object
  • workAreaSize Object

Events

The screen module emits the following events:

Event: 'display-added'

Returns:

• event Event
• newDisplay Object

Emitted when newDisplay has been added.

Event: 'display-removed'

Returns:

• event Event
• oldDisplay Object

Emitted when oldDisplay has been removed.

Event: 'display-metrics-changed'

Returns:

• event Event
• display Object
• changedMetrics Array

Emitted when one or more metrics change in a display. The changedMetrics is an array of strings that describe the changes. Possible changes are bounds, workArea, scaleFactor and rotation.

Methods

The screen module has the following methods:

screen.getCursorScreenPoint()

Returns the current absolute position of the mouse pointer.

screen.getPrimaryDisplay()

Returns the primary display.

screen.getAllDisplays()

Returns an array of displays that are currently available.

screen.getDisplayNearestPoint(point)

• point Object
  • x Integer
  • y Integer

Returns the display nearest the specified point.

screen.getDisplayMatching(rect)

• rect Object
  • x Integer
  • y Integer
  • width Integer
  • height Integer

Returns the display that most closely intersects the provided bounds.