How to use multiple screens

Oct 10, 2022 — Updated May 19, 2023

The modern way #

Using `window.getScreenDetails()` #

To make sure your browser supports the getScreenDetails() method, first check if it exists on the window object. Then, call window.getScreenDetails() to get attached screens. Adding an event listener to adapt to changed screen details allows you to manage multiple screens according to the needs of your app.

if ('getScreenDetails' in window) {
  // The Window Management API is supported.
  const screenDetails = await window.getScreenDetails();
  screenDetails.addEventListener('screenschange', (event) => {
    // Handle screens change.
  });
}

Browser support

Chrome 100, Supported 100
Firefox, Not supported
Edge 100, Supported 100
Safari, Not supported

The classic way #

Using the window.screen method #

There's no classic way to control multi-screen layouts, but you can fall back to controlling the current screen by using the window.screen property and polyfill the new API shape.

if (!('getScreenDetails' in window)) {
  // Returning a one-element array with the current screen,
  // noting that there might be more.
  window.getScreenDetails = async () => [window.screen];
  // Set to `false`, noting that this might be a lie.
  window.screen.isExtended = false;
}

Browser support

Chrome 1, Supported 1
Firefox 1, Supported 1
Edge 12, Supported 12
Safari 1, Supported 1

Source

Progressive enhancement #

The demo below shows how you can handle multiple screens with the Window Management API. The code checks the browser capability first and then falls back to the classic way.

const detectButton = document.querySelector('#detectScreen');
const createButton = document.querySelector('#create');
const permissionLabel = document.querySelector('#permissionStatus');
const screensAvailLabel = document.querySelector('#screensAvail');
const popupUrl = './popup.html';
let screenDetails = undefined;
let permission = undefined;
let currentScreenLength = undefined;

detectButton.addEventListener('click', async () => {
  if ('getScreenDetails' in window) {
    screenDetails = await window.getScreenDetails();
    screenDetails.addEventListener('screenschange', (event) => {
      if (screenDetails.screens.length !== currentScreenLength) {
        currentScreenLength = screenDetails.screens.length;
        updateScreenInfo();
      }
    });
    try {
      permission =
        (await navigator.permissions.query({ name: 'window-management' })).state === 'granted'
          ? 'Granted'
          : 'No Permission';
    } catch (err) {
      console.error(err);
    }
    currentScreenLength = screenDetails.screens.length;
    updateScreenInfo();
  } else {
    screenDetails = window.screen;
    permission = 'Window Management API - NOT SUPPORTED';
    currentScreenLength = 1;
    updateScreenInfo();
  }
});

createButton.addEventListener('click', () => {
  let screen = screenDetails.screens[Math.floor(Math.random() * currentScreenLength)];
  options = {
    x: screen.availLeft,
    y: screen.availTop,
    width: screen.availWidth,
    height: screen.availHeight,
  };
  window.open(popupUrl, '_blank', getFeaturesFromOptions(options));
});

function getFeaturesFromOptions(options) {
  return (
    'left=' +
    options.x +
    ',top=' +
    options.y +
    ',width=' +
    options.width +
    ',height=' +
    options.height
  );
}

updateScreenInfo = () => {
  screensAvailLabel.innerHTML = currentScreenLength;
  permissionLabel.innerHTML = permission;
  if ('getScreenDetails' in window && screenDetails.screens.length > 1) {
    createButton.disabled = false;
  } else {
    createButton.disabled = true;
  }
};

Demo #

<!DOCTYPE html>
<html lang="en">
  <head>
    <meta charset="utf-8" />
    <meta name="viewport" content="width=device-width, initial-scale=1" />
    <link
      rel="icon"
      href="data:image/svg+xml,<svg xmlns=%22http://www.w3.org/2000/svg%22 viewBox=%220 0 100 100%22><text y=%22.9em%22 font-size=%2290%22>🎉</text></svg>"
    />
    <title>How to use multiple screens</title>
    <link rel="stylesheet" href="/style.css" />
    <script src="/script.js" type="module"></script>
  </head>
  <body>
    <h1>How to use multiple screens</h1>
    <div>
      <div>
        Permission Status:
        <span id="permissionStatus"></span>
      </div>
      <div>Screens Available: <span id="screensAvail"></span></div>
    </div>
    <button id="detectScreen">Detect Screens</button>
    <button id="create" disabled>Create Page On Random Screen</button>
  </body>
</html>

const detectButton = document.querySelector('#detectScreen');
const createButton = document.querySelector('#create');
const permissionLabel = document.querySelector('#permissionStatus');
const screensAvailLabel = document.querySelector('#screensAvail');
const popupUrl = 'supporting-popup.html';
let screenDetails = undefined;
let permission = undefined;
let currentScreenLength = undefined;

detectButton.addEventListener('click', async () => {
  if ('getScreenDetails' in window) {
    screenDetails = await window.getScreenDetails();
    screenDetails.addEventListener('screenschange', (event) => {
      if (screenDetails.screens.length !== currentScreenLength) {
        currentScreenLength = screenDetails.screens.length;
        updateScreenInfo();
      }
    });
    try {
      permission =
        (await navigator.permissions.query({ name: 'window-placement' }))
          .state === 'granted'
          ? 'Granted'
          : 'No Permission';
    } catch (err) {
      console.error(err);
    }
    currentScreenLength = screenDetails.screens.length;
    updateScreenInfo();
  } else {
    screenDetails = window.screen;
    permission = 'Multi-Screen Window Placement API - NOT SUPPORTED';
    currentScreenLength = 1;
    updateScreenInfo();
  }
});

createButton.addEventListener('click', () => {
  const screen =
    screenDetails.screens[Math.floor(Math.random() * currentScreenLength)];
  const options = {
    x: screen.availLeft,
    y: screen.availTop,
    width: screen.availWidth,
    height: screen.availHeight,
  };
  window.open(popupUrl, '_blank', getFeaturesFromOptions(options));
});

const getFeaturesFromOptions = (options) => {
  return (
    'left=' +
    options.x +
    ',top=' +
    options.y +
    ',width=' +
    options.width +
    ',height=' +
    options.height
  );
};

const updateScreenInfo = () => {
  screensAvailLabel.innerHTML = currentScreenLength;
  permissionLabel.innerHTML = permission;
  if ('getScreenDetails' in window && screenDetails.screens.length > 1) {
    createButton.disabled = false;
  } else {
    createButton.disabled = true;
  }
};

:root {
  color-scheme: dark light;
}

html {
  box-sizing: border-box;
}

*,
*:before,
*:after {
  box-sizing: inherit;
}

body {
  margin: 1rem;
  font-family: system-ui, sans-serif;
}

<!DOCTYPE html>
<html lang="en">
  <head>
    <meta charset="utf-8" />
    <meta name="viewport" content="width=device-width, initial-scale=1.0" />
    <link
      rel="icon"
      href="data:image/svg+xml,<svg xmlns=%22http://www.w3.org/2000/svg%22 viewBox=%220 0 100 100%22><text y=%22.9em%22 font-size=%2290%22>🎉</text></svg>"
    />
    <title>How to use multiple screens</title>
    <link rel="stylesheet" href="/style.css" />
  </head>
  <body>
    <script>
      function randomBackgroundColor() {
        const r = Math.floor(Math.random() * 256);
        const g = Math.floor(Math.random() * 256);
        const b = Math.floor(Math.random() * 256);
        var bgColor = 'rgb(' + r + ',' + g + ',' + b + ')';
        document.body.style.backgroundColor = bgColor;
      }
      randomBackgroundColor();
    </script>
  </body>
</html>

Open demo

Last updated

May 19, 2023 — Improve article