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Test Info: Warnings

<!DOCTYPE html>
<meta charset="utf-8">
<meta name="timeout" content="long">
<!-- user agents are not required to support open features other than `noopener`
and on some platforms position and size features don't make sense -->
<meta name="flags" content="may">
<title>Multi-Screen Window Management test:</title>
<link rel="help" href="">
This test uses multi-screen details to open a popup window on each screen.<br>
It runs automated or manually with `wpt serve` and a compatible browser.<br><br>
<button id="setUpButton">Request screen details</button>
<ul id="popupButtons"></ul>
<button id="cleanUpButton">Close any open popups</button><br>
<input id="autoCleanUp" type="checkbox" checked=true>Auto-close popups</input>
<ul id="logger"></ul>
<script src="/resources/testharness.js"></script>
<script src="/resources/testharnessreport.js"></script>
<script src="/resources/testdriver.js"></script>
<script src="/resources/testdriver-vendor.js"></script>
<script src="resources/helpers.js"></script>
'use strict';
let popups = [];
cleanUpButton.addEventListener('click', async () => {
popups.forEach(p => p.close());
function checkPopupPlacement(popup, x, y, allowSameScreenClamping) {
// Window.screenX|Y may be zero, if the user agent wishes to hide information
// about the screen of the output device. They also may incorrectly reflect
// the origin of content viewport; in that case, estimate window coordinates
// by subtracing estimated frame insets (top-heavy, horizontally centered).
// Synchronous estimated placements may be clamped to the current screen.
const error = 10;
const dX = popup.screenX - x - (popup.outerWidth - popup.innerWidth) / 2;
const dY = popup.screenY - y - (popup.outerHeight - popup.innerHeight);
assert_true(!popup.screenX || popup.screenX == x || Math.abs(dX) <= error ||
(allowSameScreenClamping && popup.screenX >= screen.availLeft &&
popup.screenX < screen.availLeft + screen.availWidth));
assert_true(!popup.screenY || popup.screenY == y || Math.abs(dY) <= error ||
(allowSameScreenClamping && popup.screenY >= screen.availTop &&
popup.screenY < screen.availTop + screen.availHeight));
async function testPopupOnScreen(popupTest, screen) {
// Show a popup child window on the associated screen.
const left = screen.availLeft + Math.floor(screen.availWidth / 2) - 150;
const top = screen.availTop + Math.floor(screen.availHeight / 2) - 50;
log(`Opening a popup on '${screen.label}' at (${left}, ${top})`);
let popup =
'/resources/blank.html', '',
if (autoCleanUp.checked)
// synchronously returns a Window with estimated screenX|Y.
// Initial `screenX` and `screenY` values should match `left` and `top`.
log(`<div style='margin-left: 40px'>Initial bounds:
(${popup.screenX}, ${popup.screenY})
// Allow synchronous estimated placements to be clamped to the current screen.
checkPopupPlacement(popup, left, top, true);
popup.initialScreenX = popup.screenX;
popup.initialScreenY = popup.screenY;
// Await document.visibilitychange to check resolved Window.screenX|Y values
// after asynchronous window creation and clamped placement has occurred.
const visibilitychangeWatcher =
new EventWatcher(popupTest, popup.document, ['visibilitychange']);
await visibilitychangeWatcher.wait_for('visibilitychange');
popup.document.write(`Expected: (${left}, ${top}) <br> \
Initial: (${popup.initialScreenX}, ${popup.initialScreenY}) <br> \
Resolved: (${popup.screenX}, ${popup.screenY}) `);
log(`<div style='margin-left: 40px'>Resolved bounds:
(${popup.screenX}, ${popup.screenY})
// Do not allow resolved placements to be clamped to the current screen.
checkPopupPlacement(popup, left, top, false);
promise_test(async setUpTest => {
await setUpWindowManagement(setUpTest, setUpButton);
const screenDetails = await getScreenDetails();
assert_true(!!screenDetails, 'Error getting screen details');
assert_greater_than(screenDetails.screens.length, 0, 'Connect a screen');
for (const s of screenDetails.screens) {
promise_test(async popupTest => {
await addTestTriggerButtonAndAwaitClick(popupButtons,
`Open a popup on '${s.label}'`,
await testPopupOnScreen(popupTest, s);
}, `Open a popup on '${s.label}'`);
}, 'Use multi-screen details to open a popup window on each screen');