Bug 216395

Summary:	"display-mode: fullscreen" media query should match in fullscreen browser windows
Product:	WebKit	Reporter:	Simon Fraser (smfr) <simon.fraser>
Component:	CSS	Assignee:	Nobody <webkit-unassigned>
Status:	NEW ---
Severity:	Normal	CC:	jer.noble, johan, ntim, simon.fraser, webkit-bug-importer
Priority:	P2	Keywords:	InRadar
Version:	Safari Technology Preview
Hardware:	Unspecified
OS:	Unspecified
URL:	http://output.jsbin.com/sizejuw/quiet

Description Simon Fraser (smfr) 2020-09-10 19:36:38 PDT

https://twitter.com/simevidas/status/1304244241691029504

https://w3c.github.io/manifest/#dom-displaymodetype-fullscreen

http://output.jsbin.com/sizejuw/quiet

Comment 1 Radar WebKit Bug Importer 2020-09-10 19:36:56 PDT

<rdar://problem/68680815>

Comment 2 Johan Brook 2023-01-18 00:37:49 PST

We're having a real problem of not being able to distinguish macOS fullscreen mode from normal a "maximised" browser window.

We've tried various techniques of measuring the window width/height and comparing with window.screen values, but it yields inconsistent results for laptop and external monitor screens.

Ideally, the test below (http://output.jsbin.com/sizejuw/quiet) would say "Fullscreen: Yes" when a Safari window is put in macOS fullscreen mode. That CSS Media Query could also be used from Javascript. Second best, there'd be a Javascript API in the Fullscreen API spec for this (the existing APIs only seem to concern themselves with putting specific elements into fullscreen – not the window itself).