To prevent a user activation from opening more than one fullscreen window, entering fullscreen will consume the user activation.

Motivation

Right now fullscreen does not consume the user activation, so a single user activation allows opening as many fullscreen windows as possible. This is counterintuitive. Moreover, Chrome’s current behavior caused a security bug in the past where two different windows would go fullscreen simultaneously, with one of them spoofing browser UI without the user’s knowledge. Even though the exact repro in that bug is suppressed in M72+ by restricted activation visibility of UAv2, it still makes sense to fix the core problem.

Demo

Documentation

Status in Chromium

Blink


Enabled by default (tracking bug) in:

  • Chrome for desktop release 76
  • Chrome for Android release 76
  • Android WebView release 76

Consensus & Standardization

After a feature ships in Chrome, the values listed here are not guaranteed to be up to date.

  • No signal
  • No signal
  • No signal
  • Mixed signals

Owners

Comments

There is a bit of compatibility risk with this change: it may break webpages that request more than one fullscreen for a user activation.

Last updated on 2020-12-21