1512547 - Can't enter fullscreen after exiting on YouTube

Status: RESOLVED DUPLICATE of bug 1493331

(WebExtensions :: General, defect)

Description

[csheany]

User Agent: Mozilla/5.0 (Android 7.1.1; Tablet; rv:65.0) Gecko/65.0 Firefox/65.0

Steps to reproduce:

With full-screen-api.unprefix.enabled set to true and the Video Background Play Fix add-on installed (addons.mozilla.org/en-US/firefox/addon/video-background-play-fix/)...

1. Open YouTube
2. Request Desktop Site
3. Play a video
4. Enter fullscreen
5. Exit fullscreen


Actual results:

The video still thinks it is in fullscreen as the controls persist and don't provide the option


Expected results:

The video should be recognized as it was before

Comment 1

[Xidorn Quan [:xidorn] UTC+10]

Does it work as expected when the addon is not installed?

Comment 2

[csheany]

Yes but also with it enabled and full-screen-api.unprefix.enabled set to false.

Comment 3

[csheany]

What are your thoughts on what is happening?

Comment 4

[Xidorn Quan [:xidorn] UTC+10]

Most possible reason is that YouTube listen on prefixed fullscreenchange event and the addon listen on unprefixed one, or vice versa, and listeners on unprefixed event would mask those on prefixed one, so one of them fails to respond to fullscreen change.

Comment 5

[csheany]

Are you able to reproduce?

Comment 6

[csheany]

Does version 1.2.1 support the unprefixed version of the API?

Comment 7

[Tim Guan-tin Chien [:timdream] (please needinfo)]

I think so. Likely fixed by Jan H already.

Comment 8

[Tim Guan-tin Chien [:timdream] (please needinfo)]

I mean, I don’t think 1.2.1 supported the unprrefixed API, but it is fixed already in the new versions.

Comment 9

[csheany]

Thank you for your response.

I am aware of the updates but the functionality was removed.

I was wondering if it was worth reimplementing to keep with the original design if the problem is with the site and not the browser or add-on/ extension.

Would you mind elaborateing on why the page is not allowed to detect the fact that it has left the fullscreen mode?

Comment 10

[Tim Guan-tin Chien [:timdream] (please needinfo)]

We should really move this conversation to GitHub...

If I remember correctly at the time one of the websites targetted will pause the video when it leaves fullscreen mode. I don't remember which. Perhaps I didn't even test it right in the first place. Anyway, Jan should be able to help you as I am no longer available for working on this add-on.