1548296 - Picture-and-Picture toggle is not responsive for videos that fire their canplay events outside of the document

Status: VERIFIED FIXED

(Toolkit :: Video/Audio Controls, defect, P2)

Description

[Mike Conley (:mconley) (:⚙️)]

Attachment: Test case

PictureInPictureToggleChild inside of PictureInPictureChild.jsm uses the "canplay" event to register videos for tracking mouse movement, and hearing about clicks that might be on the toggle.

I've found an example case[1] where clicking on the toggle does nothing - this is because the "canplay" event is fired at a point where the <video> element is disconnected from the DOM tree, so the PictureInPictureToggleChild (which attaches the "canplay" listener to the message manager) doesn't hear about it.

This means that we never end up tracking the video.

I've attached a test case.

Comment 1

[Mike Conley (:mconley) (:⚙️)]

I suspect this also affects Netflix (bug 1546639), so increasing priority.

Comment 2

[Mike Conley (:mconley) (:⚙️)]

Attachment: Bug 1548296 - Attach Picture-in-Picture toggle on UAWidgetSetupOrChange event rather than canplay. r?JSON_Voorhees

Videos can fire their "canplay" events even when they're not part of the DOM. This
means that videos that have already fired that event won't get the
PictureInPictureToggleChild properly attached after being inserted.

The UAWidgetSetupOrChange event, however, is fired for video events once they've
been bound to the DOM, so we can use that instead.

Comment 3

[Mike Conley (:mconley) (:⚙️)]

Attachment: Bug 1548296 - Regression test. r?JSON_Voorhees

Depends on D44541

Comment 4

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/autoland/rev/11b2692199c2
Attach Picture-in-Picture toggle on UAWidgetSetupOrChange event rather than canplay. r=JSON_voorhees
https://hg.mozilla.org/integration/autoland/rev/78e7e7cb5073
Regression test. r=JSON_voorhees

Comment 5

[Cristina Coroiu [:ccoroiu]]

https://hg.mozilla.org/mozilla-central/rev/11b2692199c2
https://hg.mozilla.org/mozilla-central/rev/78e7e7cb5073

Comment 6

[Cristian Craciun]

Build ID 20190906094324
User Agent Mozilla/5.0 (Windows NT 10.0; rv:71.0) Gecko/20100101 Firefox/71.0

Verified as fixed on the latest Nightly build. The PiP toggle is now displayed for the Netflix videos (bug 1546639).