1352879 - Seeking in video is interrupted by focus changes on the page

Status: RESOLVED WONTFIX

(Toolkit :: Video/Audio Controls, defect)

Description

[684sigma]

Attachment: Focus changes don't allow to seek in video, by reporter.html

I have a problem with Firefox Beta 53. It also happens in Nightly 55. Doesn't happen in Beta 52, ESR 45.
Seeking in video by dragging stops if web page changes focused element. I encountered this bug on a web page that put focus into input field while I was seeking in video.
Here's how to reproduce it:

1. Open attached page
2. Start seeking in video (by dragging).

Result: seeking is interrupted when <input> is focused
Expected: not interrupted

Comment 1

[Ray Lin[:ralin]]

I'm not sure the old behavior is desirable for users. Focus stealing not only breaks timeline in video control, but also interrupts all input[type="range"]. I also wondering how many website can be affected by this. There might has a point that focus stolen while dragging, but not every certain interval unless it's intentional. I'd like to turn this issue into a more generic problem: should input[type="range"] or others native widget like <select>, autocomplete, popup, etc interrupted by focus change?

Comment 2

[Stefan [:StefanG_QA]]

I was able to reproduce the reported issue on Beta 53 and latest Nightly (20170403030207). I can observe the interruption when dragging the playing point in the video. I've used mozregression to find a regression range. Here are my findings: 

Last good revision: ec7fb4f14d3ec23ded7eea40ff49ebbcbec6bde1
First bad revision: 8d2eecb7ea5a16e02862dd326ce4519082ce9901
Pushlog: https://hg.mozilla.org/integration/autoland/pushloghtml?fromchange=ec7fb4f14d3ec23ded7eea40ff49ebbcbec6bde1&tochange=8d2eecb7ea5a16e02862dd326ce4519082ce9901

Comment 3

[Liz Henry (:lizzard) (relman/hg->git project)]

Too late to consider for 53, sounds like something for the video team to consider what behavior they think is correct.

Comment 4

[Ray Lin[:ralin]]

Attachment: changing focus interfere select and range input.

In this attachment, I just want to point out something might more interruptible cases by this. i.e. <select> popup. I don't understand the intention of changing focus by intervals, IMO it affects more to like <select> than timeline inside video controls.

Comment 5

[Ray Lin[:ralin]]

Hey Stone,

Dragging on range input can interrupted by focus change(see comment 4), however, the same case work fine for Chrome or Safari, do you have any idea about this? Thanks.

Comment 6

[Ming-Chou Shih [:stone]]

This is handled in input element [1]. Looks like we already behaved so for years.

[1] http://searchfox.org/mozilla-central/rev/944f87c575e8a0bcefc1ed8efff10b34cf7a5169/dom/html/HTMLInputElement.cpp#4322

Comment 7

[Ray Lin[:ralin]]

(In reply to Ming-Chou Shih [:stone] from comment #6)
> This is handled in input element [1]. Looks like we already behaved so for
> years.
> 
> [1]
> http://searchfox.org/mozilla-central/rev/
> 944f87c575e8a0bcefc1ed8efff10b34cf7a5169/dom/html/HTMLInputElement.cpp#4322


Thank you :stone,

Then I'd prefer that all slider-like components in Firefox behave similarly in order not to confuse users. Flagging this bug as wontfix as I could not see affecting timeline of videocontrols would affect more severe problem than input element, also it will need some hacks in input DOM implementation for only videocontrols wich I'm not sure it's worthy.