756512 - Set full-screen-api.exit-on-deactivate to false by default

Status: RESOLVED DUPLICATE of bug 724554

(Firefox :: General, defect)

Description

[david]

User Agent: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:12.0) Gecko/20100101 Firefox/12.0
Build ID: 20120420145725

Steps to reproduce:

http://html5-demos.appspot.com/static/fullscreen.html
Go to the supplied URL and toggle into fullscreen and move your mouse to another monitor and change focus to another window.




Actual results:

Fullscreen is lost.


Expected results:

In response to bug #724554, full-screen-api.exit-on-deactivate was added which can be set to false to fix this issue.

But exit-on-deactivate should be set to false by default because most users aren't going to know that they need to change this flag in the configuration to fix the problem.  So it will continue to cause confusion and frustration for users with multiple monitors.

In response to demand from users, later version of Flash eventually stopped automatically exiting fullscreen.  So currently, Flash will stay in fullscreen video, but Firefox won't by default.  This is causing confusion for users as more sites are beginning to switch to using HTML5 video and users don't understand why they are having a problem making video stay in fullscreen when using Firefox.

As evidence that this is starting to be an issue for users, note that this issue has already been raised several times...

https://support.mozilla.org/ms/questions/927294
https://bugzilla.mozilla.org/show_bug.cgi?id=729307
https://bugzilla.mozilla.org/show_bug.cgi?id=706555
https://bugzilla.mozilla.org/show_bug.cgi?id=746522
https://bugzilla.mozilla.org/show_bug.cgi?id=724554

I recommend setting full-screen-api.exit-on-deactivate to false by default.

Comment 1

[Jason Smith [:jsmith]]

Matthias - Do you know who works on full-screen API? If so, could you cc them on the bug?

Comment 2

[Matthias Versen [:Matti]]

I would vote for Chris as fullscreen feature maintainer :-)

Comment 3

[Chris Pearce [:cpearce (Not reading bugmail)]]

I also find this feature annoying, which is why I added the pref to disable it.

Exiting fullscreen on browser window blur was requested by the security team in the first security review (see action item "Full-screen mode must be disabled when the browser/tab is not actively focused (https://bugzilla.mozilla.org/show_bug.cgi?id=685402)" at https://wiki.mozilla.org/Security/Reviews/Firefox10/CodeEditor/FullScreenAPI ).

I'm not opposed to disabling this simply because it means people will stop nagging me about it, but since the security team suggested this behaviour they may argue for keep the current exit-on-window-blur behaviour...

Comment 4

[david]

The security issue is that there is concern full-screen could be used to spoof the user's desktop.  A couple points about that... 

- Does exit-on-window-blur really do anything to ameliorate that concern?  I don't see how exit-on-window-blur significantly limits the possibility of a desktop spoof.

- A more effective creative solution to the security concern could be something like showing a browser window controls at the top of the screen when the mouse is moved over a full-screen window.  Or something along those lines just to indicate that to the user that it's actually a browser window.

Comment 5

[Karl Tomlinson (:karlt)]

This sounds reasonable to me, but this is really the same request as bug 724554, so let's try to keep discussion in one place.