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Mozilla Firefox: website steals focus preventing task switching

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Mark Hobley

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Sep 19, 2009, 9:08:02 PM9/19/09
to
I am using Debian Iceweasel, which is essentially an unbranded version
of Mozilla Firefox. There appears to be a bug in the browser, which can
cause a website to steal focus, preventing normal task switching
operations to take place within the X11 system. (The browser will regain
focus, if a task switch takes place).

http://www.digicrime.com/blackhole.html

This appears to be a facility provided by Javascript. I have disabled
the raise or lower windows facility, but the window still gains focus:

Menu, Edit, Preferences, Button: Advanced, Tickbox: Raise or lower
windows: unticked

What facility in Javascript is causing this?
Maybe there is a setting in about:config to prevent this.

Mark.

--
Mark Hobley
Linux User: #370818 http://markhobley.yi.org/

des...@verizon.net

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Sep 19, 2009, 9:53:06 PM9/19/09
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markh...@hotpop.donottypethisbit.com (Mark Hobley) writes:

This appears to be the suspect part of the page:

<script language="JavaScript">
function test()
{
this.focus();
setTimeout('test()',10);
};
test();
</script>

It's just asking for focus.

Under Fvwm2, it doesn't do much. If I try to switch to another
page, it switches back. I'm pretty sure I can configure that
out of Fvwm2, but it's no big deal.

I can just point at the X in the tab bar and close the tab
or close the tab with C-w.

I think your WM is co-operating too much with the application.

DenverD

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Sep 20, 2009, 4:05:39 AM9/20/09
to

here, on the sig listed machine using firefox 3.0.14 that page is not
very exciting...seems to do nothing..i'm writing this reply with it
open in the window below my Thunderbird...and, the ho hum page is easy
to close without using Alt-F4..

so, once again the truth behind the FUD is not as scary as some in
Redmond might have hoped..

--
DenverD (Linux Counter 282315) via Thunderbird 3.0.1-1.1, KDE 3.5.7,
openSUSE Linux 10.3, 2.6.22.19-0.4-default #1 SMP i686 athlon

Mark Hobley

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Sep 20, 2009, 7:08:02 AM9/20/09
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In comp.infosystems.www.browsers.x des...@verizon.net wrote:
>
> <script language="JavaScript">
> function test()
> {
> this.focus();
> setTimeout('test()',10);
> };
> test();
> </script>
>
> It's just asking for focus.

Right. I thought raise and lower windows would be part of this mechanism.
The window currently becomes raised when it gains focus. That should not
be allowed if raise or lower windows is disabled IMHO.

> Under Fvwm2, it doesn't do much. If I try to switch to another
> page, it switches back.

Right. under icewm, it switches applications and even virtual desktop
to put the browser window back in focus.

> I think your WM is co-operating too much with the application.

Maybe. I'll have a look to see if I can find a window manager that does
not support focus stealing (Do you know of any which don't?) and I
will have a look again this.

There is another quirk in the browser that I have noticed as a result of
this:

The cursor does not appear in the URL bar, when the address bar is
clicked, and I am unable to change the address of the focused window.

Mark Hobley

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Sep 20, 2009, 7:08:02 AM9/20/09
to
In comp.infosystems.www.browsers.x DenverD <spam...@somewhere.dk> wrote:

> here, on the sig listed machine using firefox 3.0.14 that page is not
> very exciting...seems to do nothing..

That is interesting. What window manager are you using?

Presumably you have got Javascript enabled on the browser. Maybe this
facility does not affect some versions of firefox, or your window
manager does not support focus stealing.

Mark Hobley

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Sep 20, 2009, 8:08:02 AM9/20/09
to
In comp.infosystems.www.browsers.x Mark Hobley <markh...@hotpop.donottypethisbit.com> wrote:

> I'll have a look to see if I can find a window manager that does not
> support focus stealing (Do you know of any which don't?) and I
> will have a look again this.

I just tried this on fvwm, and it looks as though focus stealing can
still occur away from other applications. I still cannot edit the
URL address.

I'll keep testing ...

The Natural Philosopher

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Sep 20, 2009, 9:12:43 AM9/20/09
to
DenverD wrote:
> Mark Hobley wrote:
>> I am using Debian Iceweasel, which is essentially an unbranded version
>> of Mozilla Firefox. There appears to be a bug in the browser, which can
>> cause a website to steal focus, preventing normal task switching
>> operations to take place within the X11 system. (The browser will regain
>> focus, if a task switch takes place).
>>
>> http://www.digicrime.com/blackhole.html
>>
>> This appears to be a facility provided by Javascript. I have disabled
>> the raise or lower windows facility, but the window still gains focus:
>>
>> Menu, Edit, Preferences, Button: Advanced, Tickbox: Raise or lower
>> windows: unticked
>>
>> What facility in Javascript is causing this?
>> Maybe there is a setting in about:config to prevent this.
>
> here, on the sig listed machine using firefox 3.0.14 that page is not
> very exciting...seems to do nothing..i'm writing this reply with it
> open in the window below my Thunderbird...and, the ho hum page is easy
> to close without using Alt-F4..
>
> so, once again the truth behind the FUD is not as scary as some in
> Redmond might have hoped..
>
I can confirm it doesn't do a lot on Firefox 3.5.3 either.

des...@verizon.net

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Sep 20, 2009, 10:15:37 AM9/20/09
to
markh...@hotpop.donottypethisbit.com (Mark Hobley) writes:

> In comp.infosystems.www.browsers.x Mark Hobley <markh...@hotpop.donottypethisbit.com> wrote:
>
>> I'll have a look to see if I can find a window manager that does not
>> support focus stealing (Do you know of any which don't?) and I
>> will have a look again this.
>
> I just tried this on fvwm, and it looks as though focus stealing can
> still occur away from other applications. I still cannot edit the
> URL address.
>
> I'll keep testing ...

Yeah, the Fvwm man page says it can't stop an application from
grabbing focus:


Grabbing the focus when a new window is created

New normal or transient windows with the FPGrabFocus or
FPGrabFocusTransient style automatically receive the focus when they are
created. FPGrabFocus is the default for windows with the ClickToFocus
style. Note that even if these styles are disabled, the application may
take the focus itself. Fvwm can not prevent this.

...

Raising the window is a different issue. Some WMs will automatically
raise anything focused. Pretty annoying. I think most WMs have an
option to turn it off.

Florian Diesch

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Sep 20, 2009, 11:44:08 AM9/20/09
to
markh...@hotpop.donottypethisbit.com (Mark Hobley) writes:

> I am using Debian Iceweasel, which is essentially an unbranded version
> of Mozilla Firefox. There appears to be a bug in the browser, which can
> cause a website to steal focus, preventing normal task switching
> operations to take place within the X11 system. (The browser will regain
> focus, if a task switch takes place).
>
> http://www.digicrime.com/blackhole.html

With Compiz 0.8.2 the browser comes back when I switch to an empty
desktop. Switching between windows on the same desktop or switching to a
desktop that contains windows works as usual.

Florian
--
<http://www.florian-diesch.de/software/shell-scripts/>

DenverD

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Sep 20, 2009, 6:10:40 PM9/20/09
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> That is interesting. What window manager are you using?

window manager i'm not sure, does metacities sound like a window
manager? other stuff in sig..

> Presumably you have got Javascript enabled on the browser. Maybe this
> facility does not affect some versions of firefox, or your window
> manager does not support focus stealing.

and, yes javascript is enabled..

after i sent my earlier post i saw that i couldn't do much with the
_tab_ which had that page loaded other than close that tab...but, i
don't see that as a problem, that is i didn't have to do anything
special to close the tab, just a click and it was gone...and, firefox
and everything else was ready to go some more...in fact i loaded
http://www.digicrime.com/ directly and that was kinda fun...it first
threw up a edge to edge, top to bottom full blue screen with some
kinda funny text...and, then the blue screen went away and the firefox
window said something like you can't ever use your computer again..

which was kinda funny since i just clicked to close that tab and all
was well again..

Mark Hobley

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Sep 21, 2009, 2:08:02 AM9/21/09
to
In comp.infosystems.www.browsers.x DenverD <spam...@somewhere.dk> wrote:
> window manager i'm not sure, does metacities sound like a window
> manager? other stuff in sig..

Yeah, metacity is a window manager. I will have a look at that.

Cheers,

Joe Beanfish

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Sep 21, 2009, 2:15:54 PM9/21/09
to

Using Firefox 3.5.3, KDE 4.3.1.
Focus under mouse. Focus stealing prevention none.

It prevents any inputs in the blackhole window from maintaining focus.
And it disrupts alt-tab by bringing the window back to fore. But manually
giving any other window focus using the mouse defeats it.

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