Alt-Tab is broken while Compiz scale plugin is active

[Feathertail]

Binary package hint: unity

PROBLEM

When the scale plugin is used to switch windows, the behavior of normal Alt-Tabbing becomes unpredictable. Even if you use scale to switch between the same two windows, when you then hit Alt-Tab it will take you to a random window, instead of the one you were just using.

HOW TO REPRODUCE

1. Enable the scale plugin using Compiz Config. (I have it set to use the lower-left and lower-right screen corners, to switch between all applications.)
2. Open a handful of windows, at least three or four.
3. Use scale to flip between any two windows a couple of times.
4. Press Alt-Tab.

EXPECTED BEHAVIOR

Using mouse gestures to switch between windows won't foul up the keyboard shortcuts.

ProblemType: Bug
DistroRelease: Ubuntu 11.04
Package: unity 3.6.6-0ubuntu2
ProcVersionSignature: Ubuntu 2.6.38-7.37-generic 2.6.38
Uname: Linux 2.6.38-7-generic i686
Architecture: i386
CompizPlugins: [core,bailer,detection,composite,opengl,decor,resize,grid,vpswitch,compiztoolbox,gnomecompat,regex,imgpng,mousepoll,move,place,session,animation,workarounds,wall,expo,ezoom,staticswitcher,fade,scale,unityshell]
Date: Fri Mar 25 00:06:48 2011
EcryptfsInUse: Yes
InstallationMedia: Ubuntu 10.04 LTS "Lucid Lynx" - Release i386 (20100429)
InstallationMedia_: Ubuntu 10.04 LTS "Lucid Lynx" - Release i386 (20100429)
ProcEnviron:
 LANGUAGE=en_US:en
 PATH=(custom, user)
 LANG=en_US.UTF-8
 SHELL=/bin/bash
ProcVersionSignature_: Ubuntu 2.6.38-7.37-generic 2.6.38
SourcePackage: unity
UpgradeStatus: Upgraded to natty on 2011-03-18 (7 days ago)

[Sam Spilsbury (smspillaz)]

Alt-Tab should not be allowed at the same time as scale for now

On Fri, Mar 25, 2011 at 12:12 PM, Feathertail <email address hidden> wrote:
> Public bug reported:
>
> Binary package hint: unity
>
> PROBLEM
>
> When the scale plugin is used to switch windows, the behavior of normal
> Alt-Tabbing becomes unpredictable. Even if you use scale to switch
> between the same two windows, when you then hit Alt-Tab it will take you
> to a random window, instead of the one you were just using.
>
> HOW TO REPRODUCE
>
> 1. Enable the scale plugin using Compiz Config. (I have it set to use the lower-left and lower-right screen corners, to switch between all applications.)
> 2. Open a handful of windows, at least three or four.
> 3. Use scale to flip between any two windows a couple of times.
> 4. Press Alt-Tab.
>
> EXPECTED BEHAVIOR
>
> Using mouse gestures to switch between windows won't foul up the
> keyboard shortcuts.
>
> ProblemType: Bug
> DistroRelease: Ubuntu 11.04
> Package: unity 3.6.6-0ubuntu2
> ProcVersionSignature: Ubuntu 2.6.38-7.37-generic 2.6.38
> Uname: Linux 2.6.38-7-generic i686
> Architecture: i386
> CompizPlugins: [core,bailer,detection,composite,opengl,decor,resize,grid,vpswitch,compiztoolbox,gnomecompat,regex,imgpng,mousepoll,move,place,session,animation,workarounds,wall,expo,ezoom,staticswitcher,fade,scale,unityshell]
> Date: Fri Mar 25 00:06:48 2011
> EcryptfsInUse: Yes
> InstallationMedia: Ubuntu 10.04 LTS "Lucid Lynx" - Release i386 (20100429)
> InstallationMedia_: Ubuntu 10.04 LTS "Lucid Lynx" - Release i386 (20100429)
> ProcEnviron:
>  LANGUAGE=en_US:en
>  PATH=(custom, user)
>  LANG=en_US.UTF-8
>  SHELL=/bin/bash
> ProcVersionSignature_: Ubuntu 2.6.38-7.37-generic 2.6.38
> SourcePackage: unity
> UpgradeStatus: Upgraded to natty on 2011-03-18 (7 days ago)
>
> ** Affects: unity (Ubuntu)
>     Importance: Undecided
>         Status: New
>
>
> ** Tags: apport-bug i386 natty running-unity
>
> --
> You received this bug notification because you are a member of Unity
> Bugs, which is subscribed to unity in Ubuntu.
> https://bugs.launchpad.net/bugs/742237
>
> Title:
>  Alt-Tab is broken while Compiz scale plugin is active
>
> Status in “unity” package in Ubuntu:
>  New
>
> Bug description:
>  Binary package hint: unity
>
>  PROBLEM
>
>  When the scale plugin is used to switch windows, the behavior of
>  normal Alt-Tabbing becomes unpredictable. Even if you use scale to
>  switch between the same two windows, when you then hit Alt-Tab it will
>  take you to a random window, instead of the one you were just using

[Paul Sladen (sladen)]

I'm tempted to dup this to bug #175874 ("Compiz switcher Alt-Tab order is not predictable - should maintain LIFO ordering in application switcher") and re-open that despite it being "Fix Released" as the solution clearly wasn't generic enough.

Sam: it the shared-code of all of the switchers, would it be possible to perhaps save the stack order array at the start of the Alt-tab initiation and then restore that array as-was whenever Esc is pressed, or Alt-tab is released on a target window?

[Sam Spilsbury (smspillaz)]

On Fri, Mar 25, 2011 at 2:10 PM, Paul Sladen <email address hidden> wrote:
> I'm tempted to dup this to bug #175874 ("Compiz switcher Alt-Tab order
> is not predictable - should maintain LIFO ordering in application
> switcher") and re-open that despite it being "Fix Released" as the
> solution clearly wasn't generic enough.
>

This is not the same issue. The problem here is that you can change
the currently active window with the switchers but the window that
actually ends up getting selected is the one that you click on to exit
scale mode.

In reality, the switcher and scale plugins should not be used at the same time.

> Sam: it the shared-code of all of the switchers, would it be possible to
> perhaps save the stack order array at the start of the Alt-tab
> initiation and then restore that array as-was whenever Esc is pressed,
> or Alt-tab is released on a target window?
>
> ** Also affects: unity (Ubuntu Lucid)
>   Importance: Undecided
>       Status: New
>
> ** Also affects: unity (Ubuntu Natty)
>   Importance: Undecided
>       Status: New
>
> ** Changed in: unity (Ubuntu Lucid)
>       Status: New => Won't Fix
>
> ** Changed in: unity (Ubuntu Natty)
>       Status: New => Incomplete
>
> ** Changed in: unity (Ubuntu Natty)
>    Milestone: None => ubuntu-11.04
>
> --
> You received this bug notification because you are a member of Unity
> Bugs, which is subscribed to unity in Ubuntu.
> https://bugs.launchpad.net/bugs/742237
>
> Title:
>  Alt-Tab is broken while Compiz scale plugin is active
>
> Status in “unity” package in Ubuntu:
>  Incomplete
> Status in “unity” source package in Lucid:
>  Won't Fix
> Status in “unity” source package in Natty:
>  Incomplete
>
> Bug description:
>  Binary package hint: unity
>
>  PROBLEM
>
>  When the scale plugin is used to switch windows, the behavior of
>  normal Alt-Tabbing becomes unpredictable. Even if you use scale to
>  switch between the same two windows, when you then hit Alt-Tab it will
>  take you to a random window, instead of the one you were just using

[Feathertail (feathertail-deactivatedaccount)]

@Sam: You're incorrect. This does sound very much like the bug that Paul mentions.

I should have clarified: I'm not pressing Alt-Tab while the scale plugin is active, I'm pressing it after I've successfully used it to switch back and forth between windows. I use scale to flip to one window, then I use it to flip back to another, then I press Alt-Tab and it takes me to a random third or fourth window.

I'm sorry for the confusion.

[Sam Spilsbury (smspillaz)]

On Fri, Mar 25, 2011 at 2:34 PM, Feathertail <email address hidden> wrote:
> @Sam: You're incorrect. This does sound very much like the bug that Paul
> mentions.
>
> I should have clarified: I'm not pressing Alt-Tab while the scale plugin
> is active, I'm pressing it after I've successfully used it to switch
> back and forth between windows. I use scale to flip to one window, then
> I use it to flip back to another, then I press Alt-Tab and it takes me
> to a random third or fourth window.

Ah right.

In this case it is *still* not a bug in the switchers, but rather the
fact that some plugins will change the window activity state (eg
active -> inactive) and this indirectly affects the sorting order of
alt-tab.

The real solution here is to provide a way to show that a window
*would* be active by some user input but not actually activate it in
that case. However, since that would require an API change, it is too
late to put into Natty.

The stop-gap that we took in the switchers was to not show the window
in the "active" state while it was highlighted. I think that this is a
perfectly fine behavior for the scale plugin too.

>
> I'm sorry for the confusion.
>
> --
> You received this bug notification because you are a member of Unity
> Bugs, which is subscribed to unity in Ubuntu.
> https://bugs.launchpad.net/bugs/742237
>
> Title:
>  Alt-Tab is broken while Compiz scale plugin is active
>
> Status in “unity” package in Ubuntu:
>  Incomplete
> Status in “unity” source package in Lucid:
>  Won't Fix
> Status in “unity” source package in Natty:
>  Incomplete
>
> Bug description:
>  Binary package hint: unity
>
>  PROBLEM
>
>  When the scale plugin is used to switch windows, the behavior of
>  normal Alt-Tabbing becomes unpredictable. Even if you use scale to
>  switch between the same two windows, when you then hit Alt-Tab it will
>  take you to a random window, instead of the one you were just using

[Sam Spilsbury (smspillaz)]

On Fri, Mar 25, 2011 at 2:53 PM, Sam Spilsbury <email address hidden> wrote:
> On Fri, Mar 25, 2011 at 2:34 PM, Feathertail <email address hidden> wrote:
>> @Sam: You're incorrect. This does sound very much like the bug that Paul
>> mentions.
>>
>> I should have clarified: I'm not pressing Alt-Tab while the scale plugin
>> is active, I'm pressing it after I've successfully used it to switch
>> back and forth between windows. I use scale to flip to one window, then
>> I use it to flip back to another, then I press Alt-Tab and it takes me
>> to a random third or fourth window.
>
> Ah right.
>
> In this case it is *still* not a bug in the switchers, but rather the
> fact that some plugins will change the window activity state (eg
> active -> inactive) and this indirectly affects the sorting order of
> alt-tab.

Clarification: Alt-tab sorts in order of activity, so the first active
window, then the next one that was active and so on and so forth.

>
> The real solution here is to provide a way to show that a window
> *would* be active by some user input but not actually activate it in
> that case. However, since that would require an API change, it is too
> late to put into Natty.
>
> The stop-gap that we took in the switchers was to not show the window
> in the "active" state while it was highlighted. I think that this is a
> perfectly fine behavior for the scale plugin too.
>
>>
>> I'm sorry for the confusion.
>>
>> --
>> You received this bug notification because you are a member of Unity
>> Bugs, which is subscribed to unity in Ubuntu.
>> https://bugs.launchpad.net/bugs/742237
>>
>> Title:
>>  Alt-Tab is broken while Compiz scale plugin is active
>>
>> Status in “unity” package in Ubuntu:
>>  Incomplete
>> Status in “unity” source package in Lucid:
>>  Won't Fix
>> Status in “unity” source package in Natty:
>>  Incomplete
>>
>> Bug description:
>>  Binary package hint: unity
>>
>>  PROBLEM
>>
>>  When the scale plugin is used to switch windows, the behavior of
>>  normal Alt-Tabbing becomes unpredictable. Even if you use scale to
>>  switch between the same two windows, when you then hit Alt-Tab it will
>>  take you to a random window, instead of the one you were just using.
>>
>>  HOW TO REPRODUCE
>>
>>  1. Enable the scale plugin using Compiz Config. (I have it set to use the lower-left and lower-right screen corners, to switch between all applications.)
>>  2. Open a handful of windows, at least three or four.
>>  3. Use scale to flip between any two windows a couple of times.
>>  4. Press Alt-Tab.
>>
>>  EXPECTED BEHAVIOR
>>
>>  Using mouse gestures to switch between windows won't foul up the
>>  keyboard shortcuts.
>>
>>  ProblemType: Bug
>>  DistroRelease: Ubuntu 11.04
>>  Package: unity 3.6.6-0ubuntu2
>>  ProcVersionSignature: Ubuntu 2.6.38-7.37-generic 2.6.38
>>  Uname: Linux 2.6.38-7-generic i686
>>  Architecture: i386
>>  CompizPlugins: [core,bailer,detection,composite,opengl,decor,resize,grid,vpswitch,compiztoolbox,gnomecompat,regex,imgpng,mousepoll,move,place,session,animation,workarounds,wall,expo,ezoom,staticswitcher,fade,scale,unityshell]
>>  Date: Fri Mar 25 00:06:48 2011
>>  EcryptfsInUse: Yes
>>  InstallationMedia: Ubunt...

[Omer Akram (om26er)]

not an issue in Ubuntu 12.04