Alt+Tab Switcher randomly activates itself

[Michael Bazzinotti]

I am running Ubuntu 13.10 on my Macbook Pro 2009 laptop. I cannot find a report on this bug when googling it. So I thought I would file the bug.

Literally, the switcher randomly just activates itself, and then the icons show in the middle of the screen as per usual. The stranger behavior is what happens next:

1) The switcher might automatically switch to a seemingly random app from the selection.
2) The switcher will just be displayed, but I cannot actually make it go away by clicking on one of the app icons. Instead, it just displays for however long it 'feels like,' typically ~5 seconds.

So.. That's it. Hope I can get some help :D

^___^ <3

[John Kim (kotux)]

Thank you for taking the time to report this bug and helping to make Ubuntu better. Please answer these questions:

* Is this reproducible?
* If so, what specific steps should we take to recreate this bug?

This will help us to find and resolve the problem.

[dreh23 (johannes-amorosa-7)]

I have the same phenomena on my macbook air and my macbook pro with trusty and precise.

Bootet Ubuntu daily (22.3.2014) trusty from a USB stick. I get random alt+tab switching. I'm not 100% sure
if this is a Compiz problem I believe it could be a faulty synaptic trackpad driver.

How can I verify this.

[dreh23 (johannes-amorosa-7)]

Added some info:

  Model Name: MacBook Air
  Model Identifier: MacBookAir6,2
  Processor Name: Intel Core i7
  Processor Speed: 1,7 GHz
  Number of Processors: 1
  Total Number of Cores: 2
  L2 Cache (per Core): 256 KB
  L3 Cache: 4 MB
  Memory: 8 GB
  Boot ROM Version: MBA61.0099.B04
  SMC Version (system): 2.13f7

[Bagus Tris (bagustris)]

Same problem here. Ubuntu trusty (dev) on macbook pro 9.2 (mid 2012)

[Duarte (dmendonca)]

I have the same issue, MacBoo pro 9,1 (mid 2012), problem existed in 13.10 and persists in 14.04 LTS..
App switcher randonly appears, switches applications on me, but I am unable to switch..

[Duarte (dmendonca)]

It is reproducible, it happens in various/ all apps, Thunderbird, Firefox, System settings, etc it happends constantly, (twice now since I've been typing this). It is very annoying. If I invoke app switcher myself, it works fine, but this unintentional app switcher does not, I can't navigate the apps or do anything until it times out. Not sure if it is a Compiz issue, or a trackpad driver bug.. but I suspect the latter.. any help would be great. It's driving me nuts and preventing full time use of Ubuntu.
I'd be happy to provide any more info or do any troubleshooting suggested.

[Stephen M. Webb (bregma)]

Since this problem only occurs on certain Macbook Pro models, and the Alt-Tab switcher is activated by a certain sequence of 3-finger taps, I'm going to go with a problem in the trackpad hardware. It sounds like a random capacitive discharge issue.

I think the obvious solution is to be able to disable that particular gesture in Unity.

[Duarte (dmendonca)]

I have tried disbaling every app-switcher related setting in Compiz settings mamager that I could find, problem persists..
Also the issue occurs even without and contcat with the trackpad..

[Duarte (dmendonca)]

 the issue occurs even without any contact with the trackpad..

[Stephen M. Webb (bregma)]

Unfortunately, this functionality is provided directly by Unity without any configuration option. If you're not using Unity, let me know but it's the only reasonable explanation that fits the data at this point.

If the problem is stray capacitive discharge in the device itself, you don't need to touch it. It doesn't show up in other applications because it requires a particular sequence that gets interpreted as three separate simultaneous touchpoints followed by three more separate simultaneous touchpoints, and that sort of thing could happen easily if the dielectric in the touchpad has a thin spot or is misaligned on one edge. Few applications look for that sequence of events, if any, and it's likely that hardware QA processes also don't check for such a thing.

Really, adding a new configuration option to disable 3-touch application switching is the simplest solution.

[Duarte (dmendonca)]

"Really, adding a new configuration option to disable 3-touch application switching is the simplest solution."

How would I go about doing this?
Thanks!

[Duarte (dmendonca)]

Here are my synclient settings:

Parameter settings:
    LeftEdge = -3898
    RightEdge = 4428
    TopEdge = 434
    BottomEdge = 6146
    FingerLow = 70
    FingerHigh = 75
    MaxTapTime = 180
    MaxTapMove = 535
    MaxDoubleTapTime = 180
    SingleTapTimeout = 180
    ClickTime = 100
    EmulateMidButtonTime = 0
    EmulateTwoFingerMinZ = 283
    EmulateTwoFingerMinW = 7
    VertScrollDelta = 243
    HorizScrollDelta = 243
    VertEdgeScroll = 0
    HorizEdgeScroll = 0
    CornerCoasting = 0
    VertTwoFingerScroll = 1
    HorizTwoFingerScroll = 1
    MinSpeed = 1
    MaxSpeed = 1.75
    AccelFactor = 0.0164447
    TouchpadOff = 2
    LockedDrags = 0
    LockedDragTimeout = 5000
    RTCornerButton = 0
    RBCornerButton = 0
    LTCornerButton = 0
    LBCornerButton = 0
    TapButton1 = 0
    TapButton2 = 0
    TapButton3 = 0
    ClickFinger1 = 1
    ClickFinger2 = 3
    ClickFinger3 = 0
    CircularScrolling = 0
    CircScrollDelta = 0.1
    CircScrollTrigger = 0
    CircularPad = 0
    PalmDetect = 0
    PalmMinWidth = 10
    PalmMinZ = 200
    CoastingSpeed = 20
    CoastingFriction = 50
    PressureMotionMinZ = 30
    PressureMotionMaxZ = 160
    PressureMotionMinFactor = 1
    PressureMotionMaxFactor = 1
    ResolutionDetect = 1
    GrabEventDevice = 1
    TapAndDragGesture = 1
    AreaLeftEdge = 0
    AreaRightEdge = 0
    AreaTopEdge = 0
    AreaBottomEdge = 0
    HorizHysteresis = 40
    VertHysteresis = 27
    ClickPad = 1
    RightButtonAreaLeft = 0
    RightButtonAreaRight = 0
    RightButtonAreaTop = 0
    RightButtonAreaBottom = 0
    MiddleButtonAreaLeft = 0
    MiddleButtonAreaRight = 0
    MiddleButtonAreaTop = 0
    MiddleButtonAreaBottom = 0

[Karen S (karen-j-s)]

I also have this problem, on a Dell Xps 13 Ubuntu developer edition, running Ubuntu 13.10.

[DuarteM (dmendonc)]

I have been using the gnome desktop in Ubuntu 14.04 and the issue does not occur in gnome. I've also tried KDE, Gnome Classic, the other two versions of gnome desktop (flashback Compiz and flashback metacity?) and he issue did not manifest itself, so clearly this is a Unity thing. Stinks, because I much prefer Unity desktop to gnome.

[dreh23 (johannes-amorosa-7)]

I have the same error. This sometimes happens when I have two fingers just touching the touchpad.

Linux slim 3.13.0-46-generic #77-Ubuntu SMP Mon Mar 2 18:23:39 UTC 2015 x86_64 x86_64 x86_64 GNU/Linux
Ubuntu 14.04 || MacBookAir6,2

[Michael Bazzinotti (mbazzinotti)]

So there are 2 solutions for us hackers.. before a real fix comes out [how does that work?]
1) Switch to Gnome
http://askubuntu.com/questions/450294/how-to-switch-from-unity-to-gnome

2) Patch Unity Source, and rebuild [untested]
http://askubuntu.com/questions/57586/how-can-i-disable-arbitrary-default-multitouch-gestures-in-unity/205045#205045

[Gaele Strootman (gaele)]

Same problem here (Macbook Pro 2013, Vivid, Unity).

Would it be possible, as a work-around, to disable 3-finger taps using Ginn (https://wiki.ubuntu.com/Multitouch/Ginn)?

[Stephen M. Webb (bregma)]

Unfortunately no, you can not use Ginn to preemptively grab the 3-finger taps because the shell already has a grab on the root window for 3-finger taps.

[shz (afer)]

I have the same behaviour reported in tbe bug with an Asus N550JK with Ubuntu 15.04.

[West Alto (westalto)]

Same here. MacBookPro6,2/Ubuntu 15.04.

[shz (afer)]

This seems connected

http://ubuntuforums.org/showthread.php?t=2276619

[fcole90 (fcole90)]

Thank you for taking the time to report this bug. We have tried to recreate this on the latest release of Ubuntu and cannot reproduce it. This bug is being marked as Invalid. If you believe the problem to still exist in the latest version of Ubuntu please comment on why that is the case and change the bug status to NEW.

[Gaele Strootman (gaele)]

It's still there.
This happens SOME times with SOME hardware. You cannot really test it.
See #10 for what happens, and for the solution.

[Alan Pope 🍺🐧🐱 🦄 (popey)]

Have checked this on my MacBook Pro 7,1 with a clean install and fully updated Ubuntu 15.10 and it does still happen, so not invalid I'm afraid.

[professordes (d-a-johnston-hw)]

This is still present on an ASUS UX305, Ubuntu 15.10, running Unity. A 3 fingered tap _sometimes_ brings up the alt-tab switcher. Seems to be easier to summon when tapping inside a Chrome window than elsewhere. Seen on both my own machine and a colleague's.

[professordes (d-a-johnston-hw)]

Multiple quickfire 3 finger taps seem to the "best" way to get the pesky alt-tab switcher to pop up....

[Niranjan (nagar-g)]

Happens on ASUS UX305L on both Trusty and now on xenial. Have switched to Gnome to not have this very annoying problem

[professordes (d-a-johnston-hw)]

The bug is still present in the 16.04 Xenial beta for me on a Macbook Air 11" 6,1 and an ASUS UX305 running Unity (as of 21/03/16).

Rapid three finger taps will bring up the switcher, but it sometimes pops up for no obvious reason. The behaviour is also seen on a colleague's UX305 running 15.10.

[GRGendron (gregory-gendron)]

Bug occurs on 15.10 and a recent Xenial daily build. I have an Asus UX31A. I see it randomly while using 2 finger scrolling.

[Alberto Milone (albertomilone)]

Just an update. I have written a workaround, so that users can disable gestures from dconf. I have used it for a few days on my Macbook, and it makes the problem go away.

I have proposed my branch for merging. You can follow the bug report here: LP: #1589520

P.S. it's a separate bug report, as the actual bug is probably in the driver, rather than in Unity.

[Paul (pf+)]

I've been doing some research after experiencing this issue, and stumbled across this. It may be nothing but for me this only seems to happen when my MacBook Pro is connected to the mains. When unplugged it goes away, and also when keeping a finger touching the chassis whilst using the touchpad, it also hasn't happened yet.

I didn't notice this under OSX so maybe there's some extra checks going on behind the scenes there for contact patch size or reduced touchpad sensitivity.

Steps whilst plugged in,
1, use laptop for a while
2, two fingers together on touchpad (not touching anything else), swipe slowly and gently upwards to scroll the page
3, alt tab switcher opens, switches to next window, closes, instead of scrolling upwards

Laptop unplugged or with a 3rd finger touching the metal body? Nothing unexpected happens.

[Sithu Thwin (sithu-a)]

Still having same problem on Dell Inspiron 14, 5000 series on Ubuntu 16.04 freshly installed.
Mostly happen when touching touch pad.

[shz (afer)]

Have the same problem also after upgrading to 16.10.
Should not this be solved with #1589520?
Does dconf get updated with the upgrade to 16.10?

[Daniel Parkes (myph)]

Having the same problem on a fresh install of 16.04 LTS on an Acer Aspire E 15. Occurs frequently (multiple times per minute) if my finger is sitting on the touch pad. I’m running Unity. I’m hoping this can be solved soon, but since this post now goes back more than 3 years, I’m having my doubts.

[lediableboiteux (lediableboiteux)]

My girlfriend has similar issue on her Dell Inspiron 5000 bought last year. Ubuntu 16.04.

[Robert Cooksey (amodal1)]

I have the same issue on a Dell XPS running 16.04. VERY reproducible every time I leave two fingers on the touchpad for more than a second or so.

Typical behavior is two finger scrolling, pause to scan without lifting fingers, alt-tab behavior is triggered and quickly switches to another window. Terribly annoying. Makes laptop virtually useless for work.

[Rebecca J. (rebeccaj)]

I have a Dell XPS 13, 9360, running 16.04. Tapping with three fingers switches me to another app, reliably and reproducibly.

The real problem is that I get switched to another app while I'm typing - the bases of my hands must rest on the touchpad in a similar way.

This happens even though I have "Tap to click" disabled.

For now, I have disabled my touchpad entirely - this is the only way I can type on my laptop without the window switching (at least when I use the laptop on a table - having it on my lap changes my angle a little and makes the problem slightly less prevalent).

[John Greeley (john.greeley)]

This also effects my Dell Precision 5520 in Ubuntu 16.10. It's been driving me crazy because I can't reliably reproduce it, but it usually happens after I pause scrolling and just switches randomly to another application.

[Brian Gavazzi (strokednbored)]

This issue is happening on my 2012 MBP 13inch as well.

I am dual booting OSX and Ubuntu 16.04

The issue does not manifest itself when booted into OSX - only Ubuntu.

How to prevent: Remove the power connector. When removed, the trackpad works normally.

How to reproduce: Plug in the power connector. After connected for several seconds, the trackpad begins to right-click randomly and/or initiate the alt-tab command.

[totymedli (totymedli)]

I found a solution! At least for my case.

I have a 2015 MacBook Pro with Ubuntu 16.04 LTS.

According to these:
https://askubuntu.com/questions/456299/state-of-multitouch-gestures-in-14-04-unity
https://wiki.ubuntu.com/Multitouch

This happens, because sometimes the touchpad's 3 finger tap followed by 3 fingers hold is triggered randomly. You can disable this, by overwriting the TapButton3 option in synclient. Just like this doc says:
https://wiki.ubuntu.com/Multitouch/TouchpadSupport

I set it to behave like a middle mouse click (which is more handy because if you select/copy some text then 3 finger tap, it behaves like a paste in input fields).

Here is an Ask Ubuntu post that explains the process:
https://askubuntu.com/a/156545/323990

In short:
echo synclient TapButton3=2 > ~/.config/touchpad_settings
chmod +x ~/.config/touchpad_settings
Then run this script at startup. Searching for "Startup Applications" in the dash then add a new startup program with the command: "/home/your-user-name-here/.config/touchpad_settings". Don't forget to replace the "your-user-name-here" part in the path with your username.

[teodoro musacchio (tmusacchio)]

I've used Ubuntu 16.4 in variuos computer mainly hp g4 250 without any problems. No I'm using the Aspire 5 A517-41G-7161 and I got the problem . Its particularly annoying because the applications switcher pops up randomly and lasts on the screen for a few seconds. The solutions here proposed are too technical for me to access. I need a more easy explanation if there is someone that have solved the problem. It's a pity, after so many years where I've been using Ubuntu, I'm thinking to migrate somewhere else.