Configure touchpad double-tap

Fri Feb 28 22:28:50 UTC 2014

On 2/27/2014 8:10 PM, John Hupp wrote:
> On 2/26/2014 6:41 PM, John Hupp wrote:
>> On 2/25/2014 7:00 PM, John Hupp wrote:
>>> On 2/22/2014 8:24 PM, John Hupp wrote:
>>>> On 2/20/2014 12:07 PM, John Hupp wrote:
>>>>> On 2/20/2014 3:05 AM, Ali Linx wrote:
>>>>>>
>>>>>> On 02/20/2014 05:26 AM, John Hupp wrote:
>>>>>>> I just installed Lubuntu Saucy on a Lenovo 3000 laptop and I'm 
>>>>>>> finding that touchpad double-tap does not seem to work 
>>>>>>> (Synaptics touchpad).
>>>>>>>
>>>>>>> I've seen a few other complaints on related topics but haven't 
>>>>>>> found anything that really defines what can be configured on 
>>>>>>> touchpads and how.
>>>>>>>
>>>>>>> Options?
>>>>>>>
>>>>>> Hi,
>>>>>>
>>>>>> AskUbuntu? Ubuntu Forums?
>>>>>> Try :)
>>>>>>
>>>>>
>>>>> I could have added that one of the posts I saw said that 
>>>>> double-tap worked fine in Ubuntu, but not in Lubuntu.
>>>>>
>>>>> So it would seem that this list ought to be a good place to bring 
>>>>> this up.
>>>>>
>>>>>
>>>>
>>>> After further playing around, it seemed that double-tap was not 
>>>> disabled, but required *VERY* fast tapping.
>>>>
>>>> I found synclient, which is installed in Lubuntu Saucy and supposed 
>>>> to control Synaptics touchpad behavior, with documentation at 
>>>> http://manpages.ubuntu.com/manpages/saucy/man1/synclient.1.html
>>>>
>>>> That documentation indicates that the related config file is at 
>>>> /etc/X11/xorg.conf, but that doesn't exist on my machine, so at the 
>>>> moment I don't know what the universal/user configuration locations 
>>>> are.
>>>>
>>>> synclient -l reports MaxDoubleTapTime=180 initially, and it allowed 
>>>> me to set 'synclient MaxDoubleTapTime=360.'  I'm guessing that it 
>>>> could probably be set as high as 1000.
>>>>
>>>> This seemed to help, but double-tap is still unreliable: sometimes 
>>>> it seems to require unreasonably forceful tapping.
>>>>
>>>> synclient also reports settings for:
>>>>     PressureMotionMinZ
>>>>     PressureMotionMaxZ
>>>>     PressureMotionMinFactor
>>>>     PressureMotionMaxFactor
>>>> But it is not self-evident to me what behaviors those settings are 
>>>> supposed to govern and if any of them would set the touchpad to 
>>>> respond to a lighter touch.
>>>>
>>>> I have not yet found any better documentation, and maybe that would 
>>>> help me achieve better control.  So I'm still open to further help!
>>>>
>>>
>>> I know more now but still don't have a resolution.
>>>
>>> Documentation of the settings reported and governed per-session by 
>>> synclient are at 
>>> http://manpages.ubuntu.com/manpages/saucy/man4/synaptics.4.html
>>>
>>> FingerLow and FingerHigh are the settings that should govern 
>>> sensitivity, if that is my issue.
>>>
>>> Default settings are automatically configured by Xorg, but may be 
>>> temporarily changed during a session via synclient.  Make permanent 
>>> changes by editing /usr/share/X11/xorg.conf.d/50-synaptics.conf and 
>>> adding Options to the existing InputClass section that has the 
>>> Identifier "touchpad catchall."  An example with Options for 
>>> FingerLow and FingerHigh:
>>>
>>> Section "InputClass"
>>>     Identifier "touchpad catchall"
>>>     Driver "synaptics"
>>>     MatchIsTouchpad "on"
>>>     MatchDevicePath "/dev/input/event*"
>>>     Option "FingerLow" "10"
>>>     Option "FingerHigh" "16"
>>> EndSection
>>>
>>> This laptop is dual-booting Saucy with Windows Vista, and so far I 
>>> have not been able to configure the touchpad so that it double-taps 
>>> easily and consistently/reliably the way it does in Windows.  (Which 
>>> is also to say that I know that the touchpad hardware is OK because 
>>> it works fine in Windows.)
>>>
>>
>> I booted into the *Ubuntu* Live DVD on this laptop, and touchpad 
>> double-tapping performed very smoothly.
>>
>> Under Ubuntu, synclient reported different values for VertEdgeScroll 
>> and HorizTwoFingerScroll than Lubuntu reported, but changing those 
>> settings to match in Lubuntu did not help the double-tap problem.
>>
>> I installed Lubuntu Saucy on another laptop, and double-tap worked 
>> beautifully on that machine, but it has an Alps touchpad rather than 
>> Synaptics.
>>
>> I booted into the Lubuntu Trusty 2/14 Daily Build Live DVD on the 
>> problem laptop and found that it had the same problem with 
>> double-tap, but while there I discovered that a *TRIPLE-TAP* reliably 
>> yielded the behavior expected for a double-tap.
>>
>> So I booted back into Saucy from the hard drive, and found that there 
>> too, a triple-tap reliably yielded the behavior wanted for a double-tap.
>>
>> It seems like this information could be used to alter the settings to 
>> get expected behavior from a double-tap, but I'm not sure how.
>>
>> Does this tell anyone something?
>>
>
> It seems to me like this behavior is a bug, probably related to Xorg, 
> or more likely LXDE since it does not occur under Ubuntu.
>
> I like the idea that Trusty is a bug-fix-oriented release, and I'd 
> like to see what I can do to help get this fixed for Trusty as well as 
> Saucy.
>
> I've been reading https://wiki.ubuntu.com/Lubuntu/Testing/ and linked 
> docs.  It seems like I would be required to join a QA team in order to 
> do anything (e.g. access the QA mail list), even if my focus were 
> fixing one problem.  Then I read about laptop testing, and it seemed 
> that one would have to join a laptop testing team that was 
> Ubuntu-oriented rather than focused on Lubuntu, and the job 
> description also seems focused on execution of prescribed test cases.
>
> I should say that I also have an interest in certain other bug-fixes 
> for Trusty -- most of them for the desktop -- but admitting my 
> immediate interest in this specific laptop problem, does anyone have 
> advice on how to proceed?
>
> One late, parting thought: Instead of joining a QA team, etc., can I 
> file a standard bug report at Launchpad for issues with Trusty?
>

OK, without knowing for sure if this was the best way to proceed, I 
filed a bug report for Saucy at 
https://bugs.launchpad.net/ubuntu/+source/xserver-xorg-input-synaptics/+bug/1286326 
and for Trusty at 
https://bugs.launchpad.net/ubuntu/+source/xserver-xorg-input-synaptics/+bug/1286372

In both cases I filed against xserver-xorg-input-synaptics, even while 
wondering why the same package would work under Ubuntu but not Lubuntu.