Configure touchpad double-tap

John Hupp lubuntu at
Fri Feb 28 01:10:14 UTC 2014

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 
>>> 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 
>> 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 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?

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