Configure touchpad double-tap

[John Hupp]

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.)