Jumping cursor during text input

[pwabrahams]

Often, randomly, my text cursor jumps around during textual input. The effect is that insertion point suddenly moves to somewhere on a line or so behind where I'm working -- and whatever I'm typing actually gets inserted there. This occurs both in Firefox and in OpenOffice. What's going on?

[oshunluvr]

Re: Jumping cursor during text input

you on a laptop with a touchpad?

[pwabrahams]

Touchpad

Yes, I am on a laptop with a touchpad. I've considered that as a possible cause, but I can't see what accidental touches would produce these particular effects.

[oshunluvr]

Re: Jumping cursor during text input

?

I suggest you try disabling the touchpad and reporting your results...

[skunk]

Re: Jumping cursor during text input

Does this help

xinput --set-prop "SynPS/2 Synaptics TouchPad" "Synaptics Two-Finger Pressure" 280

[pwabrahams]

Disabling or modifying touchpad

I've temporarily disabled the touchpad, but setting the properties of the touchpad would be a better solution if I could get it to work. Here's what I got:

pwa@Asus-laptop:~$ xinput --set-prop "SynPS/2 Synaptics TouchPad" "Synaptics Two-Finger Pressure" 280
unable to find device SynPS/2 Synaptics TouchPad

The trouble with any of this is that since the problem occurs unpredictably, it's difficult to know with any confidence whether I've solved it.

[oshunluvr]

Re: Jumping cursor during text input

Sorry I wasn't more verbose, I meant to disconnect the touchpad temporarily to test my theory. I assumed you intended to keep using it but your immediate disbelief it might be the cause needs to be confirmed or refuted before we can move forward. Frankly, I was surprised you wouldn't suspect the touchpad right away because I can't think of anything more obvious.

My Dell can be so sensitive the heal of my hand passing over it will cause a jump. The best setup I had was on an old HP that had a physical switch to turn off the touchpad whenever I wanted.

xinput likely had the wrong input name. You should be able to see the correct device name by typing xinput --list then try the above command with the correct device label.

Also, look to see if you have an /etc/X11/xorg.conf file and if so, what it contains under "Input Device" that pertains to your touchpad. If you don't have this file (or it just has generic mouse), look through your /var/log/Xorg.0.log and look for input devices. If you have the file, search for xorg.conf examples for your laptop.

[jeremy1701]

Re: Jumping cursor during text input

I had this issue to. I solved it by disabling 'tapping' to click on the touch pad. I never really use it anyway as I always use the button.

[pwabrahams]

I usually use a USB mouse -- but ...

I thought all along that the touchpad might be the problem, but I didn't see quite how that could happen, especially since the particular movements didn't have an obvious relationship to possible touches. I usually use a USB mouse anyway, but having the touchpad available is handy once in a while.

I've now disabled tapping on the touchpad from System Settings, and I'll see if the problem recurs. If it does, I'll then try disabling the entire touchpad and see if that solves the problem. But if I don't see the problem, I still can't be sure that I won't see it later on, unfortunately. That's the trouble with intermittencies in general -- an apparent solution can turn out to be an illusion.

[GreyGeek]

Re: Jumping cursor during text input

Disabling the touch pad will solve your problem. I "thought" I was a careful touch-typist, but even the slightest relaxation of either hand which resulted in part of the heel of thumbs of either hand even slightly touching the pad resulted in the cursor moving the text insertion point to some other random place, sometimes triggering undesired page actions. At first I used a script which used synclient:

#!/bin/bash
# toggle synaptic touchpad on/off

# get current state
SYNSTATE=$(synclient -l | grep TouchpadOff | awk '{ print $3 }')

# change to other state
if [ $SYNSTATE = 0 ]; then
  synclient touchpadoff=1
elif [ $SYNSTATE = 1 ]; then
  synclient touchpadoff=0
else
  echo "Couldn't get touchpad status from synclient"
  exit 1
fi
exit 0

and called it from the autostartup tool in system settings. When system settings began including an improved touchpad utility I used it to disable the touchpad. Now I NEVER have a problem with the cursor jumping around.

[pwabrahams]

Disabling or modifying touchpad

The consensus seems clear that disabling the touchpad will work. But disabling the tapping only is a less drastic solution, so if that works also, it would seem to be preferable. Time will tell, I suppose.

As an experiment, I just now grazed the heel of my hand across the touchpad with tapping disabled. The cursor moved around but the insertion point didn't move.

[oshunluvr]

Re: Jumping cursor during text input

As an end-goal once you figure out how to prevent the problem, you could script a file to change settings for mouse/no-mouse times...

[pwabrahams]

Script for mouse / no mouse times

I don't see how to characterize the mouse/no mouse times, so such a script would for me just be excess baggage. Even if I were not using an external mouse, I probably wouldn't use the tap on the main pad -- the side buttons are quite sufficient and less vulnerable to fat fingers.

Fortunately the mouse pad behavior can be configured in System Settings / Input Devices / Touchpad, and the facilities there offer a lot of useful choices.

[oshunluvr]

Re: Jumping cursor during text input

I use a mouse when I settle in for several hours work, but if I'm just doing a one-off or on a train or airplane- I usually don't bother grabbing the mouse out of my briefcase. It depends on your overall use of the laptop.