scrolling with trackpoint doesn't stop when you release buttons

[maticmatija]

In some apps, like firefox and openoffice (but not Evince, for exmaple), I have problem with trackpoint.

You can scroll a document, page, site with it if you press middle button and push it in any direction.
But sometime the scrolling doesn't stop when you release the button or trackpoint (normal behavior). This happens when a page/document is long and you try to scroll more than just line or two at the same time. Usually it stops at bottom of page.
It should stop at the moment you release the middle button or the trackpoint.

My laptop is Thinkpad R50e
I'm using Ubuntu 8.10 - Intrepid Ibex, but had same problem with 8.04

[A.Kromic (akromic)]

Experienced the same problem, ever since I started using Ubuntu with ThinkPads.

[maticmatija (maticmatija)]

I did some additional research and I think I found the reason.

Some macbook user have similar problem with Firefox when they are using their mighty mouse and/or touchpad. They don't have problems with Safari. This is probably because Safari is optimised for mighty mouse and touchpad with "unlimited input" scroll function. (The amount of input is not limited to pre-defined wheel move but it depend how much you press/drag/rotate the device/button).

It seems that scrolling in Firefox and similar programs are written for mouse wheels, where amount of input is quite low (few turns of wheel at once) and program can do the scrolling that is requested by that input almost at same time. Devices like trackpoint, mighty mouse's wheel or touchpad can have much higher input. So when you press a trackpoint a bit harder the input is much greater comparing to wheel. The program cannot execute requested scrolling while you are pressing the trackpoint and does it afterwards.

I also made a little experiment to prove this. I opened a very long page (http://www.election.demon.co.uk/lifepeers.html), turned my wheel mouse upside down and drag it over a rug to achieve greater input than usual. Even though the result was not as bad as with trackpoint, the scrolling didn't stop when I lifted it.

One solution is to rewrite the scrolling feature in Firefox and other programs with same problem. In generally this probably won't happen until more devices will use "unlimited" input scrolling. But because scrolling function can be added to Firefox as add-on, I hope some programer using thinkpad or any other device that behaves similar will do that for us at least for Firefix (or at least create while loop for scrolling -> scroll while trackpoint or middle button is pressed).

Other way to fix this is to modify the trackpoint driver. Trackpoint scrolls (and moves cursor) at different speed regarding how hard you press it. I've noticed that if you press it gently the scrolling stops when you release it (the scrolling is still fast and usable). The problem only occurs when you press it a bit harder. So if you manage to ignore the input that comes with harder press the problem would probably be solved (in other words - limit the maximum speed of trackpoint). Other way to deal with it is to give it constant speed of scrolling.

But this is only my opinion and I'm not a programer or something.

Please share with us if you find a solution because this problem is really annoying.

[maticmatija (maticmatija)]

I found a way how to make things much better!
There is an application called gpointing-device-settings that allows you to set the inertia level for scrolling (the speed of mouse cursor stays intact). By setting it bit higher the scrolling gets a bit slower but its much more responsive. The program is in repositories of Ubuntu 9.10 (Karmic).