Problem with scrolling with mouse wheel in Chrome / Chromium

[timt]

I've just installed 17.04, and nearly everything is working very well. However, I've just come across a problem when scrolling through web pages using my mouse wheel in Google Chrome (and the same happens in Chromium, but not in any other application that I have tried so far).

The problem is related to the fact that if you don't move the mouse pointer for a few seconds, it disappears until it is moved again. This in itself seems to be a general behaviour of the Plasma desktop, and happens wherever the pointer is (over *any* application or just over the workspace). (As an aside - is this the expected default behaviour? I couldn't see anywhere to toggle this behaviour on/off in the settings).

So, on to the problem... if I am scrolling through a long web page using my mouse wheel, but not moving the mouse (so the pointer stays in one place), when the pointer disappears after a few seconds, Chrome/Chromium no longer recognises that the mouse wheel is being used, and I can no longer scroll through the page until I move the mouse again to reawaken the pointer.

I've tried using two different mice, one wired USB and the other wireless, and get the same behaviour in both.

In other applications, when the pointer disappears the app still recognises that the mouse wheel is turning and continues to scroll.

I'm not sure if this is a problem with KDE/Plasma or with Chrome.

Any suggestions?

One solution would be simply to disable the behaviour of the mouse pointer disappearing after a few seconds of inactivity (I might prefer that in any case). Is there any way to do that?

Thanks,

Tim

[timt]

Ahh.. that's interesting: I've just tried this on my laptop, which I have also just upgraded to 17.04. When doing the upgrade on both laptop and desktop, I wiped all KDE/gtk/etc config dot files/dirs in my home dir before logging into KDE for the first time, so that I start off with a fresh set of config files for the new system. So the KDE/Plasma setup on both laptop and desktop should be the same.

However, on the laptop I do not see the disappearing pointer behaviour if the mouse is not moved. The pointer just stays put indefinitely, and hence I don't experience the problem with scrolling in Chrome.

So the question is, why on my desktop (but not laptop) does the mouse pointer disappear if it hasn't been moved for a few seconds? And how can I stop it from doing this?

[SpecialEd]

I'm a noob so take it or leave it but when in doubt, video drivers.

[timt]

Thanks SpecialEd! It turned out not to be caused by video drivers, although your comment did prompt me to do a bit more digging around.

It turns out that the pointer disappearing after a short time of inactivity is due to a small utility program called "unclutter". I've never heard of it before, but for some reason it turns out it was installed on my desktop but not on my laptop.

I've fixed the problem by disabling this program (by setting the option START_UNCLUTTER to "false" in /etc/defaults/unclutter -- although of course I could have just uninstalled it instead).

So my mouse pointer no longer disappears on my desktop, and I don't have any problems using the mouse wheel to scroll. Happy days!

[SpecialEd]

Cool.

[GreyGeek]

I was watching this thread but haven't had any experience with a disappearing mouse pointer. I would have though it was either a setting in System Settings Input Devices Mouse, or a bug in the video driver or hardware, like SpecialEd suggested. However, this "bug" points out how difficult fixing what is perceived to be a problem can be. In reality your system was working perfectly. How would anyone know to ask if such a program was installed? The assumption would be either an OS problem or a video hardware problem. Someone could even forget that they had that program installed, or wouldn't know that hiding the mouse pointer was part of its job of "uncluttering". *shakes head*

[timt]

I absolutely agree, GreyGeek. There's some irony in the fact that I had to unclutter my system by disabling a program called unclutter :-)

It seems like unclutter has not been updated for a long time (although I might be wrong there) - so I guess there must have been some recent change in the way that Chromium responds to mouse events. I've never experienced this problem until upgrading to 17.04. Oh well, all sorted now.