Bug 426716

Summary:	Touchpad-scrolling on breadcrumbs address bar is very jumpy
Product:	[Frameworks and Libraries] frameworks-kio	Reporter:	Frank Steinmetzger <dev+kde>
Component:	URL navigator	Assignee:	KIO Bugs <kio-bugs-null>
Status:	CONFIRMED ---
Severity:	minor	CC:	1i5t5.duncan, a.samirh78, kdelibs-bugs-null, kfm-devel, nate
Priority:	NOR	Keywords:	usability
Version First Reported In:	git master
Target Milestone:	---
Platform:	Other
OS:	Linux
Latest Commit:		Version Fixed In:
Sentry Crash Report:

Description Frank Steinmetzger 2020-09-19 10:26:25 UTC

Dear devs,

for a long time now I have a problem with the breadcrumb address bar. On the laptop I mostly use two-finger-scrolling on the touchpad. It works nicely in other applications, such as Okular or even Dolphin’s file view – albeit the latter is a little too fast.

When I try scrolling on a directory in the breadcrumbs address bar, either nothing happens at all (presumably because I move the fingers too slowly) or it jumps several directories at once. It is practically impossible to browse through directories in a controlled manner. My most often use case is to view several picture directories in succession in Gwenview.

When I decrease the scrolling distance in the Touchpad Settings to slow down scrolling and be less jumpy in general, then I can’t get the directory to change at all.

It is absolutely no problem when using a wheel mouse. The wheel produces discrete scroll events with one rotation index of the wheel, and I can move from one dir to the next very precisely.

STEPS TO REPRODUCE
1. Use a laptop with a touchpad
2. Open a file view with an address bar set to breadcrumbs style (e.g. Dolphin or Gwenview)
3. Open a directory that has sibling directories and move the mouse cursor over its entry in the address bar
4. Try scrolling with the touchpad

OBSERVED RESULT
Either nothing happens or it scrolls through too fast.

EXPECTED RESULT
It should be more easy to scroll through one directory at a time. Perhaps the trigger is based on some scroll event, that is only produced above a certain scrolling speed, but then in too large numbers. Maybe it should be triggered by scrolling distance instead. I must assume that touchpad scrolling works differently to mouse wheel scrolling. Otherwise the observed smooth movement in Okular wouldn’t be possible.

Thank you.

SOFTWARE/OS VERSIONS
KDE Frameworks 5.74.0
Qt 5.15.1
KDE Plasma 5.19.5

Comment 1 Nate Graham 2020-09-21 04:31:55 UTC

Can confirm. Happens in KDirOperator too so it must be a bug in the URL Navigator component itself rather than Dolphin. Moving to KIO, when KURLNavigator lives.

Comment 2 Frank Steinmetzger 2020-10-01 07:25:20 UTC

I just noticed the same problem in Korganizer when trying to scroll on the main view to go from one month to the next.

Comment 3 Ahmad Samir 2020-10-12 12:41:44 UTC

Then it's not KUrlNavigator specific.

Comment 4 Duncan 2025-04-24 00:29:08 UTC

In bug #476047 comment #10 Frank asked if this bug was related to that one. I replied (comment 11) saying I'd reply here to avoid spamming that bug.

First, thanks. It had never occurred to me to even try scrolling on the breadcrumbs (I knew about clicking on them) so I never knew of that functionality. Unfortunately the bug still seems to be there and a hi-rez "pixel-scrolling" touchpad is my only pointing device so I can't really observe the /intended/ behavior (I see something happens but it doesn't appear particularly usable ATM with this type of device).

To your question (answering as not a dev, but as a user that tracks live-git and is accustomed to "dev-speak" and doing the occasional simple patch of my own): Yes, it's related, but in the sense that it seems every scroll-usage needs its own code to treat hi-res/pixel-scrolling differently than mouse-wheel incremental-click-scrolling. Apparently, there's no way to fix it once in the input handling code and have it apply everywhere, tho fixing it in for example the kio breadcrumbs-handler would fix it for the breadcrumbs component (but not other components) of all apps that use it.

So until hi-rez/pixel-scrolling gets fixed for kio's breadcrumbs, looks like clicking the arrow-separators and selecting the appropriate subdir will remain the working UI for us.

The good news is that with the ports to wayland and to qt6 now basically done and the totally-breaks-functionality bugs generally fixed, as evidenced by that other bug, the devs seem to be focusing more on these "papercut" type bugs in the UI where there were other working ways to do the same thing making it less pressing to fix the still-broken ways. So while this bug has been basically stalled for 4-1/2 years, there's some reasonable hope now for a fix in the next (say) 2-6 months, and with any luck, your pointer on that other bug back to this related one will be the trigger to get it fixed too! =:^)