Bug 508684

Sorry for not finishing everything in the first comment, I've clicked enter too soon and it just uploaded the issue without having finished the first comment.

SUMMARY
Also, as you can see from the video, I can highlight the icon if I move the mouse cursor on top of the icon from the right, top, and left, but if I move it from the bottom it doesn't get highlighted, and this issue doesn't happen on desktop icons that only have one line of text.

STEPS TO REPRODUCE
1. Move the cursor from the bottom of a desktop icon with 2 lines of text

OBSERVED RESULT
The Desktop icon doesn't get highlighted 

EXPECTED RESULT
The Desktop icon gets highlighted 

SOFTWARE/OS VERSIONS
Linux/KDE Plasma: Fedora 42
KDE Plasma Version: 6.4.4
KDE Frameworks Version: 6.17.0
Qt Version: 6.9.1

ADDITIONAL INFORMATION

Can reproduce on Plasma 6.4.4 when moving cursor from wallpaper to icon.

This is already fixed in Plasma 6.5.0, thankfully.

(In reply to Nate Graham from comment #3)
> This is already fixed in Plasma 6.5.0, thankfully.

thank you! but why doesn't the fix get backported into 6.4.5 too?

It actually may have. I can't quite remember which specific release it went into.

(In reply to Nate Graham from comment #5)
> It actually may have. I can't quite remember which specific release it went
> into.

This issue is still happening in KDE Plasma 6.5.1

In fact it actually got worse now!

The desktop icons now don't get highlighted even when I move the cursor from left to right too!

Created attachment 186408 [details]
Desktop Icon issue got worse

This specific bug was fixed; the issue you're seeing now is subtly different and tracked with Bug 511025.

(In reply to Nate Graham from comment #9)
> This specific bug was fixed; the issue you're seeing now is subtly different
> and tracked with Bug 511025.

I see that bug has gotten fixed, thanks!
Although I'm still experiencing the bug that I've reported in the first post here, where desktop icons with 2 lines of text still don't get highlighted if I hover the mouse cursor on them from the bottom

Yeah, it came back and will be fixed again in Plasma 6.5.4.

(In reply to Nate Graham from comment #11)
> Yeah, it came back and will be fixed again in Plasma 6.5.4.

ok thanks!

(In reply to Nate Graham from comment #11)
> Yeah, it came back and will be fixed again in Plasma 6.5.4.

It is still happening in Plasma 6.5.4

(In reply to Nate Graham from comment #11)
> Yeah, it came back and will be fixed again in Plasma 6.5.4.

It is still happening in Plasma 6.5.4

I'm acutally testing on KDE Linux with the plasma 6.6 dev version and this issue is happening there also

I'm also on KDE Linux and I can't reproduce the issue.

Does it happen for you in a new clean user account on the same computer with only one screen?

(In reply to Nate Graham from comment #16)
> I'm also on KDE Linux and I can't reproduce the issue.
> 
> Does it happen for you in a new clean user account on the same computer with
> only one screen?

yes it happens on a new clean user account on the same computer with only one screen.
I'm just talking about the issue where the icon with two lines of text doesn't get highlighted if I move the cursor from the bottom

Right, I can't reproduce it. :/

Any chance you could share a screen recording of it still happening?

And what scale factor are you using?

(In reply to Nate Graham from comment #18)
> Right, I can't reproduce it. :/
> 
> Any chance you could share a screen recording of it still happening?
> 
> And what scale factor are you using?

Sure! I'm using 100% scaling

Created attachment 187762 [details]
Issue still present in KDE Plasma 6.6

I've added the wrong video, sorry

Created attachment 187763 [details]
Issue still in KDE 6.6

That's so weird. I can't reproduce it at all. Not with a link, like you've got in the video, and not when the desktop isn't focused; never.

(In reply to Nate Graham from comment #23)
> That's so weird. I can't reproduce it at all. Not with a link, like you've
> got in the video, and not when the desktop isn't focused; never.

I can reproduce it also on my laptop that has an intel igpu, meanwhile my desktop has a nvidia gpu

Created attachment 187807 [details]
Issue happening on another system

I clearly see the issue in the screen recording. I'm not able to reproduce the bug on Plasma built from git-master at a couple of different screen resolutions. 
I also can't reproduce in 6.5.4

Created attachment 187885 [details]
Reproducible on KDE Linux 2025-12-22

Can reproduce it on KDE Linux 2025-12-22.

Created attachment 187886 [details]
Screen recording - cannot reproduce

Screen recording where I try to reproduce the bug

Could it be a nvidia driver bug with qt? I have a 4060 with the 580 driver from fedora

actually not because I can reproduce the issue also on my laptop with an intel igpu, so it can't be just a nvidia issue

Created attachment 187887 [details]
diagram showing the areas where hovering triggers

It's not a graphics card driver bug, it's a FolderView bug. I can reproduce it and figured out the cause.

Consider the attached diagrams. There's two things that fight about what is hovered, the delegate and the overall view. They disagree about when something is hovered.

The green lines show the exact areas where the delegates themselves starts to think they're hovered. The blue line shows approximately where the view begins to consider them hovered.

As you can see, there's a small gap where the green part goes further than the blue line. If the pointer crosses slowly enough, the delegate will say "hey, I'm hovered now!", the view will say "no you're not", and no hover happens. Then when you move further up, the delegate will say "hey, nothing's changed, all good", and the view is all like "well, I guess you're hovered now, but I don't tell things when they're hovered, I only tell them when they're not hovered, so my job is done". In the end, the mouse is squarely over the icon, but not considered hovered.

So as far as I can tell this can only happen

- with two-line labels, because otherwise the blue line is always outside the green line
- without a row of icons directly below them, as otherwise the green areas directly touch, and then there doesn't seem to be an issue - in that case the green and blue lines are the same
- if you move rather slowly over the relevant parts - if you're moving quickly, you might skip the gap completely, and then both immediately agree that they should be hovered. That's why it happens inconsistently.

What I don't know yet is

- why the blue line is where it is, and not aligning with the blue line - might be a Qt GridView issue, or more likely FolderView is doing something wrong
- how to fix this - the best solution would obviously be "don't have several components fight over when one of them is hovered", but that requires cleaning up the logic across several long and very complex files crammed full of arcane and fragile functionality where everything depends on everything else. Long-term something that 100% has to happen, but also a lot of work and it carries the risk of breaking lots of things.

A possibly relevant merge request was started @ https://invent.kde.org/plasma/plasma-desktop/-/merge_requests/3414

(In reply to Bug Janitor Service from comment #32)
> A possibly relevant merge request was started @
> https://invent.kde.org/plasma/plasma-desktop/-/merge_requests/3414

thanks!

Thanks cwo, for what it's worth, I compiled your branch (folderview_hover_fix_delegatesize) locally and tested, for me the bug is fixed and so far I could see no problems with folder view widget, desktop icons, other widgets etc.