Bug 369286

Summary:	dolphin 16.08.1's Mousewheel scrolling is very small at all settings in non-Plasma5-desktops (regression from 16.04)
Product:	[Applications] dolphin	Reporter:	Shlomi Fish <shlomif>
Component:	general	Assignee:	Dolphin Bug Assignee <dolphin-bugs-null>
Status:	RESOLVED FIXED
Severity:	normal	CC:	elvis.angelaccio, jdchoate, kolAflash, marius.steffen, martin.sandsmark, nate, rdieter, tonurics, wbauer1
Priority:	NOR
Version:	16.12.2
Target Milestone:	---
Platform:	Mageia RPMs
OS:	Linux
URL:	https://bugs.mageia.org/show_bug.cgi?id=19362
See Also:	https://bugs.kde.org/show_bug.cgi?id=365968
Latest Commit:		Version Fixed In:
Sentry Crash Report:

Description Shlomi Fish 2016-09-24 15:01:06 UTC

When I'm using dolphin in detailed view in JWM or Xfce, then the mousewheel scrolling is small regardless of the systemsettings5 setting for number of lines to scroll. This is fine in the Plasma5 desktop. It also happens in a new user. This is not working in dolphin 16.08.1 and is fine in a dolphin 16.04.3 package that I built from an old svn checkout

Reproducible: Always

Steps to Reproduce:
1. New user.
2. startx as JWM or Xfce (non-plasma5).
3. start dolphin in detailed files mode.
4. scroll using the mousewheel.

Actual Results:  
The scrolling does not scroll a lot.

Expected Results:  
The scrolling should be more substantial.

I'm on Mageia x86-64 v6.

Comment 1 Shlomi Fish 2016-09-24 16:10:37 UTC

According to git bisect:

<<<<<<
8d61c9c7b6f5a97803bf154529b413ee69bc2a1c is the first bad commit
commit 8d61c9c7b6f5a97803bf154529b413ee69bc2a1c
Author: Martin T. H. Sandsmark <martin.sandsmark@kde.org>
Date:   Wed Jul 13 00:29:15 2016 +0200

    Fix scrolling on hidpi screens
    
    Scrolling with libinput was unbearably slow.
    
    QScrollBar is much better at scrolling than us, so let it handle it.
    
    REVIEW: 128432
    BUG: 357618

:040000 040000 356cc733e7cfb01d864d645b63919fe8beccce03 33b98e096f14a4ca83ff3ab5640aba301cf014a6 M      src
shlomif@telaviv1:~/Download/unpack/kde/dolphin/dolphin$ 
>>>>>

Comment 2 Tonurics 2016-10-29 11:28:17 UTC

I believe this bug is related to https://bugs.kde.org/show_bug.cgi?id=365968

Comment 3 Elvis Angelaccio 2016-11-20 12:08:27 UTC

Please try again with the latest git master (or Applications/16.12 branch)

Comment 4 Shlomi Fish 2016-11-20 14:46:30 UTC

(In reply to Elvis Angelaccio from comment #3)
> Please try again with the latest git master (or Applications/16.12 branch)

The bug/problem still happens with:

<quote>
shlomif@lap:~/Download/unpack/dolphin/dolphin$ git show | cat
commit 4322ef4114b0b92eee8aa1e941e23188496fbab5
Merge: 341a09f 90beb4a
Author: Elvis Angelaccio <elvis.angelaccio@kde.org>
Date:   Sun Nov 20 13:04:47 2016 +0100

    Merge branch 'Applications/16.12'
    
    * Applications/16.12:
      Fix slow scrolling in dock panels

shlomif@lap:~/Download/unpack/dolphin/dolphin$ 
</quote>

on fedora 25 x86-64.

Comment 5 Elvis Angelaccio 2016-11-20 18:29:12 UTC

I just tried on a Fedora 25 Gnome VM and scrolling works fine in the Detail view mode (latest git master). What's your input driver? evdev or libinput?

Comment 6 Shlomi Fish 2016-11-20 19:43:54 UTC

(In reply to Elvis Angelaccio from comment #5)
> I just tried on a Fedora 25 Gnome VM and scrolling works fine in the Detail
> view mode (latest git master). What's your input driver? evdev or libinput?

How do I tell exactly? Based on ~/.local/share/xorg/Xorg.0.log it seems to be evdev because it is mentioned several times whereas libinput is completely absent.

Comment 7 Elvis Angelaccio 2016-11-21 10:40:36 UTC

(In reply to Shlomi Fish from comment #6)
> (In reply to Elvis Angelaccio from comment #5)
> > I just tried on a Fedora 25 Gnome VM and scrolling works fine in the Detail
> > view mode (latest git master). What's your input driver? evdev or libinput?
> 
> How do I tell exactly? Based on ~/.local/share/xorg/Xorg.0.log it seems to
> be evdev because it is mentioned several times whereas libinput is
> completely absent.

Yes, that's how you check it. Btw I tried with evdev and still cannot reproduce on Gnome...
There must be something else going on.

Comment 8 John Choate 2016-12-27 23:27:20 UTC

This bug was fixed in Dolphin 16.12.0 and all scrolls well in dolphin now. But this bug still affects the applications launcher/menu. :(

Comment 9 Elvis Angelaccio 2016-12-28 10:31:48 UTC

(In reply to John Choate from comment #8)
> This bug was fixed in Dolphin 16.12.0 and all scrolls well in dolphin now.
> But this bug still affects the applications launcher/menu. :(

It's a different bug, see https://bugs.kde.org/show_bug.cgi?id=355410