Bug 420770 - okular-20.04.0: very sluggish scrolling behavior
Summary: okular-20.04.0: very sluggish scrolling behavior
Status: RESOLVED FIXED
Alias: None
Product: okular
Classification: Applications
Component: general (show other bugs)
Version: 20.04.0
Platform: Gentoo Packages Linux
: NOR normal
Target Milestone: ---
Assignee: Okular developers
URL:
Keywords:
Depends on:
Blocks:
 
Reported: 2020-04-29 21:18 UTC by Till Schäfer
Modified: 2020-04-30 21:12 UTC (History)
0 users

See Also:
Latest Commit:
Version Fixed In:
Sentry Crash Report:


Attachments
example of the scrolling behaviour (3.34 MB, video/x-matroska)
2020-04-29 21:18 UTC, Till Schäfer
Details

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Description Till Schäfer 2020-04-29 21:18:33 UTC
Created attachment 128014 [details]
example of the scrolling behaviour

When scrolling fast with the mouse wheel through a document in okular 20.04.0 it is now a very sluggish experience. When using the scrollbar on the other hand everything is very fast. 

I have attached an example video. You can see the jumpiness of the scroll bar, when using the mouse wheel. Furthermore, the wheel scroll speed is almost identical through this video. When it comes to the bottom of the document it slows down a lot. In the second part of the video, I am using the scroll bar. As you can see, the scrolling is much smoother. 

I am using 
Okular 20.04.0
Frameworks 5.69.0
Plasma 5.18.4.1

.. on a not so slow pc (i7-4790K, with Geforce GTX 970 (nvidia drivers 440.82)
Comment 1 Till Schäfer 2020-04-29 21:19:48 UTC
maybe related to Bug 420755
Comment 2 Till Schäfer 2020-04-30 21:12:33 UTC
this is fixed for me by the following commit 


Git commit 08d368c13b0fa7368be9720b8de1b7a67188b8e9 by Nate Graham, on behalf of Kezi Olio.
Committed on 29/04/2020 at 22:15.
Pushed by ngraham into branch 'release/20.04'.

Fix scroll speed with free-spinning mouse wheels
FIXED-IN: 1.10.1

This just removes the smooth mouse wheel scrolling, fixing that problem.

M  +4    -10   ui/pageview.cpp

https://invent.kde.org/kde/okular/commit/08d368c13b0fa7368be9720b8de1b7a67188b8e9