Bug 424095

Summary: Since okular in kde applications 20.04 scrolling using up/down keys inconvenient
Product: [Applications] okular Reporter: vyacheslav <galdralag>
Component: generalAssignee: Okular developers <okular-devel>
Status: RESOLVED INTENTIONAL    
Severity: normal CC: nate
Priority: NOR    
Version First Reported In: 1.10.3   
Target Milestone: ---   
Platform: Other   
OS: Linux   
Latest Commit: Version Fixed/Implemented In:
Sentry Crash Report:

Description vyacheslav 2020-07-11 10:06:51 UTC 
SUMMARY
Okular from kde applications 19.12 and earlier scrolls approximately one text line when using up/down keys.
Since 20.04 when pressing up/down key okular jumps over several text lines.
When reading text this jump confuse eyes from current reading position. It is very inconvenient.

STEPS TO REPRODUCE
Compare scroll lines/pixels count using up/down keys in okular from kde applications 19.12 and 20.04

EXPECTED RESULT
Scroll count using up/down keys should be as it was in okular from 19.12


SOFTWARE/OS VERSIONS
Linux/KDE Plasma: ArchLinux
KDE Plasma Version: 5.19.3
KDE Frameworks Version: 5.71
Qt Version: 5.15
Comment 1 Nate Graham 2020-09-11 14:29:08 UTC 
This is intentional now that there's a smooth animated scrolling effect, which will be re-enabled in Okular 1.11.2 (AKA from kde applications 20.08.2). It should be nicer now and hopefully it's not annoying anymore.
Comment 2 Laura David Hurka 2020-09-12 18:38:23 UTC 
If I make the window small, arrow keys scroll almost half of the page. In item based views, a scroll step is usually 3 lines, but not more than one line less than fits on screen.

Currently PageView scrolls by 100 device independent pixels. How about scrolling 5 Em, but not more than 25% of the viewport height?
Comment 3 Nate Graham 2020-09-14 19:56:34 UTC 
That seems reasonable, but shouldn't be be 3em to match the default number of lines to scroll? I fact we should just make sure that the arrow keys scroll exactly as much as one "tick" of a mouse's scroll wheel.