[okular] [Bug 389947] New: touchpad scrolling: Okular jumps several lines down first when scrolling after the cursor moves out and back again

[GuHua]

https://bugs.kde.org/show_bug.cgi?id=389947

            Bug ID: 389947
           Summary: touchpad scrolling: Okular jumps several lines down
                    first when scrolling after the cursor moves out and
                    back again
           Product: okular
           Version: 1.3.1
          Platform: Archlinux Packages
                OS: Linux
            Status: UNCONFIRMED
          Severity: normal
          Priority: NOR
         Component: general
          Assignee: okular-devel at kde.org
          Reporter: renyuneyun at gmail.com
  Target Milestone: ---

Created attachment 110368
  --> https://bugs.kde.org/attachment.cgi?id=110368&action=edit
Desmonstrative screen recording

When scrolling in okular, it normally goes well.
However, the only (annoying) exception is that when I scroll using my touchpad,
sometimes okular jumps "randomly" first and then it scrolls normalls from where
it has jumped to.
After some observation and experienment, I have pinned down the situation where
this happens and the behaviour:
0. It only happens when I'm using touchpad to scroll, and only in okular (as
far as I have observed);
1. It only happens when my cursor moves from outside of okular application
frame (e.g. move to title bar, or a kde panel, or another application) to
inside of okular application frame; The toolbar is considered as "inside";
2. The "randomly" jumping isn't really random: it is always "several lines"
"down" (about half a page in most documents);
3. The jumping happens immediately (without annimation);
4. After the jump, okular scrolls normally at the position where it has jumped
to.

Sometimes, okular continues jumping even after the first jump and the cursor is
not moved outside of okular. Closing okular can "solve" this problem.

The attachment is a screen recording of this problem. Watch the cursor and the
left "thumbnail" view in okular.

-- 
You are receiving this mail because:
You are the assignee for the bug.