[Libreoffice-bugs] [Bug 140537] Unnecessary scrolling in Math's Element pane

[bugzilla-daemon at bugs.documentfoundation.org]

https://bugs.documentfoundation.org/show_bug.cgi?id=140537

--- Comment #9 from dante19031999 at gmail.com ---
> I don't understand your comment:
Starmath depends on those two. Coming from a non very distant branch,
rebuilding those should be enough to reproduce starmath current behavior.

I guess this means it doesn't work.
The odds where not very great.
The only possible gap I could found was what looked like the scroll event
handler without checking if it was able to scroll.
There's no much more I can do since the new info aims somewhere out of my
knowledge (vcl). 
Some useful information could be extracted from the behavior of writer's right
panel.

My thoughts:
It happens with default UI but not GTK3.
Starmath implementation is independent of GUI, it's managed by vcl.
That makes me suspect from vcl more than starmath. 
Checking the right panel and other similar panels may help.
If the bug is reproduced with another panel then it's vcl.
If not we can not know for sure.
Judging in the structure of the ElementsDockingWindow I would say it's
SmElementsControl::LayoutOrPaintContents if mxScroll->vadjustment_get_value()
could actually return a negative value.
There could be two implementations if there was scripting via macros and some
virtual dependencies (virtual functions overriding), one for gtk3 (works) and
others (not works).
see: https://opengrok.libreoffice.org/s?defs=vadjustment_get_value&project=core
SalInstanceScrolledWindow & GtkInstanceScrolledWindow
My guess would be somewhere a missing sign check.
In other words, it doesn't cut at 0 and let you scroll into the negative space.

> You can give a try with gen rendering by typing in a terminal/console:
> export SAL_USE_VCLPLUGIN=gen && soffice --math

This ask me to install more stuff. Stuff which by the way is old (7.0.4), I
guess from my system repo.

If ∃ UI team I would suggest to ask them about it and maybe moving this to the
UI sector.

-- 
You are receiving this mail because:
You are the assignee for the bug.
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <https://lists.freedesktop.org/archives/libreoffice-bugs/attachments/20210220/72d1c314/attachment.htm>