285071 - Chatzilla output pane anchor to bottom lost on default font upsize

Status: NEW

(Other Applications :: ChatZilla, defect)

Description

[Felix Miata]

I thought this was bug 64926, but according to
https://bugzilla.mozilla.org/show_bug.cgi?id=64926#c37 and private email from
one of the repeat commenters there it seems not. It's been around in the trunk
for as long as I can remember and is multi-platform.

To reproduce:
1-Open a bunch of Chatzilla channels, and let them populate with chat output a
while so that all have vertical scrollbars
2-Change default proportional font size smaller in main prefs and exit prefs
3-Change default proportional font size larger in main prefs and exit prefs

Actual result:
1-Most or all channel output panes have the vertical scroll position moved up
from the bottom
2-Additional channel output stays below the visible portion of the output panes

Expected result:
1-All channel output panes remain anchored to bottom (scroll position remains at
the bottom)
2-Additional channel output is always visible

Reproduction step 2 may not be necessary, but represents how I routinely hit the
problem. With a lot of channels open, it's no small nuisance to have to go into
each and move the scroll position back to the bottom after a default font size
increase.

Comment 1

[David Baron :dbaron: (⌚️UTC-4, no longer working on Mozilla)]

This seems like an app bug that may require some core APIs.  The app-level bug
should be in the app component; if core APIs are needed, a bug describing the
API needed should be filed.

Comment 2

[James Ross]

When bug 64926 is fixed it will be less of a problem, but frankly I don't see
what we can do in ChatZilla... it is not like we ever get told that the font
size has changed (or any other style changes).

Very tempted to WONTFIX.

Comment 3

[Robert Ginda]

In theory we could watch a pref and scroll all windows down when it changes,
right?  Or, as a workaround, introduce a new command that scrolls every tab to
the bottom in one step.

Comment 4

[:Gijs (he/him)]

Looking into this bug, I found that having your window scrolled up instead of
down at the bottom will actually result in having it scrolled down all at once
when you  enlarge the font size. I'm guessing that is also not ChatZilla's
fault, but I'm not sure. 

I'm not sure how we're going to do anything about it, though rginda's suggestion
sounds okay. I'm just not sure how to do it properly, and also stopping it from
scrolling back down when you already have your view scrolled up.

Comment 5

[Felix Miata]

It's worse today. Now all *start* anchored to top.

Comment 6

[Robert O'Callahan (:roc) (email my personal email if necessary)]

What do you mean?

Comment 7

[Felix Miata]

When I start CZ up in today's trunk, the output panes of all channels are
anchored to the top instead of the bottom. Until I scroll each of them down
manually with the too narrow scrollbar, nothing ever shows in them.