1829470 - Restore option for connecting lines in thread pane

Status: NEW

(Thunderbird :: Folder and Message Lists, defect, P3)

Description

[Francesco]

User Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/112.0.0.0 Safari/537.36

Steps to reproduce:

The new thread pane is missing the connecting lines that were present in previous versions.

See discussion here:
https://thunderbird.topicbox.com/groups/beta/Tebdbe4ab4dd7d3e3-Mb091acc12e316e5e05136d28

Comment 1

[BB]

https://github.com/Betterbird/thunderbird-patches/blob/main/115/bugs/1829470-thread-lines.patch
This only adds the rightmost thread line via CSS as a background image. For reference, here the code that drew multiple lines:
https://searchfox.org/mozilla-central/rev/373d05f4eabdb90a6480d5d36d983b8bff36c9d8/layout/xul/tree/nsTreeBodyFrame.cpp#3036-3057

Comment 2

[Alessandro Castellani [:aleca]]

What is the usefulness of that dashed line?
Indentation hierarchy is already pretty obvious. That dashed line only adds noise and it doesn't bring any benefit to visually connect strangely indented threads since it's interrupted when the rows don't align.

Comment 3

[Alfred Peters [:infofrommozilla]]

Attachment: Screenshot 2023-05-15 221409.png

(In reply to Alessandro Castellani [:aleca] from comment #2)

Indentation hierarchy is already pretty obvious. That dashed line only adds noise and it doesn't bring any benefit to visually connect strangely indented threads since it's interrupted when the rows don't align.

This depends...
For example, on the depth of the thread.

Comment 4

[Thomas D. (:thomas8)]

(In reply to Alfred Peters from comment #3)

Created attachment 9333762 [details]
(In reply to Alessandro Castellani [:aleca] from comment #2)

Indentation hierarchy is already pretty obvious. That dashed line only adds noise and it doesn't bring any benefit to visually connect strangely indented threads since it's interrupted when the rows don't align.

This depends...
For example, on the depth of the thread.

I would agree with Alfred that indentation hierarchy may not be easy to determine depending on the depth, structure and volume of the thread. Interrupted lines would probably be rare and still better than no lines. It's pretty hard to figure out indentation with bare eye for deep and long threads.

Not urgent, but would certainly be nice to have this back, at least as an option. Ymmv, yes, for others with less deep and smaller threads this may just be noise.

Comment 5

[Alessandro Castellani [:aleca]]

Attachment: WIP: Bug 1829470 - Reimplement thread level indicators for threaded messages

Comment 6

[Alessandro Castellani [:aleca]]

I uploaded an initial patch just as an experiment.
This implementation is not easy if we want to do it right, and the offered solution in comment 1 is not complete since it doesn't account for the most important feature, which is the connected lines for siblings on the same level that are separated by other messages with deeper levels.

This is tricky, since a message might need to represent multiple level of threading and there's only so many CSS elements we can dynamically add.

Comment 7

[BB]

Please add the appropriate attribution of this work as can be seen here even if only parts were taken from our patch:
https://hg.mozilla.org/comm-central/log?rev=betterbird, look for "based on". Or something like this:
https://hg.mozilla.org/comm-central/rev/4dbfe690171b

Comment 10

[EarlgreyTea]

A question was posted in the MozillaZine.jp forum about making thread connecting lines visible again.
https://forums.mozillazine.jp/viewtopic.php?f=3&t=22291
When I told the person asking the question that it had been removed, he said,
"This is very troubling...The reason I've been using Thunderbird until today is because of this feature. And yet..."
The person then decided to downgrade Thunderbird.

Thread connection lines seem to be an essential feature for people who use Thunderbird to display long and deep threads.
I think the severity of this bug should be reconsidered

Comment 11

[[:AlanK]]

I would also agree with #10 EarlgreyTea.
An example of lines by #3 Alfred Peters is nice but the connectors in that image are still a bit disjointed in my opinion.
In version 102 I was able to put code in my userChrome.css and produce this display.
https://postimg.cc/TyBz6c0c
file:///home/alan/Downloads/New-Threads.png
The junctions of line have arrows to show that I replied or forwarded or an icon, in this case a sheet of paper, just to make that junction.
It was simple in 102, the markers were there so I could code reply/forward/read/unread, etc and pick the appropriate icon both in news and email. I found it easy to see a line coming up from below indicating that someone late to the discussion added something and that reply is several lines down off the screen.

Comment 12

[Ed]

See also https://new.reddit.com/r/Thunderbird/comments/1d99atc/is_there_a_way_to_add_vertical_lines_in_threads/.