541876 - [SM][tabmail] Scroll position (message and thread pane) is lost when switching tabs

Status: NEW

(SeaMonkey :: MailNews: Message Display, defect)

Description

[Jens Hatlak (:InvisibleSmiley)]

When switching MailNews tabs, the scroll position is lost, both in the message pane (mail, news and feeds) and thread pane. Thus it defeats the potential benefit of tabbed browsing, the ability to read longer texts in different tabs incrementally and in turn. This single issue weighs even more than the fact that tab switching forces a reload of external sources like feeds.

Unless it is too hard to find a workaround for this single issue, this bug should focus on fixing the scrolling issue. Maybe we can even get branch approval, who knows. In case there's a difference in difficulty I further recommend prioritizing fixing the message pane over the thread pane (content is more important than meta data).

Technically, saving the scroll position(s) shouldn't be too hard, we probably only need to add some data to the tabInfo that's fed into saveTabState(). Restoring the state in showTab() might be harder since we need to delay it until after the message/content has loaded.

The corresponding general TB bug is bug 487386. AFAIK no complement has been filed for SM yet.

Comment 1

[Karsten Düsterloh]

Attachment: ugly proof of concept

(In reply to comment #0)
> When switching MailNews tabs, the scroll position is lost, both in the 
> message pane (mail, news and feeds) 

... and potentially the header pane ...

> and thread pane.

Hm? This works for me on 2.0.x.

> Technically, saving the scroll position(s) shouldn't be too hard, we probably
> only need to add some data to the tabInfo that's fed into saveTabState().

Yep.

> Restoring the state in showTab() might be harder since we need to delay it
> until after the message/content has loaded.

Jens, can you try this patch?
I'm not taking/requesting reviews yet, because I'm not quite sure I like this hack. ;-)

Comment 2

[Jens Hatlak (:InvisibleSmiley)]

(In reply to comment #1)
> > and thread pane.
> 
> Hm? This works for me on 2.0.x.

Well, scrollToRow() is not exactly the same as restoring the scroll position but it comes close. As far as I'm concerned we can leave it as it is.

> > Restoring the state in showTab() might be harder since we need to delay it
> > until after the message/content has loaded.
> 
> Jens, can you try this patch?

Works pretty well with ordinary messages (both if displayed in the message pane and when displayed individually) but unfortunately not with feeds (web pages). I guess we need a different/better page load trigger.

> I'm not taking/requesting reviews yet, because I'm not quite sure I like this
> hack. ;-)

I could create an extension if I knew how to overlay XBL... :-/

Comment 3

[WBT]

See also Bug 487386.

Comment 4

[Thomas D. (:thomas8)]

As this is a Seamonkey bug, it cannot depend on a Thunderbird bug. Let's just keep the topical link in see-also.