700028 - Position pinned tabs even when the tab bar doesn't overflow

Status: RESOLVED WONTFIX

(Firefox :: Tabbed Browser, defect)

Description

[Jez]

The patch to resolve bug #601228 (hg changeset at http://hg.mozilla.org/mozilla-central/rev/5e3c0dc7434b) stopped Firefox from doing anything in tabbrowser's _positionPinnedTabs method when the tab bar is not overflowing:

http://mxr.mozilla.org/mozilla-central/source/browser/base/content/tabbrowser.xml#3004

This is because of the check:
var doPosition = this.getAttribute("overflow") == "true" && numPinned > 0;

I would like this changed to:
var doPosition = numPinned > 0;

So that pinned tabs are once again positioned even if the tab bar doesn't overflow.  I tried making this change in my omni.jar and it didn't seem to cause any problems; I can't reproduce the 'overlapping app tabs' even with the change in place.  Maybe some other code has fixed the 'overlapping app tabs' problem.

Rationale for change:
I added functionality into my extension that forces the left/right tabbar scroll arrows always to be shown.  The main reason I have for this is that I want to be able to have something to separate pinned app tabs from non-pinned ones, and the left scroll arrow is a nice natural separator.  So, it acts as one when Firefox positions it correctly even when tabs are not overflowing (see screenshot 1).

However, if Firefox doesn't position pinned tabs when tabs are not overflowing, the left arrow doesn't separate app tabs from normal tabs when tabs are not overflowing (see screenshot 2).

This seems like a very minor change that causes things to Just Work.  If people want to separate pinned app tabs from non-pinned ones, they can just force the tabbar scroll arrows never to be collapsed and they have a natural separator (the left scroll arrow).  In fact later on, we might even want a pref that allows scroll arrows to be always visible, so you don't need an extension to do it.

Comment 1

[Jez]

Attachment: Screenshot 1 - desired new behaviour

Comment 2

[Jez]

Attachment: Screenshot 2 - current behaviour