1625945 - Scrolling in tab bar to change tabs doesn't work when the scrollbox overflows (with toolkit.tabbox.switchByScrolling=true)

Status: RESOLVED FIXED

(Toolkit :: UI Widgets, defect, P5)

Description

[Brian Grinstead [:bgrins]]

+++ This bug was initially created as a clone of Bug #1592798 +++

Steps to reproduce:

• Enable toolkit.tabbox.switchByScrolling in about:config
• Open a bunch of tabs to overflow the scrollbox
• Use the mouse wheel while hovering the tab bar

Actual results:

Scrollbox position changes

Expected results:

The mouse wheel should switch between tabs, I guess.

Comment 1

[Brian Grinstead [:bgrins]]

veron, you reported this originally in https://bugzilla.mozilla.org/show_bug.cgi?id=1592798#c8. Do you know if this is a regression or if it's always worked this way?

Comment 2

[veron]

(In reply to Brian Grinstead [:bgrins] from comment #1)

veron, you reported this originally in https://bugzilla.mozilla.org/show_bug.cgi?id=1592798#c8. Do you know if this is a regression or if it's always worked this way?

This bug has always been.

Brian, thanks for creating this thread. I will look forward to an early solution to this problem in the new version of Firefox.

Comment 3

[veron]

Attachment: bug view.gif

Comment 4

[Brian Grinstead [:bgrins]]

(In reply to veron from comment #2)

(In reply to Brian Grinstead [:bgrins] from comment #1)

veron, you reported this originally in https://bugzilla.mozilla.org/show_bug.cgi?id=1592798#c8. Do you know if this is a regression or if it's always worked this way?

This bug has always been.

Brian, thanks for creating this thread. I will look forward to an early solution to this problem in the new version of Firefox.

To be upfront, a patch would be welcome but fixing this isn't going to be a high priority right now. Since it only occurs when an off-by-default pref is set it's just going to be lower priority relative to other ongoing work.

If anyone wants to give it a shot - https://searchfox.org/mozilla-central/rev/9c6e7500c0015a2c60be7b1b888261d95095ce27/toolkit/content/widgets/tabbox.js#453 is the code that does the tab switching. My best guess is that there's a handler preventing that from firing in the arrowscrollbox, probably https://searchfox.org/mozilla-central/rev/9c6e7500c0015a2c60be7b1b888261d95095ce27/toolkit/content/widgets/arrowscrollbox.js#646.

Comment 5

[BugBot [:suhaib / :marco/ :calixte]]

Bugbug thinks this bug is a regression, but please revert this change in case of error.

Comment 6

[veron]

Attachment: bug_view_2.gif

I'm tired of waiting for a fix (((
Is it really that hard to fix? This is a very VERY useful feature. I always have a lot of tabs open and I need to scroll through them all with the mouse scroll.

PLEASE fixed!!!

Comment 7

[Adrian]

Yeah, who actually wants this behavior change once there are too many tabs? If you keep that many tabs there's a good chance that you either:

• know which tab is where or
• just scroll through the tabs to get to the one you are looking for.

But why would anyone want the tab bar itself to scroll in that case?

Comment 8

[veron]

I believe that if the "toolkit.tabbox.switchByScrolling = true" function exists, then it should work not only in the visibility of the tabs, but also outside it (across all existing tabs).
If this function seems uncomfortable to someone, then let them switch the value to "false" and use the navigation buttons.

For me, it is easier and more convenient to use the movement of all open tabs using the mouse wheel.

Comment 9

[Patrick Storz]

Came here as I agree tabs should be changed by scrolling, regardless of whether the tab bar overflows or not.

However, thinking about implementation possibilities, it needs to be decided how one would scroll the (overflowed) tab bar when toolkit.tabbox.switchByScrolling is set to true? I'm skeptical that it is an option to simply loose that functionality and require people to use the arrow buttons (it's tedious....).

• My first idea: Hold down right mouse button to scroll tab bar in this case, change active tab otherwise.
  Unfortunately this won't work on Linux/Mac unless ui.context_menus.after_mouseup is set (right click mousedown event seems to trigger context menu on these OSs)
• An alternative could be to use a modifier key (e.g. Ctrl), but that kind of defeats the purpose of being able to navigate without keyboard.
• Any other ideas?

Comment 10

[James Picone]

Attachment: Bug 1625945: Intercept wheel events in tabbrowser-tabs if switchByScrolling is true so tabs also switch when it's overflown, r=gijs

Comment 11

[James Picone]

Attachment: WIP: Bug 1625945 - Add test for tab scrolling behaviour

Depends on D158077

Comment 12

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/autoland/rev/a2f814b6e074
Intercept wheel events in tabbrowser-tabs if switchByScrolling is true so tabs also switch when it's overflown, r=Gijs

Comment 13

[Norisz Fay [:noriszfay]]

https://hg.mozilla.org/mozilla-central/rev/a2f814b6e074