Comment 87 for bug 1228250

(In reply to Jan Keromnes [:janx] from comment #80)
> > Additionally, I think that most web developers don't design such pages which needs to be scrolled
> > horizontally. Actually, I don't use horizontal scroll in most web pages...
>
> Actually if you like to split your screen and use your browser only on one
> half of it, you're going to realize that most web pages are too large and
> therefore broken.
>
> > And I'd like to know if other browsers have this feature?
>
> It's expected standard behaviour in software handling 2D surfaces (e.g. a
> web page). In my experience, Shift+Scroll scrolls horizontally in Chrome,
> Gimp, Evince, Photoshop, MSPaint. Some programs use other modifier keys to
> scroll horizontally, hence the idea to make it configurable in prefs.
>
> > 1. Many people still want this in these days?
>
> I would guess so. Many people still use 1D scrolling (either with mouse or
> basic touchpad) and Shift+Scroll is a good standard way to scroll
> horizontally, even better than tilt wheels or trackpads in my opinion
> because you get the speed and control of a scrollwheel/touchpad.
>
> > 2. If it's not enabled in default settings, how many people would use (realize) this feature?
>
> Giving frustrated users no option to enable this is bad. Currently,
> searching for how to enable this feature in firefox gives a lot of "not
> possible, use chrome", a few strange addons, and eventually this bug (or one
> of the 9 other duplicates).
>
> > 3. If it doesn't swap DOM wheel event's delta values, users won't scroll custom scrollable elements
> > implemented with JS horizontally.
>
> That sounds like a minor problem that could be fixed in this bug or a
> follow-up.
>
> > 4. If it's enabled in default settings, web applications NEVER receive raw delta values with Shift key
> > or other modifier. It's very bad thing for web application developers. E.g., game developers.
>
> I think you're wrong here, because web applications already do not receive
> raw delta values / modifier in case of Shift+Scroll: In default Firefox,
> they see the user back up in his history, and as nandhp said in default
> Chrome they see a horizontal scroll event.
>
> > 5. Swapping delta value may be broken easy at maintaining nsEventStateManager. For preventing it, we
> > need a lot of automated tests as far as possible.
>
> I'm willing to address your nits to my patch and add reasonable test
> coverage for it.
>
> > Oops, you're not janx. But I still wonder why we need to implement a complex feature which is not
> > enabled in default settings.
>
> It doesn't look that complex. Changing the default behavior would probably
> surprise users who are used to navigating their history with Shift+Scroll.
> But hscroll is a feature that makes sense and needs to be configurable in
> firefox.
>
> > Oh, Shift + Wheel is now navigating history on non-Mac platforms...
>
> I find this default behaviour extremely annoying, because coming from Chrome
> I have the Shift+Scroll reflex, and every time I want to hscroll I find
> myself back on my homepage!

Just wanna say that EVERYTHING @Jan Keromnes has answered is EXACTLY what I'm feeling. I've been a loyal Firefox user since around 2001. I live the net through it. In the very least, being able to *enable* this behaviour - if only through "about:config" - is very, very important to power users.

PS: It's not a good idea to assume that users will have mice with horizontal scroll, nor is it guaranteed that if they have horz-scroll on the mouse, that they'll actually use it that way. I have a Logitech G700 and I've mapped copy/paste to my left/right horz-scroll cause that's what I use practically once every two minutes while working.

Thanks for your efforts @everyone!