Daniel Luz Reporter
	Description • 16 years ago

User-Agent:       Mozilla/5.0 (Macintosh; U; Intel Mac OS X 10.5; en-US; rv:1.9.1b3pre) Gecko/20081202 Shiretoko/3.1b3pre
Build Identifier: Mozilla/5.0 (Macintosh; U; Intel Mac OS X 10.5; en-US; rv:1.9.1b3pre) Gecko/20081202 Shiretoko/3.1b3pre

The Mighty Mouse and the MacBook trackpad both support continuous scrolling (as opposed to the scrolling in steps you see on Windows with the usual mice). The tab strip seems to translate all the very small increments as one unique-sized jump of a whole tab, making it very hard to navigate using the aforementioned devices (a very soft movement jumps over three tabs).

Reproducible: Always

Steps to Reproduce:
1. Place the cursor over the tab strip with lots of tabs open
2. Move the mouse scroll, or use the two-finger movement on the trackpad, very slowly
Actual Results:  
The tab strip scrolls whole tabs for every small movement you do. If you scroll at once more than what should be a few pixels, it becomes almost impossible to keep visual track of the movement.

Expected Results:  
The tab strip should scroll very slowly, just like the browser already does on other widgets. That probably means no "rounding" to whole tabs, but a sufficiently smart algorithm could still handle that.

This might also be the case for the other operating systems, since AFAIK Windows does support smaller scrolling increments. But it's probably not as much of an issue, as most popular pointing devices only offer the "stepped" standard increment of 120.

	Tyler Downer [He/Him]
	Comment 1 • 16 years ago

Thank you for this report. However, in order to make it more useful, please follow the steps found at http://new.quality.mozilla.org/bug-writing-guidelines and report back with your results.

	Markus Stange [:mstange]
	Comment 2 • 16 years ago

(In reply to comment #1)
Not necessary, I have no problem understanding Daniel's report.

	Tyler Downer [He/Him]
	Comment 3 • 16 years ago

No, that link is to request the reporter try in Safe mode, in a new profile, etc. Those are general triage requests that need to be answered before a bug can be confirmed, because it could be an extension/theme, or a corruption in the profile.
This looks like it could end up being a dupe.

	Markus Stange [:mstange]
	Comment 4 • 16 years ago

(In reply to comment #3)
> because it could be an extension/theme, or a corruption in
> the profile.

This is not the case here.

> This looks like it could end up being a dupe.

OK, that's a possibility. But I couldn't find a dupe.

Daniel, if you want to have a go at this bug, the code is here:
http://mxr.mozilla.org/mozilla-central/source/toolkit/content/widgets/scrollbox.xml?mark=369-380#367

I think it should be fine to just add an MozMousePixelScroll listener there that calls scrollByPixels instead of scrollByIndex, but only use that on Mac OS X using an #ifdef XP_MACOSX (and #ifndef-ing the DOMMouseScroll case).

	Markus Stange [:mstange]
	Comment 5 • 16 years ago

Oh, that would break smooth scrolling with the mouse wheel, so when this.smoothScroll is true, _smoothScrollByPixels should be called instead.

	:Gijs (he/him)
	Comment 6 • 8 years ago

Is this fixed by bug 1263975?

	Markus Stange [:mstange]
	Comment 7 • 8 years ago

Oh, yes it is!