284550 - Firefox scroll bar positioning goes against Fitts' Law (Windows XP/Luna)

Status: RESOLVED FIXED

(Core :: Widget: Win32, defect)

Description

[Greg Edwards]

User-Agent:       Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:1.7.6) Gecko/20050223 Firefox/1.0.1
Build Identifier: Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:1.7.6) Gecko/20050223 Firefox/1.0.1

The scroll bar in the main Firefox window (maximized) is positioned exactly one
pixel from the edge of the screen. Moving it to the edge of the screen would
make it an infinitely larger target in the X direction (making it easier to
click and drag).

Reproducible: Always

Steps to Reproduce:
1. Open a page which scrolls.
2. Move the mouse to the edge of the screen.
3. Drag.

Actual Results:  
Nothing.

Expected Results:  
The scroll bar should be selected and the page should scroll.

Using the standard Firefox theme, Microsoft Royale visual style.

Comment 1

[Greg Edwards]

(In reply to comment #0)

I just noticed that this only applies when using an XP visual style. Disabling
visual styles is a possible "workaround."

Comment 2

[Gervase Markham [:gerv]]

This is an automated message, with ID "auto-resolve01".

This bug has had no comments for a long time. Statistically, we have found that
bug reports that have not been confirmed by a second user after three months are
highly unlikely to be the source of a fix to the code.

While your input is very important to us, our resources are limited and so we
are asking for your help in focussing our efforts. If you can still reproduce
this problem in the latest version of the product (see below for how to obtain a
copy) or, for feature requests, if it's not present in the latest version and
you still believe we should implement it, please visit the URL of this bug
(given at the top of this mail) and add a comment to that effect, giving more
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If it is not a problem any longer, you need take no action. If this bug is not
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Thank you for your help in this matter.

The latest beta releases can be obtained from:
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Seamonkey:   http://www.mozilla.org/projects/seamonkey/

Comment 3

[Greg Edwards]

Here's a simple test case:

1. Under Windows XP, set the visual style to any of the "Windows XP Style"
(Luna) themes (Normal/Blue, Silver, Olive, or the Tablet PC Royale style).
2. Run Firefox. Maximize the window if not already.
3. Move the mouse to the left of the screen, but vertically over the scroll bar.
4. Attempt to scroll. It won't since the bar's one pixel from the edge of the
screen.

Note that the scroll bar *is* at the edge of the screen in Classic (no visual
style), or in many user-made visual styles (StyleXP or uxtheme.dll hack). I've
experinced this minor annoyance on every Firefox/WinXP setup I've used, so I'm
pretty confident it's not an isolated issue or theme glitch.

Comment 4

[Greg Edwards]

> 3. Move the mouse to the left of the screen

Sorry, I mean right.. >_<
My apologies.

Comment 5

[u63580]

Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:1.8b5) Gecko/20051013
Firefox/1.4.

Seems to be WFM

Comment 6

[Simon Bünzli]

Confirming (using a Luna theme). This is especially sad because the one reason why Firefox' content area doesn't look sunken (as IE's) is precisely because of Fitts' law.

Comment 7

[Mike Connor [:mconnor]]

nice-to-have, not a blocker

Comment 8

[Greg Edwards]

For the record, this bug affects ALL scroll bars in Firefox, not just the main one, though it is much more trivial in other cases.

Comment 9

[Simon Bünzli]

Attachment: no border for scrollbar tracks

This seems to have been a trivial oversight. By making sure that Luna scrollbars don't have any margins, we get them working again as Classic's scrollbars. Not sure whether we should make sure that NS_THEME_SCROLLBAR_* are margin-less as well (as they are for Classic), but this patch fixes the issue for me already.

Comment 10

[Simon Bünzli]

Renominating for Gecko 1.8.1 since we've now got a very simple, low-risk patch.

Comment 11

[[e-mail]]

To save me from switching theme and OS theme to see the effect, can you explain a) if it changes the way Luna scrollbars are drawn in any way b) if not, why not c) if so, whether this affects all scrollbars or just ones that Firefox wants to style to line up with the edge of the screen? d) if just the latter, why?

Comment 12

[Simon Bünzli]

This indeed changes the way Luna scrollbars are drawn by removing the incorrect 1 pixel margin on the left and right (vertical scrollbars) resp. above and below (horizontal scrollbar). And this affects all Luna scrollbars drawn by Gecko.

See the second part of http://cheeaun.phoenity.com/weblog/2004/08/scrollbar-tweaks.html for an analysis of the problem fixed by this patch.

Comment 13

[[e-mail]]

Comment on attachment 232328 [details] [diff] [review]
no border for scrollbar tracks

As it turns out I needed to test another Luna-related bug anyway...

Comment 14

[:Gavin Sharp [email: [e-mail]]]

mozilla/widget/src/windows/nsNativeThemeWin.cpp 	3.69

Comment 15

[Mike Beltzner [:beltzner, not reading bugmail]]

Not a blocker. If the patch bakes w/o regressions, nominate for approval to get it in on the branch.

Comment 16

[Simon Bünzli]

Comment on attachment 232328 [details] [diff] [review]
no border for scrollbar tracks

Drivers: This patch prevents a 1 pixel border for Luna scrollbars which doesn't exist in any other Windows application and neither for Classic scrollbars. It is virtually zero-risk (the same code path already exists in similar circumstances) and could at most have a minimal impact on themes (wrongly) presupposing that border (those themes would be broken for Classic already though).

Comment 17

[Mike Beltzner [:beltzner, not reading bugmail]]

Comment on attachment 232328 [details] [diff] [review]
no border for scrollbar tracks

a=drivers, go ahead and land it on the branch.

Comment 18

[:Gavin Sharp [email: [e-mail]]]

mozilla/gfx/src/windows/nsNativeThemeWin.cpp 	3.45.4.3