385058 - Grey marks (turds, remnants, ghosts) appear on scrollbars

Status: VERIFIED FIXED

(Core :: XUL, defect)

Description

[Alex Faaborg [:faaborg] (Firefox UX)]

Attachment: Grey marks on scroll bar in OS X

When scrolling with minefield, I often notice thin grey marks appearing on the back of the scroll bars.  Image is attached.

If I scroll by down clicking on the bar and dragging, the marks appear on drag, and disappear on up-click.  If I scroll using the mouse wheel (either horizontal or vertical), the marks persist.

Comment 1

[Chris Lawson (gone)]

Not Intel-specific, so changing platform to All.

Comment 2

[Colin Barrett [:cbarrett]]

This is a known bug, and a workaround for a much worse bug. What you're actually seeing is the top pixel of the scrollbar not getting repainted.

I believe the reason I had to compromise here was because if I made it bigger, cases where we have smaller thumbs look poor too. See bug 370439. I might be able to fix it by doing another rewrite of the scrollbar drawing code to use NSScroller instead of HIThemeDrawTrack, but we'll see.

Comment 5

[Chris Lawson (gone)]

Tweaking summary to make it easier to find.

Comment 8

[Markus Stange [:mstange]]

Attachment: Redraw whole scrollbar when position changes

This patch removes a broken optimization from nsSliderFrame.cpp.
The calculation of the dirty rect was based on the assumption that the graphical representation of the scrollbar thumb does not extend beyond the scrollbar thumb's rect. However, this is the case in aqua scrollbars (due to the rounded corner / anti-aliasing eye candy, I suppose).

Comment 9

[Markus Stange [:mstange]]

This bug should be relocated to "Core: XP Toolkit/Widgets", as the bug is in layout/xul/base/src/nsSliderFrame.cpp, even though it only shows on OS X.

Comment 10

[Stefan [:stefanh]]

Moving to XP Toolkit/Widgets per comment #9. Markus, in order to get the patch in you'll need to request approval-1.9 (https://bugzilla.mozilla.org/attachment.cgi?id=301168&action=edit).

Comment 11

[Markus Stange [:mstange]]

Comment on attachment 301168 [details] [diff] [review]
Redraw whole scrollbar when position changes

requesting approval-1.9 (thanks Stefan)

Comment 12

[Stefan [:stefanh]]

Markus, I forgot to mention:

Once (if) you get approval, and you would like the patch checked in, add "checkin-needed" in the keywords field. There are people (reed) monitoring bugs with those keywords, so this is the best way to ensure that the patch won't be forgotten and doomed to bitrot (yes, this have happened - Bugzilla is huge).

Comment 13

[Reed Loden [:reed]]

Checking in layout/xul/base/src/nsSliderFrame.cpp;
/cvsroot/mozilla/layout/xul/base/src/nsSliderFrame.cpp,v  <--  nsSliderFrame.cpp
new revision: 1.173; previous revision: 1.172
done

Comment 14

[Stephen Donner [:stephend] Not actively reading bugmail]

Verified FIXED with:

Mozilla/5.0 (Macintosh; U; Intel Mac OS X 10.4; en-US; rv:1.9b4pre) Gecko/2008022404 Minefield/3.0b4pre

-and-

Thunderbird: version 3.0a1pre (2008022403); in pre-patch versions of both of these products I was plagued by this problem, and now am no longer.