416192 - scrollbar handle doesn't respect min-slider-length

Status: NEW

(Core :: Widget: Gtk, defect, P5)

Description

[Ori Avtalion (salty-horse)]

Attachment: Video showing the small scrollbar handle

Using Gecko/2008020708 Minefield/3.0b4pre and the Human theme.

When the history sidebar has many elements, the scrollbar handle is sized below the allowed minimal width. This means that any decorations that should be inside the handle spill out. [See the attached video for an example]

I think the problem is specific to the sidebar. I tried opening a long page, and the page's scrollbar kept to the correct minimum allowed size.

Comment 1

[Michael Ventnor]

I can confirm this.

Mozilla/5.0 (X11; U; Linux i686; en-US; rv:1.9b3pre) Gecko/2008020717 Minefield/3.0b3pre

Comment 2

[Julien "_FrnchFrgg_" RIVAUD]

It's strange, since GetMinimumWidgetSize calls moz_gtk_get_scrollbar_metrics which queries the minimal width (for an horiz scrollbar) or height (vertical). The only explanation I can find is that the comment that says "Setting aIsOverridable to PR_TRUE has no effect for thumbs" is wrong and that we should do it.

If it's not that, then it's probably a layout bug and it would be really difficult to track down.

Comment 3

[Julien "_FrnchFrgg_" RIVAUD]

No, sorry, it's the other way around: aIsOverridable should be set to PR_FALSE, so the code is correct (or the name aIsOverridable is wrong). I don't understand why layout doesn't obey this minimal size.

Comment 4

[Julien "_FrnchFrgg_" RIVAUD]

I tested, and it works for me, both when using the default theme value, and when returning 100px for the minimum size. I tested with the history sidebar scrollbar, with approx 130 entries and a 200px window height.

Comment 5

[Julien "_FrnchFrgg_" RIVAUD]

Michael: How did you succeed in reproducing ?

Comment 6

[Julien "_FrnchFrgg_" RIVAUD]

OK, now I see it. It's indeed only visible at startup, and with any refresh of the scrollbar (folder opening, changing search options, etc...) the correct size is used. I don't see the problem with the "size=100px" hack, so the problem is that at startup the call to moz_gtk_get_scrollbar_metrics doesn't return the right thing.

Comment 7

[Ori Avtalion (salty-horse)]

I think the handle is drawn incorrectly only when "launching" the sidebar.
After I filtered results with the search box, and removed the filter, the handle appeared correctly (respecting the minimum length).

Comment 8

[Julien "_FrnchFrgg_" RIVAUD]

In fact, it's not the call to moz_gtk_get_scrollbar_metrics who returns the wrong value. It's rect.width and rect.height which are wrongly 0, so

PR_MIN(NSAppUnitsToIntPixels(rect.height, p2a), metrics.min_slider_size)

is 0.

Comment 9

[Firefox Bug Husbandry Bot]

https://bugzilla.mozilla.org/show_bug.cgi?id=1552613