Darkens widgets with transparent bg colors

[Tsu Jan]

I am the author of a GTK3+Gnome-Shell theme named GnomishGray, which uses transparent bg colors for many widgets to show the gray gradient behind them. The theme is OK on Debian, Fedora, OpenSUSE, .... but some Ubuntu users reported blackened areas with it.

I'm not an Ubuntu user myself but saw the same thing with the latest version of Ubuntun Quantal Beta on VirtualBox. The darkening effect was random but often occurred on resizing scrollable widgets.

However, after removing overlay-scrollbar, the problem was completely fixed, so I'm reporting this bug here.

I'll attach a preliminary version of the theme for GNOME 3.4 if Launchpad allows that.

Sorry that I can't give more info on this as my distro is Debian.

[Tsu Jan (tsujan2000)]

Pardon me! The attached theme is for GNOME 3.6, NOT 3.4.

[Launchpad Janitor (janitor)]

Status changed to 'Confirmed' because the bug affects multiple users.

[Omer Akram (om26er)]

Can you also attach a screenshot of the problem?

[Tsu Jan (tsujan2000)]

This is just one of the screenshots an Ubuntu user had sent to me. gucharmap showed the symptom in a distinct way. Almost all treeviews (open-file and save-as dialogs included) were blackened before removing overlay-scrollbar. But, a few minutes ago, he confirmed that they're OK after the removal.

[Alin Andrei (nilarimogard)]

I can confirm the bug in Ubuntu 12.10 with all packages up-to-date.

[Andrea Cimitan (cimi)]

Unfortunately, fixing this is not trivial at all... it is probably a rendering flaw between the child windows used for the scrollbar and the treeview rendering in Gtk+. In the overlay scrollbar code, I can't remove the child windows, and I don't think gtk+ will spend time in understanding what's wrong here.
Sorry

[Jeremy Bícha (jbicha)]

Tsu, I recommend you point your Ubuntu users to https://help.ubuntu.com/12.10/ubuntu-help/unity-scrollbars-intro.html Ubuntu GNOME users shouldn't be affected as it doesn't ship the overlay scrollbars.

[Tsu Jan (tsujan2000)]

Thank you, Jeremy. I'll do so with the next update.

[Tsu Jan (tsujan2000)]

Apart from this bug, the gtk3 module of overlay-scrollbar works well in Debian too. I found it both attractive and practical . I hope the bug could be fixed somehow.