If the panel background is changed in panel preferences, the battery monitor's background remains with the default system-style background.
Created attachment 3499 Fix transparency bug. The attached patch fixes the transparency bug by making the gtk event box invisible.
Thanks, Harald! I tried your patch and it works well except that there's still an opaque rectangle around the battery meter. Would it be possible to make it transparent too?
Sorry, I cannot reproduce this, everything looks nice here. This might depend on the gtk theme though, which theme do you use / where can I download it? Could you attach a screenshot, maybe it gives me a clue what to look for? Although I suppose bug 7329 won't fix this, you might be interested in that too.
Created attachment 3505 Battery with QtCurve Here's a screenshot of the battery monitor with the QtCurve theme. After switching through the other themes I have installed, it seems like QtCurve is the only one with a rounded groove, so most likely it's might be a problem with the theme.
I see, so it's just the progress bar. What about other plugins (systemload, netload, diskperf)? Do they have the same problem or are they displayed correctly? If they all look ugly, then I'd rather say it is the fault of qtcurve. To narrow down the issue, we need one plugin which does it right.
Looks like they all need the same fix you made - they all don't have transparent background.
Just recompile against 4.8.1 panel and most the eventbox windows will be unset.
I did compile everything against 4.8.1 and not all eventbox windows were transparent (systemload-plugin or wavelan-plugin for example). That's why I created patches for those plugins. However, I think the problem with the progress bars is still there even with the patch applied. I'm not using qtcurve like Alec Moskvin, but MurrinaCandido (gtk-engines-murrine), and there are small, barely noticable white pixels at the rounded corners of the progress bars. It's not as obvious as with the qtcurve theme, but when I decrease Alpha on a black background, I can see it. There are other themes like H2O-gtk2-*, where it is easier noticable. I tried setting bg and base colors of those widgets and of their containing boxes, but that did not help. With H2O-gtk2 and Murrina themes it is only visible when you decrease Alpha. So is this a problem of these gtk themes?
Applied the patch to fix the main transparency problem. The problem around the bars remains, but I am not sure this is specific to this plugin. Isn't there the same problem in all plugins?
Yep, they all have that.
Then I wonder if the bug isn't more of a gtk bug... Could you take the discussion to the xfce4-dev@xfce.org mailing list, to see if anyone has an idea at which level this should be investigated, or if we can do anything at all?