PATCH: Double buffering and other cosmetic fixes

[Valentine Sinitsyn]

Hi Michael, hi, all,

MB> I maintain the Debian package of knetworkmanager and received a bug
MB> report today regarding this patch. It seems to cause problems [1].

MB> I can reproduce this bug in a way:
MB> When I resume from suspend to ram, and if I use kscreensaver I get the
MB> exact same behaviour (see the attached screenshot). It seems, that under
MB> certain circumstances, the wrong background color is chosen. I'm not
MB> sure if in my case it is because kscreensaver blanks the screen and so
MB> knetworkmanager picks black as bg color.
MB> Any ideas how to solve this problem? How do other systray applet handle
MB> this?
We've discussed this issue with Timo a while ago - maybe somewhere in
August when we were considering double buffering patch for inclusion
to the KNetworkManager SVN. The problem is (to the best of my
knowledge) X11 doesn't allow one to retrieve the background from the
underlying window - only grab pixels from screen. This mean that, if
the window we are interested in (KnetworkManager icon) is obscured, we
get wrong pixels - one can also observe similar effect in KDE when menu
shadows are enabled. KNM does its best to avoid this situation (before
pixels are grabbed, we call erase() to clear the area) but this
doesn't always help. In the recent KNM release (0.1), double buffering
is used only when connecting to network, so the background will be
alright again when the user will connect.

If you have some ideas on how to avoid this bug completely, I'll be
very glad to hear it.

P.S. I'll be out till the weekend so please excuse me for the lack of
answers.

Regards,
Valentine