Between Linux and Anime

If you use Konsole or Yakuake with transparency you might have noticed that Kwin’s blur effect, that has been around for awhile and that blurs the background of various transparent elements in the UI (eg panels and plasma popups), does not apply to transparent Konsole or Yakuake windows. This has always irked me a tiny bit, but when I discovered that you can blur transparent terminal windows on OSX, that got me itchy enough to do the token research.

The story is a familiar one: it’s not too hard just to GET WORKING, and patches to do it exist, however getting it to work in a sensible way is non-trivial, and so the patches are rejected and the feature itself is pending future structural changes. Basically, it’s not going to happen on it’s own anytime soon.

Fortunately, there are ways to get it working on your own – and they do not involve applying custom patches and rebuilding anything. Turns out there is a terminal command one can run to immediately apply blur on, for example, current active Konsole windows:

xprop -f _KDE_NET_WM_BLUR_BEHIND_REGION 32c -set _KDE_NET_WM_BLUR_BEHIND_REGION 0 -id `qdbus org.kde.konsole /konsole/MainWindow_1 winId`

And for a currently active Yakuake:

xprop -f _KDE_NET_WM_BLUR_BEHIND_REGION 32c -set _KDE_NET_WM_BLUR_BEHIND_REGION 0 -name Yakuake

Now to do this automatically so that your yakuake and konsole windows are ALWAYS blurred, you can simply add the following lines to your ~/.bashrc:

Edit: commenters have posted improved versions of the code, thanks commenters! See improved version below:

Edit2: KF5 Konsole and Yakuake 3 onwards requires updated code, as well as xdotool to be installed so we can fetch yakuake’s win id:

konsolex=$(qdbus | grep konsole | cut -f 2 -d\ )
if [ -n "$konsolex" ]; then
for konsole in `xdotool search --class konsole`; do
xprop -f _KDE_NET_WM_BLUR_BEHIND_REGION 32c -set _KDE_NET_WM_BLUR_BEHIND_REGION 0 -id $konsole;
done
fi
if [ `qdbus | grep yakuake` ]; then
xprop -f _KDE_NET_WM_BLUR_BEHIND_REGION 32c -set _KDE_NET_WM_BLUR_BEHIND_REGION 0 -id `xdotool search --class yakuake`;
fi


Of course, this often results in the command being run redundantly, but that doesn’t appear to bring any tangible ill-effects. It all works well enough for a quick hackaround. And the results are delicious indeed.

I’ve had more frustration than I’m comfortable admitting to trying to get this to work – I actually gave up and compiled kvkbd at one point. Now that I have it down though it all looks infuriatingly obvious in hindsight. Anyway..

The problem: if you have the official Plasma Active 3 image installed and running on some device, and at some point or another installed/ran a gtk app on your system, you’ll quickly realize that the Maliit-based virtual keyboard does not trigger in your gtk app. That’s contrary to what was promised from the Maliit move! And in fact Maliit predates Plasma Active and should have perfect gtk support, so what gives? It turns out that Plasma Active only includes the Maliit input context plugin for Qt and not for gtk, and that’s basically the problem. (Presumably they decided to save it since the image does not include anything gtk)

The solution: You basically need to install that gtk input context plugin. What I did was I took the package from the recommended repos for openSUSE linked from the Maliit website (specifically this repo). The commands to run (as root!) are:

# zypper ar http://download.opensuse.org/repositories/M17N:/Maliit/openSUSE_Factory/ maliitosfact
# zypper refresh
# zypper in maliit-inputcontext-gtk2


And then update the gtk immodules before rebooting:

# gtk-query-immodules-2.0 > /etc/gtk-2.0/gtk.immodules

Note: Zypper will complain about different maliit versions and prompt you to fix by pulling and replacing packages from the openSUSE repo – DON’T DO IT! Just tell it to break maliit-inputcontext-gtk2 by ignoring some dependencies so you install only one package!

You might also want to disable the openSUSE maliit repo after you’re done so you don’t inadvertently pull stuff from it in future:

zypper mr -d maliitosfact

I’m not 100% sure pulling and replacing those packages will actually cause bad things to happen, but I’ve learnt by being bitten – painfully – multiple times not to risk these things if at all possible :) Anyway, the plugin in fact does work perfectly with the Maliit stuff from Plasma Active despite the zypper warnings:

Plasma Active Maliit Keyboard working on an old Fennec build

Of course, this all only works assuming you’re on an i586/x86 device. It’ll probably be harder to find binary packages for the input plugin on arm for example, but this should hopefully at least point you in the right direction. Perhaps you could just build it from source or something.

I know it’s probably already near the end of PA3’s lifecycle now, but hopefully this will still help some frustrated soul out :)