Can't move windows anymore

[Duncan]

Jerome Yuzyk posted on Tue, 23 May 2017 23:53:05 -0600 as excerpted:

> [KDE 4.14.30 on Fedora 25]
> 
> The darnedest thing: suddenly I can't move a window by grabbing the
> title bar.
> Neither full height windows nor dialogs. Others have reported this, but
> mostly in past releases. It seems I need to kill the kwin process and
> restart it with "kwin --replace". Failing that, logout and back in. I'd
> rather not do that.
> 
> First off, I don't have a "kwin" process, though I do have a "kwin_x11"
> process. Secondly, is "kwin --replace" the right way to start kwin?

Using the replace option is indeed the correct way, and yes, it's kwin_x11 
now, tho I had /thought/ that change was in plasma5 for kde-frameworks5, 
not kde4, which would make sense given that the devs didn't really focus 
on wayland porting and thus need the _x11 specifier suffix until 5.  I'm 
a gentooer not a fedora guy[1], so wouldn't know, but are you sure you're 
not getting that 4.14.30 off of the legacy kdelibs4 that's still around 
to support apps that haven't been ported to frameworks5 yet, and you're 
actually running the plasma5 by kde desktop?

FWIW, running (in a terminal window, konsole or whatever) ldd 
/path/to/kwin_x11 should confirm one way or the other for sure, as it'll 
either list libQt5* and libKF5* libs, or qt4/kde4 versions.  If it's the 
5 versions as I expect, it's plasma5.

Of course you can probably query your package manager to see what package 
and version contains the kwin_x11 file, but how to do that is package 
manager specific, and my telling you how to do it on gentoo using portage 
isn't going to help you much.  But ldd is standard, shipped as a 
troubleshooting script by glibc, unless your distro has split it out 
separately.

Anyway... with xorg at least, there's exactly one window manager allowed, 
so pretty much any window manager should either replace whatever else is 
the current window manager by default, or have a parameter like kwin's
--replace, to do it.  If kwin is not run with the --replace parameter, 
it'll check to see if another window manager is already running, and will 
simply quit if so -- --replace is required to actually replace an 
existing window manager (including an earlier copy of kwin itself).  So 
yes, running it with the --replace parameter is correct. =:^)

Of course if you're running wayland the rules will differ a bit.  I'm not 
running it yet here, so don't know the details, but I guess Fedora 25 
runs wayland by default, with a gnome shell session anyway.  What it does 
for a kde/plasma session I don't know, tho I'd guess it doesn't run 
wayland by default for kde/plasma, as while they're working on it, plasma 
on wayland definitely wasn't ready for fedora 25, and while from reports 
it's working reasonably well in live-git plasma now, I seriously doubt 
it'll make it into fedora 26, either, but may well make fedora 27.

FWIW, I'm actually running live-git kde-frameworks/plasma/apps here (via 
the gentoo/kde project's overlay ebuilds), and due to various normally 
temporary instability issues with the live-git builds, I have a variety 
of hotkey shortcuts setup to reset/restart various plasma components, 
including krunner, plasmashell (was plasma-desktop in kde4), kwin_x11, 
sni-proxy (the applet that provides compatibility for legacy tray applets 
that don't do things the new way yet), etc, should they go unstable and 
need reset/restarted. =:^)

So here when kwin starts acting up on me, I just hit a couple keys to 
trigger the hotkey launcher for it, and I'm back in business.  And yes, 
kwin_x11 --replace is exactly what the kwin relauncher is configured to 
do. =:^)

---
[1] I always did dislike hats, unless it's down near or below freezing.  
Might that be related to the fact that I never was much one for red hat, 
preferring mandrake even back when I did binary-based distros (I've been 
on gentoo for nearing a decade and a half, now, as I quickly outgrew 
binary distros along with my Linux newbie status and wanted more control 
over my own systems than the binary distros normally give you)?  Hard to 
say, but I suppose it's possible it had some subconscious biasing effect.

-- 
Duncan - List replies preferred.   No HTML msgs.
"Every nonfree program has a lord, a master --
and if you use the program, he is your master."  Richard Stallman