Life with KDE [5]: Install on Debian over XFCE

So I haven’t written too much on this blog for a couple of weeks. Now I am writing about KDE because I have decided which computers will have it and which won’t. serverpc gets it installed because it is fast and has 16 GB of memory, and mediapc will be the one that doesn’t because it only has 4 GB, this is the one that will stay on XFCE for now and at least have working MTP which KDE doesn’t do very well at the moment.
So for serverpc instead of installing Debian 9.5 from scratch (a big deal having to reinstall at the best of times, though with my systems configuration with a separate system drive, nowhere near as big a deal as reinstalling Windows) I decided just to install kde-full package on top of XFCE, using Synaptic to find the package and it’s quite a big download, nearly 900 packages of dependencies in all, something like 2.5 GB.
At the same time I am changing screens around yet again because the most optimum use of screens is a key issue and serverpc really needs two screens to make the best use of it, one portrait and one landscape. And with another screen added on for pc4 and pc4’s screen getting added to mediapc it can all work, because mediapc doesn’t need both of the screens it currently has so one of those can go to serverpc with minimal work, just changing a few cables around.
Anyway back to that KDE overinstall. Synaptic had some problem with a missing package so I just did it in a terminal with apt install kde-full and away it went. You will get a popup screen asking which display manager you want to use, lightdm or sddm. This is because XFCE on Debian by default uses lightdm, and KDE uses sddm. So of course I chose sddm. Now the only real issue is the command that I use to rotate the logon screen is in the lightdm config file and doesn’t apply to sddm. However as you only have to type in the password it is only a small thing. 

There are a few extra things that are worth installing: eog and viewnior as image viewers (in this case already installed by me under XFCE), and pcmanfm-qt and thunar as additional file managers. The latter two are improvements for the following reasons: pcmanfm-qt (from LXQt) doesn’t have the annoying Dolphin/Thunar behaviour of trying to reconnect network shares that may not be connected (which also affects KDialog). Thunar (which does at least have the option of turning off network drive management, unlike Dolphin) has the bulk renamer built into it, which I have used a lot. But Thunar is already there anyway, being part of the XFCE install. I also like the PopupLauncher widget which I use as a favourites menu instead of the KDE one; partly because repositioning the KDE launcher to the right corner of the taskbar causes it to default to the Leave section of the menu when opened, rather than Favourites. 
What you do have to be aware of though is that you now have more than one session and by default the XFCE one will load, which puts you back into XFCE. This is how you can run more than one desktop environment at a time. It’s a little bit weird to see some KDE widgets running under XFCE. If you want to stay in KDE then either you change the default Xsession (the first one in the list) or else remove all of them other than plasma (which is the one for KDE). In previous times I have simply renamed all the others except the one I wanted. This time I chose to change the default xsession away from XFCE, and leave all the files as they were. The command to change the default Xsession in Debian is as follows:
update-alternatives –config x-session-manager
When you run this it gives you a list of, in my case, four options, which were:
0 – the default
1 – startkde, the command to start KDE
2 – startxfce4, the command to start XFCE4, which was the current default
3 – xfce4-session – I have no idea how this is different from startxfce4
There are a few other situations that create more entries. Notably, if you install Kodi, it installs its own session. And of course, if you have more than two window managers, there will be even more. The session files are actually stored in /usr/share/xsessions directory and are .desktop files like the ones that create application launcher / menu entries. So after rebooting, KDE was the default.

mediapc had some issues, among them non working MTP so I reinstalled it with Debian 9.5 expecting to see my experience of other computers when MTP automatically came up after installation. This didn’t in fact occur this time and I had to complete the MTP setup manually as shown on this page from the Debian wiki. Basically you just install mtp-tools and jmtpfs, reboot and it works in Thunar as expected. On an Android device there may be a device menu you have to go through to choose the mode; my Nexus defaults to charging and you have to go into Settings -> Connected Devices -> USB (Android 8.1). On the other two devices I tested (Moto and Galaxy J2), this setting cannot be accessed directly from the menu; instead you have to watch for a notification that you are connected via USB and you can change the setting through that. It is not necessary to enable developer mode. As it happens on both of these it defaults to MTP making a setting change unnecessary, unlike the Nexus.

From experience so far with KDE a number of the widgets aren’t optimised to save space, and so on my two screen computers, I have three panels: the two along the bottom for tasks and launchers, and a third one on top of the secondary screen for the other stuff, like the disk free space, system load, clock, system tray and notifications etc. I tried having this on the side of a portrait screen but the widgets in some cases won’t work on a side panel. So then I have ended up with it on the top of the screen where unforunately it has to be a double height to work with some widgets, but I can get by with that on the secondary display.

Rearranging the screens has now been further extended by adding another screen over the desk for pc4 so it can be used easily again. Otherwise there would be little point in having pc4 at all. To achieve this win10pc has gone down to a single screen in landscape mode (for compatibility with Remmina when remoting to it, which is the way I use it 99% of the time).