Validated: Ubuntu 11-09
If you use multiple screens on Linux you don't want to have to reset your layouts persistently. In my experience, KDE can be spotty about maintaining your layouts, particularly (for some reason) when you go above 3 physical displays.
These are some notes and scripts to make things a bit more stable.
Step 1: Go into display config (via the GUI) and get things set up as you like them and then apply.
If you're already in your working setup, the quick workaround is to just change one trivial value (like refresh rate), apply, change it back, reapply.
Step 2:
Using kscreen-doctor record the params you are using.
To get a human readable:
kscreen-doctor -o
You can pipe to a txt like:
kscreen-doctor -o > myscreens.txt
Next, grab the JSON for this conifg. The operator is -j:
kscreen-doctor -j > myscreens.json
Recommendation: call your something descriptive like good-config.json
Recommedation 2: if you want to alternate between a couple of configs, set them up and repeat the process. I don't always want to use the mini display for IP cam viewing, so I exported one without it to no_ip_cam.json
Recommendation 3: save a 1 screen config for recovery if your system is messed up. This will simplify your workspace to one good (physical) output. If you have a Stream Deck or macropad on hand this can be really handy. Then you can just go back to your regular setup when you've fixed things.
Some notes for others who (like me) like these things spelled out!
You'll notice that kscreen-doctor spits out a large JSON file that contains far more than just your active configs (as xrandr might). The export iterates through all the possible modes (resolutions).
To replicate a configuration reliably, however, you only need to know your desired configuration, of course.
Namely:
- Which physical (GPU) port
- Which mode we wish to set that output to
- What position we wish to define that as - in X and Y
I have my four monitors set up in this order, left to right: HDMI-2, DP-1, DP-2, HDMI-1 (names simplified). You can rearrange your cables to make this more logical or just deal with the randomness.
The first three screens are displaying at 1920x1080 as they are 1080P. The furthest left screen has an offset of 0,0. Screen 1 (center) is 1920 pixels to the right of that (and no vertical offset); the right screen is 1920x2=3860. So its position is 3860,0.
Simply adjust these calculations based upon your displays and layouts.
Kscreen-doctor is atomic so you pass the whole config in one go.
By looking at your current setup and ignoring the modes you're not using, you can form the command needed to set this layout or force it back:
kscreen-doctor \
output.HDMI-A-2.enable output.HDMI-A-2.mode.1920x1080@60 output.HDMI-A-2.position.0,0 \
output.DP-1.enable output.DP-1.mode.1920x1080@60 output.DP-1.position.1920,0 \
output.DP-2.enable output.DP-2.mode.1920x1080@60 output.DP-2.position.3840,0 \
output.HDMI-A-1.enable output.HDMI-A-1.mode.1024x600@60 output.HDMI-A-1.position.5760,240 output.HDMI-A-1.rotation.inverted
Next, write a simple wrapper to it (see: default-laytout.sh)
Note: Kscreen does not include a parameter for screen priority.
If (like me) you use the same specific monitor layout day to day, and that changes very infrequently, save the JSON you pulled out to a couple of places.
These are my recommendations (we'll use them later):
~/.local/share/kscreen
This is the default Kscreen directory.
So you can:
kscreen-doctor -j > ~/local/share/kscreen/default_config.json
Now, I'll create a folder for keybindings:
mkdir -p ~/scripts/keybindings/monitor-control
If you've got multiple monitors and are working on this in the middle of your work day, pick one config to play around with to verify that the syntax and commands work.