Display settings (sway)
A wrong output setting makes the whole desktop unusable, so: query first, apply once, verify with a screenshot, keep a way back.
1. Query (tier: observe)
swaymsg -t get_outputs
Note each output's name (e.g. Virtual-1), current_mode, scale, and the modes list.
2. Apply (tier: reversible)
Everything is one command, applied live:
swaymsg 'output <NAME> mode <W>x<H> scale <S>'
Quote the whole command as one argument, otherwise swaymsg parses --custom itself and fails.
Rules:
- Scale changes the logical size.
scale 2on a 1280x800 output leaves 640x400 logical pixels: everything becomes huge and windows no longer fit. That is almost never what the user wants. - HiDPI / "retina" / "crisper": keep the logical size and double the physical one:
swaymsg 'output <NAME> mode --custom 2560x1600 scale 2'(a custom mode; the VM or monitor must accept it). In a UTM VM, the user must also enable "Retina Mode" in the VM's display settings. - Bigger text only: prefer a fractional scale like
scale 1.25over a lower resolution. - Never apply more than one change before verifying.
3. Verify (mandatory)
Take a full-screen screenshot with desktop_screenshot (no window). Check that the panel spans the top edge, windows fit, text is readable, and nothing is cut off. If it looks wrong, roll back immediately.
4. Roll back
swaymsg 'output <NAME> scale 1 mode <previous WxH>'
Say what you rolled back to.
5. Persist
Only after the user confirms it looks right. Write the same output ... line to ~/.config/slate/sway.d/output.conf (create the directory; the Slate sway profile includes ~/.config/slate/sway.d/*.conf). Do not edit /etc/sway/config or /etc/nixos. To undo persistence, delete that file.