Unintuitive / unintended sway-output behaviour

[geryzhydrox]

Hello,
I recently installed a new monitor with a refresh rate of 120 Hz (technically 144Hz, but Sway only allows 120 Hz for it, so let's keep it at that).
Anticipating that sway (or guile-swayer) wouldn't auto-detect it, I set it explicitly in my guile-swayer init.scm.
I included the following lines:

(sway-output "HDMI-A-1"
	     #:refresh-rate 120)

However, after checking swaymsg -t get_outputs, it turns out it didn't change the refresh rate.
I tried setting the position and then setting the resolution and it turns out that setting the resolution fixed it.
To summarize, the refresh-rate option of sway-output will ONLY apply if BOTH the refresh-rate AND resolution options are (manually) set. This definitely tripped me up and seems like unintended behaviour.

Thanks in advance.

[ebeem]

Thanks for pointing that out, indeed what you just mentioned is correct
guile-swayer will ignore the refresh-rate if it's not accompanied with a resolution.
That's because sway itself only accepts setting the refresh rate in the format widthxheight@ref
For example, you can give the output command 1920x1080 or 1920x1080@60Hz
But you can't just set it without the resolution.

I will add this to the docs

[geryzhydrox]

On a side note, would it somehow be possible to extract Sway's auto-detected resolution for a specific display and pass that into the string if no resolution argument is given? Might be a lot of added complexity for such a small edge case though.

[ebeem]

sure, you can find all the parameters you will need in sway-get-outputs.
I don't think it makes sense to pick one of the parameters as I don't know how consistent this will be.

However, in theory, you can apply the first mode you receive from sway-get-outputs
If you try executing

(format #t "~a\n"
		(car (sway-output-modes (car (sway-get-outputs)))))

You will receive the first monitor's first detected mode (which should be the recommended one)
In my case, it's

#<<sway-mode> picture-aspect-ratio: "none" refresh: 143996 height: 1080 width: 1920>

you can pass width and height in addition to your custom refresh rate, the values displayed in outputs in sway is in mhz, so if you want to use it you will have to divide it by 1000