Screenshot in Sway with GUIX

Screenshots in Sway with Guix Home Manager

A blog post documented an elegant way to configure screenshots in wayland using grim and grimshot. After moving my sway config to use the GUIX sway-service to generate the config file Iost my configured screenshot bindings.

Output Files

The screenshots will be placed in the Pictures/screenshots folder with the timestamp as filename. To avoid duplication and ensure consistency we'll add a variable to generate the filename

(sway-configuration
  (variables (append %sway-default-variables
		     `((menu .  ,#~(string-append
                                    #$fuzzel
                                    "/bin/fuzzel"
                                    " -w 50 -x 8 -y 8 -r 3 -b 232635ff -t A6Accdff -s A6Accdff -S 232635ff -C c792eacc -m c792eacc -f \"JetBrains Mono:weight=light:size=10\" --icon-theme=\"Papirus-Dark\" --no-exit-on-keyboard-focus-loss"))
		       (term . ,(file-append alacritty "/bin/alacritty"))
		       (screenshot_out . "$(xdg-user-dir PICTURES)/screenshots/$(date +\"%Y%m%d-%H%M%S\").png"))
		     ))
  ...)

Key Bindings

I often use various screenshots pasted in chat windows or Jira tickets so the clipboard is an important destination. Alternatively saving them to move them to a target folder for inclusion whereverr they needed is an important secondary use-case.

We can now use the variable made previously and add the following keybindings:

(sway-configuration
	    ...
	    (keybindings (append
			  `(...
			    ;; Special key to take a screenshot with grim
			    ($mod+Shift+p . "exec grimshot copy anything")
			    ($mod+Shift+s . "exec grimshot save screen $screenshot_out")
			    ($mod+Shift+w . "exec grimshot save window $screenshot_out")
			    ($mod+Shift+a . "exec grimshot save area $screenshot_out")
			    ...

			    )

Deploying the configuration

To activate the configuration

$ make home
echo Loading modules from ~/.config/dotfiles/guix/src
Loading modules from /home/pti/.config/dotfiles/guix/src
guix home reconfigure -L ~/.config/dotfiles/guix/channel -c 32 ~/.config/dotfiles/guix/home-config-`hostname | cut -d. -f1`.scm
...

which quickly (for some value of quick) updates the home configuration, writing a new ~/.config/sway/config file.

When the prompt returns a quick reload of the sway config with $mod+Shift+c and testing if the modifications are active.

Testing it Out

I opened libre office writer to paste copied screenshots and made a mess to show the copy anything works as expected. It does, it highlights what it understands depending on your mouse location, a window if hovering over a window, a rectangle if you start selecting and all the screen if you move the mouse outside all windows (i.e. the boundary on a tiling wm). It is a bit fiddly so sometimes I select the wrong thing, but since it only clobbers the clipboard and I can quickly try again, this seems reasonable.

Similarly using the 3 other bindings to save different type of screenshots.

  $ ls ~/Pictures/screenshots/
20251025-141106.png  20251025-145006.png  20251025-145019.png

Cool, that made a mess in the folder and displaying them show that it are actually screenshots. Cool.