steamdeck_maxwin

A simple bash script to force maximize non-steam apps in Steam Deck's Gamescope. This is intended to work on other resolutions when using an external display.

I made this due to those pesky apps that don't offer an easy way to maximize on init and/or have problems in fullscreen (I am looking at you Discord and Firefox).

Warning

I am still messing around with this and it probably doesn't work with all applications (specially the apps that limit window dimensions).

Guide

1. Go into desktop mode.
2. Install the wmctrl binary. You can also use the one in this repository and put it on a directory of your choice (I recommend in $PATH). In my case, I have installed it via pacman and so it's in /usr/bin/wmctrl. The script will try to locate it in any $PATH directory or if set with the --wmctrl_path optional argument.
3. Download the maxwin file and put it in a directory of your choice, I recommend ~/.local/bin/maxwin.
4. Add an application to steam. (E.g. right click executable > Add to Steam).
5. Go into gamemode and then to the newly added application properties.
6. Change 'Game Resolution' to 'Native'.
7. Copy the command in 'Target' and append it to the beginning of the 'Launch Options', and change 'Target' to the maxwin script path (e.g. Target was /usr/bin/flatpak and Launch Options: run com.discordapp.Discord and it becomes, in my case, Target=/home/deck/.local/bin/maxwin and Launch Options=/usr/bin/flatpak -- run com.discordapp.Discord).
8. Modify 'Launch Options' according to the maxwin guide (use maxwin --help to check help and examples).

Some examples

Discord

Target: /home/deck/.local/bin/maxwin

Start in: /home/deck/.local/bin/

Launch Options: name "Friends - Discord" -- flatpak run com.discordapp.Discord

Firefox

Target: /home/deck/.local/bin/maxwin

Start in: /home/deck/.local/bin/

Launch Options: name "Mozilla Firefox" -- flatpak "run" "--branch=stable" "--arch=x86_64" "--command=firefox" "--file-forwarding" "org.mozilla.firefox"

Steamos-nested-desktop

Target: /home/deck/.local/bin/maxwin

Start in: /home/deck/.local/bin/

Launch Options: viewable -- "/usr/bin/steamos-nested-desktop"