gnome-fs-duplicate-cursor-fix/README.md

GNOME Fractional Scaling duplicate cursor fix

Fix Ubuntu/GNOME's "duplicate cursor" fractional scaling bug.

Warning: this tool is no longer maintained. I have moved to another distro and have no time to track GNOME's upstream neglected bugs.

How to install

1. Enable X11 fractional scaling:

gsettings set org.gnome.mutter experimental-features "['x11-randr-fractional-scaling']"

2. Configure your monitors accordingly:

• Go to "System Settings" -> "Monitors" and move/scale them to your preference.

3. Install Java:

sudo apt install default-jre

4. Download latest version of .JAR file from releases:

wget -O ~/ScreenScalingFixer.jar https://github.com/mind-overflow/gnome-fs-duplicate-cursor-fix/releases/download/v1.0/ScreenScalingFixer-1.0-SNAPSHOT.jar

5. Create a directory in your home folder and put the JAR file inside of it:

mkdir ~/screen-scaling-fixer/
mv ~/ScreenScalingFixer.jar ~/screen-scaling-fixer/ScreenScalingFixer.jar

6. Create a startup script:

echo "sh -c \"cd ~/screen-scaling-fixer/ && java -jar ~/screen-scaling-fixer/ScreenScalingFixer.jar\"" > ~/screen-scaling-fixer/start.sh
chmod +x ~/screen-scaling-fixer/start.sh

7. Enable the startup script:

printf \
"[Desktop Entry]\n\
Name=fs-fixer\n\
GenericName=fs-fixer\n\
Comment=fix gnome scaling duplicate cursor\n\
Exec=sh -c ~/screen-scaling-fixer/start.sh\n\
Terminal=false\n\
Type=Application\n\
X-GNOME-Autostart-enabled=true\n\
X-GNOME-Autostart-Delay=1\n" > ~/.config/autostart/fractional-scaling-fix.desktop

chmod +x ~/.config/autostart/fractional-scaling-fix.desktop

8. Run the JAR file and let config.yml generate:

cd ~/screen-scaling-fixer
./start.sh

9. Edit config.yml accordingly:

enable: false # set this to true, or the script won't run!
delay: 2000 # chose how long to wait after login before restarting GNOME.
monitor-connector: 'DisplayPort-1' # chose ONE monitor that requires fractional scaling to be enabled. Don't worry if you have multiple ones.
scale: 1.5 # set the desired fractional scale.

Explanation:

• delay: this is mandatory, because if you try restarting GNOME without any delay after login, it will not be restarted. Waiting a few seconds (~2) should be enough.
• monitor-connector: this is a monitor that requires fractional scaling. You should be able to gather its connector name by using command xrandr.
• scale: the scale of the chosen monitor. if you have multiple monitors, just chose one, as we only need to apply those changes to a single one to fix it for everyone else.

10. Final step: log out and log back in.

How this works

The concept behind this fix is simple.
If you enabled the experimental fractional-scaling feature in eg. Ubuntu 20.04, you probably noticed that, upon login, a dead cursor gets stuck on screen, and a second bigger one appears.
This problem is fixed, however, if you switch back to 1.0x scale, apply, and then get back to your desired one.
To automate this process, I developed a small Java tool that automatically does it after logging in.
You simply have to input your screen settings in config.yml, logout, re-login and you should notice your screen flashing twice.
The dead cursor should disappear.