autoscroll

Middle-click autoscroll for Linux on Wayland (KDE Plasma).

Replicates the autoscroll behavior found in Windows and Firefox — hold down the middle mouse button and move the mouse to scroll. Move slowly for slow scroll, move fast for fast scroll.

Why

KDE Plasma on Wayland has no built-in middle-click autoscroll. This daemon runs in the background and adds that functionality system-wide, across all applications.

How it works

The script listens passively to raw mouse input via evdev and injects scroll events through a virtual uinput device. It does not grab exclusive control of the mouse, so the mouse always works normally — the daemon crashing or stopping will never lock up your mouse.

Requirements

• Linux with Wayland (tested on KDE Plasma / CachyOS)
• python-evdev
• User must be in the input group

Installation

1. Install dependency

sudo pacman -S python-evdev

2. Add yourself to the input group

sudo usermod -aG input $USER

Log out and back in for this to take effect.

3. Copy the script

cp autoscroll.py ~/.local/bin/autoscroll.py
chmod +x ~/.local/bin/autoscroll.py

4. Install the systemd user service

mkdir -p ~/.config/systemd/user
cp autoscroll.service ~/.config/systemd/user/autoscroll.service
systemctl --user daemon-reload
systemctl --user enable --now autoscroll.service

Usage

Hold the middle mouse button and move the mouse to scroll. No configuration needed.

Tuning

In autoscroll.py, adjust this value to your preference:

SCROLL_THRESHOLD = 15  # pixels of mouse movement per scroll tick (lower = more sensitive)

Useful commands

# Check status
systemctl --user status autoscroll

# View logs
journalctl --user -u autoscroll -f

# Stop
systemctl --user stop autoscroll

# Uninstall
systemctl --user disable --now autoscroll
rm ~/.local/bin/autoscroll.py
rm ~/.config/systemd/user/autoscroll.service

Files

File	Description
autoscroll.py	The daemon
autoscroll.service	Systemd user service (auto-start on login)

License

MIT