This program builds off marsqing's libinput-three-finger-drag, expanding it to support computers with touchpads running in Wayland sessions (notably KDE Plasma 6). It only depends on libinbut and uinput, so the program should run in any desktop environment that has libinput installed, reagrdless of whether it uses X or Wayland.

¹ Developed on this setup.

Three-finger dragging is a feature originally for trackpads on Mac devices: instead of holding down the left click on the pad to drag, you can simply rest three fingers on the trackpad to start a mouse hold, and move the fingers together to continue the drag in whatever direction you move them in. In short, it interprets three fingers on the trackpad as a mouse-down input, and motion with three fingers afterwards for mouse movement. It can be quite handy, as it will save your hand some effort for moving windows around and highlighting text.

Here is an example of three-finger dragging in action on a MacBook.

The included install.sh installs the program as a SystemD user unit. It also updates the libinput-gestures config files (if you have that installed) so that all 3-finger gestures become 4-finger gestures.

It requires root permissions and will reboot your system afterward (if allowed by prompted response) to update program permissions for libinput and uinput (see Manual installation, step 3 below for details).

You can execute the install script with the following:

sudo bash install.sh

If you are using GNOME or KDE Plasma for your desktop environment, you already have libinput installed (it's a dependency of those environments). There is also a set of helper tools for libinput accessible from the command line that linux-3-finger-drag depends on, which may also be already installed.

Regardless, you can confirm whether you have these helper tools by running:

libinput --version

If you get a version number from this command, you can proceed to the next step.

If it's not installed, you can install it with the following for common distributions:

sudo apt install libinput-tools

sudo dnf install libinput-utils

sudo zypper install libinput-tools

Other common distributions (e.g. Arch) include the helper tools in their libinput packages.

For other distributions, see the pkgs.org site for libinput-tools and libinput-utils.

git clone https://github.com/lmr97/linux-3-finger-drag.git
cd linux-3-finger-drag

If you already like your existing 3-finger gestures, but still want a multi-finger drag, check out the n-finger-drag branch of this repostory, where the number of fingers to trigger the drag is configurable. It's still experimental, so any feedback would be welcome!

GNOME users will need to install the Window Gestures Shell Extension. Once installed, you'll be able to change the finger number for swipe gestures from your settings. You can get it from either the GNOME Extensions website or the GitHub repository. Once installed, disable all three finger gestures.

If you haven't installed libinput-gestures, you can skip to the next step.

If you have, though, modify the config file /etc/libinput-gestures.conf or ~/.config/libinput-gestures.conf. Add 4 in the finger_count column to convert 3 finger swipes to 4 finger swipes, to prevent confusion for the desktop environment and frustration for yourself.

change

gesture swipe up     xdotool key super+Page_Down 

to

gesture swipe up  4  xdotool key super+Page_Down

(The only difference is the 4 before "xdotool").

The process is essentially the same: there is typically a configuration file somewhere that includes the number of fingers for swipe gestures, and if there are any responding to 3-finger swipes, increase the finger count to 4. Consult your program's documentation for the specifics.

This programs reads from libinput, and writes to /dev/uinput, and it requires an adjustment of permissions to accomplish both.

We need to alter the rules for /dev/uinput to make it accessible to all logged-in users, so the program doesn't require root permissions to run. For more info about what's being done here, see this section of the ArchWiki article on udev. You may need to create the folder rules.d in /etc/udev.

For Arch users: You will need to set the uinput kernel module to load on boot, if you haven't already. For instructions on this, see the relevant ArchWiki page.

sudo cp ./60-uinput.rules /etc/udev/rules.d

libinput will only let members of the group input read its debug output, so add yourself to the group by running:

sudo gpasswd --add your_username_here input

You will need to reboot to update the groups.

cargo build --release

Check to make sure the executable works by running

./target/release/linux-3-finger-drag

You will see a warning about not being able to find a configuration file. Just ignore that for now, as it will not impact functionality; we'll get to configuration in step 7.

I've tried to make error messages as informative as I can, with recommended actions included to remedy them, so look to those error messages for help first. But if they don't help, please submit an issue here, with information about your OS, desktop environment, and any error output you get, and I'll get on it as soon as I can.

Once you've got it working, copy it into /usr/bin for ease and consistency of access:

sudo cp ./target/release/linux-3-finger-drag /usr/bin

See the Configuration section below about the included 3fd-config.json file. If you'd like to configure the behavior of this program, run the following:

mkdir ~/.config/linux-3-finger-drag
cp 3fd-config.json ~/.config/linux-3-finger-drag

Now you can configure to your heart's content!

This is a part of the graphical interface. You can find the Autostart menu in System Settings > Autostart (near the bottom). Once there, click the "+ Add..." button in the upper right of the window, and select "Add Application" from the dropdown menu. Then, in text bar in the window that pops up, paste

/usr/bin/linux-3-finger-drag

and click OK.

Now select the program in the Autostart menu, and press Start in the upper right-hand corner of the window to start using it in the current session. It will automatically start in the next session you log into.

Alternatively you can add this program to the autostart in any linux desktop and autostart it via systemd. To do this copy this file create the local systemd folder if not already created:

mkdir -p ~/.config/systemd/user

After that copy the service file in this repo to the folder you just created (or just the folder if you already have one):

cp three-finger-drag.service ~/.config/systemd/user/

Now you just need to enable and start the service:

systemctl --user enable --now three-finger-drag.service

There is a JSON configuration file, assumed to be in ~/.config/linux-3-finger-drag/ called 3fd-config.json, which is read into the program at startup. You can specify an acceleration value (acceleration), which will be multiplied with all 3-finger gesture movements. You can also specify the time (in milliseconds) that the mouse hold will persist for after you lift your fingers (to give you a moment to reposition your fingers), with drag_end_delay. It's entirely optional: if the file cannot be read for any reason, the program will simply warn the user that the file could not be read (with the reason), and default to an acceleration multiplier of 1 and a drag end delay value of 0.

This program uses the regex parsing structure of marsqing's libinput-three-finger-drag to detect three-finger gestures, and translating them into write-calls to /dev/uinput via a virtual mouse. This flow of control bypasses the display server layer entirely, which ensures compatability with any desktop environment (at least with some modifications).