i3 and KDE Plasma

How to install the i3 window manager on KDE Plasma.

Preview image:

Situation before the installation

• Manjaro KDE Edition, all updates installed
• KDE Plasma
• KWin

Installation

Packages

We're gonna install a couple packages that are required or nice-to-haves on i3. This consists of:

• i3-gaps, obviously
• feh to set up the background
• dmenu (not required)
• morc_menu (not required)
• i3status for the status bar of i3
• wmctrl to add to the i3 config (if you're not on an English installation of Plasma)

Here's a oneliner on how I installed everything: $ sudo pacman -Syu && sudo pacman -S i3-gaps feh i3-dmenu-desktop morc_menu i3status wmctrl

Configuration

Create a new XSession

Create a new file called plasma-i3.desktop in the /usr/share/xsessions directory as su. [1]

Write the following into /usr/share/xsessions/plasma-i3.desktop:

[Desktop Entry]
Type=XSession
Exec=env KDEWM=/usr/bin/i3 /usr/bin/startplasma-x11
DesktopNames=KDE
Name=Plasma with i3
Comment=Plasma with i3

The i3 installation could have installed other .desktop files, you can remove them if you'd like. I only have the default plasma.dektop and plasma-i3.desktop in my folder.

For the following use your existing i3 config or create a new config using $ i3-config-wizard (this also works when you're still in KWin).

Your i3 config should be located at ~/.config/i3/config, although other locations are possible (depending on your personal configuration).

Adding stuff to the i3 config

To improve compatibility with Plasma, add the following lines in your i3 config.

# Plasma compatibility improvements
for_window [window_role="pop-up"] floating enable
for_window [window_role="task_dialog"] floating enable

for_window [class="yakuake"] floating enable
for_window [class="systemsettings"] floating enable
for_window [class="plasmashell"] floating enable;
for_window [class="Plasma"] floating enable; border none
for_window [title="plasma-desktop"] floating enable; border none
for_window [title="win7"] floating enable; border none
for_window [class="krunner"] floating enable; border none
for_window [class="Kmix"] floating enable; border none
for_window [class="Klipper"] floating enable; border none
for_window [class="Plasmoidviewer"] floating enable; border none
for_window [class="(?i)*nextcloud*"] floating disable
for_window [class="plasmashell" window_type="notification"] border none, move right 700px, move down 450px
no_focus [class="plasmashell" window_type="notification"]

Killing the existing window that covers everything

With my installation, there was a Plasma Desktop window that covered everything and had to be closed with $mod+Shift+q every time I logged in. To circumvent that, follow this tutorial.

...
0x04400006  0 alex-mi Arbeitsfläche — Plasma
...

for_window [title="Desktop — Plasma"] kill; floating enable; border none
for_window [title="Arbeitsfläche — Plasma"] kill; floating enable; border none

Disabling a shortcut that breaks stuff

Launch the Plasma System Settings and go to Category Workspace > Shortcuts > Category System Services > Plasma and disable the shortcut "Activities..." that uses the combination Meta+Q.

Using the plasma shutdown screen

To use the plasma shutdown/logout/reboot screen, delete this line (or comment out)

bindsym $mod+Shift+e exec "i3-nagbar " ...

and add the following one(s) instead:

# using plasma's logout screen instead of i3's
bindsym $mod+Shift+e exec --no-startup-id qdbus org.kde.ksmserver /KSMServer org.kde.KSMServerInterface.logout -1 -1 -1

(Note: This seems to not work on some distros.)

Setting the Background (optional)

(Note: This section is outdated. The "Andromeda" packages are no longer in the Manjaro repositories.)

By default, i3 doesn't set a background and it requires a third party to do that. I am using the default background provided by the Plasma theme with the name of "Andromeda" and a program called feh to set the background.

I installed these following packages for the background and theme:

$ sudo pacman -S andromeda-wallpaper plasma5-themes-andromeda sddm-andromeda-theme andromeda-icon-theme

and enabled the theming in the Plasma settings.

To set up the same wallpaper in i3, add the following line to the i3 config:

exec --no-startup-id feh --bg-scale /usr/share/plasma/look-and-feel/org.manjaro.andromeda.desktop/contents/components/artwork/background.png

Editing the bar (optional)

The i3 bar has a nice feature that allows it to be hidden, unless you press $mod. I enabled this, because I have the Plasma status bar.

This is my bar config. It sets the command that should be called to get the current system status, makes it a bit larger and a bit less black. To use the i3 bar instead of the plasma one, you should be able to just remove it with your mouse (navigate through the right click menus of the bar).

bar {
    status_command i3status
    mode hide
    height 30
    colors {
      background #242424
    }
}

That's it! I hope this little tutorial helped you, and if you see anything you'd like to improve, absolutely feel free to do so! My issues are open, as are pull requests.

If you'd like to buy me a coffee, follow this link.

Enable transparency (optional)

If you'd like to enable transparency, you need to install a compositor. I use picom, and it works really well with minimal (no) configuration. First, install picom: $ sudo pacman -S picom

Then, add this line to your i3 config: exec_always --no-startup-id picom -bc

The result is something like this:

Dual Kawase blur (optional)

This was a bit more tricky to do. Instead of the normal picom from Manjaro's repository, I used a fork called picom-tryone-git to replace my existing picom.

To configure picom, I copied /etc/xdg/picom.conf.example to ~/.config/picom.conf. Picom should already pick up this config. There are a couple of things you need to change.

My changes were:

...
shadow = true;
shadow-radius = 12;
...
shadow-opacity = 1;
shadow-red = 0.0;
shadow-green = 0.0;
shadow-blue = 0.0;
...
# inactive opacity = 1;
...
frame_opacity = 1;
...
fading = false;
...
backend = "glx";
...
blur:
{
method = "dual_kawase";
size = 25;
deviation = 5.0;
}

Make sure the blur: section is on the bottom of the file.

To start picom in a way that supports kawase blur, replace the line in your i3 config that starts picom with this one:

exec --no-startup-id picom --backend glx --experimental-backends -bc

The result can look something like this: