Draw a GPU accelerated dock panel on your desktop¶

Draw the desktop wallpaper or docks and panels using arbitrary terminal programs, For example, have btop or cava be your desktop wallpaper.

It is useful for showing status information or notifications on your desktop using terminal programs instead of GUI toolkits.

The screenshot to the side shows some uses of the panel kitten to draw various desktop components such as the background, a quick access floating terminal and a dock panel showing system information (Linux only).

Added in version 0.42.0: Support for macOS, see compatibility matrix for details. and X11 (background and overlay).

Added in version 0.34.0: Support for Wayland. See below for which Wayland compositors work.

Using this kitten is simple, for example:

kitten panel sh -c 'printf "\n\n\nHello, world."; sleep 5s'

This will show Hello, world. at the top edge of your screen for five seconds. Here, the terminal program we are running is sh with a script to print out Hello, world!. You can make the terminal program as complex as you like, as demonstrated in the screenshots.

If you are on Wayland or macOS, you can, for instance, run:

kitten panel --edge=background htop

to display htop as your desktop background. Remember this works in everything but GNOME and also, in sway, you have to disable the background wallpaper as sway renders that over the panel kitten surface.

There are projects that make use of this facility to implement generalised panels and desktop components:

kitty panel

pawbar

Controlling panels via remote control¶

You can control panels via the kitty remote control facility. Create a panel with remote control enabled:

kitten panel -o allow_remote_control=socket-only --lines=2 \
    --listen-on=unix:/tmp/panel kitten run-shell

Now you can control this panel using remote control, for example to show/hide it, use:

kitten @ --to=unix:/tmp/panel resize-os-window --action=toggle-visibility

To move the panel to the bottom of the screen and increase its height:

kitten @ --to=unix:/tmp/panel resize-os-window --action=os-panel \
    --incremental edge=bottom lines=4

To create a new panel running the program top, in the same instance (like creating a new OS window):

kitten @ --to=unix:/tmp/panel launch --type=os-panel --os-panel edge=top \
    --os-panel lines=8 top

Source code for panel¶

The source code for this kitten is available on GitHub.

Command Line Interface¶

kitty +kitten panel [options] [cmdline-to-run ...]

Use a command line program to draw a GPU accelerated panel on your desktop

Options¶

--lines <LINES>¶: The number of lines shown in the panel. Ignored for background, centered, and vertical panels. If it has the suffix px then it sets the height of the panel in pixels instead of lines. Default: 1

--columns <COLUMNS>¶: The number of columns shown in the panel. Ignored for background, centered, and horizontal panels. If it has the suffix px then it sets the width of the panel in pixels instead of columns. Default: 1

--margin-top <MARGIN_TOP>¶: Set the top margin for the panel, in pixels. Has no effect for bottom edge panels. Only works on macOS and Wayland compositors that supports the wlr layer shell protocol. Default: 0

--margin-left <MARGIN_LEFT>¶: Set the left margin for the panel, in pixels. Has no effect for right edge panels. Only works on macOS and Wayland compositors that supports the wlr layer shell protocol. Default: 0

--margin-bottom <MARGIN_BOTTOM>¶: Set the bottom margin for the panel, in pixels. Has no effect for top edge panels. Only works on macOS and Wayland compositors that supports the wlr layer shell protocol. Default: 0

--margin-right <MARGIN_RIGHT>¶: Set the right margin for the panel, in pixels. Has no effect for left edge panels. Only works on macOS and Wayland compositors that supports the wlr layer shell protocol. Default: 0

--edge <EDGE>¶: Which edge of the screen to place the panel on. Note that some window managers (such as i3) do not support placing docked windows on the left and right edges. The value background means make the panel the “desktop wallpaper”. Note that when using sway if you set a background in your sway config it will cover the background drawn using this kitten. Additionally, there are three more values: center, center-sized and none. The value center anchors the panel to all sides and covers the entire display (on macOS the part of the display not covered by titlebar and dock). The panel can be shrunk and placed using the margin parameters. The value none anchors the panel to the top left corner and should be placed using the margin parameters. Its size is set by --lines and --columns. The value center-sized is just like none except that the panel is centered instead of in the top left corner and the margins have no effect. Default: top Choices: background, bottom, center, center-sized, left, none, right, top

--layer <LAYER>¶: On a Wayland compositor that supports the wlr layer shell protocol, specifies the layer on which the panel should be drawn. This parameter is ignored and set to background if --edge is set to background. On macOS, maps these to appropriate NSWindow levels. Default: bottom Choices: background, bottom, overlay, top

--config <CONFIG>, -c <CONFIG>¶: Path to config file to use for kitty when drawing the panel.

--override <OVERRIDE>, -o <OVERRIDE>¶: default= Override individual kitty configuration options, can be specified multiple times. Syntax: name=value. For example: kitty +kitten panel -o font_size=20

--output-name <OUTPUT_NAME>¶: The panel can only be displayed on a single monitor (output) at a time. This allows you to specify which output is used, by name. If not specified the compositor will choose an output automatically, typically the last output the user interacted with or the primary monitor. Use the special value list to get a list of available outputs. Use listjson for a json encoded output.

--app-id <CLS>, --class <CLS>¶: On Wayland set the namespace of the layer shell surface. On X11 set the class part of the WM_CLASS window property. Default: kitty-panel

--name <NAME>, --os-window-tag <NAME>¶: On X11 sets the name part of the WM_CLASS property on X11, when unspecified uses the value from kitty --class on X11.

--focus-policy <FOCUS_POLICY>¶: On a Wayland compositor that supports the wlr layer shell protocol, specify the focus policy for keyboard interactivity with the panel. Please refer to the wlr layer shell protocol documentation for more details. Note that different Wayland compositors behave very differently with exclusive, your mileage may vary. On macOS, exclusive and on-demand are currently the same. Default: not-allowed Choices: exclusive, not-allowed, on-demand

--hide-on-focus-loss [=no]¶: Automatically hide the panel window when it loses focus. Using this option will force --focus-policy to on-demand. Note that on Wayland, depending on the compositor, this can result in the window never becoming visible.

--grab-keyboard [=no]¶: Grab the keyboard. This means global shortcuts defined in the OS will be passed to kitty instead. Useful if you want to create an OS modal window. How well this works depends on the OS/window manager/desktop environment. On Wayland it works only if the compositor implements the inhibit-keyboard-shortcuts protocol. On macOS Apple doesn’t allow applications to grab the keyboard without special permissions, so it doesn’t work.

--exclusive-zone <EXCLUSIVE_ZONE>¶: On a Wayland compositor that supports the wlr layer shell protocol, request a given exclusive zone for the panel. Please refer to the wlr layer shell documentation for more details on the meaning of exclusive and its value. If --edge is set to anything other than center or none, this flag will not have any effect unless the flag --override-exclusive-zone is also set. If --edge is set to background, this option has no effect. Ignored on X11 and macOS. Default: -1

--override-exclusive-zone [=no]¶: On a Wayland compositor that supports the wlr layer shell protocol, override the default exclusive zone. This has effect only if --edge is set to top, left, bottom or right. Ignored on X11 and macOS. Default: no

--single-instance [=no], -1 [=no]¶: If specified only a single instance of the panel will run. New invocations will instead create a new top-level window in the existing panel instance. Default: no

--instance-group <INSTANCE_GROUP>¶: default= Used in combination with the --single-instance option. All panel invocations with the same --instance-group will result in new panels being created in the first panel instance within that group.

--wait-for-single-instance-window-close [=no]¶: Normally, when using kitty --single-instance, kitty will open a new window in an existing instance and quit immediately. With this option, it will not quit till the newly opened window is closed. Note that if no previous instance is found, then kitty will wait anyway, regardless of this option.

--listen-on <LISTEN_ON>¶: Listen on the specified socket address for control messages. For example, kitty --listen-on=unix:/tmp/mykitty or kitty --listen-on=tcp:localhost:12345. On Linux systems, you can also use abstract UNIX sockets, not associated with a file, like this: kitty --listen-on=unix:@mykitty. Environment variables are expanded and relative paths are resolved with respect to the temporary directory. To control kitty, you can send commands to it with kitten @ using the kitten @ --to option to specify this address. Note that if you run kitten @ within a kitty window, there is no need to specify the kitten @ --to option as it will automatically read from the environment. Note that this will be ignored unless allow_remote_control is set to either: yes, socket or socket-only. This can also be specified in kitty.conf.

--toggle-visibility [=no]¶: When set and using --single-instance will toggle the visibility of the existing panel rather than creating a new one. Default: no

--start-as-hidden [=no]¶: Start in hidden mode, useful with --toggle-visibility. Default: no

--detach [=no]¶: Detach from the controlling terminal, if any, running in an independent child process, the parent process exits immediately. Default: no

--detached-log <DETACHED_LOG>¶: default= Path to a log file to store STDOUT/STDERR when using --detach

--debug-rendering [=no]¶: For internal debugging use.

--debug-input [=no]¶: For internal debugging use.

How the screenshots were generated¶

The system statistics in the background were created using:

kitten panel --edge=background -o background_opacity=0.2 -o background=black btop

This creates a kitty background window and inside it runs the btop program to display the statistics.

The floating quick access window was created by running:

kitten quick-access-terminal kitten run-shell \
   zsh -c 'printf "\e]66;s=4;Quick access kitty in Hyprland\a\n\n\n\nAlso uses kitty to draw desktop background\n"'

This starts the quick access window and inside it runs kitten run-shell, which in turn first runs zsh to print out the message and then starts the users login shell.

The Linux dock panel was:

wm bar

This is a custom program I wrote for my personal use. It uses kitty’s kitten infrastructure to implement the bar in a few hundred lines of code. This was designed for my personal use only, but, there are public projects implementing general purpose panels using kitty.

Compatibility with various platforms¶

Generated with the help of the panels.py test script.

Wayland

Below is a list of the status of various Wayland compositors. The panel kitten relies of the wlr layer shell protocol, which is technically supported by almost all Wayland compositors, but the implementation in some of them is quite buggy.

🟢 Hyprland: Fully working, no known issues
🟢 labwc: Fully working, no known issues
🟠 KDE (kwin): Mostly working, except that clicks outside background panels cause kwin to erroneously hide the panel. KDE uses an undocumented mapping under Wayland to set the window type from the kitten panel --app-id flag. You might want to use --app-id=dock so that KDE treats the window as a dock panel, and disables window appearing/disappearing animations for it.
🟠 Sway: Renders its configured background over the background window instead of under it. This is because it uses the wlr protocol for backgrounds itself.
🟠 river: Not all functionality has been tested, but the quick access terminal appears as it should and the keyboard focus is properly restored too.
🟠 niri: Hiding a dock panel (unmapping the window) does not release the space used by the dock.
🔴 GNOME (mutter): Does not implement the wlr protocol at all, nothing works.

macOS

Mostly everything works, with the notable exception that dock panels do not prevent other windows from covering them. This is because Apple does not provide and way to do this in their APIs.

X11

Support is highly dependent on the quirks of individual window managers. See the matrix below:

Compatibility matrix¶
WM	Desktop	Dock	Quick	Notes
KDE	🟠	🟢	🟢	transparency does not work for `--edge=background`
GNOME	🟢	🟢	🟢
XFCE	🟢	🟢	🟢
i3	🔴	🟠	🔴	only top and bottom dock panels, without transparency
xmonad	🔴	🔴	🔴	doesn’t support the needed NET_WM protocols