shikane

shikane (/ʃiˈkaːnə/) is a dynamic output configuration tool focusing on accuracy and determinism.

It automatically detects and configures connected displays based on a set of profiles. Each profile specifies a set of outputs with additional parameters (e.g., mode, position, scale). A profile will be applied automatically if all specified outputs and modes can be perfectly matched to the currently connected displays and their capabilities.

This is a Wayland equivalent for tools like autorandr. It aims to fully replace kanshi, surpass its inaccuracies and add new features. shikane works with Wayland compositors supporting versions >=3 of the wlr-output-management protocol (e.g., compositors using wlroots v0.16).

Features

• generation of all compatible (display, output, mode)-combinations, ranked by exactness
• specify multiple matching rules per output
• restrict the matching to only certain display attributes
• choose between regex, substring or full text based attribute matching
• full cardinality matching algorithm
• ad-hoc profile switching
• export current display setup as shikane config.toml
• state machine defined execution
• execute commands, profile and display names are supplied as env vars
• one-shot mode

How the matching process works

shikane selects possible profiles automatically at startup and when a change in the set of currently connected displays occurs. A profile is taken into consideration if every currently connected display can be matched to at least one output and no output is unmatched.
A display matches an output if:

• the search parameter matches against the properties of the display
• AND the display supports the mode that is specified in the output table.

After assembling a list of possible profiles shikane generates all variants of every profile. Once all variants have been verified and sorted by exactness, shikane tries to apply them one after the other until one succeeds or there are no variants left to try.

Variants are slightly different versions of the same profile.
For example, a given display has a set of supported modes: 1920x1080@60Hz and 1920x1080@50Hz. If the mode in the config.toml is specified as "1920x1080" both modes would fit the specification. Instead of choosing just one mode and using that, shikane takes both into account by generating two variants based on the same profile. One variant uses the 1920x1080@60Hz mode and the other variant uses the 1920x1080@50Hz mode.
The same goes for the search parameter. If multiple (display,output,mode)-combinations are possible, shikane generates variants with all of them.

Usage

1. Create your configuration file. See configuration for a short overview or have a look at the man page man 5 shikane for more detailed information.
2. Start shikane.

   shikane

Using shikanectl to generate configurations

1. Start shikane.
2. Configure your outputs by hand with a (GUI) tool.
3. Export the current configuration.

   shikanectl export "room04"

4. Append the printed TOML to shikanes config.toml.
5. Reload the config file.

   shikanectl reload

Documentation

Documentation is provided as man pages:

man 1 shikane
man 5 shikane
man 1 shikanectl

They are also viewable online.

Installation

Via your $AURhelper from the AUR:

$AURhelper -S shikane

Via cargo from crates.io (without man pages):

cargo install shikane

Building

Dependencies:

• a rust toolchain >=1.70
• pandoc (for building the man pages)

Building shikane:

cargo build --release

Building the man pages:

./scripts/build-docs.sh man

man -l build/man/shikane.1.gz
man -l build/man/shikane.5.gz
man -l build/man/shikanectl.1.gz

Configuration

shikane uses the TOML file format for its configuration file and contains an array of profiles. Each profile is a table containing an array of output tables. The configuration file should be placed at $XDG_CONFIG_HOME/shikane/config.toml.

[[profile]]
name = "dual_foo"
exec = ["notify-send shikane \"Profile $SHIKANE_PROFILE_NAME has been applied\""]
    [[profile.output]]
    # search for a matching serial number and model by full text comparison
    search = ["s=SERIAL123", "m=1Q2X5T"]
    enable = true
    mode = "1920x1080@50"
    position = "0,0"
    scale = 1.3

    [[profile.output]]
    search  = "n/HDMI-[ABC]-[1-9]" # search for a matching name by regex
    enable = true
    exec = ["echo This is output $SHIKANE_OUTPUT_NAME"]
    mode = "2560x1440@75Hz"
    position = "1920,0"
    transform = "270"

Acknowledgements

• kanshi being the inspiration and motivation
• wayland-rs providing the wayland bindings

License

MIT