yabai_relative_focus

#!/bin/sh

# in yabai, focus the window relative to the current one in a given direction

# There are 2 types of layouts: binary space partition (bsp) and floating. BSP Windows
# are considered "managed" and floating windows are considered "unmanaged".
#
# this script is necessary because the `yabai -m window --focus ...` command only
# works on "managed windows", but I use "unmanaged windows". The reason for that is that
# I want to split my screen # into 3 panels with a 25-50-25 ratio, but that's not possible
# through bsp. the first split # of the bsp tree is always 50-50 so there's no configuration of
# opening and closing windows that I could do to achieve 25-50-25. so, I must use a floating
# layout and I need a way of switching between windows
#
# Eventually, I imagine I would wait for someone to create a "centered bsp" mode in yabai's
# source code or I would create it myself.

# This script is slightly slower than the normal `yabai -m window --focus {east,west}` command :(
# Everything in this script uses 1-based indexing since that's how grep counts lines

if [ -z "${1}" ]; then
    echo "argument required" >&2
    exit 1
fi

current_space=$( \
    yabai -m query --spaces \
    | jq '.[]
        | select(.focused == 1)
        | .index'
)

# we use an intermediate array so that this command is easier to debug.
# it lets us read the name of the applications running in each window
window_ids_left_to_right=$( \
    yabai -m query --windows --space "${current_space}" \
    | jq '
        [.[]
            | {
                id: .id,
                app: .app,
                left_x: .frame.x
            }
        ]
        | sort_by(.left_x)
        | unique_by(.left_x)
        | .[]
        | .id'
)

current_window_id=$( \
    yabai -m query --windows \
    | jq '.[]
        | select(.focused == 1)
        | .id'
)

current_window_index=$( \
    echo "${window_ids_left_to_right}" \
    | grep --line-number "${current_window_id}" \
    | cut -f 1 -d ":"
)

num_windows=$( \
    echo "${window_ids_left_to_right}" \
    | wc -l
)

# don't change the current window if we're as far east or west as we can go
case "${1}" in
    "west")
        [[ "${current_window_index}" -gt 0 ]] \
            && (( current_window_index-- ))
    ;;

    "east")
        [[ "${current_window_index}" -lt "${num_windows}" ]] \
            && (( current_window_index++ ))
    ;;

    *)
        echo "woops can't do \"${1}\"" >&2
        exit 1
    ;;
esac

# the sed command looks at every line and asks "is it $current_window_index ?"
# if it's not, then it deletes the line from the stream
# if it is, it prints the line and immediately quits and closes the pipe
window_id_to_focus=$( \
    echo "${window_ids_left_to_right}" \
    | sed "${current_window_index}q;d"
)

yabai -m window --focus "${window_id_to_focus}"