sway-track-prev-focus - Add transparency to unfocused windows

sway-track-prev-focus.bash

#!/usr/bin/env bash

# Source: https://gitlab.com/wef/dotfiles/-/blob/master/bin/i3-track-prev-focus

# https://gitlab.com/wef/dotfiles/-/blob/master/bin/sway-track-prev-focus
# shellcheck disable=SC2034
TIME_STAMP="20231126.172745"

# Copyright (C) 2020-2021 Bob Hepple <bob dot hepple at gmail dot com>

# This program is free software: you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation, either version 3 of the License, or (at
# your option) any later version.
# 
# This program is distributed in the hope that it will be useful, but
# WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
# General Public License for more details.
# 
# You should have received a copy of the GNU General Public License
# along with this program. If not, see <http://www.gnu.org/licenses/>.

# from https://gist.github.com/ckafi
wm="i3"
msg="i3-msg"
term="i3-sensible-terminal"
[[ "$SWAYSOCK" ]] && {
    wm="sway"
    msg="swaymsg"
}

case $1 in
    -h|--help)
        echo "Usage: $( basename "$0" )"
        echo
        echo "Tracks focus changes in i3/sway, makes unfocused windows transparent."
        exit 0
        ;;
esac

[[ "$SWAYSOCK" ]] && prev_focus=$( $msg -r -t get_seats | jq '.[0].focus' ) # fails on i3

$msg -m -t subscribe '["window"]' 2> /dev/null | \
    jq --unbuffered -r 'select(.change == "focus").container.id' | \
    while read -r new_focus; do
        $msg -- "[con_id=${prev_focus}] opacity 0.91" &>/dev/null
        $msg -- "[con_id=${new_focus}] opacity 1" &>/dev/null
        prev_focus=$new_focus
    done