Bash script to change Gnome and Shell themes and Terminal profiles between dark and light modes

toggle-gnome-themes.sh

#!/usr/bin/env bash

set -e
set -o pipefail


# Some useful commands to figure out what to tweak:
# https://askubuntu.com/questions/971067/how-can-i-script-the-settings-made-by-gnome-tweak-tool#971577
# * watch dconf changes being made: 
#   'dconf watch /'
# * List gsettings keys: 
#   'gsettings list-keys org.gnome....'

# https://stackoverflow.com/questions/41156442/glib-gio-message-using-the-memory-gsettings-backend-happened-in-ubuntu-16-10
## annotating this line because this is no needed in fedora 33
# export GIO_EXTRA_MODULES=/usr/lib/gio/modules

# Gnome Terminal themes
# Avaialable at: http://mayccoll.github.io/Gogh/ (https://github.com/Mayccoll/Gogh)
# After installing or creating the desired terminal themes;
# 1. Retrieve the ID: `dconf dump /org/gnome/terminal/legacy/profiles:/ | awk '/\[:/||/visible-name=/'`
# 2. Set which one to use for Dark and Light mode.
TERMINAL_LIGHT=ae51e137-4925-40d3-8652-da4d08bd3d18  # Hemisu Light
TERMINAL_DARK=879b1b17-e168-4ed9-af48-f80f52196c1d   # Chalk
# TERMINAL_DARK=8ca1aef4-972e-46fc-ab35-9fcde4d3312c

# GTK3 Themes
# vimix-gtk-themes: https://github.com/vinceliuice/vimix-gtk-themes
# NOTE: Themes should be installed first. i.e.: Copied to ~/.themes
GTK_LIGHT='vimix-light-laptop-doder'
GTK_DARK='vimix-dark-laptop-doder'

# Similar to the above but for the Gnome Shell (i.e.: top desktop bar, ...)
SHELL_LIGHT='vimix-light-laptop-doder'
SHELL_DARK='vimix-dark-laptop-doder'

say() {
 echo "$@" | sed \
         -e "s/\(\(@\(red\|green\|yellow\|blue\|magenta\|cyan\|white\|reset\|b\|u\)\)\+\)[[]\{2\}\(.*\)[]]\{2\}/\1\4@reset/g" \
         -e "s/@red/$(tput setaf 1)/g" \
         -e "s/@green/$(tput setaf 2)/g" \
         -e "s/@yellow/$(tput setaf 3)/g" \
         -e "s/@blue/$(tput setaf 4)/g" \
         -e "s/@magenta/$(tput setaf 5)/g" \
         -e "s/@cyan/$(tput setaf 6)/g" \
         -e "s/@white/$(tput setaf 7)/g" \
         -e "s/@reset/$(tput sgr0)/g" \
         -e "s/@b/$(tput bold)/g" \
         -e "s/@u/$(tput sgr 0 1)/g"
}

# =============================================
# ================ Gnome Shell ================
set-shell-theme() {
    theme=$1
    say @blue[["Setting SHELL theme to: @b$theme"]]
    # gsettings doesn't have a scheme for this, so we use dconf directly
    dconf write /org/gnome/shell/extensions/user-theme/name "'$theme'"
}

get-shell-theme() {
    echo $(gsettings get org.gnome.shell.extensions.user-theme name)
}

# =============================================
# ================ GTK Theme ==================

set-gtk-theme() {
    theme=$1
    say @blue[["Setting GTK theme to: @b $theme"]]
    gsettings set org.gnome.desktop.interface gtk-theme $theme
}

get-gtk-theme() {
    echo $(gsettings get org.gnome.desktop.interface gtk-theme)
}

# =============================================
# ================ Terminal ===================
set-terminal-profile() {
    theme=$1
    say @blue[["Setting TERMINAL theme to: @b$theme"]]
    gsettings set org.gnome.Terminal.ProfilesList default $theme
}

get-terminal-profile() {
    # dconf dump /org/gnome/terminal/legacy/profiles:/ | awk '/\[:/||/visible-name=/'
    echo $(gsettings get org.gnome.Terminal.ProfilesList default)
}

## if your terminal theme profile is "use theme by system theme" or "default", set-terminal-profile can be annotated

set-light() {
    set-gtk-theme $GTK_LIGHT
    set-shell-theme $SHELL_LIGHT
#    set-terminal-profile $TERMINAL_LIGHT
}

set-dark() {
    set-gtk-theme $GTK_DARK
    set-shell-theme $SHELL_DARK
#    set-terminal-profile $TERMINAL_DARK
}

toggle-theme() {
    current_gtk_theme=$(get-gtk-theme)
    say @blue[["Current GTK theme: @b@magenta $current_gtk_theme" ]]
    current_shell_theme=$(get-shell-theme)
    say @blue[["Current SHELL theme: @b@magenta $current_shell_theme" ]]

    if [ $current_gtk_theme == "'$GTK_LIGHT'" ];
    then
        say @blue[["Switching to DARK mode:"]]
        set-dark
    else
        say @blue[["Switching to LIGHT mode:"]]
        set-light
    fi
}

# Toggle between Light & Dark
toggle-theme