Toggle between light and dark colorschemes for both neovim and kitty

1. Toggle-kitty-and-neovim-colors.md

Requirements:

• Neovim v0.4+
• Python 3.4+ and pynvim
• Kitty
• Zsh, but would probably work with any shell if configured properly
• Your favorite dark and light colorschemes

Installation

1. Add below python script to ~/.config/kitty/ folder. Make sure to make it executable (chmod +x ~/.config/kitty/colors)
2. Set up your dark/light colorscheme, and where to store kitty colors configuration (line 4 to 9)
3. Run the script for first time manually to initialize the colors: ~/.config/kitty/colors dark. It will set up the color scheme and print some env vars, ignore it
4. Add chunk of code from this .zshrc file to your ~/.zshrc
5. Add chunk of code from this init.vim to your init.vim
6. Add include to your kitty.conf (Check example below)
7. Reopen kitty

Usage

• To set specific background type, do colors light or colors dark
• To toggle bg type, do colors toggle
• To reload the current set up configuration, just run colors

How it works

• Python script starts headless nvim instance and sets the selected colorscheme on it
• All necessary colors for kitty colorscheme are then parsed from that instance (bg, fg, cursor, selection, terminal color pallete 0 to 15)
• color_file provided is written with the kitty configuration, alongside with env variables needed for nvim
• Env variables are returned from script so shell can export them in real time

colors

#!/usr/bin/python3

# Where to store kitty configuration
color_file = '/home/kristijan/.cache/main_colorscheme.conf'
# Hash with dark/light colorschemes, background type => vim colorscheme nane
colorschemes = {
    'dark': 'gruvbox',
    'light': 'xcodelight',
}

import pynvim
import argparse
import os
import sys
from pathlib import Path

parser = argparse.ArgumentParser()
parser.add_argument('bg', nargs='?', default=None, choices=['dark', 'light', 'toggle'])

args = parser.parse_args()
bg = args.bg
current_bg = os.getenv('NVIM_COLORSCHEME_BG')

def set_env(background):
    os.system('kitty @ set-colors --all --configured ' + color_file)
    cmd = ['export NVIM_COLORSCHEME_BG=' + background]
    cmd += ['export NVIM_COLORSCHEME=' + colorschemes[background]]
    return cmd

if Path(color_file).exists():
    cfile = open(color_file, 'r')
    first_line = cfile.readline().rstrip()
    current_bg = first_line.split('=')[1]
elif not bg:
    print('You must provide background type argument on first run', file=sys.stderr)
    exit()

if not bg:
    print(';'.join(set_env(current_bg)))
    exit()

if bg == 'toggle':
    bg = 'dark' if current_bg == 'light' else 'light'

os.environ['NVIM_COLORSCHEME_BG'] = bg
os.environ['NVIM_COLORSCHEME'] = colorschemes[bg]
nvim = pynvim.attach('child', argv=["/usr/bin/env", "nvim", "--embed", "--headless"])

def get_hl_color(name):
    hl_output = nvim.call('execute', 'hi ' + name)
    bgcolor = None
    fgcolor = None
    for item in hl_output.split('\n')[1].split():
        if item.startswith('guifg'):
            fgcolor = item.split('=')[1]
        if item.startswith('guibg'):
            bgcolor = item.split('=')[1]
    return fgcolor or '', bgcolor or ''

normal_fg, normal_bg = get_hl_color('Normal')
cursor_fg, cursor_bg = get_hl_color('Cursor')
selection_fg, selection_bg = get_hl_color('Visual')

command = [
    'env NVIM_COLORSCHEME_BG=' + bg,
    'env NVIM_COLORSCHEME=' + colorschemes[bg],
    'foreground ' + normal_fg,
    'background ' + normal_bg,
    'cursor ' + (cursor_bg.startswith('#') and cursor_bg or normal_fg),
    'cursor_text_color ' + (cursor_fg.startswith('#') and cursor_fg or 'background'),
    'selection_foreground ' + (selection_fg.startswith('#') and selection_fg or 'none'),
    'selection_background ' + (selection_bg.startswith('#') and selection_bg or normal_fg)
]

for i in range(0, 16):
    command.append('color' + str(i) + ' ' + nvim.eval('g:terminal_color_' + str(i)))

nvim.close()

file = open(color_file, 'w')
file.write('\n'.join(command))
file.close()

cmd = set_env(bg)
is_bg_changed = bg != current_bg
if is_bg_changed:
    # Do some additional work if needed

print(';'.join(cmd))

init.vim

silent! exe 'set background='.$NVIM_COLORSCHEME_BG
silent! exe 'colorscheme '.$NVIM_COLORSCHEME

kitty.conf

allow_remote_control yes

# Must match path set in python script for "color_file" variable
include ~/.cache/main_colorscheme.conf

zshrc

colors() {
  color_vars=$(~/.config/kitty/colors $1)
  # Eval ensures that proper env variables are loaded in real time
  eval ${color_vars}
}