file_gtk_style.py

#! /usr/bin/env python3

# Taken from MATE-HUD github.com/ubuntu-mate/mate-hud
# Used for rofi css

# Usage
# ./file_gtk_style.py [input file] > [output file]

# examples
# background-color: {@theme_bg_color}

# see the array below for list of style context to use

import sys

if len(sys.argv)<2:
 sys.exit(1)

import gi
gi.require_version("Gtk", "3.0")
from gi.repository import Gio, GLib, Gtk

#Converts from rgba <GTK R, G, B> to hex #RRGGBB
def rgba_to_hex(color):
    return "#{0:02x}{1:02x}{2:02x}".format( int(color.red   * 255), int(color.green * 255), int(color.blue * 255))

window = Gtk.Window()
style_context = window.get_style_context()

#List of style contexts
lists = [ 
 #Foreground
 'theme_fg_color', 'theme_selected_fg_color', 'theme_fg_color',
 'warning_fg_color', 'info_fg_color',
 #Background
 'theme_bg_color', 'theme_selected_bg_color', 'error_bg_color',
 'warning_bg_color', 'info_bg_color',
 #Others
 'theme_unfocused_fg_color', 'theme_text_color'
]

with open(sys.argv[1]) as f:
 file=f.read()
 for style in lists:
  file=file.replace("{@" + style + "}", rgba_to_hex(style_context.lookup_color(style)[1]))
 print(file)