Pre-create thumbnails for e.g. Nautilus (Gnome Files)

make-thumbs

#!/usr/bin/env python3
# make-thumbs -- pre-create thumbnails for e.g. Nautilus (Gnome Files)
#
# Usage: make-thumbs <directory>...
#
# Adapted from <https://askubuntu.com/a/201997/466189> to work on
# Ubuntu 22.04 by updating to Python 3 and fixing up errors.
#
# CC BY-SA <https://creativecommons.org/licenses/by-sa/3.0/>

import os
import sys

from gi import require_version as gi_require_version
gi_require_version('GnomeDesktop', '3.0')
from gi.repository import Gio, GnomeDesktop

def make_thumbnail(factory, filename):
    mtime = os.path.getmtime(filename)
    # Use Gio to determine the URI and mime type
    f = Gio.file_new_for_path(filename)
    uri = f.get_uri()
    info = f.query_info(
        'standard::content-type', Gio.FileQueryInfoFlags.NONE, None)
    mime_type = info.get_content_type()

    if factory.lookup(uri, mtime) is not None:
        print("FRESH       %s" % uri)
        return False

    if not (mime_type and factory.can_thumbnail(uri, mime_type, mtime)):
        print("UNSUPPORTED %s" % uri)
        return False

    thumbnail = factory.generate_thumbnail(uri, mime_type)
    if thumbnail is None:
        print("ERROR       %s" % uri)
        return False

    print("OK          %s" % uri)
    factory.save_thumbnail(thumbnail, uri, mtime)
    return True

def thumbnail_folder(factory, folder):
    for dirpath, dirnames, filenames in os.walk(folder):
        for filename in filenames:
            make_thumbnail(factory, os.path.join(dirpath, filename))

def main(argv):
    factory = GnomeDesktop.DesktopThumbnailFactory()
    for filename in argv[1:]:
        if os.path.isdir(filename):
            thumbnail_folder(factory, filename)
        else:
            make_thumbnail(factory, filename)

if __name__ == '__main__':
    sys.exit(main(sys.argv))