'Check that\'s everythings ready:
- local capability to resize images
- thumbnail dirs exist (create them if needed)
- detect whether we\'ll use PIL or IM
- detect whether we\'ll use GIO or Python to get URIs'

def _check_local_ok(self):

    if (not ArtResizer.shared.local):
        self._log.warning(u'No    local    image    resizing    capabilities,    cannot    generate    thumbnails')
        return False
    for dir in (NORMAL_DIR, LARGE_DIR):
        if (not os.path.exists(dir)):
            os.makedirs(dir)
    if get_im_version():
        self.write_metadata = write_metadata_im
        tool = 'IM'
    else:
        assert get_pil_version()
        self.write_metadata = write_metadata_pil
        tool = 'PIL'
    self._log.debug(u'using    {0}    to    write    metadata', tool)
    uri_getter = GioURI()
    if (not uri_getter.available):
        uri_getter = PathlibURI()
    self._log.debug(u'using    {0.name}    to    compute    URIs', uri_getter)
    self.get_uri = uri_getter.uri
    return True
