#!/usr/bin/env python3
# -*- mode: python; coding: utf-8 -*-
#
# Copyright 2013 Andrej A Antonov <polymorphm@gmail.com>.
#
# This program is free software: you can redistribute it and/or modify
# it under the terms of the GNU Lesser General Public License as published by
# the Free Software Foundation, either version 3 of the License, or
# (at your option) any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
# GNU Lesser General Public License for more details.
#
# You should have received a copy of the GNU Lesser General Public License
# along with this program. If not, see <http://www.gnu.org/licenses/>.

assert str is not bytes

import sys

def tk_async(root, target, busy_state_id, callback=None):
    assert callback is None or callable(callback)
    
    def after_func():
        try:
            result = target()
        except Exception:
            if callback is not None:
                root.after_idle(lambda: callback(sys.exc_info(), busy_state_id, None))
        else:
            if callback is not None:
                root.after_idle(lambda: callback(None, busy_state_id, result))
    
    root.after_idle(after_func)
