Files
cartridges/src/utils/task.py
2023-06-17 16:27:10 +02:00

87 lines
2.9 KiB
Python

# task.py
#
# Copyright 2023 Geoffrey Coulaud
#
# This program is free software: you can redistribute it and/or modify
# it under the terms of the GNU 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 General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program. If not, see <http://www.gnu.org/licenses/>.
#
# SPDX-License-Identifier: GPL-3.0-or-later
from functools import wraps
from gi.repository import Gio
def create_task_thread_func_closure(func, data):
"""Wrap a Gio.TaskThreadFunc with the given data in a closure"""
def closure(task, source_object, _data, cancellable):
func(task, source_object, data, cancellable)
return closure
def decorate_set_task_data(task):
"""Decorate Gio.Task.set_task_data to replace it"""
def decorator(original_method):
@wraps(original_method)
def new_method(task_data):
task.task_data = task_data
return new_method
return decorator
def decorate_run_in_thread(task):
"""Decorate Gio.Task.run_in_thread to pass the task data correctly
Creates a closure around task_thread_func with the task data available."""
def decorator(original_method):
@wraps(original_method)
def new_method(task_thread_func):
closure = create_task_thread_func_closure(task_thread_func, task.task_data)
original_method(closure)
return new_method
return decorator
# pylint: disable=too-few-public-methods
class Task:
"""Wrapper around Gio.Task to patch task data not being passed"""
@classmethod
def new(cls, source_object, cancellable, callback, callback_data):
"""Create a new, monkey-patched Gio.Task.
The `set_task_data` and `run_in_thread` methods are decorated.
As of 2023-05-19, pygobject does not work well with Gio.Task, so to pass data
the only viable way it to create a closure with the thread function and its data.
This class is supposed to make Gio.Task comply with its expected behaviour
per the docs:
http://lazka.github.io/pgi-docs/#Gio-2.0/classes/Task.html#Gio.Task.set_task_data
This code may break if pygobject overrides change in the future.
We need to manually pass `self` to the decorators since it's otherwise bound but
not accessible from Python's side.
"""
task = Gio.Task.new(source_object, cancellable, callback, callback_data)
task.set_task_data = decorate_set_task_data(task)(task.set_task_data)
task.run_in_thread = decorate_run_in_thread(task)(task.run_in_thread)
return task