Current File : //lib/python3.9/site-packages/dasbus/signal.py
#
# Representation of a signal
#
# Copyright (C) 2019 Red Hat, Inc. All rights reserved.
#
# This library 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 2.1 of the License, or (at your option) any later version.
#
# This library 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 library; if not, write to the Free Software
# Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301
# USA
#
__all__ = ["Signal"]
class Signal(object):
"""Default representation of a signal."""
__slots__ = [
"_callbacks",
"__weakref__"
]
def __init__(self):
"""Create a new signal."""
self._callbacks = []
def connect(self, callback):
"""Connect to a signal.
:param callback: a function to register
"""
self._callbacks.append(callback)
def __call__(self, *args, **kwargs):
"""Emit a signal with the given arguments."""
self.emit(*args, **kwargs)
def emit(self, *args, **kwargs):
"""Emit a signal with the given arguments."""
# The list of callbacks can be changed, so
# use a copy of the list for the iteration.
for callback in self._callbacks.copy():
callback(*args, **kwargs)
def disconnect(self, callback=None):
"""Disconnect from a signal.
If no callback is specified, then all functions will
be unregistered from the signal.
If the specified callback isn't registered, do nothing.
:param callback: a function to unregister or None
"""
if callback is None:
self._callbacks.clear()
return
try:
self._callbacks.remove(callback)
except ValueError:
pass
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