Current File : //snap/core20/2379/lib/python3/dist-packages/pyudev/glib.py
# -*- coding: utf-8 -*-
# Copyright (C) 2010, 2011, 2012, 2013 Sebastian Wiesner <lunaryorn@gmail.com>
# 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 St, Fifth Floor, Boston, MA 02110-1301 USA
"""pyudev.glib
===========
Glib integration.
:class:`MonitorObserver` integrates device monitoring into the Glib
mainloop by turing device events into Glib signals.
:mod:`glib` and :mod:`gobject` from PyGObject_ must be available when
importing this module. PyGtk is not required.
.. _PyGObject: http://www.pygtk.org/
.. moduleauthor:: Sebastian Wiesner <lunaryorn@gmail.com>
.. versionadded:: 0.7
"""
from __future__ import (print_function, division, unicode_literals,
absolute_import)
# thanks to absolute imports, this really imports the glib binding and not this
# module again
import glib
import gobject
class _ObserverMixin(object):
"""Mixin to provide observer behavior to the old and the new API."""
# pylint: disable=too-few-public-methods
def _setup_observer(self, monitor):
# pylint: disable=attribute-defined-outside-init
self.monitor = monitor
self.event_source = None
self.enabled = True
@property
def enabled(self):
"""
Whether this observer is enabled or not.
If ``True`` (the default), this observer is enabled, and emits events.
Otherwise it is disabled and does not emit any events.
.. versionadded:: 0.14
"""
return self.event_source is not None
@enabled.setter
def enabled(self, value):
if value and self.event_source is None:
# pylint: disable=attribute-defined-outside-init
self.event_source = glib.io_add_watch(
self.monitor, glib.IO_IN, self._process_udev_event)
elif not value and self.event_source is not None:
glib.source_remove(self.event_source)
def _process_udev_event(self, source, condition):
# pylint: disable=unused-argument
if condition == glib.IO_IN:
device = self.monitor.poll(timeout=0)
if device is not None:
self._emit_event(device)
return True
def _emit_event(self, device):
self.emit('device-event', device)
class MonitorObserver(gobject.GObject, _ObserverMixin):
"""
An observer for device events integrating into the :mod:`glib` mainloop.
This class inherits :class:`~gobject.GObject` to turn device events into
glib signals.
>>> from pyudev import Context, Monitor
>>> from pyudev.glib import MonitorObserver
>>> context = Context()
>>> monitor = Monitor.from_netlink(context)
>>> monitor.filter_by(subsystem='input')
>>> observer = MonitorObserver(monitor)
>>> def device_event(observer, device):
... print('event {0} on device {1}'.format(device.action, device))
>>> observer.connect('device-event', device_event)
>>> monitor.start()
This class is a child of :class:`gobject.GObject`.
"""
__gsignals__ = {
# explicitly convert the signal to str, because glib expects the
# *native* string type of the corresponding python version as type of
# signal name, and str() is the name of the native string type of both
# python versions. We could also remove the "unicode_literals" import,
# but I don't want to make exceptions to the standard set of future
# imports used throughout pyudev for the sake of consistency.
str('device-event'): (gobject.SIGNAL_RUN_LAST, gobject.TYPE_NONE,
(gobject.TYPE_PYOBJECT,)),
}
def __init__(self, monitor):
gobject.GObject.__init__(self)
self._setup_observer(monitor)
gobject.type_register(MonitorObserver)
class GUDevMonitorObserver(gobject.GObject, _ObserverMixin):
"""
An observer for device events integrating into the :mod:`glib` mainloop.
.. deprecated:: 0.17
Will be removed in 1.0. Use :class:`MonitorObserver` instead.
"""
_action_signal_map = {
'add': 'device-added', 'remove': 'device-removed',
'change': 'device-changed', 'move': 'device-moved'}
__gsignals__ = {
str('device-event'): (gobject.SIGNAL_RUN_LAST, gobject.TYPE_NONE,
(gobject.TYPE_STRING, gobject.TYPE_PYOBJECT)),
str('device-added'): (gobject.SIGNAL_RUN_LAST, gobject.TYPE_NONE,
(gobject.TYPE_PYOBJECT,)),
str('device-removed'): (gobject.SIGNAL_RUN_LAST, gobject.TYPE_NONE,
(gobject.TYPE_PYOBJECT,)),
str('device-changed'): (gobject.SIGNAL_RUN_LAST, gobject.TYPE_NONE,
(gobject.TYPE_PYOBJECT,)),
str('device-moved'): (gobject.SIGNAL_RUN_LAST, gobject.TYPE_NONE,
(gobject.TYPE_PYOBJECT,)),
}
def __init__(self, monitor):
gobject.GObject.__init__(self)
self._setup_observer(monitor)
import warnings
warnings.warn('Will be removed in 1.0. '
'Use pyudev.glib.MonitorObserver instead.',
DeprecationWarning)
def _emit_event(self, device):
self.emit('device-event', device.action, device)
signal = self._action_signal_map.get(device.action)
if signal is not None:
self.emit(signal, device)
gobject.type_register(GUDevMonitorObserver)
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