Qt for Python DBusIntegration
Jump to navigation
Jump to search
To get PySide2 and DBus working together you can use the glib mainloop integration already done in dbus-python.
The examples below show how to export Qt objects to Python and emit a D-Bus signal when a Qt signal is emitted. The code comments explain what you need to know about PySide2 and D-Bus.
Also refer to the dbus-python tutorial.
D-Bus Client
#!/usr/bin/env python
# -'''- coding: utf-8 -'''-
# DBUS Client using PySide2 integration
import sys
from traceback import print_exc
# import python dbus module
import dbus
# import python dbus GLib mainloop support
import dbus.mainloop.glib
# import QtCore
from PySide2.QtCore import *
# signal handler
def button_clicked():
print("button clicked")
# main function
if __name__ == '__main__':
# Enable glib main loop support
dbus.mainloop.glib.DBusGMainLoop(set_as_default=True)
# Get the session bus
bus = dbus.SessionBus()
try:
# Get the remote object
remote_object = bus.get_object("com.example.SampleService",
"/DBusWidget")
# Get the remote interface for the remote object
iface = dbus.Interface(remote_object, "com.example.SampleWidget")
except dbus.DBusException:
print_exc()
sys.exit(1)
# Start the application
app = QCoreApplication([])
# Call some methods of the remote interface
iface.show()
iface.setText("Emit signal")
# connect the DBus signal clicked to the function button_clicked
iface.connect_to_signal("clicked", button_clicked)
iface.connect_to_signal("lastWindowClosed", app.quit)
# enter in the main loop
app.exec_()
D-Bus Server
#!/usr/bin/env python
#-'''- coding: utf-8 -'''-
# DBUS Server Example of use PySide2 with dbus-python library
import dbus
import dbus.service
import dbus.mainloop.glib
import random
from PySide2.QtCore import *
from PySide2.QtWidgets import QPushButton, QApplication
# The adaptor, MUST inherit dbus.service.Object
class DBusWidget(dbus.service.Object):
def __init__(self, name, session):
# export this object to dbus
dbus.service.Object.__init__(self, name, session)
# create a simple widget
self.widget = QPushButton()
self.widget.resize(200, 50)
# To export a Qt signal as a DBus-signal, you need to connect it to
# a method in this class.
# The method MUST have the signal annotation, so dbus-python will
# export it as a dbus-signal
QObject.connect(self.widget, SIGNAL ("clicked()"), self.clicked)
QObject.connect(QApplication.instance(), SIGNAL ("lastWindowClosed()"),
self.lastWindowClosed)
# You can export methods to dbus like you do in python-dbus.
@dbus.service.method("com.example.SampleWidget", in_signature='', out_signature='')
def show(self):
self.widget.show()
# Another method… now with a parameter
@dbus.service.method("com.example.SampleWidget", in_signature='s', out_signature='')
def setText(self, value):
self.widget.setText(value)
# Another one…
@dbus.service.method("com.example.SampleWidget", in_signature='', out_signature='')
def exit(self):
qApp().quit()
# A signal that will be exported to dbus
@dbus.service.signal("com.example.SampleWidget", signature='')
def clicked(self):
pass
# Another signal that will be exported to dbus
@dbus.service.signal("com.example.SampleWidget", signature='')
def lastWindowClosed(self):
pass
if __name__ == "__main__":
print("holi")
app = QApplication([])
# Use qt/glib mainloop integration to get dbus mainloop working
dbus.mainloop.glib.DBusGMainLoop(set_as_default=True)
session_bus = dbus.SessionBus()
print(session_bus)
# Export the service
name = dbus.service.BusName("com.example.SampleService", session_bus)
# Export the object
widget = DBusWidget(session_bus, '/DBusWidget')
print("Running
Running the examples
Copy the client code to a file called example-client.py and the server to a file called example-server.py and type:
python example-server.py &
python example-client.py
A small window should appear on screen. Click on the button to emit a Qt signal. The signal will be converted to a D-Bus signal that will be caught by our D-Bus client.