Add Python3 DBUS example

examples/dbus/dbus.py

@@ -0,0 +1,83 @@
+#!/bin/env python
+
+import subprocess
+
+# three possibilities for DBUS in python:
+# * dbus-python (it's legacy and when i tried it, it didn't really work -- missing SessionBus(), ...)
+# * pydbus      (seems pretty neat)
+# * txdbus      (haven't tried it; apparently it's a native python dbus implementation)
+#
+#
+# official python doc on dbus
+# https://wiki.python.org/moin/DbusExamples
+#
+# pydbus tutorial
+# https://github.com/LEW21/pydbus/blob/master/doc/tutorial.rst
+from pydbus import SessionBus, SystemBus
+
+# required for the mainloop
+from gi.repository import GLib
+
+(rows, cols) = subprocess.check_output(["stty", "size"]).split()
+
+def send_desktop_notification(title="Hello World", msg="pydbus works!"):
+    """Send a notification to the desktop environment to display"""
+    bus = SessionBus()
+    notifications = bus.get('.Notifications')
+    notifications.Notify('test', 0, 'dialog-information', title, msg, [], {}, 5000)
+
+def list_systemd_units():
+    """Fetch all systemd units and print them"""
+    bus = SystemBus()
+
+    # systemd is now a proxy for the .systemd1 remote object
+    systemd = bus.get(".systemd1")
+
+    for unit in systemd.ListUnits():
+        print("Unit:\n")
+        print(unit)
+        print("-" * int(cols))
+
+def stop_start_systemd_unit(name="ssh.service"):
+    """Stop and restart a systemd unit"""
+    bus = SystemBus()
+
+    # systemd is now a proxy for the .systemd1 remote object
+    systemd = bus.get(".systemd1")
+    job1 = systemd.StopUnit(name, "fail")
+    job2 = systemd.StartUnit(name, "fail")
+
+def watch_for_new_systemd_jobs():
+    """Wait for new systemd units and when they are created, print them out"""
+    bus = SystemBus()
+
+    # systemd is now a proxy for the .systemd1 remote object
+    systemd = bus.get(".systemd1")
+    systemd.JobNew.connect(print)
+    GLib.MainLoop().run()
+
+    # or
+    #
+    # systemd.onJobNew = print
+    # GLib.MainLoop.run()
+
+def hibernate():
+    try:
+        bus = SessionBus()
+        power = bus.get('org.gnome.PowerManager', '/org/gnome/PowerManager')
+
+        if power.CanHibernate():
+            answer = input("Do you want to hibernate? [Y/n]:")
+            if answer.lower() == "y":
+                power.Hibernate()
+
+        else:
+            print("Cannot hibernate")
+
+    except GLib.Error as e:
+        print("Could not get PowerManager from DBUS")
+
+if __name__ == "__main__":
+    send_desktop_notification("Guten Tag", "pydbus funktioniert, mein Herr!")
+    # list_systemd_units()
+    hibernate()