D-Bus#

There are several classes that can help you interact with D-Bus.

class ignis.dbus.DBusService(*args: Any, **kwargs: Any)#

Class to help create DBus services.

Properties:

name (str, required, read-only): The well-known name to own.
object_path (str, required, read-only): An object path.
info (Gio.DBusInterfaceInfo, required, read-only): A Gio.DBusInterfaceInfo instance. You can get it from XML using load_interface_xml.
on_name_acquired (Callable, optional, read-write): Function to call when name is acquired.
on_name_lost (Callable, optional, read-write): Function to call when name is lost.
connection (Gio.DBusConnection, not argument, read-only): The Gio.DBusConnection instance.
methods (Dict[str, Callable], not argument, read-only): The dictionary of registred DBus methods. See register_dbus_method().
properties (Dict[str, Callable], not argument, read-only): The dictionary of registred DBus properties. See register_dbus_property().

DBus methods:

Must accept Gio.DBusMethodInvocation as the first argument.
Must accept all other arguments typical for this method (specified by interface info).
Must return GLib.Variant or None, as specified by interface info.

DBus properties:

Must return GLib.Variant, as specified by interface info.

from gi.repository import Gio, GLib
from ignis.dbus import DBusService

def _MyMethod(invocation: Gio.DBusMethodInvocation, prop1: str, prop2: str, *args) -> GLib.Variant:
    print("do something")
    return GLib.Variant("(is)", (42, "hello"))

def _MyProperty() -> GLib.Variant:
    return GLib.Variant("(b)", (False,))

dbus = DBusService(...)
dbus.register_dbus_method("MyMethod", _MyMethod)
dbus.register_dbus_property("MyProperty", _MyProperty)

register_dbus_method(name: str, method: Callable) → None#

Register a D-Bus method for this service.

Parameters:

name (str) -- The name of the method to register.
method (Callable) -- A function to call when the method is invoked (from D-Bus).

register_dbus_property(name: str, method: Callable) → None#

Register D-Bus property for this service.

Parameters:

name (str) -- The name of the property to register.
method (Callable) -- A function to call when the property is accessed (from DBus).

emit_signal(signal_name: str, parameters: GLib.Variant | None = None) → None#

Emit a D-Bus signal on this service.

Parameters:

signal_name (str) -- The name of the signal to emit.
parameters -- The GLib.Variant containing paramaters to pass with the signal.

unown_name() → None#: Release ownership of the name.

class ignis.dbus.DBusProxy(*args: Any, **kwargs: Any)#

Class to interact with D-Bus services (create a D-Bus proxy). Unlike Gio.DBusProxy, this class also provides convenient pythonic property access.

Properties:

name (str, required, read-only): A bus name (well-known or unique).
object_path (str, required, read-only): An object path.
interface_name (str, required, read-only): A D-Bus interface name.
info (Gio.DBusInterfaceInfo, required, read-only): A Gio.DBusInterfaceInfo instance. You can get it from XML using load_interface_xml.
proxy (Gio.DBusProxy, not argument, read-only): The Gio.DBusProxy instance.
methods (list[str], not argument, read-only): A list of methods exposed by D-Bus service.
properties (list[str], not argument, read-only): A list of properties exposed by D-Bus service.
has_owner (bool, not argument, read-only): Whether the name has an owner.

To call a D-Bus method, use the standart pythonic way. The first argument always needs to be the DBus signature tuple of the method call. Subsequent arguments must match the provided D-Bus signature. If the D-Bus method does not accept any arguments, do not pass arguments.

from ignis.dbus import DBusProxy
proxy = DBusProxy(...)
proxy.MyMethod("(is)", 42, "hello")

To get a D-Bus property, also use the standart pythonic way.

from ignis.dbus import DBusProxy
proxy = DBusProxy(...)
value = proxy.MyValue
print(value)

signal_subscribe(signal_name: str, callback: Callable | None = None) → int#

Subscribe to D-Bus signal.

Parameters:

signal_name (str) -- The signal name to subscribe.
callback (Callable, optional) -- A function to call when signal is emitted.

Returns:

a subscription ID that can be used with signal_unsubscribe()

Return type:

int

signal_unsubscribe(id: int) → None#

Unsubscribe from D-Bus signal.

Parameters:: id (int) -- The ID of the subscription.

watch_name(on_name_appeared: Callable | None = None, on_name_vanished: Callable | None = None) → None#

Watch name.

Parameters:

on_name_appeared (Callable, optional) -- A function to call when name appeared.
on_name_vanished (Callable, optional) -- A function to call when name vanished.

unwatch_name() → None#: Unwatch name.