Drop the Device.Id from the DBus interface

The Device is an object on DBus, there is no need for another opaque ID, we
can just emulate this in the client. In our case by using the object
path and generating a sha1 from it.

Signed-off-by: Peter Hutterer <peter.hutterer@who-t.net>

doc/dbus.rst

@@ -98,16 +98,6 @@ org.freedesktop.ratbag1.Device
 The **org.freedesktop.ratbag1.Device** interface describes a single device
 known to ratbagd.
 
-.. attribute:: Id
-
-        :type: as
-        :flags: read-only, constant
-
-        A unique ID describing this device. This ID should not be used for presentation to
-	the user. This ID may be recycled when the device is removed. The
-	content of the ID is undefined, the client should treat it as an
-	opaque string.
-
 .. attribute:: Model
 
 	:type: s

ratbagd/ratbagd-device.c

@@ -217,7 +217,6 @@ ratbag_device_get_model(sd_bus *bus,
 
 const sd_bus_vtable ratbagd_device_vtable[] = {
 	SD_BUS_VTABLE_START(0),
-	SD_BUS_PROPERTY("Id", "s", NULL, offsetof(struct ratbagd_device, sysname), SD_BUS_VTABLE_PROPERTY_CONST),
 	SD_BUS_PROPERTY("Model", "s", ratbag_device_get_model, 0, SD_BUS_VTABLE_PROPERTY_CONST),
 	SD_BUS_PROPERTY("Name", "s", ratbagd_device_get_device_name, 0, SD_BUS_VTABLE_PROPERTY_CONST),
 	SD_BUS_PROPERTY("Profiles", "ao", ratbagd_device_get_profiles, 0, SD_BUS_VTABLE_PROPERTY_CONST),

tools/ratbagctl.in

@@ -61,7 +61,7 @@ def list_devices(r, args):
         print("No devices available.")
 
     for d in r.devices:
-        print("{:10s} {:32s}".format(d.id + ":", d.name))
+        print("{:20s} {:32s}".format(d.id + ":", d.name))
 
 
 def find_device(r, args):

tools/ratbagd.py

@@ -23,6 +23,7 @@
 
 import os
 import sys
+import hashlib
 
 from enum import IntEnum
 from evdev import ecodes
@@ -299,6 +300,9 @@ class RatbagdDevice(_RatbagdDBus):
         for profile in self._profiles:
             profile.connect("notify::is-active", self._on_active_profile_changed)
 
+        # Use a SHA1 of our object path as our device's ID
+        self._id = hashlib.sha1(object_path.encode('utf-8')).hexdigest()
+
     def _on_signal_received(self, proxy, sender_name, signal_name, parameters):
         if signal_name == "Resync":
             self.emit("resync")
@@ -309,8 +313,7 @@ class RatbagdDevice(_RatbagdDBus):
 
     @GObject.Property
     def id(self):
-        """The unique identifier of this device."""
-        return self._get_dbus_property("Id")
+        return self._id
 
     @GObject.Property
     def model(self):