device: expose assigned seat

Devices that can be assigned to a seat has tag - seat and such
devices are always assigned to one seat. If device is not assigned
to other seat it is implicitly assigned to seat0.

https://www.freedesktop.org/software/systemd/man/sd-login.html
https://www.freedesktop.org/wiki/Software/systemd/multiseat/

README.md

@@ -5,7 +5,7 @@ Requirements:
 ```text
   glib-2.0             >= 2.66.0
   gio-2.0              >= 2.16.1
-  gudev-1.0            >= 235    (Linux)
+  gudev-1.0            >= 238    (Linux)
   libimobiledevice-1.0 >= 0.9.7  (optional)
   polkit-gobject-1     >= 124
 ```

dbus/org.freedesktop.UPower.Device.xml

@@ -943,6 +943,19 @@ method return sender=:1.386 -> dest=:1.477 reply_serial=2
         </doc:description>
       </doc:doc>
     </property>
+
+    <property name="Seat" type="s" access="read">
+      <doc:doc>
+        <doc:description>
+          <doc:para>
+            Seat name.
+          </doc:para><doc:para>
+            Non-empty value indicates that device has been assigned to a seat.
+          </doc:para>
+        </doc:description>
+      </doc:doc>
+    </property>
+
   </interface>
 
 </node>

libupower-glib/up-client.c

@@ -51,6 +51,7 @@ static void	up_client_finalize			(GObject	*object);
 struct _UpClientPrivate
 {
 	UpExportedDaemon *proxy;
+	char             *seat;
 };
 
 enum {
@@ -122,7 +123,7 @@ up_client_get_devices_full (UpClient      *client,
 		const char *object_path = devices[i];
 		gboolean ret;
 
-		device = up_device_new ();
+		device = g_object_new (UP_TYPE_DEVICE, "client", client, NULL);
 		ret = up_device_set_object_path_sync (device, object_path, cancellable, NULL);
 		if (!ret)
 			continue;
@@ -236,7 +237,7 @@ up_client_get_display_device (UpClient *client)
 	gboolean ret;
 	UpDevice *device;
 
-	device = up_device_new ();
+	device = g_object_new (UP_TYPE_DEVICE, "client", client, NULL);
 	ret = up_device_set_object_path_sync (device, "/org/freedesktop/UPower/devices/DisplayDevice", NULL, NULL);
 	if (!ret) {
 		g_object_unref (G_OBJECT (device));
@@ -348,7 +349,7 @@ up_client_add (UpClient *client, const gchar *object_path)
 	gboolean ret;
 
 	/* create new device */
-	device = up_device_new ();
+	device = g_object_new (UP_TYPE_DEVICE, "client", client, NULL);
 	ret = up_device_set_object_path_sync (device, object_path, NULL, NULL);
 	if (!ret)
 		goto out;
@@ -528,6 +529,50 @@ up_client_class_init (UpClientClass *klass)
 			      G_TYPE_NONE, 1, G_TYPE_STRING);
 }
 
+static char *
+get_seat (GCancellable *cancellable)
+{
+	g_autoptr(GError) error = NULL;
+	g_autoptr(GDBusConnection) connection = NULL;
+	g_autoptr(GVariant) variant = NULL;
+	g_autoptr(GVariant) inner = NULL;
+
+	connection = g_bus_get_sync (G_BUS_TYPE_SYSTEM,
+	                             cancellable,
+	                             &error);
+
+	if (connection == NULL) {
+		if (!g_error_matches (error, G_IO_ERROR, G_IO_ERROR_CANCELLED))
+			g_warning ("system bus not available: %s", error->message);
+
+		return NULL;
+	}
+
+	variant = g_dbus_connection_call_sync (connection,
+	                                       "org.freedesktop.login1",
+	                                       "/org/freedesktop/login1/seat/auto",
+	                                       "org.freedesktop.DBus.Properties",
+	                                       "Get",
+	                                       g_variant_new ("(ss)",
+	                                                      "org.freedesktop.login1.Seat",
+	                                                      "Id"),
+	                                       NULL,
+	                                       G_DBUS_CALL_FLAGS_NONE,
+	                                       -1,
+	                                       cancellable,
+	                                       &error);
+
+	if (variant == NULL) {
+		if (!g_error_matches (error, G_IO_ERROR, G_IO_ERROR_CANCELLED))
+			g_debug ("Failed to get seat name: %s", error->message);
+
+		return NULL;
+	}
+
+	g_variant_get (variant, "(v)", &inner);
+	return g_variant_dup_string (inner, NULL);
+}
+
 /*
  * up_client_init:
  * @client: This class instance
@@ -548,6 +593,8 @@ up_client_initable_init (GInitable *initable, GCancellable *cancellable, GError
 	if (client->priv->proxy == NULL)
 		return FALSE;
 
+	client->priv->seat = get_seat (cancellable);
+
 	/* all callbacks */
 	g_signal_connect (client->priv->proxy, "device-added",
 			  G_CALLBACK (up_device_added_cb), client);
@@ -587,6 +634,7 @@ up_client_finalize (GObject *object)
 	client = UP_CLIENT (object);
 
 	g_clear_object (&client->priv->proxy);
+	g_clear_pointer (&client->priv->seat, g_free);
 
 	G_OBJECT_CLASS (up_client_parent_class)->finalize (object);
 }
@@ -716,3 +764,11 @@ up_client_new_finish (GAsyncResult  *res,
 
   return g_task_propagate_pointer (G_TASK (res), error);
 }
+
+const char *
+up_client_get_seat (UpClient *client)
+{
+  g_return_val_if_fail (UP_IS_CLIENT (client), NULL);
+
+  return client->priv->seat;
+}

libupower-glib/up-client.h

@@ -100,6 +100,8 @@ G_DEPRECATED
 gboolean	 up_client_get_lid_is_present		(UpClient		*client);
 gboolean	 up_client_get_on_battery		(UpClient		*client);
 
+const char	*up_client_get_seat			(UpClient		*client);
+
 G_END_DECLS
 
 #endif /* __UP_CLIENT_H */

libupower-glib/up-device.c

@@ -35,6 +35,7 @@
 #include <glib-object.h>
 #include <string.h>
 
+#include "up-client.h"
 #include "up-device.h"
 #include "up-device-generated.h"
 #include "up-stats-item.h"
@@ -51,6 +52,8 @@ static void	up_device_finalize	(GObject		*object);
  **/
 struct _UpDevicePrivate
 {
+	UpClient		*client;
+
 	UpExportedDevice		*proxy_device;
 
 	/* For use when a UpDevice isn't backed by a D-Bus object
@@ -60,6 +63,7 @@ struct _UpDevicePrivate
 
 enum {
 	PROP_0,
+	PROP_CLIENT,
 	PROP_UPDATE_TIME,
 	PROP_VENDOR,
 	PROP_MODEL,
@@ -97,6 +101,7 @@ enum {
 	PROP_VOLTAGE_MIN_DESIGN,
 	PROP_VOLTAGE_MAX_DESIGN,
 	PROP_CAPACITY_LEVEL,
+	PROP_SEAT,
 	PROP_LAST
 };
 
@@ -613,6 +618,14 @@ up_device_set_property (GObject *object, guint prop_id, const GValue *value, GPa
 {
 	UpDevice *device = UP_DEVICE (object);
 
+	switch (prop_id) {
+	case PROP_CLIENT:
+		device->priv->client = g_value_dup_object (value);
+		break;
+	default:
+		break;
+	}
+
 	if (device->priv->proxy_device == NULL) {
 		GValue *v;
 
@@ -735,6 +748,8 @@ up_device_set_property (GObject *object, guint prop_id, const GValue *value, GPa
 		break;
 	case PROP_CAPACITY_LEVEL:
 		up_exported_device_set_capacity_level (device->priv->proxy_device, g_value_get_string (value));
+	case PROP_SEAT:
+		up_exported_device_set_seat (device->priv->proxy_device, g_value_get_string (value));
 		break;
 	default:
 		G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
@@ -873,6 +888,8 @@ up_device_get_property (GObject *object, guint prop_id, GValue *value, GParamSpe
 		break;
 	case PROP_CAPACITY_LEVEL:
 		g_value_set_string (value, up_exported_device_get_capacity_level (device->priv->proxy_device));
+	case PROP_SEAT:
+		g_value_set_string (value, up_exported_device_get_seat (device->priv->proxy_device));
 		break;
 	default:
 		G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
@@ -891,6 +908,16 @@ up_device_class_init (UpDeviceClass *klass)
 	object_class->set_property = up_device_set_property;
 	object_class->get_property = up_device_get_property;
 
+	g_object_class_install_property (object_class,
+					 PROP_CLIENT,
+					 g_param_spec_object ("client",
+							      "UpClient",
+							      "UpClient reference",
+							      UP_TYPE_CLIENT,
+							      G_PARAM_STATIC_STRINGS |
+							      G_PARAM_WRITABLE |
+							      G_PARAM_CONSTRUCT_ONLY));
+
 	/**
 	 * UpDevice:update-time:
 	 *
@@ -1387,6 +1414,20 @@ up_device_class_init (UpDeviceClass *klass)
 					 g_param_spec_string ("capacity-level",
 							      NULL, NULL, NULL,
 							      G_PARAM_READWRITE));
+
+	/**
+	 * UpDevice:seat:
+	 *
+	 * The seat of the device.
+	 *
+	 * Since: 1.90.10
+	 **/
+	g_object_class_install_property (object_class,
+					 PROP_SEAT,
+					 g_param_spec_string ("seat",
+							      NULL, NULL,
+							      NULL,
+							      G_PARAM_READWRITE));
 }
 
 static void
@@ -1427,6 +1468,7 @@ up_device_finalize (GObject *object)
 						      device);
 	}
 
+	g_clear_object (&device->priv->client);
 	g_clear_object (&device->priv->proxy_device);
 	g_clear_pointer (&device->priv->offline_props, g_hash_table_unref);
 
@@ -1447,3 +1489,37 @@ up_device_new (void)
 {
 	return UP_DEVICE (g_object_new (UP_TYPE_DEVICE, NULL));
 }
+
+/**
+ * up_device_is_available_to_user:
+ * @device: a #UpDevice instance.
+ *
+ * If supported by OS backend returns device availability to user otherwise
+ * it is assumed that device is available.
+ *
+ * Returns: #TRUE if device is available or #FALSE otherwise.
+ *
+ * Since: 1.90.10
+ **/
+gboolean
+up_device_is_available_to_user (UpDevice *device)
+{
+	const char *client_seat;
+	const char *device_seat;
+
+	g_return_val_if_fail (UP_IS_DEVICE (device), TRUE);
+
+	if (device->priv->client == NULL)
+		return TRUE;
+
+	client_seat = up_client_get_seat (device->priv->client);
+	if (client_seat == NULL)
+		return TRUE;
+
+	/* NULL/empty seat means that device is available to all seats */
+	device_seat = up_exported_device_get_seat (device->priv->proxy_device);
+	if (device_seat == NULL || *device_seat == '\0')
+		return TRUE;
+
+	return g_str_equal (client_seat, device_seat);
+}

libupower-glib/up-device.h

@@ -68,6 +68,8 @@ GType		 up_device_get_type			(void);
 UpDevice	*up_device_new				(void);
 gchar		*up_device_to_text			(UpDevice		*device);
 
+gboolean	 up_device_is_available_to_user		(UpDevice               *device);
+
 /* sync versions */
 G_DEPRECATED
 gboolean	 up_device_refresh_sync			(UpDevice		*device,

src/linux/up-enumerator-udev.c

@@ -97,6 +97,34 @@ is_macbook (gpointer data)
 	return GINT_TO_POINTER(g_str_has_prefix (product, "MacBook"));
 }
 
+static char *
+get_seat_from_device (GUdevDevice *native)
+{
+	const char *const *tags;
+	g_autoptr(GUdevDevice) parent = NULL;
+
+	tags = g_udev_device_get_current_tags (native);
+
+	if (g_strv_contains (tags, "seat")) {
+		int i;
+
+		for (i = 0; tags[i] != NULL; i++) {
+			if (g_str_has_prefix (tags[i], "seat") &&
+			    strlen (tags[i]) > strlen ("seat"))
+				return g_strdup (tags[i]);
+		}
+
+		return g_strdup ("seat0");
+	}
+
+	parent = g_udev_device_get_parent (native);
+
+	if (parent != NULL)
+		return get_seat_from_device (parent);
+
+	return NULL;
+}
+
 static UpDevice *
 device_new (UpEnumeratorUdev *self, GUdevDevice *native)
 {
@@ -108,12 +136,15 @@ device_new (UpEnumeratorUdev *self, GUdevDevice *native)
 
 	subsys = g_udev_device_get_subsystem (native);
 	if (g_strcmp0 (subsys, "power_supply") == 0) {
+		g_autofree char *seat = NULL;
 		UpDevice *device;
 
+		seat = get_seat_from_device (native);
 		device = g_initable_new (UP_TYPE_DEVICE_SUPPLY_BATTERY, NULL, NULL,
 		                       "daemon", daemon,
 		                       "native", native,
 		                       "ignore-system-percentage", GPOINTER_TO_INT (is_macbook (NULL)),
+		                       "seat", seat,
 		                       NULL);
 		if (device)
 			return device;
@@ -121,6 +152,7 @@ device_new (UpEnumeratorUdev *self, GUdevDevice *native)
 		return g_initable_new (UP_TYPE_DEVICE_SUPPLY, NULL, NULL,
 		                       "daemon", daemon,
 		                       "native", native,
+		                       "seat", seat,
 		                       NULL);
 
 	} else if (g_strcmp0 (subsys, "tty") == 0) {
@@ -302,6 +334,8 @@ uevent_signal_handler_cb (UpEnumeratorUdev *self,
 				g_signal_emit_by_name (self, "device-added", up_dev);
 
 		} else {
+			const gchar *subsys;
+
 			if (!UP_IS_DEVICE (obj)) {
 				g_autoptr(GUdevDevice) d = get_latest_udev_device (self, obj);
 				if (d)
@@ -309,6 +343,14 @@ uevent_signal_handler_cb (UpEnumeratorUdev *self,
 				return;
 			}
 
+			subsys = g_udev_device_get_subsystem (device);
+			if (g_strcmp0 (subsys, "power_supply") == 0) {
+				g_autofree char *seat = NULL;
+
+				seat = get_seat_from_device (device);
+				g_object_set (obj, "seat", seat, NULL);
+			}
+
 			g_debug ("refreshing device for path %s", g_udev_device_get_sysfs_path (device));
 			if (!up_device_refresh_internal (UP_DEVICE (obj), UP_REFRESH_EVENT))
 				g_debug ("no changes on %s", up_device_get_object_path (UP_DEVICE (obj)));