socketservice: add an "active" property

We already have start, stop and is_active methods, but turning it
into a real property is useful for a few reasons:
 - it allows us to bind the property to an UI or a setting
 - it allows us to get notified when the state changes
 - it allows us to instantiate objects directly in the stopped state

https://bugzilla.gnome.org/show_bug.cgi?id=752089

gio/gsocketservice.c

@@ -63,6 +63,7 @@
 #include <gio/gio.h>
 #include "gsocketlistener.h"
 #include "gsocketconnection.h"
+#include "glibintl.h"
 
 struct _GSocketServicePrivate
 {
@@ -77,6 +78,12 @@ G_LOCK_DEFINE_STATIC(active);
 
 G_DEFINE_TYPE_WITH_PRIVATE (GSocketService, g_socket_service, G_TYPE_SOCKET_LISTENER)
 
+enum
+{
+  PROP_0,
+  PROP_ACTIVE
+};
+
 static void g_socket_service_ready (GObject      *object,
 				    GAsyncResult *result,
 				    gpointer      user_data);
@@ -117,6 +124,90 @@ do_accept (GSocketService  *service)
   service->priv->outstanding_accept = TRUE;
 }
 
+static gboolean
+get_active (GSocketService *service)
+{
+  gboolean active;
+
+  G_LOCK (active);
+  active = service->priv->active;
+  G_UNLOCK (active);
+
+  return active;
+}
+
+static void
+set_active (GSocketService *service, gboolean active)
+{
+  gboolean notify = FALSE;
+
+  active = !!active;
+
+  G_LOCK (active);
+
+  if (active != service->priv->active)
+    {
+      service->priv->active = active;
+      notify = TRUE;
+
+      if (active)
+        {
+          if (service->priv->outstanding_accept)
+            g_cancellable_cancel (service->priv->cancellable);
+          else
+            do_accept (service);
+        }
+      else
+        {
+          if (service->priv->outstanding_accept)
+            g_cancellable_cancel (service->priv->cancellable);
+        }
+    }
+
+  G_UNLOCK (active);
+
+  if (notify)
+    g_object_notify (G_OBJECT (service), "active");
+}
+
+static void
+g_socket_service_get_property (GObject    *object,
+                               guint       prop_id,
+                               GValue     *value,
+                               GParamSpec *pspec)
+{
+  GSocketService *service = G_SOCKET_SERVICE (object);
+
+  switch (prop_id)
+    {
+    case PROP_ACTIVE:
+      g_value_set_boolean (value, get_active (service));
+      break;
+    default:
+      G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
+      break;
+    }
+}
+
+static void
+g_socket_service_set_property (GObject      *object,
+                               guint         prop_id,
+                               const GValue *value,
+                               GParamSpec   *pspec)
+{
+  GSocketService *service = G_SOCKET_SERVICE (object);
+
+  switch (prop_id)
+    {
+    case PROP_ACTIVE:
+      set_active (service, g_value_get_boolean (value));
+      break;
+    default:
+      G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
+      break;
+    }
+}
+
 static void
 g_socket_service_changed (GSocketListener *listener)
 {
@@ -151,12 +242,9 @@ g_socket_service_changed (GSocketListener *listener)
 gboolean
 g_socket_service_is_active (GSocketService *service)
 {
-  gboolean active;
+  g_return_val_if_fail (G_IS_SOCKET_SERVICE (service), FALSE);
 
-  G_LOCK (active);
-  active = service->priv->active;
-  G_UNLOCK (active);
-  return active;
+  return get_active (service);
 }
 
 /**
@@ -174,19 +262,9 @@ g_socket_service_is_active (GSocketService *service)
 void
 g_socket_service_start (GSocketService *service)
 {
-  G_LOCK (active);
+  g_return_if_fail (G_IS_SOCKET_SERVICE (service));
 
-  if (!service->priv->active)
-    {
-      service->priv->active = TRUE;
-
-      if (service->priv->outstanding_accept)
-	g_cancellable_cancel (service->priv->cancellable);
-      else
-	do_accept (service);
-    }
-
-  G_UNLOCK (active);
+  set_active (service, TRUE);
 }
 
 /**
@@ -210,20 +288,11 @@ g_socket_service_start (GSocketService *service)
 void
 g_socket_service_stop (GSocketService *service)
 {
-  G_LOCK (active);
+  g_return_if_fail (G_IS_SOCKET_SERVICE (service));
 
-  if (service->priv->active)
-    {
-      service->priv->active = FALSE;
-
-      if (service->priv->outstanding_accept)
-	g_cancellable_cancel (service->priv->cancellable);
-    }
-
-  G_UNLOCK (active);
+  set_active (service, FALSE);
 }
 
-
 static gboolean
 g_socket_service_incoming (GSocketService    *service,
                            GSocketConnection *connection,
@@ -243,6 +312,8 @@ g_socket_service_class_init (GSocketServiceClass *class)
   GSocketListenerClass *listener_class = G_SOCKET_LISTENER_CLASS (class);
 
   gobject_class->finalize = g_socket_service_finalize;
+  gobject_class->set_property = g_socket_service_set_property;
+  gobject_class->get_property = g_socket_service_get_property;
   listener_class->changed = g_socket_service_changed;
   class->incoming = g_socket_service_real_incoming;
 
@@ -271,6 +342,20 @@ g_socket_service_class_init (GSocketServiceClass *class)
                   g_signal_accumulator_true_handled, NULL,
                   NULL, G_TYPE_BOOLEAN,
                   2, G_TYPE_SOCKET_CONNECTION, G_TYPE_OBJECT);
+
+  /**
+   * GSocketService:active:
+   *
+   * Whether the service is currently accepting connections.
+   *
+   * Since: 2.46
+   */
+  g_object_class_install_property (gobject_class, PROP_ACTIVE,
+                                   g_param_spec_boolean ("active",
+                                                         P_("Active"),
+                                                         P_("Whether the service is currently accepting connections"),
+                                                         TRUE,
+                                                         G_PARAM_CONSTRUCT | G_PARAM_READWRITE | G_PARAM_STATIC_STRINGS));
 }
 
 static void
@@ -309,7 +394,6 @@ g_socket_service_ready (GObject      *object,
   G_UNLOCK (active);
 }
 
-
 /**
  * g_socket_service_new:
  *