1 files changed, 107 insertions, 1 deletions

diff --git a/libdbusmenu-glib/client.c b/libdbusmenu-glib/client.c
index 22f65fa..d5e4334 100644
--- a/libdbusmenu-glib/client.c
+++ b/libdbusmenu-glib/client.c
@@ -64,6 +64,8 @@ struct _DbusmenuClientPrivate
 	DBusGProxy * menuproxy;
 	DBusGProxy * propproxy;
 	DBusGProxyCall * layoutcall;
+
+	DBusGProxy * dbusproxy;
 };
 
 #define DBUSMENU_CLIENT_GET_PRIVATE(o) \
@@ -148,6 +150,8 @@ dbusmenu_client_init (DbusmenuClient *self)
 	priv->propproxy = NULL;
 	priv->layoutcall = NULL;
 
+	priv->dbusproxy = NULL;
+
 	return;
 }
 
@@ -168,6 +172,10 @@ dbusmenu_client_dispose (GObject *object)
 		g_object_unref(G_OBJECT(priv->propproxy));
 		priv->propproxy = NULL;
 	}
+	if (priv->dbusproxy != NULL) {
+		g_object_unref(G_OBJECT(priv->dbusproxy));
+		priv->dbusproxy = NULL;
+	}
 	priv->session_bus = NULL;
 
 	if (priv->root != NULL) {
@@ -277,6 +285,84 @@ id_update (DBusGProxy * proxy, guint id, DbusmenuClient * client)
 	return;
 }
 
+/* Watches to see if our DBus savior comes onto the bus */
+static void
+dbus_owner_change (DBusGProxy * proxy, const gchar * name, const gchar * prev, const gchar * new, DbusmenuClient * client)
+{
+	DbusmenuClientPrivate * priv = DBUSMENU_CLIENT_GET_PRIVATE(client);
+
+	if (!(new != NULL && prev == NULL)) {
+		/* If it's not someone new getting on the bus, sorry we
+		   simply just don't care.  It's not that your service isn't
+		   important to someone, just not us.  You'll find the right
+		   process someday, there's lots of processes out there. */
+		return;
+	}
+
+	if (g_strcmp0(new, priv->dbus_name)) {
+		/* Again, someone else's service. */
+		return;
+	}
+
+	/* Woot!  A service for us to love and to hold for ever
+	   and ever and ever! */
+	return build_proxies(client);
+}
+
+/* This function builds the DBus proxy which will look out for
+   the service coming up. */
+static void
+build_dbus_proxy (DbusmenuClient * client)
+{
+	DbusmenuClientPrivate * priv = DBUSMENU_CLIENT_GET_PRIVATE(client);
+	GError * error = NULL;
+
+	if (priv->dbusproxy != NULL) {
+		return;
+	}
+
+	priv->dbusproxy = dbus_g_proxy_new_for_name_owner (priv->session_bus,
+	                                                   DBUS_SERVICE_DBUS,
+	                                                   DBUS_PATH_DBUS,
+	                                                   DBUS_INTERFACE_DBUS,
+	                                                   &error);
+	if (error != NULL) {
+		g_debug("Oh, that's bad.  That's really bad.  We can't get a proxy to DBus itself?  Seriously?  Here's all I know: %s", error->message);
+		g_error_free(error);
+		return;
+	}
+
+	dbus_g_proxy_add_signal(priv->dbusproxy, "NameOwnerChanged",
+	                        G_TYPE_STRING, G_TYPE_STRING, G_TYPE_STRING,
+	                        G_TYPE_INVALID);
+	dbus_g_proxy_connect_signal(priv->dbusproxy, "NameOwnerChanged",
+	                            G_CALLBACK(dbus_owner_change), client, NULL);
+
+	return;
+}
+
+/* A signal handler that gets called when a proxy is destoryed a
+   so it needs to clean up a little.  Make sure we don't think we
+   have a layout and setup the dbus watcher. */
+static void
+proxy_destroyed (GObject * gobj_proxy, gpointer userdata)
+{
+	DbusmenuClientPrivate * priv = DBUSMENU_CLIENT_GET_PRIVATE(userdata);
+
+	if (priv->root != NULL) {
+		g_object_unref(G_OBJECT(priv->root));
+		priv->root = NULL;
+		g_signal_emit(G_OBJECT(userdata), signals[LAYOUT_UPDATED], 0, TRUE);
+	}
+
+	if ((gpointer)priv->menuproxy == (gpointer)gobj_proxy) {
+		priv->layoutcall = NULL;
+	}
+
+	build_dbus_proxy(DBUSMENU_CLIENT(userdata));
+	return;
+}
+
 /* When we have a name and an object, build the two proxies and get the
    first version of the layout */
 static void
@@ -292,6 +378,7 @@ build_proxies (DbusmenuClient * client)
 	if (error != NULL) {
 		g_error("Unable to get session bus: %s", error->message);
 		g_error_free(error);
+		build_dbus_proxy(client);
 		return;
 	}
 
@@ -305,6 +392,8 @@ build_proxies (DbusmenuClient * client)
 		g_error_free(error);
 		return;
 	}
+	g_object_add_weak_pointer(G_OBJECT(priv->propproxy), (gpointer *)&priv->propproxy);
+	g_signal_connect(G_OBJECT(priv->propproxy), "destroy", G_CALLBACK(proxy_destroyed), client);
 
 	priv->menuproxy = dbus_g_proxy_new_for_name_owner(priv->session_bus,
 	                                                  priv->dbus_name,
@@ -316,6 +405,14 @@ build_proxies (DbusmenuClient * client)
 		g_error_free(error);
 		return;
 	}
+	g_object_add_weak_pointer(G_OBJECT(priv->menuproxy), (gpointer *)&priv->menuproxy);
+	g_signal_connect(G_OBJECT(priv->menuproxy), "destroy", G_CALLBACK(proxy_destroyed), client);
+
+	/* If we get here, we don't need the DBus proxy */
+	if (priv->dbusproxy != NULL) {
+		g_object_unref(G_OBJECT(priv->dbusproxy));
+		priv->dbusproxy = NULL;
+	}
 
 	dbus_g_proxy_add_signal(priv->menuproxy, "LayoutUpdate", G_TYPE_INVALID);
 	dbus_g_proxy_connect_signal(priv->menuproxy, "LayoutUpdate", G_CALLBACK(layout_update), client, NULL);
@@ -500,6 +597,10 @@ update_layout (DbusmenuClient * client)
 {
 	DbusmenuClientPrivate * priv = DBUSMENU_CLIENT_GET_PRIVATE(client);
 
+	if (priv->propproxy == NULL) {
+		return;
+	}
+
 	if (priv->layoutcall != NULL) {
 		return;
 	}
@@ -555,7 +656,8 @@ dbusmenu_client_new (const gchar * name, const gchar * object)
 	it could block longer.
 
 	Return value: A #DbusmenuMenuitem representing the root of
-		menu on the server.
+		menu on the server.  If there is no server or there is
+		an error receiving its layout it'll return #NULL.
 */
 DbusmenuMenuitem *
 dbusmenu_client_get_root (DbusmenuClient * client)
@@ -564,6 +666,10 @@ dbusmenu_client_get_root (DbusmenuClient * client)
 
 	DbusmenuClientPrivate * priv = DBUSMENU_CLIENT_GET_PRIVATE(client);
 
+	if (priv->propproxy == NULL) {
+		return NULL;
+	}
+
 	if (priv->layoutcall != NULL) {
 		/* Will end the current call and block on it's completion */
 		update_layout_cb(priv->propproxy, priv->layoutcall, client);