ibus/ibus-ui-gtk3-restart-via-systemd.patch

diff --git a/ui/gtk3/panel.vala b/ui/gtk3/panel.vala
index 452b14c8..81c246a2 100644
--- a/ui/gtk3/panel.vala
+++ b/ui/gtk3/panel.vala
@@ -1292,7 +1292,7 @@ class Panel : IBus.PanelService {
             m_sys_menu.append(new Gtk.SeparatorMenuItem());
 
             item = new Gtk.MenuItem.with_label(_("Restart"));
-            item.activate.connect((i) => m_bus.exit(true));
+            item.activate.connect((i) => restart_daemon());
             m_sys_menu.append(item);
 
             item = new Gtk.MenuItem.with_label(_("Quit"));
@@ -1305,6 +1305,144 @@ class Panel : IBus.PanelService {
         return m_sys_menu;
     }
 
+    private const string systemd_service_file = "org.freedesktop.IBus.session.generic.service";
+
+    GLib.DBusConnection?  get_session_bus() {
+        try {
+            return GLib.Bus.get_sync (GLib.BusType.SESSION, null);
+        } catch (GLib.IOError e) {
+            debug("%s\n", e.message);
+        }
+        return null;
+    }
+
+    string?
+    get_ibus_systemd_object_path(GLib.DBusConnection connection) {
+        string object_path = null;
+        assert(systemd_service_file != null);
+        try {
+            var variant = connection.call_sync (
+                    "org.freedesktop.systemd1",
+                    "/org/freedesktop/systemd1",
+                    "org.freedesktop.systemd1.Manager",
+                    "GetUnit",
+                    new GLib.Variant("(s)", systemd_service_file),
+                    new GLib.VariantType("(o)"),
+                    GLib.DBusCallFlags.NONE,
+                    -1,
+                    null);
+            variant.get("(o)", ref object_path);
+            debug("Succeed to get an object path \"%s\" for IBus " +
+                  "systemd service file \"%s\".\n",
+                  object_path, systemd_service_file);
+            return object_path;
+        } catch (GLib.Error e) {
+            debug("IBus systemd service file \"%s\" is not installed " +
+                  "in your system: %s\n",
+                  systemd_service_file, e.message);
+        }
+        return null;
+    }
+
+    bool
+    is_running_daemon_via_systemd(GLib.DBusConnection connection,
+                                  string              object_path) {
+        string? state = null;
+        try {
+            while (true) {
+                var variant = connection.call_sync (
+                        "org.freedesktop.systemd1",
+                        object_path,
+                        "org.freedesktop.DBus.Properties",
+                        "Get",
+                        new GLib.Variant("(ss)",
+                                        "org.freedesktop.systemd1.Unit",
+                                        "ActiveState"),
+                        new GLib.VariantType("(v)"),
+                        GLib.DBusCallFlags.NONE,
+                        -1,
+                        null);
+                GLib.Variant child = null;
+                variant.get("(v)", ref child);
+                state = child.dup_string();
+                debug("systemd state is \"%s\" for an object " +
+                      "path \"%s\".\n", state, object_path);
+                if (state != "activating")
+                    break;
+                Posix.sleep(1);
+            }
+        } catch (GLib.Error e) {
+            debug("%s\n", e.message);
+            return false;
+        }
+        if (state == "active")
+            return true;
+        return false;
+    }
+
+    bool
+    start_daemon_via_systemd(GLib.DBusConnection connection,
+                             bool                restart) {
+        string object_path = null;
+        string method = "StartUnit";
+        assert(systemd_service_file != null);
+        if (restart)
+            method = "RestartUnit";
+        try {
+            var variant = connection.call_sync (
+                    "org.freedesktop.systemd1",
+                    "/org/freedesktop/systemd1",
+                    "org.freedesktop.systemd1.Manager",
+                    method,
+                    new GLib.Variant("(ss)", systemd_service_file, "fail"),
+                    new GLib.VariantType("(o)"),
+                    GLib.DBusCallFlags.NONE,
+                    -1,
+                    null);
+            variant.get("(o)", ref object_path);
+            debug("Succeed to restart IBus daemon via IBus systemd " +
+                  "service file \"%s\": \"%s\"\n",
+                  systemd_service_file, object_path);
+            return true;
+        } catch (GLib.Error e) {
+            debug("Failed to %s IBus daemon via IBus systemd " +
+                  "service file \"%s\": %s\n",
+                  restart ? "restart" : "start",
+                  systemd_service_file, e.message);
+        }
+        return false;
+    }
+
+    private void restart_daemon() {
+        do {
+            GLib.DBusConnection? connection = get_session_bus();
+            if (connection == null)
+                break;
+            var object_path = get_ibus_systemd_object_path(connection);
+            if (object_path == null)
+                break;
+            if (is_running_daemon_via_systemd(connection,
+                                              object_path)) {
+                var result = start_daemon_via_systemd(connection, true);
+                if (!result) {
+                    var dialog = new Gtk.MessageDialog(
+                        null,
+                        Gtk.DialogFlags.DESTROY_WITH_PARENT,
+                        Gtk.MessageType.ERROR,
+                        Gtk.ButtonsType.CLOSE,
+                        "Failed to restart IBus daemon via IBus systemd");
+                    dialog.response.connect((id) => {
+                            dialog.destroy();
+                    });
+                    dialog.show_all();
+                }
+            }
+            return;
+        } while (false);
+        // ibus-daemon is not launched via systemd
+        m_bus.exit(true);
+    }
+
     private Gtk.Menu create_activate_menu() {
         m_ime_menu = new Gtk.Menu();