tools: Enable ibus restart in GNOME desktop

If ibus-daemon is called via systemd, IBus restart API cannot restart
ibus-daemon but just terminates it.
Now ibus restart command checks the systemd avaiability and restart
ibus-daemon via systemd.
ibus start command is also added to launch ibus-daemon with systemd.

BUG=https://github.com/ibus/ibus/issues/2407

4 files changed, 330 insertions, 44 deletions

diff --git a/po/ibus10.pot b/po/ibus10.pot
index 3f9843dd..09c09be7 100644
--- a/po/ibus10.pot
+++ b/po/ibus10.pot
@@ -7,8 +7,8 @@ msgid ""
 msgstr ""
 "Project-Id-Version: ibus 1.5.26\n"
 "Report-Msgid-Bugs-To: https://github.com/ibus/ibus/issues\n"
-"POT-Creation-Date: 2022-06-20 20:30+0900\n"
-"PO-Revision-Date: 2022-06-20 20:30+0900\n"
+"POT-Creation-Date: 2022-07-06 22:08+0900\n"
+"PO-Revision-Date: 2022-07-06 22:08+0900\n"
 "Last-Translator: Takao Fujiwara <takao.fujiwara1@gmail.com>\n"
 "Language-Team: Source\n"
 "Language: \n"
@@ -3099,129 +3099,145 @@ msgstr ""
 msgid "Supplementary Private Use Area-B"
 msgstr ""
 
-#: tools/main.vala:51
+#: tools/main.vala:182
 msgid "List engine name only"
 msgstr ""
 
-#: tools/main.vala:67 tools/main.vala:192 tools/main.vala:202
+#: tools/main.vala:198 tools/main.vala:395 tools/main.vala:437
 msgid "Can't connect to IBus.\n"
 msgstr ""
 
-#: tools/main.vala:93
+#: tools/main.vala:224
 #, c-format
 msgid "language: %s\n"
 msgstr ""
 
-#: tools/main.vala:161
+#: tools/main.vala:294
 msgid "No engine is set.\n"
 msgstr ""
 
-#: tools/main.vala:169
+#: tools/main.vala:302
 msgid "Set global engine failed.\n"
 msgstr ""
 
-#: tools/main.vala:174
+#: tools/main.vala:307
 msgid "Get global engine failed.\n"
 msgstr ""
 
-#: tools/main.vala:217
+#: tools/main.vala:328
+msgid "Start or restart daemon with \"direct\" or \"systemd\" TYPE."
+msgstr ""
+
+#: tools/main.vala:331
+msgid "Start or restart daemon with SYSTEMD_SERVICE file."
+msgstr ""
+
+#: tools/main.vala:334
+msgid "Show debug messages."
+msgstr ""
+
+#: tools/main.vala:454
 msgid "Read the system registry cache."
 msgstr ""
 
-#: tools/main.vala:219
+#: tools/main.vala:456
 msgid "Read the registry cache FILE."
 msgstr ""
 
-#: tools/main.vala:237 tools/main.vala:242
+#: tools/main.vala:474 tools/main.vala:479
 msgid "The registry cache is invalid.\n"
 msgstr ""
 
-#: tools/main.vala:257
+#: tools/main.vala:495
 msgid "Write the system registry cache."
 msgstr ""
 
-#: tools/main.vala:259
+#: tools/main.vala:497
 msgid "Write the registry cache FILE."
 msgstr ""
 
-#: tools/main.vala:295
+#: tools/main.vala:535
 msgid ""
 "Use engine schema paths instead of ibus core, which can be comma-separated "
 "values."
 msgstr ""
 
-#: tools/main.vala:381
+#: tools/main.vala:624
 msgid "Resetting…"
 msgstr ""
 
-#: tools/main.vala:399
+#: tools/main.vala:642
 msgid "Done"
 msgstr ""
 
-#: tools/main.vala:444
+#: tools/main.vala:691
 msgid "Set or get engine"
 msgstr ""
 
-#: tools/main.vala:445
+#: tools/main.vala:692
 msgid "Exit ibus-daemon"
 msgstr ""
 
-#: tools/main.vala:446
+#: tools/main.vala:693
 msgid "Show available engines"
 msgstr ""
 
-#: tools/main.vala:447
+#: tools/main.vala:694
 msgid "(Not implemented)"
 msgstr ""
 
-#: tools/main.vala:448
+#: tools/main.vala:695
 msgid "Restart ibus-daemon"
 msgstr ""
 
-#: tools/main.vala:449
+#: tools/main.vala:696
+msgid "Start ibus-daemon"
+msgstr ""
+
+#: tools/main.vala:697
 msgid "Show version"
 msgstr ""
 
-#: tools/main.vala:450
+#: tools/main.vala:698
 msgid "Show the content of registry cache"
 msgstr ""
 
-#: tools/main.vala:451
+#: tools/main.vala:699
 msgid "Create registry cache"
 msgstr ""
 
-#: tools/main.vala:452
+#: tools/main.vala:700
 msgid "Print the D-Bus address of ibus-daemon"
 msgstr ""
 
-#: tools/main.vala:453
+#: tools/main.vala:701
 msgid "Show the configuration values"
 msgstr ""
 
-#: tools/main.vala:454
+#: tools/main.vala:702
 msgid "Reset the configuration values"
 msgstr ""
 
-#: tools/main.vala:456
+#: tools/main.vala:704
 msgid "Save emoji on dialog to clipboard"
 msgstr ""
 
-#: tools/main.vala:458
+#: tools/main.vala:706
 msgid "Show this information"
 msgstr ""
 
-#: tools/main.vala:464
+#: tools/main.vala:713
 #, c-format
 msgid ""
 "Usage: %s COMMAND [OPTION...]\n"
 "\n"
 msgstr ""
 
-#: tools/main.vala:465
+#: tools/main.vala:714
 msgid "Commands:\n"
 msgstr ""
 
-#: tools/main.vala:494
+#: tools/main.vala:744
 #, c-format
 msgid "%s is unknown command!\n"
 msgstr ""
diff --git a/tools/Makefile.am b/tools/Makefile.am
index 5c18d3d6..e380a9aa 100644
--- a/tools/Makefile.am
+++ b/tools/Makefile.am
@@ -3,7 +3,7 @@
 # ibus - The Input Bus
 #
 # Copyright (c) 2007-2013 Peng Huang <shawn.p.huang@gmail.com>
-# Copyright (c) 2015-2017 Takao Fujiwara <takao.fujiwara1@gmail.com>
+# Copyright (c) 2015-2022 Takao Fujiwara <takao.fujiwara1@gmail.com>
 # Copyright (c) 2007-2017 Red Hat, Inc.
 #
 # This library is free software; you can redistribute it and/or
@@ -57,6 +57,7 @@ AM_LDADD = \
 AM_VALAFLAGS = \
 	--vapidir=$(top_builddir)/bindings/vala \
 	--vapidir=$(top_srcdir)/bindings/vala \
+	--pkg=gio-2.0 \
 	--pkg=ibus-1.0 \
 	--pkg=posix \
 	--pkg=config \
diff --git a/tools/ibus.1.in b/tools/ibus.1.in
index 525d972e..fe1b7157 100644
--- a/tools/ibus.1.in
+++ b/tools/ibus.1.in
@@ -3,7 +3,7 @@
 .\" Copyright (C) Takao Fujiwara <takao.fujiwara1@gmail.com>, 2013-2017.
 .\" Copyright (c) Peng Huang <shawn.p.huang@gmail.com>, 2013.
 .\"
-.TH "IBUS" 1 "May 2017" "@VERSION@" "User Commands"
+.TH "IBUS" 1 "Jul 2022" "@VERSION@" "User Commands"
 .SH NAME
 .B ibus
 \- command line utility for ibus
@@ -45,13 +45,33 @@ Exit ibus-daemon.
 \fBlist-engine\fR
 Show ibus engines list.
 .TP
-\fBrestart\fR
-Restart ibus-daemon.
+\fBrestart\fR [\fB\-\-type=TYPE|\-\-verbose|\-\-help\fR]
+Restart ibus-daemon. This command tries to restart ibus-daemon via systemd
+firstly and directly secondary by default. If
+.B \-\-type=systemd
+is given, It tries to restart via systemd only. If
+.B \-\-type=direct
+is given, It tries to restart with an IBus API only. GNOME desktop runs
+ibus-daemon via systemd and other desktops run ibus-daemon directly.
+.TP
+\fBstart\fR [\fB\-\-type=TYPE|\-\-verbose|\-\-help\fR]
+Start ibus-daemon. This command tries to start ibus-daemon via systemd
+firstly and directly secondary by default. If
+.B \-\-type=systemd
+is given, It tries to start as a background process via systemd only. If
+.B \-\-type=direct
+is given, It tries to start directly only as a foreground process and other
+option arguments of ibus command are sent to ibus-daemon. E.g.
+ibus start
+.B \-\-type=direct
+.B \-\-xim
+&
+GNOME desktop runs ibus-daemon via systemd and other desktops run ibus-daemon directly.
 .TP
 \fBversion\fR
 Show the ibus version.
 .TP
-\fBread\-cache\fR [\fB\-\-system|\-\-file=FILE\fR]
+\fBread\-cache\fR [\fB\-\-system|\-\-file=FILE|\-\-help\fR]
 Show the content of the user registry cache if
 .B \-\-system
 is not given.
@@ -64,7 +84,7 @@ if
 .B \-\-file=FILE
 is given.
 .TP
-\fBwrite\-cache\fR [\fB\-\-system|\-\-file=FILE\fR]
+\fBwrite\-cache\fR [\fB\-\-system|\-\-file=FILE|\-\-help\fR]
 Save the user registry cache if
 .B \-\-system
 is not given.
diff --git a/tools/main.vala b/tools/main.vala
index 26e7fd88..407eaf74 100644
--- a/tools/main.vala
+++ b/tools/main.vala
@@ -3,7 +3,7 @@
  * ibus - The Input Bus
  *
  * Copyright(c) 2013 Peng Huang <shawn.p.huang@gmail.com>
- * Copyright(c) 2015-2020 Takao Fujiwara <takao.fujiwara1@gmail.com>
+ * Copyright(c) 2015-2022 Takao Fujiwara <takao.fujiwara1@gmail.com>
  *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Lesser General Public
@@ -27,17 +27,23 @@ private const string IBUS_SCHEMAS_GENERAL_HOTKEY =
 private const string IBUS_SCHEMAS_PANEL = "org.freedesktop.ibus.panel";
 private const string IBUS_SCHEMAS_PANEL_EMOJI =
         "org.freedesktop.ibus.panel.emoji";
+private const string SYSTEMD_SESSION_GNOME_FILE =
+        "org.freedesktop.IBus.session.GNOME.service";
 
 bool name_only = false;
 /* system() exists as a public API. */
 bool is_system = false;
 string cache_file = null;
 string engine_id = null;
+bool verbose = false;
+string daemon_type = null;
+string systemd_service_file = null;
 
 class EngineList {
     public IBus.EngineDesc[] data = {};
 }
 
+
 IBus.Bus? get_bus() {
     var bus = new IBus.Bus();
     if (!bus.is_connected ())
@@ -45,6 +51,131 @@ IBus.Bus? get_bus() {
     return bus;
 }
 
+
+GLib.DBusConnection?  get_session_bus(bool verbose) {
+    try {
+        return GLib.Bus.get_sync (GLib.BusType.SESSION, null);
+    } catch (GLib.IOError e) {
+        if (verbose)
+            stderr.printf("%s\n", e.message);
+    }
+    return null;
+}
+
+string?
+get_ibus_systemd_object_path(GLib.DBusConnection connection,
+                             bool                verbose) {
+    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);
+        if (verbose) {
+            stderr.printf("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) {
+        if (verbose) {
+            stderr.printf("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,
+                              bool                verbose) {
+    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();
+            if (verbose) {
+                stderr.printf("systemd state is \"%s\" for an object " +
+                              "path \"%s\".\n", state, object_path);
+            }
+            if (state != "activating")
+                break;
+            Posix.sleep(1);
+        }
+    } catch (GLib.Error e) {
+        if (verbose)
+            stderr.printf("%s\n", e.message);
+        return false;
+    }
+    if (state == "active")
+        return true;
+    return false;
+}
+
+
+bool
+start_daemon_via_systemd(GLib.DBusConnection connection,
+                         bool                restart,
+                         bool                verbose) {
+    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);
+        if (verbose) {
+            stderr.printf("Succeed to restart IBus daemon via IBus systemd " +
+                          "service file \"%s\": \"%s\"\n",
+                          systemd_service_file, object_path);
+        }
+        return true;
+    } catch (GLib.Error e) {
+        if (verbose) {
+            stderr.printf("Failed to %s IBus daemon via IBus systemd " +
+                          "service file \"%s\": %s\n",
+                          restart ? "restart" : "start",
+                          systemd_service_file, e.message);
+        }
+    }
+    return false;
+}
+
+
 int list_engine(string[] argv) {
     const OptionEntry[] options = {
         { "name-only", 0, 0, OptionArg.NONE, out name_only,
@@ -99,6 +230,7 @@ int list_engine(string[] argv) {
     return Posix.EXIT_SUCCESS;
 }
 
+
 private int exec_setxkbmap(IBus.EngineDesc engine) {
     string layout = engine.get_layout();
     string variant = engine.get_layout_variant();
@@ -149,6 +281,7 @@ private int exec_setxkbmap(IBus.EngineDesc engine) {
     return Posix.EXIT_SUCCESS;
 }
 
+
 int get_set_engine(string[] argv) {
     var bus = get_bus();
     string engine = null;
@@ -182,20 +315,121 @@ int get_set_engine(string[] argv) {
     return Posix.EXIT_SUCCESS;
 }
 
+
 int message_watch(string[] argv) {
     return Posix.EXIT_SUCCESS;
 }
 
-int restart_daemon(string[] argv) {
-    var bus = get_bus();
-    if (bus == null) {
-        stderr.printf(_("Can't connect to IBus.\n"));
+
+int start_daemon_real(string[] argv,
+                      bool     restart) {
+    const OptionEntry[] options = {
+        { "type", 0, 0, OptionArg.STRING, out daemon_type,
+          N_("Start or restart daemon with \"direct\" or \"systemd\" TYPE."),
+          "TYPE" },
+        { "service-file", 0, 0, OptionArg.STRING, out systemd_service_file,
+          N_("Start or restart daemon with SYSTEMD_SERVICE file."),
+          "SYSTEMD_SERVICE" },
+        { "verbose", 0, 0, OptionArg.NONE, out verbose,
+          N_("Show debug messages."), null },
+        { null }
+    };
+
+    var option = new OptionContext();
+    option.add_main_entries(options, Config.GETTEXT_PACKAGE);
+    option.set_ignore_unknown_options(true);
+
+    try {
+        option.parse(ref argv);
+    } catch (OptionError e) {
+        stderr.printf("%s\n", e.message);
+        return Posix.EXIT_FAILURE;
+    }
+    if (daemon_type != null && daemon_type != "direct" &&
+        daemon_type != "systemd") {
+        stderr.printf("type argument must be \"direct\" or \"systemd\"\n");
+        return Posix.EXIT_FAILURE;
+    }
+    if (systemd_service_file == null)
+        systemd_service_file = SYSTEMD_SESSION_GNOME_FILE;
+
+    do {
+        if (daemon_type == "direct")
+            break;
+        GLib.DBusConnection? connection = get_session_bus(verbose);
+        if (connection == null)
+            break;
+        string? object_path = null;
+        if (restart) {
+            object_path = get_ibus_systemd_object_path(connection, verbose);
+            if (object_path == null)
+                break;
+            if (!is_running_daemon_via_systemd(connection,
+                                               object_path,
+                                               verbose)) {
+                break;
+            }
+        }
+        if (!start_daemon_via_systemd(connection, restart, verbose))
+            break;
+        // Do not check the systemd state in case of restart because
+        // the systemd file validation is already done and also stopping
+        // daemon and starting daemon take time and the state could be
+        // "inactive" with the time lag.
+        if (restart)
+            return Posix.EXIT_SUCCESS;
+        object_path = get_ibus_systemd_object_path(connection, verbose);
+        if (object_path == null)
+            break;
+        if (!is_running_daemon_via_systemd(connection, object_path, verbose))
+            break;
+        return Posix.EXIT_SUCCESS;
+    } while (false);
+
+    if (daemon_type == "systemd")
         return Posix.EXIT_FAILURE;
+    if (restart) {
+        var bus = get_bus();
+        if (bus == null) {
+            stderr.printf(_("Can't connect to IBus.\n"));
+            return Posix.EXIT_FAILURE;
+        }
+        bus.exit(true);
+        if (verbose) {
+            stderr.printf("Succeed to restart ibus-daemon with an IBus API " +
+                          "directly.\n");
+        }
+    } else {
+        string startarg = "ibus-daemon";
+        argv[0] = startarg;
+        var paths = GLib.Environment.get_variable("PATH").split(":");
+        foreach (unowned string path in paths) {
+            var full_path = "%s/%s".printf(path, startarg);
+            if (GLib.FileUtils.test(full_path, GLib.FileTest.IS_EXECUTABLE)) {
+                startarg = full_path;
+                break;
+            }
+        }
+        // When ibus-daemon is launched by GLib.Process.spawn_async(),
+        // the parent process will be systemd
+        if (verbose) {
+            stderr.printf("Running \"%s\" directly as a foreground " +
+                          "process.\n", startarg);
+        }
+        Posix.execv(startarg, argv);
     }
-    bus.exit(true);
     return Posix.EXIT_SUCCESS;
 }
 
+
+int restart_daemon(string[] argv) {
+    return start_daemon_real(argv, true);
+}
+
+int start_daemon(string[] argv) {
+    return start_daemon_real(argv, false);
+}
+
 int exit_daemon(string[] argv) {
     var bus = get_bus();
     if (bus == null) {
@@ -206,11 +440,13 @@ int exit_daemon(string[] argv) {
     return Posix.EXIT_SUCCESS;
 }
 
+
 int print_version(string[] argv) {
     print("IBus %s\n", Config.PACKAGE_VERSION);
     return Posix.EXIT_SUCCESS;
 }
 
+
 int read_cache (string[] argv) {
     const OptionEntry[] options = {
         { "system", 0, 0, OptionArg.NONE, out is_system,
@@ -251,6 +487,7 @@ int read_cache (string[] argv) {
     return Posix.EXIT_SUCCESS;
 }
 
+
 int write_cache (string[] argv) {
     const OptionEntry[] options = {
         { "system", 0, 0, OptionArg.NONE, out is_system,
@@ -283,12 +520,14 @@ int write_cache (string[] argv) {
             Posix.EXIT_SUCCESS : Posix.EXIT_FAILURE;
 }
 
+
 int print_address(string[] argv) {
     string address = IBus.get_address();
     print("%s\n", address != null ? address : "(null)");
     return Posix.EXIT_SUCCESS;
 }
 
+
 private int read_config_options(string[] argv) {
     const OptionEntry[] options = {
         { "engine-id", 0, 0, OptionArg.STRING, out engine_id,
@@ -309,6 +548,7 @@ private int read_config_options(string[] argv) {
     return Posix.EXIT_SUCCESS;
 }
 
+
 private GLib.SList<string> get_ibus_schemas() {
     string[] ids = {};
     if (engine_id != null) {
@@ -342,6 +582,7 @@ private GLib.SList<string> get_ibus_schemas() {
     return ibus_schemas;
 }
 
+
 int read_config(string[] argv) {
     if (read_config_options(argv) == Posix.EXIT_FAILURE)
         return Posix.EXIT_FAILURE;
@@ -370,6 +611,7 @@ int read_config(string[] argv) {
     return Posix.EXIT_SUCCESS;
 }
 
+
 int reset_config(string[] argv) {
     if (read_config_options(argv) == Posix.EXIT_FAILURE)
         return Posix.EXIT_FAILURE;
@@ -401,6 +643,7 @@ int reset_config(string[] argv) {
     return Posix.EXIT_SUCCESS;
 }
 
+
 #if EMOJI_DICT
 int emoji_dialog(string[] argv) {
     string cmd = Config.LIBEXECDIR + "/ibus-ui-emojier";
@@ -427,11 +670,13 @@ int emoji_dialog(string[] argv) {
 }
 #endif
 
+
 int print_help(string[] argv) {
     print_usage(stdout);
     return Posix.EXIT_SUCCESS;
 }
 
+
 delegate int EntryFunc(string[] argv);
 
 struct CommandEntry {
@@ -440,12 +685,14 @@ struct CommandEntry {
     unowned EntryFunc entry;
 }
 
+
 const CommandEntry commands[]  = {
     { "engine", N_("Set or get engine"), get_set_engine },
     { "exit", N_("Exit ibus-daemon"), exit_daemon },
     { "list-engine", N_("Show available engines"), list_engine },
     { "watch", N_("(Not implemented)"), message_watch },
     { "restart", N_("Restart ibus-daemon"), restart_daemon },
+    { "start", N_("Start ibus-daemon"), start_daemon },
     { "version", N_("Show version"), print_version },
     { "read-cache", N_("Show the content of registry cache"), read_cache },
     { "write-cache", N_("Create registry cache"), write_cache },
@@ -460,6 +707,7 @@ const CommandEntry commands[]  = {
 
 static string program_name;
 
+
 void print_usage(FileStream stream) {
     stream.printf(_("Usage: %s COMMAND [OPTION...]\n\n"), program_name);
     stream.printf(_("Commands:\n"));
@@ -470,6 +718,7 @@ void print_usage(FileStream stream) {
     }
 }
 
+
 public int main(string[] argv) {
     GLib.Intl.setlocale(GLib.LocaleCategory.ALL, "");
     GLib.Intl.bindtextdomain(Config.GETTEXT_PACKAGE, Config.LOCALEDIR);