[gnome-settings-daemon] keyboard: Add functionality to set IBus engines from input sources

[Rui Matos <rtcm src gnome org>]

commit 557bfce8705ed3dc97e290e1491610f5e0cfd319
Author: Rui Matos <tiagomatos gmail com>
Date:   Tue Apr 17 15:39:00 2012 +0200

    keyboard: Add functionality to set IBus engines from input sources
    
    We connect to IBus and tell it to switch engine when the current input
    source setting is changed and an IBus engine is specified there.
    
    If an IBus engine is specified, we flip the setting that backs the
    Gtk/IMModule XSETTING so that GTK+ applications get notified to load
    the IBus input method when needed and go back to the simple input
    method when IBus isn't required.
    
    The ibus-daemon claims a well known name in the session bus but
    doesn't ship a .service file to make it activatable so we ship one
    ourselves which will spawn it in a convenient way for us. In
    particular, we disable its 'panel' component since that functionality
    is provided by gnome-shell and would conflict at run time. We also
    tell it to replace an existing ibus-daemon since traditionally it
    would be spawned at session init time before even DBus was up and out
    of control of gnome-session so, in case that happens, our own spawned
    version will take place which is what we intend since the
    traditionally launched ibus-daemon is highly likely to be running with
    its 'panel' component enabled.
    
    https://bugzilla.gnome.org/show_bug.cgi?id=676102

 .gitignore                              |    1 +
 configure.ac                            |   18 +++-
 data/Makefile.am                        |   13 ++
 data/org.freedesktop.IBus.service.in    |    3 +
 plugins/keyboard/gsd-keyboard-manager.c |  192 +++++++++++++++++++++++++++++--
 5 files changed, 215 insertions(+), 12 deletions(-)
---
diff --git a/.gitignore b/.gitignore
index ef44002..ed51335 100644
--- a/.gitignore
+++ b/.gitignore
@@ -39,6 +39,7 @@ data/*.valid
 data/gnome-settings-daemon.desktop
 data/gnome-settings-daemon.desktop.in
 data/50-accessibility.xml
+data/org.freedesktop.IBus.service
 data/org.gnome.SettingsDaemon.service
 *.gnome-settings-plugin
 plugins/a11y-keyboard/test-a11y-preferences-dialog
diff --git a/configure.ac b/configure.ac
index 9a81e3e..e1ba389 100644
--- a/configure.ac
+++ b/configure.ac
@@ -175,7 +175,21 @@ dnl ---------------------------------------------------------------------------
 dnl - Keyboard plugin stuff
 dnl ---------------------------------------------------------------------------
 
-PKG_CHECK_MODULES(KEYBOARD, xkbfile gnome-desktop-3.0 >= $GNOME_DESKTOP_REQUIRED_VERSION)
+AC_ARG_ENABLE(ibus,
+        AS_HELP_STRING([--disable-ibus],
+                       [Disable IBus support]),
+        enable_ibus=$enableval,
+        enable_ibus=yes)
+
+if test "x$enable_ibus" = "xyes" ; then
+        IBUS_MODULE=ibus-1.0
+        AC_DEFINE(HAVE_IBUS, 1, [Defined if IBus support is enabled])
+else
+        IBUS_MODULE=
+fi
+AM_CONDITIONAL(HAVE_IBUS, test "x$enable_ibus" == "xyes")
+
+PKG_CHECK_MODULES(KEYBOARD, xkbfile $IBUS_MODULE gnome-desktop-3.0 >= $GNOME_DESKTOP_REQUIRED_VERSION)
 
 dnl ---------------------------------------------------------------------------
 dnl - Housekeeping plugin stuff
@@ -535,7 +549,7 @@ echo "
 
         Session tracking:         ${SESSION_TRACKING}
         LCMS DICT support:        ${have_new_lcms}
-
+        IBus support:             ${enable_ibus}
         Libnotify support:        ${have_libnotify}
         PackageKit support:       ${have_packagekit}
         Smartcard support:        ${have_smartcard_support}
diff --git a/data/Makefile.am b/data/Makefile.am
index 5fc9f64..64ab3ea 100644
--- a/data/Makefile.am
+++ b/data/Makefile.am
@@ -60,6 +60,8 @@ pkgconfig_DATA = gnome-settings-daemon.pc
 
 man_MANS = gnome-settings-daemon.1
 
+dbusservice_in_files = org.freedesktop.IBus.service.in
+
 EXTRA_DIST = 					\
 	$(man_MANS)				\
 	$(convert_DATA)				\
@@ -68,6 +70,7 @@ EXTRA_DIST = 					\
 	$(gsettings_ENUM_FILES)			\
 	gnome-settings-daemon.pc.in		\
 	$(api_DATA)				\
+	$(dbusservice_in_files)			\
 	$(NULL)
 
 DISTCLEANFILES = 			\
@@ -80,3 +83,13 @@ MAINTAINERCLEANFILES =			\
 	*~				\
 	Makefile.in			\
 	$(all_schemas:.xml=.valid)
+
+if HAVE_IBUS
+dbusservicedir=${datadir}/dbus-1/services
+dbusservice_DATA = $(dbusservice_in_files:.service.in=.service)
+
+org.freedesktop.IBus.service: org.freedesktop.IBus.service.in
+	$(AM_V_GEN) sed -e "s|\ bindir\@|$(bindir)|" $< > $  tmp && mv $  tmp $@
+
+CLEANFILES = $(dbusservice_DATA)
+endif
diff --git a/data/org.freedesktop.IBus.service.in b/data/org.freedesktop.IBus.service.in
new file mode 100644
index 0000000..cc88834
--- /dev/null
+++ b/data/org.freedesktop.IBus.service.in
@@ -0,0 +1,3 @@
+[D-BUS Service]
+Name=org.freedesktop.IBus
+Exec= bindir@/ibus-daemon --replace --xim --panel disable
diff --git a/plugins/keyboard/gsd-keyboard-manager.c b/plugins/keyboard/gsd-keyboard-manager.c
index bcf008c..058efa7 100644
--- a/plugins/keyboard/gsd-keyboard-manager.c
+++ b/plugins/keyboard/gsd-keyboard-manager.c
@@ -45,6 +45,10 @@
 #define GNOME_DESKTOP_USE_UNSTABLE_API
 #include <libgnome-desktop/gnome-xkb-info.h>
 
+#ifdef HAVE_IBUS
+#include <ibus.h>
+#endif
+
 #include "gnome-settings-profile.h"
 #include "gsd-keyboard-manager.h"
 #include "gsd-input-helper.h"
@@ -66,12 +70,19 @@
 #define KEY_BELL_DURATION  "bell-duration"
 #define KEY_BELL_MODE      "bell-mode"
 
+#define GNOME_DESKTOP_INTERFACE_DIR "org.gnome.desktop.interface"
+
+#define KEY_GTK_IM_MODULE    "gtk-im-module"
+#define GTK_IM_MODULE_SIMPLE "gtk-im-context-simple"
+#define GTK_IM_MODULE_IBUS   "ibus"
+
 #define GNOME_DESKTOP_INPUT_SOURCES_DIR "org.gnome.desktop.input-sources"
 
 #define KEY_CURRENT_INPUT_SOURCE "current"
 #define KEY_INPUT_SOURCES        "sources"
 
-#define INPUT_SOURCE_TYPE_XKB "xkb"
+#define INPUT_SOURCE_TYPE_XKB  "xkb"
+#define INPUT_SOURCE_TYPE_IBUS "ibus"
 
 #define DEFAULT_LANGUAGE "en_US"
 
@@ -80,7 +91,13 @@ struct GsdKeyboardManagerPrivate
 	guint      start_idle_id;
         GSettings *settings;
         GSettings *input_sources_settings;
+        GSettings *interface_settings;
         GnomeXkbInfo *xkb_info;
+#ifdef HAVE_IBUS
+        IBusBus   *ibus;
+        GHashTable *ibus_engines;
+        GCancellable *ibus_cancellable;
+#endif
         gint       xkb_event_base;
         GsdNumLockState old_state;
         GdkDeviceManager *device_manager;
@@ -91,11 +108,106 @@ struct GsdKeyboardManagerPrivate
 static void     gsd_keyboard_manager_class_init  (GsdKeyboardManagerClass *klass);
 static void     gsd_keyboard_manager_init        (GsdKeyboardManager      *keyboard_manager);
 static void     gsd_keyboard_manager_finalize    (GObject                 *object);
+static void     apply_input_sources_settings     (GSettings               *settings,
+                                                  gchar                   *key,
+                                                  GsdKeyboardManager      *manager);
 
 G_DEFINE_TYPE (GsdKeyboardManager, gsd_keyboard_manager, G_TYPE_OBJECT)
 
 static gpointer manager_object = NULL;
 
+#ifdef HAVE_IBUS
+static void
+clear_ibus (GsdKeyboardManager *manager)
+{
+        GsdKeyboardManagerPrivate *priv = manager->priv;
+
+        g_cancellable_cancel (priv->ibus_cancellable);
+        g_clear_object (&priv->ibus_cancellable);
+        g_clear_pointer (&priv->ibus_engines, g_hash_table_destroy);
+}
+
+static void
+fetch_ibus_engines_result (GObject            *object,
+                           GAsyncResult       *result,
+                           GsdKeyboardManager *manager)
+{
+        GsdKeyboardManagerPrivate *priv = manager->priv;
+        GList *list, *l;
+        GError *error;
+
+        error = NULL;
+        list = ibus_bus_list_engines_async_finish (priv->ibus,
+                                                   result,
+                                                   &error);
+        g_clear_object (&priv->ibus_cancellable);
+
+        if (!list && error) {
+                g_warning ("Couldn't finish IBus request: %s", error->message);
+                g_error_free (error);
+
+                clear_ibus (manager);
+                return;
+        }
+
+        priv->ibus_engines = g_hash_table_new_full (g_str_hash, g_str_equal, NULL, g_object_unref);
+
+        for (l = list; l; l = l->next) {
+                IBusEngineDesc *engine = l->data;
+                g_hash_table_replace (priv->ibus_engines,
+                                      (gpointer)ibus_engine_desc_get_name (engine),
+                                      engine);
+        }
+        g_list_free (list);
+
+        apply_input_sources_settings (priv->input_sources_settings, NULL, manager);
+}
+
+static void
+fetch_ibus_engines (GsdKeyboardManager *manager)
+{
+        GsdKeyboardManagerPrivate *priv = manager->priv;
+
+        priv->ibus_cancellable = g_cancellable_new ();
+
+        ibus_bus_list_engines_async (priv->ibus,
+                                     -1,
+                                     priv->ibus_cancellable,
+                                     (GAsyncReadyCallback)fetch_ibus_engines_result,
+                                     manager);
+}
+
+static void
+maybe_start_ibus (GsdKeyboardManager *manager,
+                  GVariant           *sources)
+{
+        gboolean need_ibus = FALSE;
+        GVariantIter iter;
+        const gchar *type;
+
+        g_variant_iter_init (&iter, sources);
+        while (g_variant_iter_next (&iter, "(&s&s)", &type, NULL))
+                if (g_str_equal (type, INPUT_SOURCE_TYPE_IBUS)) {
+                        need_ibus = TRUE;
+                        break;
+                }
+
+        if (!need_ibus)
+                return;
+
+        /* IBus doesn't export API in the session bus. The only thing
+         * we have there is a well known name which we can use as a
+         * sure-fire way to activate it. */
+        g_bus_unwatch_name (g_bus_watch_name (G_BUS_TYPE_SESSION,
+                                              IBUS_SERVICE_IBUS,
+                                              G_BUS_NAME_WATCHER_FLAGS_AUTO_START,
+                                              NULL,
+                                              NULL,
+                                              NULL,
+                                              NULL));
+}
+#endif  /* HAVE_IBUS */
+
 static gboolean
 xkb_set_keyboard_autorepeat_rate (guint delay, guint interval)
 {
@@ -408,6 +520,22 @@ apply_xkb_layout (GsdKeyboardManager *manager,
 }
 
 static void
+set_gtk_im_module (GsdKeyboardManager *manager,
+                   const gchar        *new_module)
+{
+        GsdKeyboardManagerPrivate *priv = manager->priv;
+        gchar *current_module;
+
+        current_module = g_settings_get_string (priv->interface_settings,
+                                                KEY_GTK_IM_MODULE);
+        if (!g_str_equal (current_module, new_module))
+                g_settings_set_string (priv->interface_settings,
+                                       KEY_GTK_IM_MODULE,
+                                       new_module);
+        g_free (current_module);
+}
+
+static void
 apply_input_sources_settings (GSettings          *settings,
                               gchar              *key,
                               GsdKeyboardManager *manager)
@@ -435,17 +563,47 @@ apply_input_sources_settings (GSettings          *settings,
                 goto exit;
         }
 
+#ifdef HAVE_IBUS
+        maybe_start_ibus (manager, sources);
+#endif
+
         g_variant_get_child (sources, current, "(&s&s)", &type, &id);
 
-        if (!g_str_equal (type, INPUT_SOURCE_TYPE_XKB)) {
-                g_warning ("Unknown input source type '%s'", type);
+        if (g_str_equal (type, INPUT_SOURCE_TYPE_XKB)) {
+                gnome_xkb_info_get_layout_info (priv->xkb_info, id, NULL, NULL, &layout, &variant);
+
+                if (!layout || !layout[0]) {
+                        g_warning ("Couldn't find XKB input source '%s'", id);
+                        goto exit;
+                }
+                set_gtk_im_module (manager, GTK_IM_MODULE_SIMPLE);
+        } else if (g_str_equal (type, INPUT_SOURCE_TYPE_IBUS)) {
+#ifdef HAVE_IBUS
+                IBusEngineDesc *engine_desc = NULL;
+
+                if (priv->ibus_engines)
+                        engine_desc = g_hash_table_lookup (priv->ibus_engines, id);
+                else
+                        goto exit; /* we'll be called again when ibus is up and running */
+
+                if (engine_desc) {
+                        layout = ibus_engine_desc_get_layout (engine_desc);
+                        variant = "";
+                } else {
+                        g_warning ("Couldn't find IBus input source '%s'", id);
+                        goto exit;
+                }
+
+                if (ibus_bus_set_global_engine (priv->ibus, id))
+                        set_gtk_im_module (manager, GTK_IM_MODULE_IBUS);
+                else
+                        g_warning ("Couldn't set IBus engine '%s'", id);
+#else
+                g_warning ("IBus input source type specified but IBus support was not compiled");
                 goto exit;
-        }
-
-        gnome_xkb_info_get_layout_info (priv->xkb_info, id, NULL, NULL, &layout, &variant);
-
-        if (!layout || !layout[0]) {
-                g_warning ("Couldn't find XKB input source '%s'", id);
+#endif
+        } else {
+                g_warning ("Unknown input source type '%s'", type);
                 goto exit;
         }
 
@@ -579,9 +737,17 @@ start_keyboard_idle_cb (GsdKeyboardManager *manager)
 	set_devicepresence_handler (manager);
 
         manager->priv->input_sources_settings = g_settings_new (GNOME_DESKTOP_INPUT_SOURCES_DIR);
-
+        manager->priv->interface_settings = g_settings_new (GNOME_DESKTOP_INTERFACE_DIR);
         manager->priv->xkb_info = gnome_xkb_info_new ();
 
+#ifdef HAVE_IBUS
+        ibus_init ();
+        manager->priv->ibus = ibus_bus_new_async ();
+        g_signal_connect_swapped (manager->priv->ibus, "connected",
+                                  G_CALLBACK (fetch_ibus_engines), manager);
+        g_signal_connect_swapped (manager->priv->ibus, "disconnected",
+                                  G_CALLBACK (clear_ibus), manager);
+#endif
         /* apply current settings before we install the callback */
         apply_settings (manager->priv->settings, NULL, manager);
         apply_input_sources_settings (manager->priv->input_sources_settings, NULL, manager);
@@ -627,8 +793,14 @@ gsd_keyboard_manager_stop (GsdKeyboardManager *manager)
 
         g_clear_object (&p->settings);
         g_clear_object (&p->input_sources_settings);
+        g_clear_object (&p->interface_settings);
         g_clear_object (&p->xkb_info);
 
+#ifdef HAVE_IBUS
+        clear_ibus (manager);
+        g_clear_object (&p->ibus);
+#endif
+
         if (p->device_manager != NULL) {
                 g_signal_handler_disconnect (p->device_manager, p->device_added_id);
                 g_signal_handler_disconnect (p->device_manager, p->device_removed_id);