[gnome-settings-daemon] keyboard: Use the gtk+ ibus module if there's at least one ibus source

[Rui Matos <rtcm src gnome org>]

commit f3974a31c16826bd25ba1b0f3a2c2e8ac29566f1
Author: Rui Matos <tiagomatos gmail com>
Date:   Tue Mar 19 15:13:53 2013 +0100

    keyboard: Use the gtk+ ibus module if there's at least one ibus source
    
    Switching the gtk+ IM module when switching input source adds delays
    and races with the input events themselves. Thus it's better to always
    use the ibus module as long as the user has at least one ibus input
    source.
    
    https://bugzilla.gnome.org/show_bug.cgi?id=696141

 plugins/keyboard/gsd-keyboard-manager.c |   61 +++++++++++++++++++++----------
 1 files changed, 42 insertions(+), 19 deletions(-)
---
diff --git a/plugins/keyboard/gsd-keyboard-manager.c b/plugins/keyboard/gsd-keyboard-manager.c
index e4de28a..2d4a344 100644
--- a/plugins/keyboard/gsd-keyboard-manager.c
+++ b/plugins/keyboard/gsd-keyboard-manager.c
@@ -123,7 +123,7 @@ static gboolean apply_input_sources_settings     (GSettings               *setti
                                                   gint                     n_keys,
                                                   GsdKeyboardManager      *manager);
 static void     set_gtk_im_module                (GsdKeyboardManager      *manager,
-                                                  const gchar             *new_module);
+                                                  GVariant                *sources);
 
 G_DEFINE_TYPE (GsdKeyboardManager, gsd_keyboard_manager, G_TYPE_OBJECT)
 
@@ -319,6 +319,43 @@ set_ibus_xkb_engine (GsdKeyboardManager *manager)
         set_ibus_engine (manager, ibus_engine_desc_get_name (engine));
 }
 
+static gboolean
+need_ibus (GVariant *sources)
+{
+        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))
+                        return TRUE;
+
+        return FALSE;
+}
+
+
+static void
+set_gtk_im_module (GsdKeyboardManager *manager,
+                   GVariant           *sources)
+{
+        GsdKeyboardManagerPrivate *priv = manager->priv;
+        const gchar *new_module;
+        gchar *current_module;
+
+        if (!sources || need_ibus (sources))
+                new_module = GTK_IM_MODULE_IBUS;
+        else
+                new_module = GTK_IM_MODULE_SIMPLE;
+
+        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);
+}
+
 /* XXX: See upstream bug:
  * https://codereview.appspot.com/6586075/ */
 static gchar *
@@ -903,22 +940,6 @@ apply_xkb_settings (GsdKeyboardManager *manager,
         g_free (rules_file_path);
 }
 
-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 gboolean
 apply_input_sources_settings (GSettings          *settings,
                               gpointer            keys,
@@ -966,8 +987,8 @@ apply_input_sources_settings (GSettings          *settings,
                         g_warning ("Couldn't find XKB input source '%s'", id);
                         goto exit;
                 }
-                set_gtk_im_module (manager, GTK_IM_MODULE_SIMPLE);
 #ifdef HAVE_IBUS
+                set_gtk_im_module (manager, sources);
                 set_ibus_xkb_engine (manager);
 #endif
         } else if (g_str_equal (type, INPUT_SOURCE_TYPE_IBUS)) {
@@ -993,7 +1014,9 @@ apply_input_sources_settings (GSettings          *settings,
                         goto exit;
                 }
 
-                set_gtk_im_module (manager, GTK_IM_MODULE_IBUS);
+                /* NULL here is a shortcut for "I already know I
+                   need the IBus module". */
+                set_gtk_im_module (manager, NULL);
                 set_ibus_engine (manager, id);
 #else
                 g_warning ("IBus input source type specified but IBus support was not compiled");