[gnome-settings-daemon] keyboard: Instruct IBus to use its XKB engine for XKB input sources

[Rui Matos <rtcm src gnome org>]

commit 3687fb700ed5858ac85aaf6f0a0d95d6d8e1eeed
Author: Rui Matos <tiagomatos gmail com>
Date:   Thu Aug 23 23:39:13 2012 +0200

    keyboard: Instruct IBus to use its XKB engine for XKB input sources
    
    Otherwise Qt and XIM supporting applications would continue using the
    last IBus engine that was set before the user switched to a XKB input
    source.
    
    https://bugzilla.gnome.org/show_bug.cgi?id=680313

 plugins/keyboard/gsd-keyboard-manager.c |   78 +++++++++++++++++++++++++++++-
 1 files changed, 75 insertions(+), 3 deletions(-)
---
diff --git a/plugins/keyboard/gsd-keyboard-manager.c b/plugins/keyboard/gsd-keyboard-manager.c
index b187590..de5080d 100644
--- a/plugins/keyboard/gsd-keyboard-manager.c
+++ b/plugins/keyboard/gsd-keyboard-manager.c
@@ -97,6 +97,7 @@ struct GsdKeyboardManagerPrivate
 #ifdef HAVE_IBUS
         IBusBus   *ibus;
         GHashTable *ibus_engines;
+        GHashTable *ibus_xkb_engines;
         GCancellable *ibus_cancellable;
         gboolean session_is_fallback;
 #endif
@@ -128,9 +129,49 @@ clear_ibus (GsdKeyboardManager *manager)
         g_cancellable_cancel (priv->ibus_cancellable);
         g_clear_object (&priv->ibus_cancellable);
         g_clear_pointer (&priv->ibus_engines, g_hash_table_destroy);
+        g_clear_pointer (&priv->ibus_xkb_engines, g_hash_table_destroy);
         g_clear_object (&priv->ibus);
 }
 
+static gchar *
+make_xkb_source_id (const gchar *engine_id)
+{
+        gchar *id;
+        gchar *p;
+        gint n_colons = 0;
+
+        /* engine_id is like "xkb:layout:variant:lang" where
+         * 'variant' and 'lang' might be empty */
+
+        engine_id += 4;
+
+        for (p = (gchar *)engine_id; *p; ++p)
+                if (*p == ':')
+                        if (++n_colons == 2)
+                                break;
+        if (!*p)
+                return NULL;
+
+        id = g_strndup (engine_id, p - engine_id + 1);
+
+        id[p - engine_id] = '\0';
+
+        /* id is "layout:variant" where 'variant' might be empty */
+
+        for (p = id; *p; ++p)
+                if (*p == ':') {
+                        if (*(p + 1) == '\0')
+                                *p = '\0';
+                        else
+                                *p = '+';
+                        break;
+                }
+
+        /* id is "layout+variant" or "layout" */
+
+        return id;
+}
+
 static void
 fetch_ibus_engines_result (GObject            *object,
                            GAsyncResult       *result,
@@ -154,13 +195,24 @@ fetch_ibus_engines_result (GObject            *object,
                 return;
         }
 
+        /* Maps IBus engine ids to engine description objects */
         priv->ibus_engines = g_hash_table_new_full (g_str_hash, g_str_equal, NULL, g_object_unref);
+        /* Maps XKB source id strings to engine description objects */
+        priv->ibus_xkb_engines = g_hash_table_new_full (g_str_hash, g_str_equal, g_free, NULL);
 
         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);
+                const gchar *engine_id = ibus_engine_desc_get_name (engine);
+
+                g_hash_table_replace (priv->ibus_engines, (gpointer)engine_id, engine);
+
+                if (strncmp ("xkb:", engine_id, 4) == 0) {
+                        gchar *xkb_source_id = make_xkb_source_id (engine_id);
+                        if (xkb_source_id)
+                                g_hash_table_replace (priv->ibus_xkb_engines,
+                                                      xkb_source_id,
+                                                      engine);
+                }
         }
         g_list_free (list);
 
@@ -292,6 +344,23 @@ got_bus (GObject            *object,
                                 (GAsyncReadyCallback)got_session_name,
                                 manager);
 }
+
+static void
+set_ibus_xkb_engine (GsdKeyboardManager *manager,
+                     const gchar        *xkb_id)
+{
+        IBusEngineDesc *engine;
+        GsdKeyboardManagerPrivate *priv = manager->priv;
+
+        if (!priv->ibus_xkb_engines)
+                return;
+
+        engine = g_hash_table_lookup (priv->ibus_xkb_engines, xkb_id);
+        if (!engine)
+                return;
+
+        ibus_bus_set_global_engine (priv->ibus, ibus_engine_desc_get_name (engine));
+}
 #endif  /* HAVE_IBUS */
 
 static gboolean
@@ -711,6 +780,9 @@ apply_input_sources_settings (GSettings          *settings,
                         goto exit;
                 }
                 set_gtk_im_module (manager, GTK_IM_MODULE_SIMPLE);
+#ifdef HAVE_IBUS
+                set_ibus_xkb_engine (manager, id);
+#endif
         } else if (g_str_equal (type, INPUT_SOURCE_TYPE_IBUS)) {
 #ifdef HAVE_IBUS
                 IBusEngineDesc *engine_desc = NULL;