Add active-surrounding-text property to IBusEngine

When this property is set to TRUE, ibus daemon will update
surrounding text on every focus(in/out) event which makes
ibus_engine_get_surrounding_text() calls from an engine
code unnecessary.
This property must be set at construct time.

BUG=https://github.com/ibus/ibus/pull/2447

4 files changed, 167 insertions, 19 deletions

diff --git a/bus/engineproxy.c b/bus/engineproxy.c
index fd1f34fb..b3e16066 100644
--- a/bus/engineproxy.c
+++ b/bus/engineproxy.c
@@ -60,6 +60,7 @@ struct _BusEngineProxy {
     /* cached properties */
     IBusPropList *prop_list;
     gboolean has_focus_id;
+    gboolean has_active_surrounding_text;
 };
 
 struct _BusEngineProxyClass {
@@ -130,6 +131,8 @@ static void     bus_engine_proxy_initable_iface_init
                                                                *initable_iface);
 static void     bus_engine_proxy_get_has_focus_id
                                                 (BusEngineProxy    *engine);
+static void     bus_engine_proxy_get_active_surrounding_text
+                                                (BusEngineProxy    *engine);
 
 G_DEFINE_TYPE_WITH_CODE (BusEngineProxy, bus_engine_proxy, IBUS_TYPE_PROXY,
                          G_IMPLEMENT_INTERFACE (
@@ -699,7 +702,6 @@ bus_engine_proxy_new_internal (const gchar     *path,
     BusEngineProxy *engine;
     BusIBusImpl *ibus = BUS_DEFAULT_IBUS;
     GHashTable *hash_table = NULL;
-    EngineFocusCategory category = ENGINE_FOCUS_CATEGORY_NONE;
 
     g_assert (path);
     g_assert (IBUS_IS_ENGINE_DESC (desc));
@@ -721,9 +723,12 @@ bus_engine_proxy_new_internal (const gchar     *path,
     if (layout != NULL && layout[0] != '\0') {
         engine->keymap = ibus_keymap_get (layout);
     }
-    if (ibus)
-        hash_table = bus_ibus_impl_get_engine_focus_id_table (ibus);
+
+    g_return_val_if_fail (ibus, engine);
+
+    hash_table = bus_ibus_impl_get_engine_focus_id_table (ibus);
     if (hash_table) {
+        EngineFocusCategory category;
         category = (EngineFocusCategory)GPOINTER_TO_INT (
                 g_hash_table_lookup (hash_table,
                                      ibus_engine_desc_get_name (desc)));
@@ -734,6 +739,21 @@ bus_engine_proxy_new_internal (const gchar     *path,
         else
             bus_engine_proxy_get_has_focus_id (engine);
     }
+
+    hash_table = bus_ibus_impl_get_engine_active_surrounding_text_table (ibus);
+    if (hash_table) {
+        EngineSurroundingTextCategory category;
+        category = (EngineSurroundingTextCategory)GPOINTER_TO_INT (
+                g_hash_table_lookup (hash_table,
+                                     ibus_engine_desc_get_name (desc)));
+        if (category == ENGINE_SURROUNDING_TEXT_CATEGORY_HAS_ACTIVE)
+            engine->has_active_surrounding_text = TRUE;
+        else if (category == ENGINE_SURROUNDING_TEXT_CATEGORY_NOT_ACTIVE)
+            engine->has_active_surrounding_text = FALSE;
+        else
+            bus_engine_proxy_get_active_surrounding_text (engine);
+    }
+
     return engine;
 }
 
@@ -1264,6 +1284,26 @@ bus_engine_proxy_set_content_type (BusEngineProxy *engine,
 }
 
 static void
+bus_engine_proxy_get_engine_property (BusEngineProxy     *engine,
+                                      const gchar        *prop_name,
+                                      GAsyncReadyCallback callback,
+                                      GHashTable         *hash_table)
+{
+    g_assert (BUS_IS_ENGINE_PROXY (engine));
+    g_assert (hash_table);
+    g_dbus_proxy_call ((GDBusProxy *) engine,
+                       "org.freedesktop.DBus.Properties.Get",
+                       g_variant_new ("(ss)",
+                                      IBUS_INTERFACE_ENGINE,
+                                      prop_name),
+                       G_DBUS_CALL_FLAGS_NONE,
+                       -1,
+                       NULL,
+                       callback,
+                       g_hash_table_ref (hash_table));
+}
+
+static void
 _get_has_focus_id_cb (GObject        *object,
                       GAsyncResult   *res,
                       gpointer        user_data)
@@ -1299,23 +1339,57 @@ static void
 bus_engine_proxy_get_has_focus_id (BusEngineProxy *engine)
 {
     BusIBusImpl *ibus = BUS_DEFAULT_IBUS;
-    GHashTable *hash_table;
-
-    g_assert (BUS_IS_ENGINE_PROXY (engine));
     g_assert (ibus);
+    bus_engine_proxy_get_engine_property (
+            engine,
+            "FocusId",
+            _get_has_focus_id_cb,
+            bus_ibus_impl_get_engine_focus_id_table (ibus));
+}
 
-    hash_table = bus_ibus_impl_get_engine_focus_id_table (ibus);
-    g_assert (hash_table);
-    g_dbus_proxy_call ((GDBusProxy *) engine,
-                       "org.freedesktop.DBus.Properties.Get",
-                       g_variant_new ("(ss)",
-                                      IBUS_INTERFACE_ENGINE,
-                                      "FocusId"),
-                       G_DBUS_CALL_FLAGS_NONE,
-                       -1,
-                       NULL,
-                       _get_has_focus_id_cb,
-                       g_hash_table_ref (hash_table));
+static void
+_get_active_surrounding_text_cb (GObject        *object,
+                                 GAsyncResult   *res,
+                                 gpointer        user_data)
+{
+    GHashTable *hash_table = (GHashTable*)user_data;
+    BusEngineProxy *engine;
+    GError *error = NULL;
+    GVariant *result;
+
+    g_return_if_fail (BUS_IS_ENGINE_PROXY (object));
+    engine = BUS_ENGINE_PROXY (object);
+    result = g_dbus_proxy_call_finish (G_DBUS_PROXY (object), res, &error);
+
+    if (result != NULL) {
+        GVariant *variant = NULL;
+        gpointer value;
+        g_variant_get (result, "(v)", &variant);
+        engine->has_active_surrounding_text = g_variant_get_boolean (variant);
+        g_variant_unref (variant);
+        g_variant_unref (result);
+        value =  GINT_TO_POINTER (
+                engine->has_active_surrounding_text
+                ? ENGINE_SURROUNDING_TEXT_CATEGORY_HAS_ACTIVE
+                : ENGINE_SURROUNDING_TEXT_CATEGORY_NOT_ACTIVE);
+        g_hash_table_replace (
+            hash_table,
+            (gpointer)ibus_engine_desc_get_name (engine->desc),
+            value);
+    }
+    g_hash_table_unref (hash_table);
+}
+
+static void
+bus_engine_proxy_get_active_surrounding_text (BusEngineProxy *engine)
+{
+    BusIBusImpl *ibus = BUS_DEFAULT_IBUS;
+    g_assert (ibus);
+    bus_engine_proxy_get_engine_property (
+            engine,
+            "ActiveSurroundingText",
+            _get_active_surrounding_text_cb,
+            bus_ibus_impl_get_engine_active_surrounding_text_table (ibus));
 }
 
 /* a macro to generate a function to call a nullary D-Bus method. */
@@ -1348,6 +1422,8 @@ bus_engine_proxy_focus_in (BusEngineProxy *engine,
     if (engine->has_focus)
         return;
     engine->has_focus = TRUE;
+    if (engine->has_active_surrounding_text)
+        g_signal_emit (engine, engine_signals[REQUIRE_SURROUNDING_TEXT], 0);
     if (engine->has_focus_id) {
         g_dbus_proxy_call ((GDBusProxy *)engine,
                            "FocusInId",
@@ -1404,6 +1480,8 @@ bus_engine_proxy_enable (BusEngineProxy *engine)
     g_assert (BUS_IS_ENGINE_PROXY (engine));
     if (!engine->enabled) {
         engine->enabled = TRUE;
+        if (engine->has_active_surrounding_text)
+            g_signal_emit (engine, engine_signals[REQUIRE_SURROUNDING_TEXT], 0);
         g_dbus_proxy_call ((GDBusProxy *)engine,
                            "Enable",
                            NULL,
diff --git a/bus/ibusimpl.c b/bus/ibusimpl.c
index 8a443545..6df86c3f 100644
--- a/bus/ibusimpl.c
+++ b/bus/ibusimpl.c
@@ -73,6 +73,7 @@ struct _BusIBusImpl {
     GHashTable *engine_table;
 
     GHashTable *engine_focus_id_table;
+    GHashTable *engine_active_surrounding_text_table;
 
     BusInputContext *focused_context;
     BusPanelProxy   *panel;
@@ -599,6 +600,8 @@ bus_ibus_impl_init (BusIBusImpl *ibus)
     ibus->global_engine_name = NULL;
     ibus->global_previous_engine_name = NULL;
     ibus->engine_focus_id_table = g_hash_table_new (g_str_hash, g_str_equal);
+    ibus->engine_active_surrounding_text_table = g_hash_table_new (g_str_hash,
+                                                                   g_str_equal);
 
     /* focus the fake_context, if use_global_engine is enabled. */
     if (ibus->use_global_engine)
@@ -681,6 +684,11 @@ bus_ibus_impl_destroy (BusIBusImpl *ibus)
 
     bus_ibus_impl_registry_destroy (ibus);
 
+    if (ibus->engine_active_surrounding_text_table != NULL) {
+        g_hash_table_destroy (ibus->engine_active_surrounding_text_table);
+        ibus->engine_active_surrounding_text_table = NULL;
+    }
+
     IBUS_OBJECT_CLASS (bus_ibus_impl_parent_class)->destroy (IBUS_OBJECT (ibus));
 }
 
@@ -2397,3 +2405,11 @@ bus_ibus_impl_get_engine_focus_id_table (BusIBusImpl *ibus)
     return ibus->engine_focus_id_table;
 }
 
+GHashTable *
+bus_ibus_impl_get_engine_active_surrounding_text_table (BusIBusImpl *ibus)
+{
+
+    g_assert (BUS_IS_IBUS_IMPL (ibus));
+
+    return ibus->engine_active_surrounding_text_table;
+}
diff --git a/bus/ibusimpl.h b/bus/ibusimpl.h
index cbe6856d..93a854de 100644
--- a/bus/ibusimpl.h
+++ b/bus/ibusimpl.h
@@ -66,6 +66,13 @@ typedef enum
     ENGINE_FOCUS_CATEGORY_HAS_ID
 } EngineFocusCategory;
 
+typedef enum
+{
+    ENGINE_SURROUNDING_TEXT_CATEGORY_NONE = 0,
+    ENGINE_SURROUNDING_TEXT_CATEGORY_NOT_ACTIVE,
+    ENGINE_SURROUNDING_TEXT_CATEGORY_HAS_ACTIVE
+} EngineSurroundingTextCategory;
+
 GType            bus_ibus_impl_get_type             (void);
 
 /**
@@ -91,5 +98,7 @@ BusInputContext *bus_ibus_impl_get_focused_input_context
                                                     (BusIBusImpl        *ibus);
 GHashTable      *bus_ibus_impl_get_engine_focus_id_table
                                                     (BusIBusImpl        *ibus);
+GHashTable      *bus_ibus_impl_get_engine_active_surrounding_text_table
+                                                    (BusIBusImpl        *ibus);
 G_END_DECLS
 #endif
diff --git a/src/ibusengine.c b/src/ibusengine.c
index 7c797103..cc12ac5a 100644
--- a/src/ibusengine.c
+++ b/src/ibusengine.c
@@ -64,6 +64,7 @@ enum {
     PROP_0,
     PROP_ENGINE_NAME,
     PROP_HAS_FOCUS_ID,
+    PROP_ACTIVE_SURROUNDING_TEXT,
 };
 
 
@@ -86,6 +87,7 @@ struct _IBusEnginePrivate {
     gboolean               enable_extension;
     gchar                 *current_extension_name;
     gboolean               has_focus_id;
+    gboolean               has_active_surrounding_text;
 };
 
 
@@ -303,6 +305,7 @@ static const gchar introspection_xml[] =
     /* FIXME properties */
     "    <property name='ContentType' type='(uu)' access='write' />"
     "    <property name='FocusId' type='(b)' access='read' />"
+    "    <property name='ActiveSurroundingText' type='(b)' access='read' />"
     "  </interface>"
     "</node>";
 
@@ -391,6 +394,23 @@ ibus_engine_class_init (IBusEngineClass *class)
                         G_PARAM_READWRITE |
                         G_PARAM_CONSTRUCT_ONLY));
 
+    /**
+     * IBusEngine:active-surrounding-text:
+     *
+     * When this property is set to %TRUE, "RequireSurroundingText" D-Bus
+     * signal will be called by ibus-daemon on every focus-in/out event, with
+     * no need for the engine to call ibus_engine_get_surrounding_text().
+     * This property can only be set at construct time.
+     */
+    g_object_class_install_property (gobject_class,
+                    PROP_ACTIVE_SURROUNDING_TEXT,
+                    g_param_spec_boolean ("active-surrounding-text",
+                        "enable surrounding text update by focus event",
+                        "Enable surrounding text update by focus event",
+                        FALSE,
+                        G_PARAM_READWRITE |
+                        G_PARAM_CONSTRUCT_ONLY));
+
     /* install signals */
     /**
      * IBusEngine::process-key-event:
@@ -988,6 +1008,9 @@ ibus_engine_set_property (IBusEngine   *engine,
     case PROP_HAS_FOCUS_ID:
         engine->priv->has_focus_id = g_value_get_boolean (value);
         break;
+    case PROP_ACTIVE_SURROUNDING_TEXT:
+        engine->priv->has_active_surrounding_text = g_value_get_boolean (value);
+        break;
     default:
         G_OBJECT_WARN_INVALID_PROPERTY_ID (engine, prop_id, pspec);
     }
@@ -1006,6 +1029,9 @@ ibus_engine_get_property (IBusEngine *engine,
     case PROP_HAS_FOCUS_ID:
         g_value_set_boolean (value, engine->priv->has_focus_id);
         break;
+    case PROP_ACTIVE_SURROUNDING_TEXT:
+        g_value_set_boolean (value, engine->priv->has_active_surrounding_text);
+        break;
     default:
         G_OBJECT_WARN_INVALID_PROPERTY_ID (engine, prop_id, pspec);
     }
@@ -1446,6 +1472,24 @@ ibus_engine_service_method_call (IBusService           *service,
 }
 
 /**
+ * _ibus_engine_get_active_surrounding_text:
+ *
+ * Implement the "ActiveSurroundingText" method call of the
+ * org.freedesktop.IBus interface.
+ */
+static GVariant *
+_ibus_engine_get_active_surrounding_text (IBusEngine      *engine,
+                                          GDBusConnection *connection,
+                                          GError         **error)
+{
+    if (error) {
+        *error = NULL;
+    }
+
+    return g_variant_new_boolean (engine->priv->has_active_surrounding_text);
+}
+
+/**
  * _ibus_engine_has_focus_id:
  *
  * Implement the "FocusId" method call of the org.freedesktop.IBus interface.
@@ -1478,7 +1522,8 @@ ibus_engine_service_get_property (IBusService        *service,
                                         GDBusConnection *,
                                         GError **);
     } methods [] =  {
-        { "FocusId",                    _ibus_engine_has_focus_id },
+        { "FocusId",                _ibus_engine_has_focus_id },
+        { "ActiveSurroundingText",  _ibus_engine_get_active_surrounding_text },
     };
 
     if (g_strcmp0 (interface_name, IBUS_INTERFACE_ENGINE) != 0) {