Notify engines of the content-type of input context

Add a new D-Bus method SetContentType to InputContext and Engine, to
notify engines of the content-type (primary purpose and hints) of
input context.  This is useful to implement intelligent features in
engines, such as automatic input-mode switch and text prediction.

The "purpose" and "hints" arguments are compatible with
GtkInputPurpose and GtkInputHints:
https://developer.gnome.org/gtk3/unstable/GtkEntry.html#GtkInputPurpose
https://developer.gnome.org/gtk3/unstable/GtkEntry.html#GtkInputHints

and the API is similar to the content_type event in the Wayland Input
Method Framework:
http://cgit.freedesktop.org/wayland/weston/tree/protocol/input-method.xml#n202

BUG=

Review URL: https://codereview.appspot.com/11422043

3 files changed, 374 insertions, 136 deletions

diff --git a/bus/engineproxy.c b/bus/engineproxy.c
index 200b89be..19c28616 100644
--- a/bus/engineproxy.c
+++ b/bus/engineproxy.c
@@ -1,8 +1,8 @@
 /* -*- mode: C; c-basic-offset: 4; indent-tabs-mode: nil; -*- */
 /* vim:set et sts=4: */
 /* ibus - The Input Bus
- * Copyright (C) 2008-2010 Peng Huang <shawn.p.huang@gmail.com>
- * Copyright (C) 2008-2010 Red Hat, Inc.
+ * Copyright (C) 2008-2013 Peng Huang <shawn.p.huang@gmail.com>
+ * Copyright (C) 2008-2013 Red Hat, Inc.
  *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Lesser General Public
@@ -642,8 +642,7 @@ bus_engine_proxy_new_internal (const gchar     *path,
     g_assert (IBUS_IS_ENGINE_DESC (desc));
     g_assert (G_IS_DBUS_CONNECTION (connection));
 
-    GDBusProxyFlags flags = G_DBUS_PROXY_FLAGS_DO_NOT_AUTO_START |
-                            G_DBUS_PROXY_FLAGS_DO_NOT_LOAD_PROPERTIES;
+    GDBusProxyFlags flags = G_DBUS_PROXY_FLAGS_DO_NOT_AUTO_START;
     BusEngineProxy *engine =
         (BusEngineProxy *) g_initable_new (BUS_TYPE_ENGINE_PROXY,
                                            NULL,
@@ -1134,6 +1133,39 @@ void bus_engine_proxy_set_surrounding_text (BusEngineProxy *engine,
     }
 }
 
+void
+bus_engine_proxy_set_content_type (BusEngineProxy *engine,
+                                   guint           purpose,
+                                   guint           hints)
+{
+    g_assert (BUS_IS_ENGINE_PROXY (engine));
+
+    GVariant *cached_content_type =
+        g_dbus_proxy_get_cached_property ((GDBusProxy *) engine,
+                                          "ContentType");
+    GVariant *content_type = g_variant_new ("(uu)", purpose, hints);
+
+    g_variant_ref_sink (content_type);
+    if (cached_content_type == NULL ||
+        !g_variant_equal (content_type, cached_content_type)) {
+        g_dbus_proxy_call ((GDBusProxy *) engine,
+                           "org.freedesktop.DBus.Properties.Set",
+                           g_variant_new ("(ssv)",
+                                          IBUS_INTERFACE_ENGINE,
+                                          "ContentType",
+                                          content_type),
+                           G_DBUS_CALL_FLAGS_NONE,
+                           -1,
+                           NULL,
+                           NULL,
+                           NULL);
+    }
+
+    if (cached_content_type != NULL)
+        g_variant_unref (cached_content_type);
+    g_variant_unref (content_type);
+}
+
 /* a macro to generate a function to call a nullary D-Bus method. */
 #define DEFINE_FUNCTION(Name, name)                         \
     void                                                    \
diff --git a/bus/engineproxy.h b/bus/engineproxy.h
index 8fe025db..528e61b7 100644
--- a/bus/engineproxy.h
+++ b/bus/engineproxy.h
@@ -1,8 +1,8 @@
 /* -*- mode: C; c-basic-offset: 4; indent-tabs-mode: nil; -*- */
 /* vim:set et sts=4: */
 /* ibus - The Input Bus
- * Copyright (C) 2008-2010 Peng Huang <shawn.p.huang@gmail.com>
- * Copyright (C) 2008-2010 Red Hat, Inc.
+ * Copyright (C) 2008-2013 Peng Huang <shawn.p.huang@gmail.com>
+ * Copyright (C) 2008-2013 Red Hat, Inc.
  *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Lesser General Public
@@ -49,7 +49,7 @@ G_BEGIN_DECLS
 typedef struct _BusEngineProxy BusEngineProxy;
 typedef struct _BusEngineProxyClass BusEngineProxyClass;
 
-GType            bus_engine_proxy_get_type          (void);
+GType           bus_engine_proxy_get_type    (void);
 
 /**
  * bus_engine_proxy_new:
@@ -59,196 +59,271 @@ GType            bus_engine_proxy_get_type          (void);
  * @callback: a function to be called when the method invocation is done.
  * @user_data: a pointer that will be passed to the callback.
  */
-void             bus_engine_proxy_new               (IBusEngineDesc        *desc,
-                                                     gint                   timeout,
-                                                     GCancellable          *cancellable,
-                                                     GAsyncReadyCallback    callback,
-                                                     gpointer               user_data);
+void            bus_engine_proxy_new         (IBusEngineDesc     *desc,
+                                              gint                timeout,
+                                              GCancellable       *cancellable,
+                                              GAsyncReadyCallback callback,
+                                              gpointer            user_data);
 
 /**
  * bus_engine_proxy_new_finish:
- * @returns: On success, return an engine object. On error, return NULL.
+ * @res: A #GAsyncResult.
+ * @error: Return location for error or %NULL.
+ * @returns: On success, return an engine object. On error, return %NULL.
  *
- * Get the result of bus_engine_proxy_new call. You have to call this function in the GAsyncReadyCallback function.
+ * Get the result of bus_engine_proxy_new() call. You have to call this
+ * function in the #GAsyncReadyCallback function.
  */
-BusEngineProxy  *bus_engine_proxy_new_finish        (GAsyncResult          *res,
-                                                     GError               **error);
+BusEngineProxy *bus_engine_proxy_new_finish  (GAsyncResult       *res,
+                                              GError            **error);
 
 /**
  * bus_engine_proxy_get_desc:
+ * @engine: A #BusEngineProxy.
  *
- * Get an IBusEngineDesc object associated with the engine.
+ * Get an #IBusEngineDesc object associated with the engine.
  */
-IBusEngineDesc  *bus_engine_proxy_get_desc          (BusEngineProxy        *engine);
+IBusEngineDesc *bus_engine_proxy_get_desc    (BusEngineProxy     *engine);
 
 /**
  * bus_engine_proxy_process_key_event:
- * @callback: a function to be called when the method invocation is done.
+ * @engine: A #BusEngineProxy.
+ * @keyval: Key symbol of the key press.
+ * @keycode: KeyCode of the key press.
+ * @state: Key modifier flags.
+ * @callback: A function to be called when the method invocation is done.
+ * @user_data: Data supplied to @callback.
  *
  * Call "ProcessKeyEvent" method of an engine asynchronously.
  */
-void             bus_engine_proxy_process_key_event (BusEngineProxy        *engine,
-                                                     guint                  keyval,
-                                                     guint                  keycode,
-                                                     guint                  state,
-                                                     GAsyncReadyCallback    callback,
-                                                     gpointer               user_data);
+void            bus_engine_proxy_process_key_event
+                                             (BusEngineProxy     *engine,
+                                              guint               keyval,
+                                              guint               keycode,
+                                              guint               state,
+                                              GAsyncReadyCallback callback,
+                                              gpointer            user_data);
 /**
  * bus_engine_proxy_set_cursor_location:
+ * @engine: A #BusEngineProxy.
+ * @x: X coordinate of the cursor.
+ * @y: Y coordinate of the cursor.
+ * @w: Width of the cursor.
+ * @h: Height of the cursor.
  *
- * Call "SetCursorLocation" method of an engine asynchronously. Unlike bus_engine_proxy_process_key_event, there's no way to know the
- * result of the method invocation. If the same coordinate is given twice or more, the function does nothing from the second time.
+ * Call "SetCursorLocation" method of an engine asynchronously. Unlike
+ * bus_engine_proxy_process_key_event(), there's no way to know the
+ * result of the method invocation. If the same coordinate is given
+ * twice or more, the function does nothing from the second time.
  */
-void             bus_engine_proxy_set_cursor_location
-                                                    (BusEngineProxy        *engine,
-                                                     gint                   x,
-                                                     gint                   y,
-                                                     gint                   w,
-                                                     gint                   h);
+void            bus_engine_proxy_set_cursor_location
+                                             (BusEngineProxy     *engine,
+                                              gint                x,
+                                              gint                y,
+                                              gint                w,
+                                              gint                h);
 /**
  * bus_engine_proxy_focus_in:
+ * @engine: A #BusEngineProxy.
  *
- * Call "FocusIn" method of an engine asynchronously. Do nothing if the engine already has a focus.
+ * Call "FocusIn" method of an engine asynchronously. Do nothing if
+ * the engine already has a focus.
  */
-void             bus_engine_proxy_focus_in          (BusEngineProxy        *engine);
+void            bus_engine_proxy_focus_in    (BusEngineProxy     *engine);
 
 /**
  * bus_engine_proxy_focus_out:
+ * @engine: A #BusEngineProxy.
  *
- * Call "FocusOut" method of an engine asynchronously. Do nothing if the engine does not have a focus.
+ * Call "FocusOut" method of an engine asynchronously. Do nothing if
+ * the engine does not have a focus.
  */
-void             bus_engine_proxy_focus_out         (BusEngineProxy        *engine);
+void            bus_engine_proxy_focus_out   (BusEngineProxy     *engine);
 
 /**
  * bus_engine_proxy_reset:
+ * @engine: A #BusEngineProxy.
  *
  * Call "Reset" method of an engine asynchronously.
  */
-void             bus_engine_proxy_reset             (BusEngineProxy        *engine);
+void            bus_engine_proxy_reset       (BusEngineProxy     *engine);
 
 /**
  * bus_engine_proxy_set_capabilities:
+ * @engine: A #BusEngineProxy.
+ * @caps: Capabilities flags of IBusEngine, see #IBusCapabilite.
  *
  * Call "SetCapabilities" method of an engine asynchronously.
  */
-void             bus_engine_proxy_set_capabilities  (BusEngineProxy        *engine,
-                                                     guint                  caps);
+void            bus_engine_proxy_set_capabilities
+                                             (BusEngineProxy     *engine,
+                                              guint               caps);
 /**
  * bus_engine_proxy_page_up:
+ * @engine: A #BusEngineProxy.
  *
  * Call "PageUp" method of an engine asynchronously.
  */
-void             bus_engine_proxy_page_up           (BusEngineProxy        *engine);
+void            bus_engine_proxy_page_up     (BusEngineProxy     *engine);
 
 /**
  * bus_engine_proxy_page_down:
+ * @engine: A #BusEngineProxy.
  *
  * Call "PageDown" method of an engine asynchronously.
  */
-void             bus_engine_proxy_page_down         (BusEngineProxy        *engine);
+void            bus_engine_proxy_page_down   (BusEngineProxy     *engine);
 
 /**
  * bus_engine_proxy_cursor_up:
+ * @engine: A #BusEngineProxy.
  *
  * Call "CursorUp" method of an engine asynchronously.
  */
-void             bus_engine_proxy_cursor_up         (BusEngineProxy        *engine);
+void            bus_engine_proxy_cursor_up   (BusEngineProxy     *engine);
 
 /**
  * bus_engine_proxy_cursor_down:
+ * @engine: A #BusEngineProxy.
  *
  * Call "CursorDown" method of an engine asynchronously.
  */
-void             bus_engine_proxy_cursor_down       (BusEngineProxy        *engine);
+void            bus_engine_proxy_cursor_down (BusEngineProxy     *engine);
 
 /**
  * bus_engine_proxy_candidate_clicked:
+ * @engine: A #BusEngineProxy.
+ * @index:  Index of candidate be clicked.
+ * @button: Mouse button.
+ * @state:  Keyboard state.
  *
  * Call "CandidateClicked" method of an engine asynchronously.
  */
-void             bus_engine_proxy_candidate_clicked (BusEngineProxy        *engine,
-                                                     guint                  index,
-                                                     guint                  button,
-                                                     guint                  state);
+void            bus_engine_proxy_candidate_clicked
+                                             (BusEngineProxy     *engine,
+                                              guint               index,
+                                              guint               button,
+                                              guint               state);
 /**
  * bus_engine_proxy_enable:
+ * @engine: A #BusEngineProxy.
  *
- * Call "Enable" method of an engine asynchronously. Do nothing if the engine is already enabled.
+ * Call "Enable" method of an engine asynchronously. Do nothing if the
+ * engine is already enabled.
  */
-void             bus_engine_proxy_enable            (BusEngineProxy        *engine);
+void            bus_engine_proxy_enable      (BusEngineProxy     *engine);
 
 /**
  * bus_engine_proxy_disable:
+ * @engine: A #BusEngineProxy.
  *
- * Call "Disable" method of an engine asynchronously. Do nothing if the engine is already disabled.
+ * Call "Disable" method of an engine asynchronously. Do nothing if
+ * the engine is already disabled.
  */
-void             bus_engine_proxy_disable           (BusEngineProxy        *engine);
+void            bus_engine_proxy_disable     (BusEngineProxy     *engine);
 
 /**
  * bus_engine_proxy_property_activate:
+ * @engine: A #BusEngineProxy.
+ * @name: Property name.
+ * @state: Property state.
  *
  * Call "PropertyActivate" method of an engine asynchronously.
  */
-void             bus_engine_proxy_property_activate (BusEngineProxy        *engine,
-                                                     const gchar           *prop_name,
-                                                     guint                  state);
+void            bus_engine_proxy_property_activate
+                                             (BusEngineProxy     *engine,
+                                              const gchar        *prop_name,
+                                              guint               state);
 /**
  * bus_engine_proxy_property_show:
+ * @engine: A #BusEngineProxy.
+ * @prop_name: Property name.
  *
  * Call "PropertyShow" method of an engine asynchronously.
  */
-void             bus_engine_proxy_property_show     (BusEngineProxy        *engine,
-                                                     const gchar           *prop_name);
+void            bus_engine_proxy_property_show
+                                             (BusEngineProxy     *engine,
+                                              const gchar        *prop_name);
 /**
  * bus_engine_proxy_property_hide:
+ * @engine: A #BusEngineProxy.
+ * @prop_name: Property name.
  *
  * Call "PropertyHide" method of an engine asynchronously.
  */
-void             bus_engine_proxy_property_hide     (BusEngineProxy *engine,
-                                                     const gchar    *prop_name);
+void            bus_engine_proxy_property_hide
+                                             (BusEngineProxy     *engine,
+                                              const gchar        *prop_name);
 /**
  * bus_engine_proxy_is_enabled:
- * @returns: TRUE if the engine is enabled.
+ * @engine: A #BusEngineProxy.
+ * @returns: %TRUE if the engine is enabled.
  */
-gboolean         bus_engine_proxy_is_enabled        (BusEngineProxy *engine);
+gboolean        bus_engine_proxy_is_enabled  (BusEngineProxy     *engine);
 
 /**
  * bus_engine_proxy_set_surrounding_text:
+ * @engine: A #BusEngineProxy.
+ * @text: The surrounding text.
+ * @cursor_pos: The cursor position on surrounding text.
+ * @anchor_pos: The anchor position on selection area.
  *
  * Call "SetSurroundingText" method of an engine asynchronously.
  */
-void             bus_engine_proxy_set_surrounding_text
-                                                    (BusEngineProxy *engine,
-                                                     IBusText       *text,
-                                                     guint           cursor_pos,
-                                                     guint           anchor_pos);
+void            bus_engine_proxy_set_surrounding_text
+                                             (BusEngineProxy     *engine,
+                                              IBusText           *text,
+                                              guint               cursor_pos,
+                                              guint               anchor_pos);
 
 /**
  * bus_engine_proxy_process_hand_writing_event:
+ * @engine: A #BusEngineProxy.
+ * @coordinates: A #GVariant containing an array of coordinates.
  *
- * Call "ProcessHandWritingEvent" method of an engine asynchronously. The type of the GVariant should be "(ad)".
- * See ibus_input_context_process_hand_writing_event for details.
+ * Call "ProcessHandWritingEvent" method of an engine
+ * asynchronously. The type of the GVariant should be "(ad)".  See
+ * ibus_input_context_process_hand_writing_event() for details.
  */
-void             bus_engine_proxy_process_hand_writing_event
-                                                    (BusEngineProxy        *engine,
-                                                     GVariant              *coordinates);
+void            bus_engine_proxy_process_hand_writing_event
+                                             (BusEngineProxy     *engine,
+                                              GVariant           *coordinates);
 
 /**
  * bus_engine_proxy_cancel_hand_writing:
+ * @engine: A #BusEngineProxy.
+ * @n_strokes: The number of strokes to be removed. 0 means "remove all".
  *
  * Call "CancelHandWriting" method of an engine asynchronously.
- * See ibus_input_context_cancel_hand_writing for details.
+ * See ibus_input_context_cancel_hand_writing() for details.
+ */
+void            bus_engine_proxy_cancel_hand_writing
+                                             (BusEngineProxy     *engine,
+                                              guint               n_strokes);
+
+/**
+ * bus_engine_proxy_set_content_type:
+ * @engine: A #BusEngineProxy.
+ * @purpose: Primary purpose of the input context, as an #IBusInputPurpose.
+ * @hints: Hints that augment @purpose, as an #IBusInputHints.
+ *
+ * Call "SetContentType" method of an engine asynchronously.
+ * See ibus_input_context_set_content_type() for details.
  */
-void             bus_engine_proxy_cancel_hand_writing
-                                                    (BusEngineProxy        *engine,
-                                                     guint                  n_strokes);
+void            bus_engine_proxy_set_content_type
+                                             (BusEngineProxy     *engine,
+                                              guint               purpose,
+                                              guint               hints);
 
 /**
  * bus_engine_proxy_get_properties:
+ * @engine: A #BusEngineProxy.
+ * @returns: An #IBusPropList.
  *
- * Get an IBusPropList object associated with the engine.
+ * Get an #IBusPropList object associated with the engine.
  */
-IBusPropList    *bus_engine_proxy_get_properties    (BusEngineProxy        *engine);
+IBusPropList   *bus_engine_proxy_get_properties
+                                             (BusEngineProxy     *engine);
 
 G_END_DECLS
 #endif
diff --git a/bus/inputcontext.c b/bus/inputcontext.c
index d7ada6ef..a2d1d52c 100644
--- a/bus/inputcontext.c
+++ b/bus/inputcontext.c
@@ -1,8 +1,8 @@
 /* -*- mode: C; c-basic-offset: 4; indent-tabs-mode: nil; -*- */
 /* vim:set et sts=4: */
 /* ibus - The Input Bus
- * Copyright (C) 2008-2010 Peng Huang <shawn.p.huang@gmail.com>
- * Copyright (C) 2008-2010 Red Hat, Inc.
+ * Copyright (C) 2008-2013 Peng Huang <shawn.p.huang@gmail.com>
+ * Copyright (C) 2008-2013 Red Hat, Inc.
  *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Lesser General Public
@@ -89,6 +89,10 @@ struct _BusInputContext {
 
     /* incompleted set engine by desc request */
     SetEngineByDescData *data;
+
+    /* content-type (primary purpose and hints) */
+    guint    purpose;
+    guint    hints;
 };
 
 struct _BusInputContextClass {
@@ -132,69 +136,83 @@ typedef struct _BusInputContextPrivate BusInputContextPrivate;
 static guint    context_signals[LAST_SIGNAL] = { 0 };
 
 /* functions prototype */
-static void     bus_input_context_destroy       (BusInputContext        *context);
+static void     bus_input_context_destroy
+                                   (BusInputContext       *context);
 static void     bus_input_context_service_method_call
-                                                (IBusService            *service,
-                                                 GDBusConnection        *connection,
-                                                 const gchar            *sender,
-                                                 const gchar            *object_path,
-                                                 const gchar            *interface_name,
-                                                 const gchar            *method_name,
-                                                 GVariant               *parameters,
-                                                 GDBusMethodInvocation  *invocation);
-static void     bus_input_context_unset_engine  (BusInputContext        *context);
-static void     bus_input_context_commit_text   (BusInputContext        *context,
-                                                 IBusText               *text);
+                                   (IBusService           *service,
+                                    GDBusConnection       *connection,
+                                    const gchar           *sender,
+                                    const gchar           *object_path,
+                                    const gchar           *interface_name,
+                                    const gchar           *method_name,
+                                    GVariant              *parameters,
+                                    GDBusMethodInvocation *invocation);
+static gboolean bus_input_context_service_set_property
+                                   (IBusService           *service,
+                                    GDBusConnection       *connection,
+                                    const gchar           *sender,
+                                    const gchar           *object_path,
+                                    const gchar           *interface_name,
+                                    const gchar           *property_name,
+                                    GVariant              *value,
+                                    GError               **error);
+static void     bus_input_context_unset_engine
+                                   (BusInputContext       *context);
+static void     bus_input_context_commit_text
+                                   (BusInputContext       *context,
+                                    IBusText              *text);
 static void     bus_input_context_update_preedit_text
-                                                (BusInputContext        *context,
-                                                 IBusText               *text,
-                                                 guint                   cursor_pos,
-                                                 gboolean                visible,
-                                                 guint                   mode);
+                                   (BusInputContext       *context,
+                                    IBusText              *text,
+                                    guint                  cursor_pos,
+                                    gboolean               visible,
+                                    guint                  mode);
 static void     bus_input_context_show_preedit_text
-                                                (BusInputContext        *context);
+                                   (BusInputContext       *context);
 static void     bus_input_context_hide_preedit_text
-                                                (BusInputContext        *context);
+                                   (BusInputContext       *context);
 static void     bus_input_context_update_auxiliary_text
-                                                (BusInputContext        *context,
-                                                 IBusText               *text,
-                                                 gboolean                visible);
+                                   (BusInputContext       *context,
+                                    IBusText              *text,
+                                    gboolean               visible);
 static void     bus_input_context_show_auxiliary_text
-                                                (BusInputContext        *context);
+                                   (BusInputContext       *context);
 static void     bus_input_context_hide_auxiliary_text
-                                                (BusInputContext        *context);
+                                   (BusInputContext       *context);
 static void     bus_input_context_update_lookup_table
-                                                (BusInputContext        *context,
-                                                 IBusLookupTable        *table,
-                                                 gboolean                visible);
+                                   (BusInputContext       *context,
+                                    IBusLookupTable       *table,
+                                    gboolean               visible);
 static void     bus_input_context_show_lookup_table
-                                                (BusInputContext        *context);
+                                   (BusInputContext       *context);
 static void     bus_input_context_hide_lookup_table
-                                                (BusInputContext        *context);
+                                   (BusInputContext       *context);
 static void     bus_input_context_page_up_lookup_table
-                                                (BusInputContext        *context);
+                                   (BusInputContext       *context);
 static void     bus_input_context_page_down_lookup_table
-                                                (BusInputContext        *context);
+                                   (BusInputContext       *context);
 static void     bus_input_context_cursor_up_lookup_table
-                                                (BusInputContext        *context);
+                                   (BusInputContext       *context);
 static void     bus_input_context_cursor_down_lookup_table
-                                                (BusInputContext        *context);
+                                   (BusInputContext       *context);
 static void     bus_input_context_register_properties
-                                                (BusInputContext        *context,
-                                                 IBusPropList           *props);
+                                   (BusInputContext       *context,
+                                    IBusPropList          *props);
 static void     bus_input_context_update_property
-                                                (BusInputContext        *context,
-                                                 IBusProperty           *prop);
-static void     _engine_destroy_cb              (BusEngineProxy         *factory,
-                                                 BusInputContext        *context);
+                                   (BusInputContext       *context,
+                                    IBusProperty          *prop);
+static void     _engine_destroy_cb (BusEngineProxy        *factory,
+                                    BusInputContext       *context);
 
 static IBusText *text_empty = NULL;
 static IBusLookupTable *lookup_table_empty = NULL;
 static IBusPropList    *props_empty = NULL;
 
-/* The interfaces available in this class, which consists of a list of methods this class implements and
- * a list of signals this class may emit. Method calls to the interface that are not defined in this XML
- * will be automatically rejected by the GDBus library (see src/ibusservice.c for details.) */
+/* The interfaces available in this class, which consists of a list of
+ * methods this class implements and a list of signals this class may
+ * emit. Method calls to the interface that are not defined in this
+ * XML will be automatically rejected by the GDBus library (see
+ * src/ibusservice.c for details.) */
 static const gchar introspection_xml[] =
     "<node>"
     "  <interface name='org.freedesktop.IBus.InputContext'>"
@@ -277,6 +295,9 @@ static const gchar introspection_xml[] =
     "    <signal name='UpdateProperty'>"
     "      <arg type='v' name='prop' />"
     "    </signal>"
+
+    /* properties */
+    "    <property name='ContentType' type='(uu)' access='write' />"
     "  </interface>"
     "</node>";
 
@@ -316,7 +337,10 @@ bus_input_context_class_init (BusInputContextClass *class)
     ibus_object_class->destroy = (IBusObjectDestroyFunc) bus_input_context_destroy;
 
     /* override the parent class's implementation. */
-    IBUS_SERVICE_CLASS (class)->service_method_call = bus_input_context_service_method_call;
+    IBUS_SERVICE_CLASS (class)->service_method_call =
+        bus_input_context_service_method_call;
+    IBUS_SERVICE_CLASS (class)->service_set_property =
+        bus_input_context_service_set_property;
     /* register the xml so that bus_ibus_impl_service_method_call will be called on a method call defined in the xml (e.g. 'FocusIn'.) */
     ibus_service_class_add_interfaces (IBUS_SERVICE_CLASS (class), introspection_xml);
 
@@ -607,14 +631,9 @@ bus_input_context_destroy (BusInputContext *context)
     IBUS_OBJECT_CLASS (bus_input_context_parent_class)->destroy (IBUS_OBJECT (context));
 }
 
-/**
- * bus_input_context_emit_signal:
- * @signal_name: The D-Bus signal name to emit which is in the introspection_xml.
- *
- * Emit the D-Bus signal.
- */
 static gboolean
-bus_input_context_emit_signal (BusInputContext *context,
+bus_input_context_send_signal (BusInputContext *context,
+                               const gchar     *interface_name,
                                const gchar     *signal_name,
                                GVariant        *parameters,
                                GError         **error)
@@ -623,7 +642,7 @@ bus_input_context_emit_signal (BusInputContext *context,
         return TRUE;
 
     GDBusMessage *message = g_dbus_message_new_signal (ibus_service_get_object_path ((IBusService *)context),
-                                                       "org.freedesktop.IBus.InputContext",
+                                                       interface_name,
                                                        signal_name);
     g_dbus_message_set_sender (message, "org.freedesktop.IBus");
     g_dbus_message_set_destination (message, bus_connection_get_unique_name (context->connection));
@@ -639,6 +658,58 @@ bus_input_context_emit_signal (BusInputContext *context,
 }
 
 /**
+ * bus_input_context_emit_signal:
+ * @signal_name: The D-Bus signal name to emit which is in the introspection_xml.
+ *
+ * Emit the D-Bus signal.
+ */
+static gboolean
+bus_input_context_emit_signal (BusInputContext *context,
+                               const gchar     *signal_name,
+                               GVariant        *parameters,
+                               GError         **error)
+{
+    if (context->connection == NULL)
+        return TRUE;
+
+    return bus_input_context_send_signal (context,
+                                          "org.freedesktop.IBus.InputContext",
+                                          signal_name,
+                                          parameters,
+                                          error);
+}
+
+/**
+ * bus_input_context_property_changed:
+ * @context: a #BusInputContext
+ * @property_name: The D-Bus property name which has changed
+ * @value: The new value of the property
+ *
+ * Emit the D-Bus "PropertiesChanged" signal for a property.
+ * Returns: %TRUE on success, %FALSE on failure
+ */
+static gboolean
+bus_input_context_property_changed (BusInputContext *context,
+                                    const gchar     *property_name,
+                                    GVariant        *value,
+                                    GError         **error)
+{
+    if (context->connection == NULL)
+        return TRUE;
+
+    GVariantBuilder *builder = g_variant_builder_new (G_VARIANT_TYPE_ARRAY);
+    g_variant_builder_add (builder, "{sv}", property_name, value);
+    return bus_input_context_send_signal (context,
+                                          "org.freedesktop.DBus.Properties",
+                                          "PropertiesChanged",
+                                          g_variant_new ("(sa{sv}as)",
+                                                         "org.freedesktop.IBus",
+                                                         builder,
+                                                         NULL),
+                                          error);
+}
+
+/**
  * _ic_process_key_event_reply_cb:
  *
  * A GAsyncReadyCallback function to be called when bus_engine_proxy_process_key_event() is finished.
@@ -948,11 +1019,6 @@ _ic_get_engine (BusInputContext       *context,
             g_variant_new ("(v)", ibus_serializable_serialize ((IBusSerializable *)desc)));
 }
 
-/**
- * bus_input_context_service_method_call:
- *
- * Handle a D-Bus method call whose destination and interface name are both "org.freedesktop.IBus.InputContext"
- */
 static void
 _ic_set_surrounding_text (BusInputContext       *context,
                           GVariant              *parameters,
@@ -985,6 +1051,11 @@ _ic_set_surrounding_text (BusInputContext       *context,
     g_dbus_method_invocation_return_value (invocation, NULL);
 }
 
+/**
+ * bus_input_context_service_method_call:
+ *
+ * Handle a D-Bus method call whose destination and interface name are both "org.freedesktop.IBus.InputContext"
+ */
 static void
 bus_input_context_service_method_call (IBusService            *service,
                                        GDBusConnection        *connection,
@@ -1024,7 +1095,7 @@ bus_input_context_service_method_call (IBusService            *service,
         { "PropertyActivate",  _ic_property_activate },
         { "SetEngine",         _ic_set_engine },
         { "GetEngine",         _ic_get_engine },
-        { "SetSurroundingText", _ic_set_surrounding_text},
+        { "SetSurroundingText", _ic_set_surrounding_text }
     };
 
     gint i;
@@ -1038,6 +1109,63 @@ bus_input_context_service_method_call (IBusService            *service,
     g_return_if_reached ();
 }
 
+static gboolean
+bus_input_context_service_set_property (IBusService     *service,
+                                        GDBusConnection *connection,
+                                        const gchar     *sender,
+                                        const gchar     *object_path,
+                                        const gchar     *interface_name,
+                                        const gchar     *property_name,
+                                        GVariant        *value,
+                                        GError         **error)
+{
+    if (g_strcmp0 (interface_name, IBUS_INTERFACE_INPUT_CONTEXT) != 0) {
+        return IBUS_SERVICE_CLASS (bus_input_context_parent_class)->
+            service_set_property (service,
+                                  connection,
+                                  sender,
+                                  object_path,
+                                  interface_name,
+                                  property_name,
+                                  value,
+                                  error);
+    }
+
+    if (g_strcmp0 (property_name, "ContentType") == 0) {
+        BusInputContext *context = (BusInputContext *) service;
+        guint purpose = 0;
+        guint hints = 0;
+
+        g_variant_get (value, "(uu)", &purpose, &hints);
+        if (purpose != context->purpose || hints != context->hints) {
+            GError *error;
+            gboolean retval;
+
+            context->purpose = purpose;
+            context->hints = hints;
+
+            if (context->has_focus && context->engine)
+                bus_engine_proxy_set_content_type (context->engine,
+                                                   purpose,
+                                                   hints);
+
+            error = NULL;
+            retval = bus_input_context_property_changed (context,
+                                                         "ContentType",
+                                                         value,
+                                                         &error);
+            if (!retval) {
+                g_warning ("Failed to emit PropertiesChanged signal: %s",
+                           error->message);
+                g_error_free (error);
+            }
+        }
+        return TRUE;
+    }
+
+    g_return_val_if_reached (FALSE);
+}
+
 gboolean
 bus_input_context_has_focus (BusInputContext *context)
 {
@@ -1066,6 +1194,7 @@ bus_input_context_focus_in (BusInputContext *context)
         bus_engine_proxy_enable (context->engine);
         bus_engine_proxy_set_capabilities (context->engine, context->capabilities);
         bus_engine_proxy_set_cursor_location (context->engine, context->x, context->y, context->w, context->h);
+        bus_engine_proxy_set_content_type (context->engine, context->purpose, context->hints);
     }
 
     if (context->capabilities & IBUS_CAP_FOCUS) {
@@ -1953,6 +2082,7 @@ bus_input_context_enable (BusInputContext *context)
     bus_engine_proxy_enable (context->engine);
     bus_engine_proxy_set_capabilities (context->engine, context->capabilities);
     bus_engine_proxy_set_cursor_location (context->engine, context->x, context->y, context->w, context->h);
+    bus_engine_proxy_set_content_type (context->engine, context->purpose, context->hints);
 }
 
 void
@@ -2057,6 +2187,7 @@ bus_input_context_set_engine (BusInputContext *context,
             bus_engine_proxy_enable (context->engine);
             bus_engine_proxy_set_capabilities (context->engine, context->capabilities);
             bus_engine_proxy_set_cursor_location (context->engine, context->x, context->y, context->w, context->h);
+            bus_engine_proxy_set_content_type (context->engine, context->purpose, context->hints);
         }
     }
     g_signal_emit (context,