chromeos_input_method_ui.cc - chromiumos/platform/cros - Git at Google

 // Copyright (c) 2010 The Chromium OS Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.

 #include "chromeos_input_method_ui.h"

 #include <base/logging.h>
 #include <base/string_util.h>
 #include <ibus.h>
 #include <ibuspanelservice.h>

 namespace chromeos {

 // IBusChromeOSPanelService is a subclass of IBusPanelService, that is
 // used for implementing input method UI for Chrome OS.
 //
 // The anonymous namespace contains boilerplate code for creating a sub
 // class with GObject, as well as member functions.
 namespace {

 const char kLanguageBarObjectPath[] = "/org/chromium/Chrome/LanguageBar";

 // Define IBusChromeOSPanelService class.
 #define IBUS_TYPE_CHROMEOS_PANEL_SERVICE        \
   (ibus_chromeos_panel_service_get_type())
 #define IBUS_CHROMEOS_PANEL_SERVICE(obj)                                \
   (G_TYPE_CHECK_INSTANCE_CAST((obj), IBUS_TYPE_CHROMEOS_PANEL_SERVICE,  \
                               IBusChromeOSPanelService))
 #define IBUS_CHROMEOS_PANEL_SERVICE_CLASS(klass)                        \
   (G_TYPE_CHECK_CLASS_CAST((klass), IBUS_TYPE_CHROMEOS_PANEL_SERVICE,   \
                            IBusChromeOSPanelServiceClass))
 #define CHROMEOS_IS_PANEL_SERVICE(obj)                                  \
   (G_TYPE_CHECK_INSTANCE_TYPE((obj), IBUS_TYPE_CHROMEOS_PANEL_SERVICE))
 #define CHROMEOS_IS_PANEL_SERVICE_CLASS(klass)                          \
   (G_TYPE_CHECK_CLASS_TYPE((klass), IBUS_TYPE_CHROMEOS_PANEL_SERVICE))
 #define IBUS_CHROMEOS_PANEL_SERVICE_GET_CLASS(obj)                      \
   (G_TYPE_INSTANCE_GET_CLASS((obj), IBUS_TYPE_CHROMEOS_PANEL_SERVICE,   \
                              IBusChromeOSPanelService))

 // The class definition.
 struct IBusChromeOSPanelService {
   // The parent object.
   IBusPanelService service;

   // The IBus connection is used for sending signals.
   // The ownership is not transferred.
   IBusConnection* ibus_connection;

   // The object of the client input method library. This will be used as
   // the first argument of monitor functions.
   void* input_method_library;

   // The monitor functions are called upon certain events.
   chromeos::InputMethodUiStatusMonitorFunctions monitor_functions;
 };

 struct IBusChromeOSPanelServiceClass {
   IBusPanelServiceClass parent_class;
 };

 G_DEFINE_TYPE(IBusChromeOSPanelService, ibus_chromeos_panel_service,
               IBUS_TYPE_PANEL_SERVICE)

 // Handles IBus's |FocusIn| method call.
 // Just sends a signal to the language bar.
 gboolean ibus_chromeos_panel_service_focus_in(IBusPanelService *panel,
                                               const gchar* input_context_path,
                                               IBusError **error) {
   // TODO(satorux): We should create an IBusError object and return it as
   // |error| if we return FALSE.  Otherwise, the program will crash in
   // ibuspanelservice.cc as the caller expects an error object to be
   // returned.
   LOG(INFO) << "Sending FocusIn signal to Chrome";
   g_return_val_if_fail(panel, FALSE);
   g_return_val_if_fail(input_context_path, FALSE);

   IBusConnection* ibus_connection =
       IBUS_CHROMEOS_PANEL_SERVICE(panel)->ibus_connection;
   ibus_connection_send_signal(ibus_connection,
                               kLanguageBarObjectPath,
                               IBUS_INTERFACE_PANEL,
                               "FocusIn",
                               G_TYPE_STRING, &input_context_path,
                               G_TYPE_INVALID);
   return TRUE;
 }

 // Handles IBus's |FocusOut| method call.
 // Just sends a signal to the language bar.
 gboolean ibus_chromeos_panel_service_focus_out(IBusPanelService *panel,
                                                const gchar* input_context_path,
                                                IBusError **error) {
   g_return_val_if_fail(panel, FALSE);
   g_return_val_if_fail(input_context_path, FALSE);

   IBusConnection* ibus_connection =
       IBUS_CHROMEOS_PANEL_SERVICE(panel)->ibus_connection;
   ibus_connection_send_signal(ibus_connection,
                               kLanguageBarObjectPath,
                               IBUS_INTERFACE_PANEL,
                               "FocusOut",
                               G_TYPE_STRING, &input_context_path,
                               G_TYPE_INVALID);
   return TRUE;
 }

 // Handles IBus's |HideAuxiliaryText| method call.
 // Calls |hide_auxiliary_text| in |monitor_functions|.
 gboolean ibus_chromeos_panel_service_hide_auxiliary_text(
     IBusPanelService *panel,
     IBusError **error) {
   g_return_val_if_fail(panel, FALSE);

   const InputMethodUiStatusMonitorFunctions& monitor_functions =
       IBUS_CHROMEOS_PANEL_SERVICE(panel)->monitor_functions;
   void* input_method_library =
       IBUS_CHROMEOS_PANEL_SERVICE(panel)->input_method_library;
   g_return_val_if_fail(monitor_functions.hide_auxiliary_text, FALSE);

   monitor_functions.hide_auxiliary_text(input_method_library);
   return TRUE;
 }

 // Handles IBus's |HideLookupTable| method call.
 // Calls |hide_lookup_table| in |monitor_functions|.
 gboolean ibus_chromeos_panel_service_hide_lookup_table(IBusPanelService *panel,
                                                        IBusError **error) {
   g_return_val_if_fail(panel, FALSE);

   const InputMethodUiStatusMonitorFunctions& monitor_functions =
       IBUS_CHROMEOS_PANEL_SERVICE(panel)->monitor_functions;
   void* input_method_library =
       IBUS_CHROMEOS_PANEL_SERVICE(panel)->input_method_library;
   g_return_val_if_fail(monitor_functions.hide_lookup_table, FALSE);

   monitor_functions.hide_lookup_table(input_method_library);
   return TRUE;
 }

 // Handles IBus's |RegisterProperties| method call.
 // Just sends a signal to the language bar.
 gboolean ibus_chromeos_panel_service_register_properties(
     IBusPanelService* panel, IBusPropList* prop_list, IBusError** error) {
   g_return_val_if_fail(panel, FALSE);
   g_return_val_if_fail(prop_list, FALSE);

   IBusConnection* ibus_connection =
       IBUS_CHROMEOS_PANEL_SERVICE(panel)->ibus_connection;
   ibus_connection_send_signal(ibus_connection,
                               kLanguageBarObjectPath,
                               IBUS_INTERFACE_PANEL,
                               "RegisterProperties",
                               IBUS_TYPE_PROP_LIST, &prop_list,
                               G_TYPE_INVALID);
   return TRUE;
 }

 // Handles IBus's |UpdateAuxiliaryText| method call.
 // Converts IBusText to a std::string, and calls |update_auxiliary_text| in
 // |monitor_functions|
 gboolean ibus_chromeos_panel_service_update_auxiliary_text(
     IBusPanelService *panel,
     IBusText *text,
     gboolean visible,
     IBusError **error) {
   g_return_val_if_fail(panel, FALSE);
   g_return_val_if_fail(text, FALSE);
   g_return_val_if_fail(text->text, FALSE);

   const InputMethodUiStatusMonitorFunctions& monitor_functions =
       IBUS_CHROMEOS_PANEL_SERVICE(panel)->monitor_functions;
   void* input_method_library =
       IBUS_CHROMEOS_PANEL_SERVICE(panel)->input_method_library;
   g_return_val_if_fail(monitor_functions.update_auxiliary_text, FALSE);

   // Convert IBusText to a std::string. IBusText is an attributed text,
   const std::string simple_text = text->text;
   monitor_functions.update_auxiliary_text(input_method_library,
                                           simple_text,
                                           visible == TRUE);
   return TRUE;
 }

 // Returns an string representation of |table| for debugging.
 std::string IBusLookupTableToString(IBusLookupTable* table) {
   std::stringstream stream;
   stream << "page_size: " << table->page_size << "\n";
   stream << "cursor_pos: " << table->cursor_pos << "\n";
   stream << "cursor_visible: " << table->cursor_visible << "\n";
   stream << "round: " << table->round << "\n";
   stream << "orientation: " << table->orientation << "\n";
   stream << "candidates:";
   for (int i = 0; ; i++) {
     IBusText *text = ibus_lookup_table_get_candidate(table, i);
     if (!text) {
       break;
     }
     stream << " " << text->text;
   }
   return stream.str();
 }

 // Handles IBus's |UpdateLookupTable| method call.
 // Creates an InputMethodLookupTable object and calls |update_lookup_table| in
 // |monitor_functions|
 gboolean ibus_chromeos_panel_service_update_lookup_table(
     IBusPanelService *panel,
     IBusLookupTable *table,
     gboolean visible,
     IBusError **error) {
   g_return_val_if_fail(panel, FALSE);
   g_return_val_if_fail(table, FALSE);

   const InputMethodUiStatusMonitorFunctions& monitor_functions =
       IBUS_CHROMEOS_PANEL_SERVICE(panel)->monitor_functions;
   void* input_method_library =
       IBUS_CHROMEOS_PANEL_SERVICE(panel)->input_method_library;
   g_return_val_if_fail(monitor_functions.update_lookup_table, FALSE);

   InputMethodLookupTable lookup_table;
   lookup_table.visible = (visible == TRUE);

   // Copy the orientation information.
   const gint orientation = ibus_lookup_table_get_orientation(table);
   if (orientation == IBUS_ORIENTATION_VERTICAL) {
     lookup_table.orientation = InputMethodLookupTable::kVertical;
   } else if (orientation == IBUS_ORIENTATION_HORIZONTAL) {
     lookup_table.orientation = InputMethodLookupTable::kHorizontal;
   }

   // Copy candidates to |lookup_table|.
   for (int i = 0; ; i++) {
     IBusText *text = ibus_lookup_table_get_candidate(table, i);
     if (!text) {
       break;
     }
     lookup_table.candidates.push_back(text->text);
   }

   lookup_table.cursor_absolute_index =
       ibus_lookup_table_get_cursor_pos(table);
   lookup_table.page_size = ibus_lookup_table_get_page_size(table);
   // Ensure that the page_size is non-zero to avoid div-by-zero error.
   if (lookup_table.page_size <= 0) {
     LOG(DFATAL) << "Invalid page size: " << lookup_table.page_size;
     lookup_table.page_size = 1;
   }

   monitor_functions.update_lookup_table(input_method_library, lookup_table);
   return TRUE;
 }

 // Handles IBus's |UpdateProperty| method call.
 // Just sends a signal to the language bar.
 gboolean ibus_chromeos_panel_service_update_property(
     IBusPanelService* panel, IBusProperty* prop, IBusError** error) {
   g_return_val_if_fail(panel, FALSE);
   g_return_val_if_fail(prop, FALSE);

   IBusConnection* ibus_connection =
       IBUS_CHROMEOS_PANEL_SERVICE(panel)->ibus_connection;
   ibus_connection_send_signal(ibus_connection,
                               kLanguageBarObjectPath,
                               IBUS_INTERFACE_PANEL,
                               "UpdateProperty",
                               IBUS_TYPE_PROPERTY, &prop,
                               G_TYPE_INVALID);
   return TRUE;
 }

 // Handles IBus's |StateChanged| method call.
 // Just sends a signal to the language bar.
 gboolean ibus_chromeos_panel_service_state_changed(IBusPanelService *panel,
                                                    IBusError **error) {
   g_return_val_if_fail(panel, FALSE);

   IBusConnection* ibus_connection =
       IBUS_CHROMEOS_PANEL_SERVICE(panel)->ibus_connection;
   // TODO(yusukes): Get rid of the dummy string. As of writing, the
   // language bar needs a dummy string parameter for some implementation
   // reason.
   static const char kDummy[] = "dummy";
   const char* dummy = kDummy;
   ibus_connection_send_signal(ibus_connection,
                               kLanguageBarObjectPath,
                               IBUS_INTERFACE_PANEL,
                               "StateChanged",
                               G_TYPE_STRING, &dummy,
                               G_TYPE_INVALID);
   return TRUE;
 }

 // Handles IBus's |SetCursorLocation| method call.
 // Calls |set_cursor_location| in |monitor_functions|.
 gboolean ibus_chromeos_panel_service_set_cursor_location(
     IBusPanelService *panel,
     gint x,
     gint y,
     gint width,
     gint height,
     IBusError **error) {
   g_return_val_if_fail(panel, FALSE);

   const InputMethodUiStatusMonitorFunctions& monitor_functions =
       IBUS_CHROMEOS_PANEL_SERVICE(panel)->monitor_functions;
   void* input_method_library =
       IBUS_CHROMEOS_PANEL_SERVICE(panel)->input_method_library;
   g_return_val_if_fail(monitor_functions.set_cursor_location, FALSE);

   monitor_functions.set_cursor_location(input_method_library,
                                         x, y, width, height);
   return TRUE;
 }

 // Creates an IBusChromeOSPanelService. Returns as IBusPanelService for
 // convenience (i.e. it can be passed to ibus_panel_service_* functions
 // without cast).
 IBusPanelService* ibus_chromeos_panel_service_new(
     IBusConnection *ibus_connection,
     void* input_method_library,
     const InputMethodUiStatusMonitorFunctions& monitor_functions) {
   IBusPanelService* service = IBUS_PANEL_SERVICE(
       g_object_new(IBUS_TYPE_CHROMEOS_PANEL_SERVICE,
                    "path", IBUS_PATH_PANEL,
                    "connection", ibus_connection,
                    NULL));

   // Set members specific to IBusChromeOSPanelService.
   IBUS_CHROMEOS_PANEL_SERVICE(service)->ibus_connection =
       ibus_connection;
   IBUS_CHROMEOS_PANEL_SERVICE(service)->input_method_library =
       input_method_library;
   IBUS_CHROMEOS_PANEL_SERVICE(service)->monitor_functions =
       monitor_functions;

   return service;
 }

 // Destroys the given IBusChromeOSPanelService object.
 void ibus_chromeos_panel_service_destroy(IBusObject* object) {
   DLOG(INFO) << "ibus_chromeos_panel_service_destroy";
   IBUS_OBJECT_CLASS(ibus_chromeos_panel_service_parent_class)
       ->destroy(IBUS_OBJECT(object));
 }

 // Initializes the IBusChromeOSPanel class.
 void ibus_chromeos_panel_service_class_init(
     IBusChromeOSPanelServiceClass* klass) {
   IBusPanelServiceClass* panel_class =
       reinterpret_cast<IBusPanelServiceClass*>(klass);
   // Install member functions. Sorted in alphabetical order.
   panel_class->focus_in = ibus_chromeos_panel_service_focus_in;
   panel_class->focus_out = ibus_chromeos_panel_service_focus_out;
   panel_class->hide_auxiliary_text =
       ibus_chromeos_panel_service_hide_auxiliary_text;
   panel_class->hide_lookup_table =
       ibus_chromeos_panel_service_hide_lookup_table;
   panel_class->register_properties =
       ibus_chromeos_panel_service_register_properties;
   panel_class->set_cursor_location =
       ibus_chromeos_panel_service_set_cursor_location;
   panel_class->state_changed =
       ibus_chromeos_panel_service_state_changed;
   panel_class->update_auxiliary_text =
       ibus_chromeos_panel_service_update_auxiliary_text;
   panel_class->update_lookup_table =
       ibus_chromeos_panel_service_update_lookup_table;
   panel_class->update_property = ibus_chromeos_panel_service_update_property;

   // Set the destructor function.
   IBusObjectClass* object_class =
       reinterpret_cast<IBusObjectClass*>(klass);
   object_class->destroy = ibus_chromeos_panel_service_destroy;
 }

 // Initializes the given IBusChromeOSPanelService object.
 void ibus_chromeos_panel_service_init(IBusChromeOSPanelService* service) {
   service->input_method_library = NULL;
   service->ibus_connection = NULL;
 }

 }  // namespace

 // A thin wrapper for IBusPanelService.
 class InputMethodUiStatusConnection {
  public:
   InputMethodUiStatusConnection(
       const InputMethodUiStatusMonitorFunctions& monitor_functions,
       void* input_method_library)
       : monitor_functions_(monitor_functions),
         input_method_library_(input_method_library),
         ibus_(NULL),
         ibus_panel_service_(NULL) {
   }

   ~InputMethodUiStatusConnection() {
     // ibus_panel_service_ depends on ibus_, thus unref it first.
     if (ibus_panel_service_) {
       g_object_unref(ibus_panel_service_);
     }
     if (ibus_) {
       g_object_unref(ibus_);
     }
   }

   // Initializes the object. Returns true on success.
   bool Init() {
     // Initialize an IBus bus.
     ibus_init();
     ibus_ = ibus_bus_new();

     // Check the IBus connection status.
     if (!ibus_) {
       LOG(ERROR) << "ibus_bus_new() failed";
       return false;
     }
     if (!ibus_bus_is_connected(ibus_)) {
       LOG(ERROR) << "ibus_bus_is_connected() failed";
       return false;
     }

     // Request the object name.
     const int status = ibus_bus_request_name(ibus_, IBUS_SERVICE_PANEL, 0);
     if (status == 0) {
       LOG(ERROR) << "ibus_bus_request_name() failed";
       return false;
     }

     // Establish the connection to ibus-daemon.  Note that the
     // ibus_connection object is owned by ibus_.
     IBusConnection* ibus_connection = ibus_bus_get_connection(ibus_);
     if (!ibus_connection) {
       LOG(ERROR) << "ibus_bus_get_connection() failed";
       return false;
     }

     // Create a ChromeOS's version of IBusPanelService.
     ibus_panel_service_ = ibus_chromeos_panel_service_new(ibus_connection,
                                                           input_method_library_,
                                                           monitor_functions_);
     if (!ibus_panel_service_) {
       LOG(ERROR) << "ibus_chromeos_panel_service_new() failed";
       return false;
     }

     return true;
   }

   IBusPanelService* ibus_panel_service() {
     return ibus_panel_service_;
   }

  private:
   InputMethodUiStatusMonitorFunctions monitor_functions_;
   void* input_method_library_;
   IBusBus* ibus_;
   IBusPanelService* ibus_panel_service_;
 };

 //
 // cros APIs
 //

 // The function will be bound to chromeos::MonitorInputMethodUiStatus with
 // dlsym() in load.cc so it needs to be in the C linkage, so the symbol
 // name does not get mangled.
 extern "C"
 InputMethodUiStatusConnection* ChromeOSMonitorInputMethodUiStatus(
     const InputMethodUiStatusMonitorFunctions& monitor_functions,
     void* input_method_library) {
   DLOG(INFO) << "MonitorInputMethodUiStatus";

   InputMethodUiStatusConnection* connection =
       new InputMethodUiStatusConnection(monitor_functions,
                                         input_method_library);
   if (!connection->Init()) {
     LOG(WARNING) << "Failed to Init() InputMethodUiStatusConnection. "
                  << "Returning NULL";
     delete connection;
     connection = NULL;
   }
   return connection;
 }

 extern "C"
 void ChromeOSDisconnectInputMethodUiStatus(
     InputMethodUiStatusConnection* connection) {
   DLOG(INFO) << "DisconnectInputMethodUiStatus";
   delete connection;
 }

 extern "C"
 void ChromeOSNotifyCandidateClicked(InputMethodUiStatusConnection* connection,
                                     int index, int button, int flags) {
   DLOG(INFO) << "NotifyCandidateClicked";
   DCHECK(connection);
   if (connection) {
     ibus_panel_service_candidate_clicked(connection->ibus_panel_service(),
                                          index,
                                          button,
                                          flags);
   }
 }

 }  // namespace chromeos
	// Copyright (c) 2010 The Chromium OS Authors. All rights reserved.
	// Use of this source code is governed by a BSD-style license that can be
	// found in the LICENSE file.

	#include "chromeos_input_method_ui.h"

	#include <base/logging.h>
	#include <base/string_util.h>
	#include <ibus.h>
	#include <ibuspanelservice.h>

	namespace chromeos {

	// IBusChromeOSPanelService is a subclass of IBusPanelService, that is
	// used for implementing input method UI for Chrome OS.
	//
	// The anonymous namespace contains boilerplate code for creating a sub
	// class with GObject, as well as member functions.
	namespace {

	const char kLanguageBarObjectPath[] = "/org/chromium/Chrome/LanguageBar";

	// Define IBusChromeOSPanelService class.
	#define IBUS_TYPE_CHROMEOS_PANEL_SERVICE \
	(ibus_chromeos_panel_service_get_type())
	#define IBUS_CHROMEOS_PANEL_SERVICE(obj) \
	(G_TYPE_CHECK_INSTANCE_CAST((obj), IBUS_TYPE_CHROMEOS_PANEL_SERVICE, \
	IBusChromeOSPanelService))
	#define IBUS_CHROMEOS_PANEL_SERVICE_CLASS(klass) \
	(G_TYPE_CHECK_CLASS_CAST((klass), IBUS_TYPE_CHROMEOS_PANEL_SERVICE, \
	IBusChromeOSPanelServiceClass))
	#define CHROMEOS_IS_PANEL_SERVICE(obj) \
	(G_TYPE_CHECK_INSTANCE_TYPE((obj), IBUS_TYPE_CHROMEOS_PANEL_SERVICE))
	#define CHROMEOS_IS_PANEL_SERVICE_CLASS(klass) \
	(G_TYPE_CHECK_CLASS_TYPE((klass), IBUS_TYPE_CHROMEOS_PANEL_SERVICE))
	#define IBUS_CHROMEOS_PANEL_SERVICE_GET_CLASS(obj) \
	(G_TYPE_INSTANCE_GET_CLASS((obj), IBUS_TYPE_CHROMEOS_PANEL_SERVICE, \
	IBusChromeOSPanelService))

	// The class definition.
	struct IBusChromeOSPanelService {
	// The parent object.
	IBusPanelService service;

	// The IBus connection is used for sending signals.
	// The ownership is not transferred.
	IBusConnection* ibus_connection;

	// The object of the client input method library. This will be used as
	// the first argument of monitor functions.
	void* input_method_library;

	// The monitor functions are called upon certain events.
	chromeos::InputMethodUiStatusMonitorFunctions monitor_functions;
	};

	struct IBusChromeOSPanelServiceClass {
	IBusPanelServiceClass parent_class;
	};

	G_DEFINE_TYPE(IBusChromeOSPanelService, ibus_chromeos_panel_service,
	IBUS_TYPE_PANEL_SERVICE)

	// Handles IBus's \|FocusIn\| method call.
	// Just sends a signal to the language bar.
	gboolean ibus_chromeos_panel_service_focus_in(IBusPanelService *panel,
	const gchar* input_context_path,
	IBusError **error) {
	// TODO(satorux): We should create an IBusError object and return it as
	// \|error\| if we return FALSE. Otherwise, the program will crash in
	// ibuspanelservice.cc as the caller expects an error object to be
	// returned.
	LOG(INFO) << "Sending FocusIn signal to Chrome";
	g_return_val_if_fail(panel, FALSE);
	g_return_val_if_fail(input_context_path, FALSE);

	IBusConnection* ibus_connection =
	IBUS_CHROMEOS_PANEL_SERVICE(panel)->ibus_connection;
	ibus_connection_send_signal(ibus_connection,
	kLanguageBarObjectPath,
	IBUS_INTERFACE_PANEL,
	"FocusIn",
	G_TYPE_STRING, &input_context_path,
	G_TYPE_INVALID);
	return TRUE;
	}

	// Handles IBus's \|FocusOut\| method call.
	// Just sends a signal to the language bar.
	gboolean ibus_chromeos_panel_service_focus_out(IBusPanelService *panel,
	const gchar* input_context_path,
	IBusError **error) {
	g_return_val_if_fail(panel, FALSE);
	g_return_val_if_fail(input_context_path, FALSE);

	IBusConnection* ibus_connection =
	IBUS_CHROMEOS_PANEL_SERVICE(panel)->ibus_connection;
	ibus_connection_send_signal(ibus_connection,
	kLanguageBarObjectPath,
	IBUS_INTERFACE_PANEL,
	"FocusOut",
	G_TYPE_STRING, &input_context_path,
	G_TYPE_INVALID);
	return TRUE;
	}

	// Handles IBus's \|HideAuxiliaryText\| method call.
	// Calls \|hide_auxiliary_text\| in \|monitor_functions\|.
	gboolean ibus_chromeos_panel_service_hide_auxiliary_text(
	IBusPanelService *panel,
	IBusError **error) {
	g_return_val_if_fail(panel, FALSE);

	const InputMethodUiStatusMonitorFunctions& monitor_functions =
	IBUS_CHROMEOS_PANEL_SERVICE(panel)->monitor_functions;
	void* input_method_library =
	IBUS_CHROMEOS_PANEL_SERVICE(panel)->input_method_library;
	g_return_val_if_fail(monitor_functions.hide_auxiliary_text, FALSE);

	monitor_functions.hide_auxiliary_text(input_method_library);
	return TRUE;
	}

	// Handles IBus's \|HideLookupTable\| method call.
	// Calls \|hide_lookup_table\| in \|monitor_functions\|.
	gboolean ibus_chromeos_panel_service_hide_lookup_table(IBusPanelService *panel,
	IBusError **error) {
	g_return_val_if_fail(panel, FALSE);

	const InputMethodUiStatusMonitorFunctions& monitor_functions =
	IBUS_CHROMEOS_PANEL_SERVICE(panel)->monitor_functions;
	void* input_method_library =
	IBUS_CHROMEOS_PANEL_SERVICE(panel)->input_method_library;
	g_return_val_if_fail(monitor_functions.hide_lookup_table, FALSE);

	monitor_functions.hide_lookup_table(input_method_library);
	return TRUE;
	}

	// Handles IBus's \|RegisterProperties\| method call.
	// Just sends a signal to the language bar.
	gboolean ibus_chromeos_panel_service_register_properties(
	IBusPanelService* panel, IBusPropList* prop_list, IBusError** error) {
	g_return_val_if_fail(panel, FALSE);
	g_return_val_if_fail(prop_list, FALSE);

	IBusConnection* ibus_connection =
	IBUS_CHROMEOS_PANEL_SERVICE(panel)->ibus_connection;
	ibus_connection_send_signal(ibus_connection,
	kLanguageBarObjectPath,
	IBUS_INTERFACE_PANEL,
	"RegisterProperties",
	IBUS_TYPE_PROP_LIST, &prop_list,
	G_TYPE_INVALID);
	return TRUE;
	}

	// Handles IBus's \|UpdateAuxiliaryText\| method call.
	// Converts IBusText to a std::string, and calls \|update_auxiliary_text\| in
	// \|monitor_functions\|
	gboolean ibus_chromeos_panel_service_update_auxiliary_text(
	IBusPanelService *panel,
	IBusText *text,
	gboolean visible,
	IBusError **error) {
	g_return_val_if_fail(panel, FALSE);
	g_return_val_if_fail(text, FALSE);
	g_return_val_if_fail(text->text, FALSE);

	const InputMethodUiStatusMonitorFunctions& monitor_functions =
	IBUS_CHROMEOS_PANEL_SERVICE(panel)->monitor_functions;
	void* input_method_library =
	IBUS_CHROMEOS_PANEL_SERVICE(panel)->input_method_library;
	g_return_val_if_fail(monitor_functions.update_auxiliary_text, FALSE);

	// Convert IBusText to a std::string. IBusText is an attributed text,
	const std::string simple_text = text->text;
	monitor_functions.update_auxiliary_text(input_method_library,
	simple_text,
	visible == TRUE);
	return TRUE;
	}

	// Returns an string representation of \|table\| for debugging.
	std::string IBusLookupTableToString(IBusLookupTable* table) {
	std::stringstream stream;
	stream << "page_size: " << table->page_size << "\n";
	stream << "cursor_pos: " << table->cursor_pos << "\n";
	stream << "cursor_visible: " << table->cursor_visible << "\n";
	stream << "round: " << table->round << "\n";
	stream << "orientation: " << table->orientation << "\n";
	stream << "candidates:";
	for (int i = 0; ; i++) {
	IBusText *text = ibus_lookup_table_get_candidate(table, i);
	if (!text) {
	break;
	}
	stream << " " << text->text;
	}
	return stream.str();
	}

	// Handles IBus's \|UpdateLookupTable\| method call.
	// Creates an InputMethodLookupTable object and calls \|update_lookup_table\| in
	// \|monitor_functions\|
	gboolean ibus_chromeos_panel_service_update_lookup_table(
	IBusPanelService *panel,
	IBusLookupTable *table,
	gboolean visible,
	IBusError **error) {
	g_return_val_if_fail(panel, FALSE);
	g_return_val_if_fail(table, FALSE);

	const InputMethodUiStatusMonitorFunctions& monitor_functions =
	IBUS_CHROMEOS_PANEL_SERVICE(panel)->monitor_functions;
	void* input_method_library =
	IBUS_CHROMEOS_PANEL_SERVICE(panel)->input_method_library;
	g_return_val_if_fail(monitor_functions.update_lookup_table, FALSE);

	InputMethodLookupTable lookup_table;
	lookup_table.visible = (visible == TRUE);

	// Copy the orientation information.
	const gint orientation = ibus_lookup_table_get_orientation(table);
	if (orientation == IBUS_ORIENTATION_VERTICAL) {
	lookup_table.orientation = InputMethodLookupTable::kVertical;
	} else if (orientation == IBUS_ORIENTATION_HORIZONTAL) {
	lookup_table.orientation = InputMethodLookupTable::kHorizontal;
	}

	// Copy candidates to \|lookup_table\|.
	for (int i = 0; ; i++) {
	IBusText *text = ibus_lookup_table_get_candidate(table, i);
	if (!text) {
	break;
	}
	lookup_table.candidates.push_back(text->text);
	}

	lookup_table.cursor_absolute_index =
	ibus_lookup_table_get_cursor_pos(table);
	lookup_table.page_size = ibus_lookup_table_get_page_size(table);
	// Ensure that the page_size is non-zero to avoid div-by-zero error.
	if (lookup_table.page_size <= 0) {
	LOG(DFATAL) << "Invalid page size: " << lookup_table.page_size;
	lookup_table.page_size = 1;
	}

	monitor_functions.update_lookup_table(input_method_library, lookup_table);
	return TRUE;
	}

	// Handles IBus's \|UpdateProperty\| method call.
	// Just sends a signal to the language bar.
	gboolean ibus_chromeos_panel_service_update_property(
	IBusPanelService* panel, IBusProperty* prop, IBusError** error) {
	g_return_val_if_fail(panel, FALSE);
	g_return_val_if_fail(prop, FALSE);

	IBusConnection* ibus_connection =
	IBUS_CHROMEOS_PANEL_SERVICE(panel)->ibus_connection;
	ibus_connection_send_signal(ibus_connection,
	kLanguageBarObjectPath,
	IBUS_INTERFACE_PANEL,
	"UpdateProperty",
	IBUS_TYPE_PROPERTY, &prop,
	G_TYPE_INVALID);
	return TRUE;
	}

	// Handles IBus's \|StateChanged\| method call.
	// Just sends a signal to the language bar.
	gboolean ibus_chromeos_panel_service_state_changed(IBusPanelService *panel,
	IBusError **error) {
	g_return_val_if_fail(panel, FALSE);

	IBusConnection* ibus_connection =
	IBUS_CHROMEOS_PANEL_SERVICE(panel)->ibus_connection;
	// TODO(yusukes): Get rid of the dummy string. As of writing, the
	// language bar needs a dummy string parameter for some implementation
	// reason.
	static const char kDummy[] = "dummy";
	const char* dummy = kDummy;
	ibus_connection_send_signal(ibus_connection,
	kLanguageBarObjectPath,
	IBUS_INTERFACE_PANEL,
	"StateChanged",
	G_TYPE_STRING, &dummy,
	G_TYPE_INVALID);
	return TRUE;
	}

	// Handles IBus's \|SetCursorLocation\| method call.
	// Calls \|set_cursor_location\| in \|monitor_functions\|.
	gboolean ibus_chromeos_panel_service_set_cursor_location(
	IBusPanelService *panel,
	gint x,
	gint y,
	gint width,
	gint height,
	IBusError **error) {
	g_return_val_if_fail(panel, FALSE);

	const InputMethodUiStatusMonitorFunctions& monitor_functions =
	IBUS_CHROMEOS_PANEL_SERVICE(panel)->monitor_functions;
	void* input_method_library =
	IBUS_CHROMEOS_PANEL_SERVICE(panel)->input_method_library;
	g_return_val_if_fail(monitor_functions.set_cursor_location, FALSE);

	monitor_functions.set_cursor_location(input_method_library,
	x, y, width, height);
	return TRUE;
	}

	// Creates an IBusChromeOSPanelService. Returns as IBusPanelService for
	// convenience (i.e. it can be passed to ibus_panel_service_* functions
	// without cast).
	IBusPanelService* ibus_chromeos_panel_service_new(
	IBusConnection *ibus_connection,
	void* input_method_library,
	const InputMethodUiStatusMonitorFunctions& monitor_functions) {
	IBusPanelService* service = IBUS_PANEL_SERVICE(
	g_object_new(IBUS_TYPE_CHROMEOS_PANEL_SERVICE,
	"path", IBUS_PATH_PANEL,
	"connection", ibus_connection,
	NULL));

	// Set members specific to IBusChromeOSPanelService.
	IBUS_CHROMEOS_PANEL_SERVICE(service)->ibus_connection =
	ibus_connection;
	IBUS_CHROMEOS_PANEL_SERVICE(service)->input_method_library =
	input_method_library;
	IBUS_CHROMEOS_PANEL_SERVICE(service)->monitor_functions =
	monitor_functions;

	return service;
	}

	// Destroys the given IBusChromeOSPanelService object.
	void ibus_chromeos_panel_service_destroy(IBusObject* object) {
	DLOG(INFO) << "ibus_chromeos_panel_service_destroy";
	IBUS_OBJECT_CLASS(ibus_chromeos_panel_service_parent_class)
	->destroy(IBUS_OBJECT(object));
	}

	// Initializes the IBusChromeOSPanel class.
	void ibus_chromeos_panel_service_class_init(
	IBusChromeOSPanelServiceClass* klass) {
	IBusPanelServiceClass* panel_class =
	reinterpret_cast<IBusPanelServiceClass*>(klass);
	// Install member functions. Sorted in alphabetical order.
	panel_class->focus_in = ibus_chromeos_panel_service_focus_in;
	panel_class->focus_out = ibus_chromeos_panel_service_focus_out;
	panel_class->hide_auxiliary_text =
	ibus_chromeos_panel_service_hide_auxiliary_text;
	panel_class->hide_lookup_table =
	ibus_chromeos_panel_service_hide_lookup_table;
	panel_class->register_properties =
	ibus_chromeos_panel_service_register_properties;
	panel_class->set_cursor_location =
	ibus_chromeos_panel_service_set_cursor_location;
	panel_class->state_changed =
	ibus_chromeos_panel_service_state_changed;
	panel_class->update_auxiliary_text =
	ibus_chromeos_panel_service_update_auxiliary_text;
	panel_class->update_lookup_table =
	ibus_chromeos_panel_service_update_lookup_table;
	panel_class->update_property = ibus_chromeos_panel_service_update_property;

	// Set the destructor function.
	IBusObjectClass* object_class =
	reinterpret_cast<IBusObjectClass*>(klass);
	object_class->destroy = ibus_chromeos_panel_service_destroy;
	}

	// Initializes the given IBusChromeOSPanelService object.
	void ibus_chromeos_panel_service_init(IBusChromeOSPanelService* service) {
	service->input_method_library = NULL;
	service->ibus_connection = NULL;
	}

	} // namespace

	// A thin wrapper for IBusPanelService.
	class InputMethodUiStatusConnection {
	public:
	InputMethodUiStatusConnection(
	const InputMethodUiStatusMonitorFunctions& monitor_functions,
	void* input_method_library)
	: monitor_functions_(monitor_functions),
	input_method_library_(input_method_library),
	ibus_(NULL),
	ibus_panel_service_(NULL) {
	}

	~InputMethodUiStatusConnection() {
	// ibus_panel_service_ depends on ibus_, thus unref it first.
	if (ibus_panel_service_) {
	g_object_unref(ibus_panel_service_);
	}
	if (ibus_) {
	g_object_unref(ibus_);
	}
	}

	// Initializes the object. Returns true on success.
	bool Init() {
	// Initialize an IBus bus.
	ibus_init();
	ibus_ = ibus_bus_new();

	// Check the IBus connection status.
	if (!ibus_) {
	LOG(ERROR) << "ibus_bus_new() failed";
	return false;
	}
	if (!ibus_bus_is_connected(ibus_)) {
	LOG(ERROR) << "ibus_bus_is_connected() failed";
	return false;
	}

	// Request the object name.
	const int status = ibus_bus_request_name(ibus_, IBUS_SERVICE_PANEL, 0);
	if (status == 0) {
	LOG(ERROR) << "ibus_bus_request_name() failed";
	return false;
	}

	// Establish the connection to ibus-daemon. Note that the
	// ibus_connection object is owned by ibus_.
	IBusConnection* ibus_connection = ibus_bus_get_connection(ibus_);
	if (!ibus_connection) {
	LOG(ERROR) << "ibus_bus_get_connection() failed";
	return false;
	}

	// Create a ChromeOS's version of IBusPanelService.
	ibus_panel_service_ = ibus_chromeos_panel_service_new(ibus_connection,
	input_method_library_,
	monitor_functions_);
	if (!ibus_panel_service_) {
	LOG(ERROR) << "ibus_chromeos_panel_service_new() failed";
	return false;
	}

	return true;
	}

	IBusPanelService* ibus_panel_service() {
	return ibus_panel_service_;
	}

	private:
	InputMethodUiStatusMonitorFunctions monitor_functions_;
	void* input_method_library_;
	IBusBus* ibus_;
	IBusPanelService* ibus_panel_service_;
	};

	//
	// cros APIs
	//

	// The function will be bound to chromeos::MonitorInputMethodUiStatus with
	// dlsym() in load.cc so it needs to be in the C linkage, so the symbol
	// name does not get mangled.
	extern "C"
	InputMethodUiStatusConnection* ChromeOSMonitorInputMethodUiStatus(
	const InputMethodUiStatusMonitorFunctions& monitor_functions,
	void* input_method_library) {
	DLOG(INFO) << "MonitorInputMethodUiStatus";

	InputMethodUiStatusConnection* connection =
	new InputMethodUiStatusConnection(monitor_functions,
	input_method_library);
	if (!connection->Init()) {
	LOG(WARNING) << "Failed to Init() InputMethodUiStatusConnection. "
	<< "Returning NULL";
	delete connection;
	connection = NULL;
	}
	return connection;
	}

	extern "C"
	void ChromeOSDisconnectInputMethodUiStatus(
	InputMethodUiStatusConnection* connection) {
	DLOG(INFO) << "DisconnectInputMethodUiStatus";
	delete connection;
	}

	extern "C"
	void ChromeOSNotifyCandidateClicked(InputMethodUiStatusConnection* connection,
	int index, int button, int flags) {
	DLOG(INFO) << "NotifyCandidateClicked";
	DCHECK(connection);
	if (connection) {
	ibus_panel_service_candidate_clicked(connection->ibus_panel_service(),
	index,
	button,
	flags);
	}
	}

	} // namespace chromeos