chrome/browser/chromeos/input_method/ refactoring [part 6 of 6]

chrome/browser/chromeos/input_method/ibus_controller_impl.cc

Index: chrome/browser/chromeos/input_method/ibus_controller_impl.cc
diff --git a/chrome/browser/chromeos/input_method/ibus_controller_impl.cc b/chrome/browser/chromeos/input_method/ibus_controller_impl.cc
new file mode 100644
index 0000000000000000000000000000000000000000..bfad07ba1829cb658d27053cb8ee13506b44bea7
--- /dev/null
+++ b/chrome/browser/chromeos/input_method/ibus_controller_impl.cc
@@ -0,0 +1,977 @@
+// Copyright (c) 2012 The Chromium 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 "chrome/browser/chromeos/input_method/ibus_controller_impl.h"
+
+#include <algorithm>  // for std::reverse.
+#include <cstdio>
+#include <cstring>  // for std::strcmp.
+#include <set>
+#include <sstream>
+#include <stack>
+#include <utility>
+
+#include "base/memory/scoped_ptr.h"
+#include "base/stringprintf.h"
+#include "base/string_split.h"
+#include "chrome/browser/chromeos/input_method/input_method_config.h"
+#include "chrome/browser/chromeos/input_method/input_method_property.h"
+#include "chrome/browser/chromeos/input_method/input_method_util.h"
+
+// TODO(nona): Remove libibus dependency from this file. Then, write unit tests
+// for all functions in this file. crbug.com/26334
+#if defined(HAVE_IBUS)
+#include <ibus.h>
+#endif
+
+namespace {
+
+// Finds a property which has |new_prop.key| from |prop_list|, and replaces the
+// property with |new_prop|. Returns true if such a property is found.
+bool FindAndUpdateProperty(
+    const chromeos::input_method::InputMethodProperty& new_prop,
+    chromeos::input_method::InputMethodPropertyList* prop_list) {
+  for (size_t i = 0; i < prop_list->size(); ++i) {
+    chromeos::input_method::InputMethodProperty& prop = prop_list->at(i);
+    if (prop.key == new_prop.key) {
+      const int saved_id = prop.selection_item_id;
+      // Update the list except the radio id. As written in
+      // chromeos_input_method.h, |prop.selection_item_id| is dummy.
+      prop = new_prop;
+      prop.selection_item_id = saved_id;
+      return true;
+    }
+  }
+  return false;
+}
+
+}  // namespace
+
+namespace chromeos {
+namespace input_method {
+
+#if defined(HAVE_IBUS)
+const char kPanelObjectKey[] = "panel-object";
+
+namespace {
+
+const char* Or(const char* str1, const char* str2) {
+  return str1 ? str1 : str2;
+}
+
+// Returns true if |key| is blacklisted.
+bool PropertyKeyIsBlacklisted(const char* key) {
+  // The list of input method property keys that we don't handle.
+  static const char* kInputMethodPropertyKeysBlacklist[] = {
+    "setup",  // used in ibus-m17n.
+    "status",  // used in ibus-m17n.
+  };
+  for (size_t i = 0; i < arraysize(kInputMethodPropertyKeysBlacklist); ++i) {
+    if (!std::strcmp(key, kInputMethodPropertyKeysBlacklist[i]))
+      return true;
+  }
+  return false;
+}
+
+// Returns IBusInputContext for |input_context_path|. NULL on errors.
+IBusInputContext* GetInputContext(const std::string& input_context_path,
+                                  IBusBus* ibus) {
+  GDBusConnection* connection = ibus_bus_get_connection(ibus);
+  if (!connection) {
+    LOG(ERROR) << "IBusConnection is null";
+    return NULL;
+  }
+  // This function does not issue an IBus IPC.
+  IBusInputContext* context = ibus_input_context_get_input_context(
+      input_context_path.c_str(), connection);
+  if (!context)
+    LOG(ERROR) << "IBusInputContext is null: " << input_context_path;
+  return context;
+}
+
+// Returns true if |prop| has children.
+bool PropertyHasChildren(IBusProperty* prop) {
+  return prop && ibus_property_get_sub_props(prop) &&
+      ibus_prop_list_get(ibus_property_get_sub_props(prop), 0);
+}
+
+// This function is called by and FlattenProperty() and converts IBus
+// representation of a property, |ibus_prop|, to our own and push_back the
+// result to |out_prop_list|. This function returns true on success, and
+// returns false if sanity checks for |ibus_prop| fail.
+bool ConvertProperty(IBusProperty* ibus_prop,
+                     int selection_item_id,
+                     InputMethodPropertyList* out_prop_list) {
+  DCHECK(ibus_prop);
+  DCHECK(out_prop_list);
+
+  const IBusPropType type = ibus_property_get_prop_type(ibus_prop);
+  const IBusPropState state = ibus_property_get_state(ibus_prop);
+  const IBusText* tooltip = ibus_property_get_tooltip(ibus_prop);
+  const IBusText* label = ibus_property_get_label(ibus_prop);
+  const gchar* key = ibus_property_get_key(ibus_prop);
+  DCHECK(key);
+
+  // Sanity checks.
+  const bool has_sub_props = PropertyHasChildren(ibus_prop);
+  if (has_sub_props && (type != PROP_TYPE_MENU)) {
+    LOG(ERROR) << "The property has sub properties, "
+               << "but the type of the property is not PROP_TYPE_MENU";
+    return false;
+  }
+  if ((!has_sub_props) && (type == PROP_TYPE_MENU)) {
+    // This is usually not an error. ibus-daemon sometimes sends empty props.
+    VLOG(1) << "Property list is empty";
+    return false;
+  }
+  if (type == PROP_TYPE_SEPARATOR || type == PROP_TYPE_MENU) {
+    // This is not an error, but we don't push an item for these types.
+    return true;
+  }
+
+  const bool is_selection_item = (type == PROP_TYPE_RADIO);
+  selection_item_id = is_selection_item ?
+      selection_item_id : InputMethodProperty::kInvalidSelectionItemId;
+
+  bool is_selection_item_checked = false;
+  if (state == PROP_STATE_INCONSISTENT) {
+    LOG(WARNING) << "The property is in PROP_STATE_INCONSISTENT, "
+                 << "which is not supported.";
+  } else if ((!is_selection_item) && (state == PROP_STATE_CHECKED)) {
+    LOG(WARNING) << "PROP_STATE_CHECKED is meaningful only if the type is "
+                 << "PROP_TYPE_RADIO.";
+  } else {
+    is_selection_item_checked = (state == PROP_STATE_CHECKED);
+  }
+
+  if (!key)
+    LOG(ERROR) << "key is NULL";
+  if (tooltip && !tooltip->text) {
+    LOG(ERROR) << "tooltip is NOT NULL, but tooltip->text IS NULL: key="
+               << Or(key, "");
+  }
+  if (label && !label->text) {
+    LOG(ERROR) << "label is NOT NULL, but label->text IS NULL: key="
+               << Or(key, "");
+  }
+
+  // This label will be localized later.
+  // See chrome/browser/chromeos/input_method/input_method_util.cc.
+  std::string label_to_use = (tooltip && tooltip->text) ? tooltip->text : "";
+  if (label_to_use.empty()) {
+    // Usually tooltips are more descriptive than labels.
+    label_to_use = (label && label->text) ? label->text : "";
+  }
+  if (label_to_use.empty()) {
+    LOG(ERROR) << "The tooltip and label are both empty. Use " << key;
+    label_to_use = Or(key, "");
+  }
+
+  out_prop_list->push_back(InputMethodProperty(key,
+                                               label_to_use,
+                                               is_selection_item,
+                                               is_selection_item_checked,
+                                               selection_item_id));
+  return true;
+}
+
+// Converts |ibus_prop| to |out_prop_list|. Please note that |ibus_prop|
+// may or may not have children. See the comment for FlattenPropertyList
+// for details. Returns true if no error is found.
+bool FlattenProperty(IBusProperty* ibus_prop,
+                     InputMethodPropertyList* out_prop_list) {
+  DCHECK(ibus_prop);
+  DCHECK(out_prop_list);
+
+  int selection_item_id = -1;
+  std::stack<std::pair<IBusProperty*, int> > prop_stack;
+  prop_stack.push(std::make_pair(ibus_prop, selection_item_id));
+
+  while (!prop_stack.empty()) {
+    IBusProperty* prop = prop_stack.top().first;
+    const gchar* key = ibus_property_get_key(prop);
+    const int current_selection_item_id = prop_stack.top().second;
+    prop_stack.pop();
+
+    // Filter out unnecessary properties.
+    if (PropertyKeyIsBlacklisted(key))
+      continue;
+
+    // Convert |prop| to InputMethodProperty and push it to |out_prop_list|.
+    if (!ConvertProperty(prop, current_selection_item_id, out_prop_list))
+      return false;
+
+    // Process childrens iteratively (if any). Push all sub properties to the
+    // stack.
+    if (PropertyHasChildren(prop)) {
+      ++selection_item_id;
+      for (int i = 0;; ++i) {
+        IBusProperty* sub_prop =
+            ibus_prop_list_get(ibus_property_get_sub_props(prop), i);
+        if (!sub_prop)
+          break;
+        prop_stack.push(std::make_pair(sub_prop, selection_item_id));
+      }
+      ++selection_item_id;
+    }
+  }
+  std::reverse(out_prop_list->begin(), out_prop_list->end());
+
+  return true;
+}
+
+// Converts IBus representation of a property list, |ibus_prop_list| to our
+// own. This function also flatten the original list (actually it's a tree).
+// Returns true if no error is found. The conversion to our own type is
+// necessary since our language switcher in Chrome tree don't (or can't) know
+// IBus types. Here is an example:
+//
+// ======================================================================
+// Input:
+//
+// --- Item-1
+//  |- Item-2
+//  |- SubMenuRoot --- Item-3-1
+//  |               |- Item-3-2
+//  |               |- Item-3-3
+//  |- Item-4
+//
+// (Note: Item-3-X is a selection item since they're on a sub menu.)
+//
+// Output:
+//
+// Item-1, Item-2, Item-3-1, Item-3-2, Item-3-3, Item-4
+// (Note: SubMenuRoot does not appear in the output.)
+// ======================================================================
+bool FlattenPropertyList(IBusPropList* ibus_prop_list,
+                         InputMethodPropertyList* out_prop_list) {
+  DCHECK(ibus_prop_list);
+  DCHECK(out_prop_list);
+
+  IBusProperty* fake_root_prop = ibus_property_new("Dummy.Key",
+                                                   PROP_TYPE_MENU,
+                                                   NULL, /* label */
+                                                   "", /* icon */
+                                                   NULL, /* tooltip */
+                                                   FALSE, /* sensitive */
+                                                   FALSE, /* visible */
+                                                   PROP_STATE_UNCHECKED,
+                                                   ibus_prop_list);
+  g_return_val_if_fail(fake_root_prop, false);
+  // Increase the ref count so it won't get deleted when |fake_root_prop|
+  // is deleted.
+  g_object_ref(ibus_prop_list);
+  const bool result = FlattenProperty(fake_root_prop, out_prop_list);
+  g_object_unref(fake_root_prop);
+
+  return result;
+}
+
+// Debug print function.
+const char* PropTypeToString(int prop_type) {
+  switch (static_cast<IBusPropType>(prop_type)) {
+    case PROP_TYPE_NORMAL:
+      return "NORMAL";
+    case PROP_TYPE_TOGGLE:
+      return "TOGGLE";
+    case PROP_TYPE_RADIO:
+      return "RADIO";
+    case PROP_TYPE_MENU:
+      return "MENU";
+    case PROP_TYPE_SEPARATOR:
+      return "SEPARATOR";
+  }
+  return "UNKNOWN";
+}
+
+// Debug print function.
+const char* PropStateToString(int prop_state) {
+  switch (static_cast<IBusPropState>(prop_state)) {
+    case PROP_STATE_UNCHECKED:
+      return "UNCHECKED";
+    case PROP_STATE_CHECKED:
+      return "CHECKED";
+    case PROP_STATE_INCONSISTENT:
+      return "INCONSISTENT";
+  }
+  return "UNKNOWN";
+}
+
+// Debug print function.
+std::string Spacer(int n) {
+  return std::string(n, ' ');
+}
+
+// Debug print function.
+std::string PrintProp(IBusProperty *prop, int tree_level) {
+  std::string PrintPropList(IBusPropList *prop_list, int tree_level);
+
+  if (!prop)
+    return "";
+
+  const IBusPropType type = ibus_property_get_prop_type(prop);
+  const IBusPropState state = ibus_property_get_state(prop);
+  const IBusText* tooltip = ibus_property_get_tooltip(prop);
+  const IBusText* label = ibus_property_get_label(prop);
+  const gchar* key = ibus_property_get_key(prop);
+
+  std::stringstream stream;
+  stream << Spacer(tree_level) << "=========================" << std::endl;
+  stream << Spacer(tree_level) << "key: " << Or(key, "<none>")
+         << std::endl;
+  stream << Spacer(tree_level) << "label: "
+         << ((label && label->text) ? label->text : "<none>")
+         << std::endl;
+  stream << Spacer(tree_level) << "tooptip: "
+         << ((tooltip && tooltip->text)
+             ? tooltip->text : "<none>") << std::endl;
+  stream << Spacer(tree_level) << "sensitive: "
+         << (ibus_property_get_sensitive(prop) ? "YES" : "NO") << std::endl;
+  stream << Spacer(tree_level) << "visible: "
+         << (ibus_property_get_visible(prop) ? "YES" : "NO") << std::endl;
+  stream << Spacer(tree_level) << "type: " << PropTypeToString(type)
+         << std::endl;
+  stream << Spacer(tree_level) << "state: " << PropStateToString(state)
+         << std::endl;
+  stream << Spacer(tree_level) << "sub_props: "
+         << (PropertyHasChildren(prop) ? "" : "<none>") << std::endl;
+  stream << PrintPropList(ibus_property_get_sub_props(prop), tree_level + 1);
+  stream << Spacer(tree_level) << "=========================" << std::endl;
+
+  return stream.str();
+}
+
+// Debug print function.
+std::string PrintPropList(IBusPropList *prop_list, int tree_level) {
+  if (!prop_list)
+    return "";
+
+  std::stringstream stream;
+  for (int i = 0;; ++i) {
+    IBusProperty* prop = ibus_prop_list_get(prop_list, i);
+    if (!prop)
+      break;
+    stream << PrintProp(prop, tree_level);
+  }
+  return stream.str();
+}
+
+}  // namespace
+
+IBusControllerImpl::IBusControllerImpl()
+    : ibus_(NULL),
+      ibus_config_(NULL),
+      should_launch_daemon_(false),
+      process_handle_(base::kNullProcessHandle) {
+}
+
+IBusControllerImpl::~IBusControllerImpl() {
+  // Disconnect signals so the handler functions will not be called with
+  // |this| which is already freed.
+  if (ibus_) {
+    g_signal_handlers_disconnect_by_func(
+        ibus_,
+        reinterpret_cast<gpointer>(G_CALLBACK(BusConnectedThunk)),
+        this);
+    g_signal_handlers_disconnect_by_func(
+        ibus_,
+        reinterpret_cast<gpointer>(G_CALLBACK(BusDisconnectedThunk)),
+        this);
+    g_signal_handlers_disconnect_by_func(
+        ibus_,
+        reinterpret_cast<gpointer>(G_CALLBACK(BusNameOwnerChangedThunk)),
+        this);
+
+    // Disconnect signals for the panel service as well.
+    IBusPanelService* ibus_panel_service = IBUS_PANEL_SERVICE(
+        g_object_get_data(G_OBJECT(ibus_), kPanelObjectKey));
+    if (ibus_panel_service) {
+      g_signal_handlers_disconnect_by_func(
+          ibus_panel_service,
+          reinterpret_cast<gpointer>(G_CALLBACK(FocusInThunk)),
+          this);
+      g_signal_handlers_disconnect_by_func(
+          ibus_panel_service,
+          reinterpret_cast<gpointer>(G_CALLBACK(RegisterPropertiesThunk)),
+          this);
+      g_signal_handlers_disconnect_by_func(
+          ibus_panel_service,
+          reinterpret_cast<gpointer>(G_CALLBACK(UpdatePropertyThunk)),
+          this);
+    }
+  }
+}
+
+bool IBusControllerImpl::Start() {
+  MaybeInitializeIBusBus();
+  should_launch_daemon_ = true;
+  if (IBusConnectionsAreAlive())
+    return true;
+  return MaybeLaunchIBusDaemon();
+}
+
+bool IBusControllerImpl::Stop() {
+  if (IBusConnectionsAreAlive()) {
+    // Ask IBus to exit *asynchronously*.
+    ibus_bus_exit_async(ibus_,
+                        FALSE  /* do not restart */,
+                        -1  /* timeout */,
+                        NULL  /* cancellable */,
+                        NULL  /* callback */,
+                        NULL  /* user_data */);
+    if (ibus_config_) {
+      // Release |ibus_config_| unconditionally to make sure next
+      // IBusConnectionsAreAlive() call will return false.
+      g_object_unref(ibus_config_);
+      ibus_config_ = NULL;
+    }
+  } else if (process_handle_ != base::kNullProcessHandle) {
+    base::KillProcess(process_handle_, -1, false /* wait */);
+    LOG(ERROR) << "Killing ibus-daemon. PID="
+               << base::GetProcId(process_handle_);
+  } else {
+    // The daemon hasn't been started yet.
+  }
+
+  process_handle_ = base::kNullProcessHandle;
+  should_launch_daemon_ = false;
+  return true;
+}
+
+bool IBusControllerImpl::ChangeInputMethod(const std::string& id) {
+  DCHECK(should_launch_daemon_);
+
+  // Sanity checks.
+  DCHECK(!InputMethodUtil::IsKeyboardLayout(id));
+  if (!whitelist_.InputMethodIdIsWhitelisted(id) &&
+      !InputMethodUtil::IsExtensionInputMethod(id))
+    return false;
+
+  // Clear input method properties unconditionally if |id| is not equal to
+  // |current_input_method_id_|.
+  //
+  // When switching to another input method and no text area is focused,
+  // RegisterProperties signal for the new input method will NOT be sent
+  // until a text area is focused. Therefore, we have to clear the old input
+  // method properties here to keep the input method switcher status
+  // consistent.
+  //
+  // When |id| and |current_input_method_id_| are the same, the properties
+  // shouldn't be cleared. If we do that, something wrong happens in step #4
+  // below:
+  // 1. Enable "xkb:us::eng" and "mozc". Switch to "mozc".
+  // 2. Focus Omnibox. IME properties for mozc are sent to Chrome.
+  // 3. Switch to "xkb:us::eng". No function in this file is called.
+  // 4. Switch back to "mozc". ChangeInputMethod("mozc") is called, but it's
+  //    basically NOP since ibus-daemon's current IME is already "mozc".
+  //    IME properties are not sent to Chrome for the same reason.
+  if (id != current_input_method_id_)
+    RegisterProperties(NULL, NULL);
+
+  current_input_method_id_ = id;
+
+  if (!IBusConnectionsAreAlive()) {
+    LOG(INFO) << "ChangeInputMethod: IBus connection is not alive (yet).";
+    // |id| will become usable shortly since Start() has already been called.
+    // Just return true.
+  } else {
+    SendChangeInputMethodRequest(id);
+  }
+
+  return true;
+}
+
+bool IBusControllerImpl::ActivateInputMethodProperty(const std::string& key) {
+  if (!IBusConnectionsAreAlive()) {
+    LOG(ERROR) << "ActivateInputMethodProperty: IBus connection is not alive";
+    return false;
+  }
+  if (current_input_context_path_.empty()) {
+    LOG(ERROR) << "Input context is unknown";
+    return false;
+  }
+
+  // The third parameter of ibus_input_context_property_activate() has to be
+  // true when the |key| points to a radio button. false otherwise.
+  bool is_radio = true;
+  size_t i;
+  for (i = 0; i < current_property_list_.size(); ++i) {
+    if (current_property_list_[i].key == key) {
+      is_radio = current_property_list_[i].is_selection_item;
+      break;
+    }
+  }
+  if (i == current_property_list_.size()) {
+    LOG(ERROR) << "ActivateInputMethodProperty: unknown key: " << key;
+    return false;
+  }
+
+  IBusInputContext* context =
+      GetInputContext(current_input_context_path_, ibus_);
+  if (!context)
+    return false;
+
+  // Activate the property *asynchronously*.
+  ibus_input_context_property_activate(context, key.c_str(), is_radio);
+
+  // We don't have to call ibus_proxy_destroy(context) explicitly here,
+  // i.e. we can just call g_object_unref(context), since g_object_unref can
+  // trigger both dispose, which is overridden by src/ibusproxy.c, and
+  // finalize functions. For details, see
+  // http://library.gnome.org/devel/gobject/stable/gobject-memory.html
+  g_object_unref(context);
+
+  return true;
+}
+
+#if defined(USE_VIRTUAL_KEYBOARD)
+// IBusController override.
+void IBusControllerImpl::SendHandwritingStroke(
+    const HandwritingStroke& stroke) {
+  if (stroke.size() < 2) {
+    LOG(WARNING) << "Empty stroke data or a single dot is passed.";
+    return;
+  }
+
+  IBusInputContext* context =
+      GetInputContext(current_input_context_path_, ibus_);
+  if (!context)
+    return;
+
+  const size_t raw_stroke_size = stroke.size() * 2;
+  scoped_array<double> raw_stroke(new double[raw_stroke_size]);
+  for (size_t n = 0; n < stroke.size(); ++n) {
+    raw_stroke[n * 2] = stroke[n].first;  // x
+    raw_stroke[n * 2 + 1] = stroke[n].second;  // y
+  }
+  ibus_input_context_process_hand_writing_event(
+      context, raw_stroke.get(), raw_stroke_size);
+  g_object_unref(context);
+}
+
+// IBusController override.
+void IBusControllerImpl::CancelHandwriting(int n_strokes) {
+  IBusInputContext* context =
+      GetInputContext(current_input_context_path_, ibus_);
+  if (!context)
+    return;
+  ibus_input_context_cancel_hand_writing(context, n_strokes);
+  g_object_unref(context);
+}
+#endif
+
+bool IBusControllerImpl::IBusConnectionsAreAlive() {
+  return (process_handle_ != base::kNullProcessHandle) &&
+      ibus_ && ibus_bus_is_connected(ibus_) && ibus_config_;
+}
+
+void IBusControllerImpl::MaybeRestoreConnections() {
+  if (IBusConnectionsAreAlive())
+    return;
+  MaybeRestoreIBusConfig();
+  if (IBusConnectionsAreAlive()) {
+    LOG(INFO) << "ibus-daemon and ibus-memconf processes are ready.";
+    ConnectPanelServiceSignals();
+    SendAllInputMethodConfigs();
+    if (!current_input_method_id_.empty())
+      SendChangeInputMethodRequest(current_input_method_id_);
+  }
+}
+
+void IBusControllerImpl::MaybeInitializeIBusBus() {
+  if (ibus_)
+    return;
+
+  ibus_init();
+  // Establish IBus connection between ibus-daemon to change the current input
+  // method engine, properties, and so on.
+  ibus_ = ibus_bus_new();
+  DCHECK(ibus_);
+
+  // Register callback functions for IBusBus signals.
+  ConnectBusSignals();
+
+  // Ask libibus to watch the NameOwnerChanged signal *asynchronously*.
+  ibus_bus_set_watch_dbus_signal(ibus_, TRUE);
+
+  if (ibus_bus_is_connected(ibus_)) {
+    LOG(ERROR) << "IBus connection is ready: ibus-daemon is already running?";
+    BusConnected(ibus_);
+  }
+}
+
+void IBusControllerImpl::MaybeRestoreIBusConfig() {
+  if (!ibus_)
+    return;
+
+  // Destroy the current |ibus_config_| object. No-op if it's NULL.
+  MaybeDestroyIBusConfig();
+
+  if (ibus_config_)
+    return;
+
+  GDBusConnection* ibus_connection = ibus_bus_get_connection(ibus_);
+  if (!ibus_connection) {
+    VLOG(1) << "Couldn't create an ibus config object since "
+            << "IBus connection is not ready.";
+    return;
+  }
+
+  const gboolean disconnected
+      = g_dbus_connection_is_closed(ibus_connection);
+  if (disconnected) {
+    // |ibus_| object is not NULL, but the connection between ibus-daemon
+    // is not yet established. In this case, we don't create |ibus_config_|
+    // object.
+    LOG(ERROR) << "Couldn't create an ibus config object since "
+               << "IBus connection is closed.";
+    return;
+  }
+  // If memconf is not successfully started yet, ibus_config_new() will
+  // return NULL. Otherwise, it returns a transfer-none and non-floating
+  // object. ibus_config_new() sometimes issues a D-Bus *synchronous* IPC
+  // to check if the org.freedesktop.IBus.Config service is available.
+  ibus_config_ = ibus_config_new(ibus_connection,
+                                 NULL /* do not cancel the operation */,
+                                 NULL /* do not get error information */);
+  if (!ibus_config_) {
+    LOG(ERROR) << "ibus_config_new() failed. ibus-memconf is not ready?";
+    return;
+  }
+
+  // TODO(yusukes): g_object_weak_ref might be better since it allows
+  // libcros to detect the delivery of the "destroy" glib signal the
+  // |ibus_config_| object.
+  g_object_ref(ibus_config_);
+  VLOG(1) << "ibus_config_ is ready.";
+}
+
+void IBusControllerImpl::MaybeDestroyIBusConfig() {
+  if (!ibus_) {
+    LOG(ERROR) << "MaybeDestroyIBusConfig: ibus_ is NULL";
+    return;
+  }
+  if (ibus_config_ && !ibus_bus_is_connected(ibus_)) {
+    g_object_unref(ibus_config_);
+    ibus_config_ = NULL;
+  }
+}
+
+void IBusControllerImpl::SendChangeInputMethodRequest(const std::string& id) {
+  // Change the global engine *asynchronously*.
+  ibus_bus_set_global_engine_async(ibus_,
+                                   id.c_str(),
+                                   -1,  // use the default ibus timeout
+                                   NULL,  // cancellable
+                                   NULL,  // callback
+                                   NULL);  // user_data
+}
+
+void IBusControllerImpl::SendAllInputMethodConfigs() {
+  DCHECK(IBusConnectionsAreAlive());
+
+  InputMethodConfigRequests::const_iterator iter =
+      current_config_values_.begin();
+  for (; iter != current_config_values_.end(); ++iter) {
+    SetInputMethodConfigInternal(iter->first, iter->second);
+  }
+}
+
+bool IBusControllerImpl::SetInputMethodConfigInternal(
+    const ConfigKeyType& key,
+    const InputMethodConfigValue& value) {
+  if (!IBusConnectionsAreAlive())
+    return true;
+
+  // Convert the type of |value| from our structure to GVariant.
+  GVariant* variant = NULL;
+  switch (value.type) {
+    case InputMethodConfigValue::kValueTypeString:
+      variant = g_variant_new_string(value.string_value.c_str());
+      break;
+    case InputMethodConfigValue::kValueTypeInt:
+      variant = g_variant_new_int32(value.int_value);
+      break;
+    case InputMethodConfigValue::kValueTypeBool:
+      variant = g_variant_new_boolean(value.bool_value);
+      break;
+    case InputMethodConfigValue::kValueTypeStringList:
+      GVariantBuilder variant_builder;
+      g_variant_builder_init(&variant_builder, G_VARIANT_TYPE("as"));
+      const size_t size = value.string_list_value.size();
+      // |size| could be 0 for some special configurations such as IBus hotkeys.
+      for (size_t i = 0; i < size; ++i) {
+        g_variant_builder_add(&variant_builder,
+                              "s",
+                              value.string_list_value[i].c_str());
+      }
+      variant = g_variant_builder_end(&variant_builder);
+      break;
+  }
+
+  if (!variant) {
+    LOG(ERROR) << "SendInputMethodConfig: unknown value.type";
+    return false;
+  }
+  DCHECK(g_variant_is_floating(variant));
+  DCHECK(ibus_config_);
+
+  // Set an ibus configuration value *asynchronously*.
+  ibus_config_set_value_async(ibus_config_,
+                              key.first.c_str(),
+                              key.second.c_str(),
+                              variant,
+                              -1,  // use the default ibus timeout
+                              NULL,  // cancellable
+                              SetInputMethodConfigCallback,
+                              g_object_ref(ibus_config_));
+
+  // Since |variant| is floating, ibus_config_set_value_async consumes
+  // (takes ownership of) the variable.
+  return true;
+}
+
+void IBusControllerImpl::ConnectBusSignals() {
+  if (!ibus_)
+    return;
+
+  // We use g_signal_connect_after here since the callback should be called
+  // *after* the IBusBusDisconnectedCallback in chromeos_input_method_ui.cc
+  // is called. chromeos_input_method_ui.cc attaches the panel service object
+  // to |ibus_|, and the callback in this file use the attached object.
+  g_signal_connect_after(ibus_,
+                         "connected",
+                         G_CALLBACK(BusConnectedThunk),
+                         this);
+
+  g_signal_connect(ibus_,
+                   "disconnected",
+                   G_CALLBACK(BusDisconnectedThunk),
+                   this);
+
+  g_signal_connect(ibus_,
+                   "name-owner-changed",
+                   G_CALLBACK(BusNameOwnerChangedThunk),
+                   this);
+}
+
+void IBusControllerImpl::ConnectPanelServiceSignals() {
+  if (!ibus_)
+    return;
+
+  IBusPanelService* ibus_panel_service = IBUS_PANEL_SERVICE(
+      g_object_get_data(G_OBJECT(ibus_), kPanelObjectKey));
+  if (!ibus_panel_service) {
+    LOG(ERROR) << "IBusPanelService is NOT available.";
+    return;
+  }
+  // We don't _ref() or _weak_ref() the panel service object, since we're not
+  // interested in the life time of the object.
+
+  g_signal_connect(ibus_panel_service,
+                   "focus-in",
+                   G_CALLBACK(FocusInThunk),
+                   this);
+  g_signal_connect(ibus_panel_service,
+                   "register-properties",
+                   G_CALLBACK(RegisterPropertiesThunk),
+                   this);
+  g_signal_connect(ibus_panel_service,
+                   "update-property",
+                   G_CALLBACK(UpdatePropertyThunk),
+                   this);
+}
+
+void IBusControllerImpl::BusConnected(IBusBus* bus) {
+  LOG(INFO) << "IBus connection is established.";
+  MaybeRestoreConnections();
+}
+
+void IBusControllerImpl::BusDisconnected(IBusBus* bus) {
+  LOG(INFO) << "IBus connection is terminated.";
+  // ibus-daemon might be terminated. Since |ibus_| object will automatically
+  // connect to the daemon if it restarts, we don't have to set NULL on ibus_.
+  // Call MaybeDestroyIBusConfig() to set |ibus_config_| to NULL temporarily.
+  MaybeDestroyIBusConfig();
+}
+
+void IBusControllerImpl::BusNameOwnerChanged(IBusBus* bus,
+                                             const gchar* name,
+                                             const gchar* old_name,
+                                             const gchar* new_name) {
+  DCHECK(name);
+  DCHECK(old_name);
+  DCHECK(new_name);
+
+  if (name != std::string("org.freedesktop.IBus.Config")) {
+    // Not a signal for ibus-memconf.
+    return;
+  }
+
+  const std::string empty_string;
+  if (old_name != empty_string || new_name == empty_string) {
+    // ibus-memconf died?
+    LOG(WARNING) << "Unexpected name owner change: name=" << name
+                 << ", old_name=" << old_name << ", new_name=" << new_name;
+    // TODO(yusukes): it might be nice to set |ibus_config_| to NULL and call
+    // a new callback function like OnDisconnect() here to allow Chrome to
+    // recover all input method configurations when ibus-memconf is
+    // automatically restarted by ibus-daemon. Though ibus-memconf is pretty
+    // stable and unlikely crashes.
+    return;
+  }
+  VLOG(1) << "IBus config daemon is started. Recovering ibus_config_";
+
+  // Try to recover |ibus_config_|. If the |ibus_config_| object is
+  // successfully created, |OnConnectionChange| will be called to
+  // notify Chrome that IBus is ready.
+  MaybeRestoreConnections();
+}
+
+void IBusControllerImpl::FocusIn(IBusPanelService* panel,
+                                 const gchar* input_context_path) {
+  if (!input_context_path)
+    LOG(ERROR) << "NULL context passed";
+  else
+    VLOG(1) << "FocusIn: " << input_context_path;
+  // Remember the current ic path.
+  current_input_context_path_ = Or(input_context_path, "");
+}
+
+void IBusControllerImpl::RegisterProperties(IBusPanelService* panel,
+                                            IBusPropList* ibus_prop_list) {
+  // Note: |panel| can be NULL. See ChangeInputMethod().
+  VLOG(1) << "RegisterProperties" << (ibus_prop_list ? "" : " (clear)");
+
+  current_property_list_.clear();
+  if (ibus_prop_list) {
+    // You can call
+    //   LOG(INFO) << "\n" << PrintPropList(ibus_prop_list, 0);
+    // here to dump |ibus_prop_list|.
+    if (!FlattenPropertyList(ibus_prop_list, &current_property_list_)) {
+      // Clear properties on errors.
+      current_property_list_.clear();
+    }
+  }
+  FOR_EACH_OBSERVER(Observer, observers_, PropertyChanged());
+}
+
+void IBusControllerImpl::UpdateProperty(IBusPanelService* panel,
+                                        IBusProperty* ibus_prop) {
+  VLOG(1) << "UpdateProperty";
+  DCHECK(ibus_prop);
+
+  // You can call
+  //   LOG(INFO) << "\n" << PrintProp(ibus_prop, 0);
+  // here to dump |ibus_prop|.
+
+  InputMethodPropertyList prop_list;  // our representation.
+  if (!FlattenProperty(ibus_prop, &prop_list)) {
+    // Don't update the UI on errors.
+    LOG(ERROR) << "Malformed properties are detected";
+    return;
+  }
+
+  // Notify the change.
+  if (!prop_list.empty()) {
+    for (size_t i = 0; i < prop_list.size(); ++i) {
+      FindAndUpdateProperty(prop_list[i], &current_property_list_);
+    }
+    FOR_EACH_OBSERVER(Observer, observers_, PropertyChanged());
+  }
+}
+
+bool IBusControllerImpl::MaybeLaunchIBusDaemon() {
+  static const char kIBusDaemonPath[] = "/usr/bin/ibus-daemon";
+
+  if (process_handle_ != base::kNullProcessHandle) {
+    LOG(ERROR) << "MaybeLaunchIBusDaemon: ibus-daemon is already running.";
+    return false;
+  }
+  if (!should_launch_daemon_)
+    return false;
+
+  // TODO(zork): Send output to /var/log/ibus.log
+  const std::string ibus_daemon_command_line =
+      base::StringPrintf("%s --panel=disable --cache=none --restart --replace",
+                         kIBusDaemonPath);
+  if (!LaunchProcess(ibus_daemon_command_line,
+                     &process_handle_,
+                     reinterpret_cast<GChildWatchFunc>(OnIBusDaemonExit))) {
+    LOG(ERROR) << "Failed to launch " << ibus_daemon_command_line;
+    return false;
+  }
+  return true;
+}
+
+bool IBusControllerImpl::LaunchProcess(const std::string& command_line,
+                                       base::ProcessHandle* process_handle,
+                                       GChildWatchFunc watch_func) {
+  std::vector<std::string> argv;
+  base::ProcessHandle handle = base::kNullProcessHandle;
+
+  base::SplitString(command_line, ' ', &argv);
+
+  if (!base::LaunchProcess(argv, base::LaunchOptions(), &handle)) {
+    LOG(ERROR) << "Could not launch: " << command_line;
+    return false;
+  }
+
+  // g_child_watch_add is necessary to prevent the process from becoming a
+  // zombie.
+  // TODO(yusukes): port g_child_watch_add to base/process_utils_posix.cc.
+  const base::ProcessId pid = base::GetProcId(handle);
+  g_child_watch_add(pid, watch_func, this);
+
+  *process_handle = handle;
+  VLOG(1) << command_line << "is started. PID=" << pid;
+  return true;
+}
+
+// static
+void IBusControllerImpl::SetInputMethodConfigCallback(GObject* source_object,
+                                                      GAsyncResult* res,
+                                                      gpointer user_data) {
+  IBusConfig* config = IBUS_CONFIG(user_data);
+  g_return_if_fail(config);
+
+  GError* error = NULL;
+  const gboolean result =
+      ibus_config_set_value_async_finish(config, res, &error);
+
+  if (!result) {
+    std::string message = "(unknown error)";
+    if (error && error->message) {
+      message = error->message;
+    }
+    LOG(ERROR) << "ibus_config_set_value_async failed: " << message;
+  }
+
+  if (error)
+    g_error_free(error);
+  g_object_unref(config);
+}
+
+// static
+void IBusControllerImpl::OnIBusDaemonExit(GPid pid,
+                                          gint status,
+                                          IBusControllerImpl* controller) {
+  if (controller->process_handle_ != base::kNullProcessHandle &&
+      base::GetProcId(controller->process_handle_) == pid) {
+    controller->process_handle_ = base::kNullProcessHandle;
+  }
+  // Restart the daemon if needed.
+  controller->MaybeLaunchIBusDaemon();
+}
+#endif  // defined(HAVE_IBUS)
+
+// static
+bool IBusControllerImpl::FindAndUpdatePropertyForTesting(
+    const chromeos::input_method::InputMethodProperty& new_prop,
+    chromeos::input_method::InputMethodPropertyList* prop_list) {
+  return FindAndUpdateProperty(new_prop, prop_list);
+}
+
+}  // namespace input_method
+}  // namespace chromeos