IME refactoring: ChromeOS introduce input methods State.

chrome/browser/chromeos/preferences.cc

 // 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/preferences.h"
 
 #include <vector>
 
 #include "ash/autoclick/autoclick_controller.h"
 #include "ash/magnifier/magnifier_constants.h"
@@ skipping 33 matching lines @@
 #include "url/gurl.h"
 
 namespace chromeos {
 
 static const char kFallbackInputMethodLocale[] = "en-US";
 
 Preferences::Preferences()
     : prefs_(NULL),
       input_method_manager_(input_method::InputMethodManager::Get()),
       user_(NULL),
-      user_is_primary_(false) {
+      user_is_primary_(false),
+      ime_state_outdated_(true) {
   // Do not observe shell, if there is no shell instance; e.g., in some unit
   // tests.
   if (ash::Shell::HasInstance())
     ash::Shell::GetInstance()->AddShellObserver(this);
 }
 
 Preferences::Preferences(input_method::InputMethodManager* input_method_manager)
     : prefs_(NULL),
       input_method_manager_(input_method_manager),
       user_(NULL),
-      user_is_primary_(false) {
+      user_is_primary_(false),
+      ime_state_outdated_(true) {
   // Do not observe shell, if there is no shell instance; e.g., in some unit
   // tests.
   if (ash::Shell::HasInstance())
     ash::Shell::GetInstance()->AddShellObserver(this);
 }
 
 Preferences::~Preferences() {
   prefs_->RemoveObserver(this);
   UserManager::Get()->RemoveSessionStateObserver(this);
   // If shell instance is destoryed before this preferences instance, there is
@@ skipping 454 matching lines @@
           ->SetAutoRepeatEnabled(enabled);
     }
   }
   if (reason != REASON_PREF_CHANGED ||
       pref_name == prefs::kLanguageXkbAutoRepeatDelay ||
       pref_name == prefs::kLanguageXkbAutoRepeatInterval) {
     if (user_is_active)
       UpdateAutoRepeatRate();
   }
 
-  if (reason != REASON_PREF_CHANGED && user_is_active) {
-    SetInputMethodList();
-  } else if (pref_name == prefs::kLanguagePreloadEngines && user_is_active) {
-    SetLanguageConfigStringListAsCSV(language_prefs::kGeneralSectionName,
-                                     language_prefs::kPreloadEnginesConfigName,
-                                     preload_engines_.GetValue());
+  if (pref_name == prefs::kLanguagePreloadEngines) {
+    if (reason == REASON_PREF_CHANGED && user_is_active) {
+      SetLanguageConfigStringListAsCSV(
+          language_prefs::kGeneralSectionName,
+          language_prefs::kPreloadEnginesConfigName,
+          preload_engines_.GetValue());
+    } else {
+      ime_state_outdated_ = true;
+    }
   }
 
   if (reason != REASON_PREF_CHANGED ||
       pref_name == prefs::kLanguageEnabledExtensionImes) {
     if (user_is_active) {
       std::string value(enabled_extension_imes_.GetValue());
 
       std::vector<std::string> split_values;
       if (!value.empty())
         base::SplitString(value, ',', &split_values);
@@ skipping 83 matching lines @@
 }
 
 void Preferences::OnTouchHudProjectionToggled(bool enabled) {
   if (touch_hud_projection_enabled_.GetValue() == enabled)
     return;
   if (!user_->is_active())
     return;
   touch_hud_projection_enabled_.SetValue(enabled);
 }
 
+void Preferences::ActivateInputMethods(const User* active_user) {
+  bool just_created = false;
+  if (!ime_state_) {

[Shu Chen, 2014/08/04 14:55:24]

I don't understand. Will there be single InputMethodManager::State shared for
multiple users?

[Alexander Alekseev, 2014/08/06 23:39:45]

No. Preferences belong to particular user, so this is lazy initialization of
per-user State object. 

+    ime_state_ = input_method::InputMethodManager::Get()->CreateNewState(
+        active_user->email());
+    just_created = true;
+  }
+  input_method::InputMethodManager::Get()->SetState(ime_state_);
+  if (just_created || ime_state_outdated_) {
+    SetInputMethodList();
+    ime_state_outdated_ = false;
+  }
+}
+
 void Preferences::ActiveUserChanged(const User* active_user) {
   if (active_user != user_)
     return;
+
+  ActivateInputMethods(active_user);
+
   ApplyPreferences(REASON_ACTIVE_USER_CHANGED, "");
 }
 
 }  // namespace chromeos