Decompose BrowserStateMonitor into two parts, simplifying unit tests and APIs.

chrome/browser/chromeos/input_method/input_method_persistence.cc

Index: chrome/browser/chromeos/input_method/input_method_persistence.cc
diff --git a/chrome/browser/chromeos/input_method/input_method_persistence.cc b/chrome/browser/chromeos/input_method/input_method_persistence.cc
new file mode 100644
index 0000000000000000000000000000000000000000..4bb10e9bd42a9e1b85ac25176ae4a46bd3f53676
--- /dev/null
+++ b/chrome/browser/chromeos/input_method/input_method_persistence.cc
@@ -0,0 +1,96 @@
+// 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/input_method_persistence.h"
+
+#include "base/logging.h"
+#include "chrome/browser/browser_process.h"
+#include "chrome/browser/chromeos/input_method/input_method_util.h"
+#include "chrome/browser/chromeos/language_preferences.h"
+#include "chrome/browser/prefs/pref_service.h"
+#include "chrome/browser/profiles/profile.h"
+#include "chrome/browser/profiles/profile_manager.h"
+#include "chrome/common/pref_names.h"
+
+namespace chromeos {
+namespace input_method {
+namespace {
+
+void PersistSystemInputMethod(const std::string& input_method) {
+  if (!g_browser_process || !g_browser_process->local_state())
+    return;
+
+  g_browser_process->local_state()->SetString(
+        language_prefs::kPreferredKeyboardLayout, input_method);
+}
+
+void PersistUserInputMethod(const std::string& input_method) {
+  PrefServiceBase* user_prefs = NULL;
+  Profile* profile = ProfileManager::GetDefaultProfile();
+  if (profile)
+    user_prefs = profile->GetPrefs();
+  if (!user_prefs)
+    return;
+
+  const std::string current_input_method_on_pref =
+      user_prefs->GetString(prefs::kLanguageCurrentInputMethod);
+  if (current_input_method_on_pref == input_method)
+    return;
+
+  user_prefs->SetString(prefs::kLanguagePreviousInputMethod,
+                        current_input_method_on_pref);
+  user_prefs->SetString(prefs::kLanguageCurrentInputMethod,
+                        input_method);
+}
+
+}  // namespace
+
+InputMethodPersistence::InputMethodPersistence(
+    InputMethodManager* input_method_manager)
+    : input_method_manager_(input_method_manager),
+      state_(InputMethodManager::STATE_LOGIN_SCREEN) {
+  input_method_manager_->AddObserver(this);
+}
+
+InputMethodPersistence::~InputMethodPersistence() {
+  input_method_manager_->RemoveObserver(this);
+}
+
+void InputMethodPersistence::InputMethodChanged(
+    InputMethodManager* manager, bool show_message) {
+  DCHECK_EQ(input_method_manager_, manager);
+  const std::string current_input_method =
+      manager->GetCurrentInputMethod().id();
+  // Save the new input method id depending on the current browser state.
+  switch (state_) {
+    case InputMethodManager::STATE_LOGIN_SCREEN:
+      if (!InputMethodUtil::IsKeyboardLayout(current_input_method)) {
+        DVLOG(1) << "Only keyboard layouts are supported: "
+                 << current_input_method;
+        return;
+      }
+      PersistSystemInputMethod(current_input_method);
+      return;
+    case InputMethodManager::STATE_BROWSER_SCREEN:
+      PersistUserInputMethod(current_input_method);
+      return;
+    case InputMethodManager::STATE_LOCK_SCREEN:
+      // We use a special set of input methods on the screen. Do not update.
+      return;
+    case InputMethodManager::STATE_TERMINATING:
+      return;
+  }
+  NOTREACHED();
+}
+
+void InputMethodPersistence::InputMethodPropertyChanged(
+    InputMethodManager* manager) {}
+
+void InputMethodPersistence::OnSessionStateChange(
+    InputMethodManager::State new_state) {
+  state_ = new_state;
+}
+
+}  // namespace input_method
+}  // namespace chromeos