Lazy initialization for ExtensionInputMethodEventRouter

chrome/browser/chromeos/extensions/input_method_api.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/extensions/input_method_api.h"
 
 #include "base/values.h"
+#include "chrome/browser/chromeos/extensions/input_method_api_factory.h"
 #include "chrome/browser/chromeos/extensions/input_method_event_router.h"
 #include "chrome/browser/chromeos/input_method/input_method_configuration.h"
 #include "chrome/browser/chromeos/input_method/input_method_manager.h"
-#include "chrome/browser/extensions/extension_service.h"
+#include "chrome/browser/extensions/event_names.h"
 #include "chrome/browser/extensions/extension_system.h"
 #include "chrome/browser/profiles/profile.h"
 
 namespace extensions {
 
 GetInputMethodFunction::GetInputMethodFunction() {
 }
 
 GetInputMethodFunction::~GetInputMethodFunction() {
 }
 
 bool GetInputMethodFunction::RunImpl() {
 #if !defined(OS_CHROMEOS)
   NOTREACHED();
   return false;
 #else
   chromeos::ExtensionInputMethodEventRouter* router =
-      extensions::ExtensionSystem::Get(profile_)->extension_service()->
-          input_method_event_router();
+      InputMethodAPI::Get(profile_)->input_method_event_router();
   chromeos::input_method::InputMethodManager* manager =
       chromeos::input_method::GetInputMethodManager();
   const std::string input_method =
       router->GetInputMethodForXkb(manager->GetCurrentInputMethod().id());

[Yoyo Zhou, 2012/12/13 18:27:03]

I was looking at this earlier and it seems like GetInputMethodForXkb should be a
static function. (And it makes more sense for it to live in InputMethodAPI than
in InputMethodEventRouter, in my opinion.)

This means the input_method_event_router doesn't have to be started except in
OnListenerAdded.

[Joe Thomas, 2012/12/17 20:56:28]

Done. that makes sense.

   SetResult(Value::CreateStringValue(input_method));
   return true;
 #endif
 }
 
+InputMethodAPI::InputMethodAPI(Profile* profile)
+    : profile_(profile) {
+  ExtensionSystem::Get(profile_)->event_router()->RegisterObserver(
+      this, event_names::kOnInputMethodChanged);
+}
+
+InputMethodAPI::~InputMethodAPI() {
+}
+
+// static
+InputMethodAPI* InputMethodAPI::Get(Profile* profile) {
+  return InputMethodAPIFactory::GetForProfile(profile);
+}
+
+chromeos::ExtensionInputMethodEventRouter*
+    InputMethodAPI::input_method_event_router() {
+  if (!input_method_event_router_) {
+    input_method_event_router_.reset(
+        new chromeos::ExtensionInputMethodEventRouter());
+  }
+  return input_method_event_router_.get();
+}
+
+void InputMethodAPI::Shutdown() {
+  ExtensionSystem::Get(profile_)->event_router()->UnregisterObserver(this);
+}
+
+void InputMethodAPI::OnListenerAdded(
+    const extensions::EventListenerInfo& details) {
+  input_method_event_router();
+  ExtensionSystem::Get(profile_)->event_router()->UnregisterObserver(this);
+}
+
 }  // namespace extensions