Add ability to add/remove observers for login ui shown/closed

to LoginUIService. This will be used by the extension API to show
login UI in a popup and then obseve when it is closed and respond back
to the extension accordingly.

Review URL: https://chromiumcodereview.appspot.com/10699013

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@146143 0039d316-1c4b-4281-b951-d872f2087c98

chrome/browser/ui/webui/signin/login_ui_service.cc

@@ -13,14 +13,26 @@ LoginUIService::LoginUIService() : ui_(NULL) {
 
 LoginUIService::~LoginUIService() {}
 
+void LoginUIService::AddObserver(LoginUIService::Observer* observer) {
+  observer_list_.AddObserver(observer);
+}
+
+void LoginUIService::RemoveObserver(LoginUIService::Observer* observer) {
+  observer_list_.RemoveObserver(observer);
+}
+
 void LoginUIService::SetLoginUI(LoginUI* ui) {
   DCHECK(!current_login_ui() || current_login_ui() == ui);
   ui_ = ui;
+  FOR_EACH_OBSERVER(Observer, observer_list_, OnLoginUIShown(ui_));
 }
 
 void LoginUIService::LoginUIClosed(LoginUI* ui) {
-  if (current_login_ui() == ui)
-    ui_ = NULL;
+  if (current_login_ui() != ui)
+    return;
+
+  ui_ = NULL;
+  FOR_EACH_OBSERVER(Observer, observer_list_, OnLoginUIClosed(ui));
 }
 
 void LoginUIService::ShowLoginUI(Browser* browser) {

chrome/browser/ui/webui/signin/login_ui_service.h

@@ -7,6 +7,7 @@
 #pragma once
 
 #include "base/basictypes.h"
+#include "base/observer_list.h"
 #include "chrome/browser/profiles/profile_keyed_service.h"
 
 class Browser;
@@ -29,6 +30,21 @@ class LoginUIService : public ProfileKeyedService {
     virtual ~LoginUI() {}
   };
 
+  // Interface for obervers of LoginUIService.
+  class Observer {
+   public:
+    // Called when a new login UI is shown.
+    // |ui| The login UI that was just shown. Will never be null.
+    virtual void OnLoginUIShown(LoginUI* ui) = 0;
+
+    // Called when a login UI is closed.
+    // |ui| The login UI that was just closed; will never be null.
+    virtual void OnLoginUIClosed(LoginUI* ui) = 0;
+
+   protected:
+    virtual ~Observer() {}
+  };
+
   LoginUIService();
   virtual ~LoginUIService();
 
@@ -37,6 +53,10 @@ class LoginUIService : public ProfileKeyedService {
     return ui_;
   }
 
+  // |observer| The observer to add or remove; cannot be NULL.
+  void AddObserver(Observer* observer);
+  void RemoveObserver(Observer* observer);
+
   // Sets the currently active login UI. It is illegal to call this if there is
   // already login UI visible.
   void SetLoginUI(LoginUI* ui);
@@ -54,6 +74,9 @@ class LoginUIService : public ProfileKeyedService {
   // Weak pointer to the currently active login UI, or null if none.
   LoginUI* ui_;
 
+  // List of observers.
+  ObserverList<Observer> observer_list_;
+
   DISALLOW_COPY_AND_ASSIGN(LoginUIService);
 };
 

chrome/browser/ui/webui/signin/login_ui_service_unittest.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/ui/webui/signin/login_ui_service.h"
+
+#include "base/compiler_specific.h"
+#include "base/logging.h"
+#include "testing/gtest/include/gtest/gtest.h"
+
+class TestLoginUI : public LoginUIService::LoginUI {
+ public:
+  TestLoginUI() { }
+  virtual ~TestLoginUI() { }
+  virtual void FocusUI() OVERRIDE { }
+  virtual void CloseUI() OVERRIDE { }
+
+ private:
+  DISALLOW_COPY_AND_ASSIGN(TestLoginUI);
+};
+
+class TestObserver : public LoginUIService::Observer {
+ public:
+  TestObserver() : ui_shown_count_(0),
+                   ui_closed_count_(0) {
+  }
+
+  int ui_shown_count() const { return ui_shown_count_; }
+  int ui_closed_count() const { return ui_closed_count_; }
+
+ private:
+  virtual void OnLoginUIShown(LoginUIService::LoginUI* ui) OVERRIDE {
+    ++ui_shown_count_;
+  }
+
+  virtual void OnLoginUIClosed(LoginUIService::LoginUI* ui) OVERRIDE {
+    ++ui_closed_count_;
+  }
+
+  int ui_shown_count_;
+  int ui_closed_count_;
+
+  DISALLOW_COPY_AND_ASSIGN(TestObserver);
+};
+
+class LoginUIServiceTest : public testing::Test {
+ public:
+  LoginUIServiceTest() { }
+  virtual ~LoginUIServiceTest() { }
+
+ protected:
+  LoginUIService service_;
+  TestObserver observer_;
+
+  DISALLOW_COPY_AND_ASSIGN(LoginUIServiceTest);
+};
+
+// Test that the observer is called back when login UI is shown
+// or closed.
+TEST_F(LoginUIServiceTest, LoginUIServiceObserver) {
+  service_.AddObserver(&observer_);
+  EXPECT_EQ(NULL, service_.current_login_ui());
+  TestLoginUI ui;
+  service_.SetLoginUI(&ui);
+  EXPECT_EQ(1, observer_.ui_shown_count());
+
+  // If a different UI is closed than the one that was shown, no
+  // notification should be fired.
+  TestLoginUI other_ui;
+  service_.LoginUIClosed(&other_ui);
+  EXPECT_EQ(1, observer_.ui_shown_count());
+
+  // If the right UI is closed, notification should be fired.
+  service_.LoginUIClosed(&ui);
+  EXPECT_EQ(1, observer_.ui_closed_count());
+  service_.RemoveObserver(&observer_);
+}

chrome/chrome_tests.gypi

@@ -1852,6 +1852,7 @@
         'browser/ui/webui/policy_ui_unittest.cc',
         'browser/ui/webui/print_preview/print_preview_handler_unittest.cc',
         'browser/ui/webui/print_preview/print_preview_ui_unittest.cc',
+        'browser/ui/webui/signin/login_ui_service_unittest.cc',
         'browser/ui/webui/sync_internals_ui_unittest.cc',
         'browser/ui/webui/sync_setup_handler_unittest.cc',
         'browser/ui/webui/theme_source_unittest.cc',