Made notification center notifications collapsed and expandable.

ui/message_center/notification_change_delegate.h

+// Copyright (c) 2013 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.
+
+#ifndef UI_MESSAGE_CENTER_NOTIFICATION_CHANGE_DELEGATE_H_
+#define UI_MESSAGE_CENTER_NOTIFICATION_CHANGE_DELEGATE_H_
+
+#include <string>
+
+#include "ui/gfx/native_widget_types.h"
+
+namespace message_center {
+
+// For classes that need to handle or propagate notification changes.
+class MESSAGE_CENTER_EXPORT NotificationChangeDelegate {

[Jun Mukai, 2013/03/02 02:23:58]

Sorry I didn't saying this, but I still don't like the name 'delegate'... I
prefer NotificationChangeController here.  Does that sound better?
I'm not certain that my naming sense is better (you know, I'm not a native
English speaker), so I believe you. Please ignore my comment if you think I'm
wrong. Thanks!

[dharcourt, 2013/03/04 21:17:52]

Yes, you're right, and "delegate" is wrong for this. Apart from anything else,
delegates typically modify the behavior of objects delegating to them, which is
not the case here.

I think "Controller" may be wrong also, as controller has a strong meaning in
user interface code associated with the MVC pattern, and NotificationChangeX
classes don't need to be MVC controllers.

How about "NotificationChangeObserver"? There are other examples of that name
being used in the code base for this kind of thing:
ui/views/widget/widget_observer.h, ui/aura/window_observer.h,
base/prefs/pref_observer.h.

In keeping with those other examples, I've change the method names to indicate
more clearly that they are event notifications with an "On" prefix.

Let me know what you think. If "NotificationChangeObserver" doesn't work for
you, alternatives may be "NotificationChangeWatcher" or
"NotificationChangeMonitor".

Thanks!

+ public:
+  virtual ~NotificationChangeDelegate() {};
+
+  virtual void RemoveNotification(const std::string& id, bool by_user) = 0;
+  virtual void RemoveAllNotifications(bool by_user) = 0;
+
+  virtual void DisableNotificationsByExtension(const std::string& id) = 0;
+  virtual void DisableNotificationsByUrl(const std::string& id) = 0;
+
+  virtual void ShowNotificationSettings(const std::string& id) = 0;
+  virtual void ShowNotificationSettingsDialog(gfx::NativeView context) = 0;
+
+  virtual void OnExpanded(const std::string& id) = 0;
+  virtual void OnClicked(const std::string& id) = 0;
+  virtual void OnButtonClicked(const std::string& id, int button_index) = 0;
+};
+
+}  // namespace message_center
+
+#endif // UI_MESSAGE_CENTER_NOTIFICATION_CHANGE_DELEGATE_H_