Re-factor Ash Message Center code part 4/4

ash/system/web_notification/message_center.h

+// 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.
+
+#ifndef ASH_SYSTEM_WEB_NOTIFICATION_MESSAGE_CENTER_H_
+#define ASH_SYSTEM_WEB_NOTIFICATION_MESSAGE_CENTER_H_
+
+#include "ash/ash_export.h"
+#include "ash/system/web_notification/web_notification_list.h"
+#include "base/memory/scoped_ptr.h"
+
+// Class for managing the WebNotificationList. The client (e.g. Chrome) calls
+// [Add|Remove|Update]Notification to create and update notifications in the
+// list. It can also implement Delegate to receive callbacks when a
+// notification is removed (closed), or clicked on.
+// If a Host is provided, it will be informed when the notification list
+// changes, and is expected to handle creating, showing, and hiding of any
+// bubbles.
+
+namespace message_center {
+
+class ASH_EXPORT MessageCenter : public WebNotificationList::Delegate {
+ public:
+  // Class that hosts the message center.
+  class ASH_EXPORT Host {
+   public:
+    // Called when the notification list has changed. |new_notification| will
+    // be true if a notification was added or updated.
+    virtual void MessageCenterChanged(bool new_notification) = 0;
+
+   protected:
+    virtual ~Host() {}
+  };
+
+  class ASH_EXPORT Delegate {
+   public:
+    // Called when the notification associated with |notification_id| is
+    // removed (i.e. closed by the user).
+    virtual void NotificationRemoved(const std::string& notifcation_id) = 0;
+
+    // Request to disable the extension associated with |notification_id|.
+    virtual void DisableExtension(const std::string& notifcation_id) = 0;
+
+    // Request to disable notifications from the source of |notification_id|.
+    virtual void DisableNotificationsFromSource(
+        const std::string& notifcation_id) = 0;
+
+    // Request to show the notification settings (|notification_id| is used
+    // to identify the requesting browser context).
+    virtual void ShowSettings(const std::string& notifcation_id) = 0;
+
+    // Called when the notification body is clicked on.
+    virtual void OnClicked(const std::string& notifcation_id) = 0;
+
+   protected:
+    virtual ~Delegate() {}
+  };
+
+  // |host| is expected to manage any notification bubbles. It may be NULL.
+  explicit MessageCenter(Host* host);
+
+  virtual ~MessageCenter();
+
+  // Called once to set the delegate.
+  void SetDelegate(Delegate* delegate);
+
+  // Informs the notification list whether the message center is visible.
+  // This affects whether or not a message has been "read".
+  void SetMessageCenterVisible(bool visible);
+
+  // Accessors to notification_list_
+  size_t NotificationCount() const;
+  size_t UnreadNotificationCount() const;
+  bool HasPopupNotifications() const;
+
+  // Adds a new notification. |id| is a unique identifier, used to update or
+  // remove notifications. |title| and |meesage| describe the notification text.
+  // Use SetNotificationImage to set the icon image. If |extension_id| is
+  // provided then 'Disable extension' will appear in a dropdown menu and the
+  // id will be used to disable notifications from the extension. Otherwise if
+  // |display_source| is provided, a menu item showing the source and allowing
+  // notifications from that source to be disabled will be shown. All actual
+  // disabling is handled by the Delegate.
+  void AddNotification(const std::string& id,
+                       const string16& title,
+                       const string16& message,
+                       const string16& display_source,
+                       const std::string& extension_id);
+
+  // Updates an existing notification with id = old_id and set its id to new_id.
+  void UpdateNotification(const std::string& old_id,
+                          const std::string& new_id,
+                          const string16& title,
+                          const string16& message);
+
+  // Removes an existing notification.
+  void RemoveNotification(const std::string& id);
+
+  // Sets the notification image.
+  void SetNotificationImage(const std::string& id,
+                            const gfx::ImageSkia& image);
+
+  WebNotificationList* notification_list() { return notification_list_.get(); }
+
+  // Overridden from WebNotificationList::Delegate.
+  virtual void SendRemoveNotification(const std::string& id) OVERRIDE;
+  virtual void SendRemoveAllNotifications() OVERRIDE;
+  virtual void DisableNotificationByExtension(const std::string& id) OVERRIDE;
+  virtual void DisableNotificationByUrl(const std::string& id) OVERRIDE;
+  virtual void ShowNotificationSettings(const std::string& id) OVERRIDE;
+  virtual void OnNotificationClicked(const std::string& id) OVERRIDE;
+  virtual message_center::WebNotificationList* GetNotificationList() OVERRIDE;
+
+ private:
+  scoped_ptr<WebNotificationList> notification_list_;
+  Host* host_;
+  Delegate* delegate_;
+
+  DISALLOW_COPY_AND_ASSIGN(MessageCenter);
+};
+
+}  // namespace message_center
+
+#endif  // ASH_SYSTEM_WEB_NOTIFICATION_MESSAGE_CENTER_H_