text: // 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_MESSAGE_CENTER_TRAY_DELEGATE_H_
  #define UI_MESSAGE_CENTER_MESSAGE_CENTER_TRAY_DELEGATE_H_
  
  #include "ui/message_center/message_center_export.h"
  
  namespace message_center {
  
  class MessageCenterTray;
  
  // A MessageCenterTrayDelegate class is responsible for managing the various UI
  // surfaces that should be displayed when the MessageCenter is changed.
  class MESSAGE_CENTER_EXPORT MessageCenterTrayDelegate {
   public:
    virtual ~MessageCenterTrayDelegate() {};
  
    // Called whenever a change to the visible UI has occurred.
    virtual void OnMessageCenterTrayChanged() = 0;
  
    // Display the popup bubbles for new notifications to the user.  Returns true
    // if popups were actually displayed to the user.
    virtual bool ShowPopups() = 0;
  
    // Remove the popup bubbles from the UI.
    virtual void HidePopups() = 0;
  
    // Display the message center containing all undismissed notifications to the
    // user.  Returns true if the center was actually displayed to the user.
    virtual bool ShowMessageCenter() = 0;
  
    // Remove the message center from the UI.
    virtual void HideMessageCenter() = 0;
  
    // Display the notifier settings as a bubble.
    virtual bool ShowNotifierSettings() = 0;
  
    // Returns true if the context menu for a notification is currently enabled.
    virtual bool IsContextMenuEnabled() const = 0;
  
    // Show a platform-specific UI that informs the user how to open the message
    // center.
    virtual void DisplayFirstRunBalloon() {}
  
    virtual MessageCenterTray* GetMessageCenterTray() = 0;
  };
  
  }  // namespace message_center
  
  #endif  // UI_MESSAGE_CENTER_MESSAGE_CENTER_TRAY_DELEGATE_H_
  