src/apps/mediaplayer/support/Notifier.h

   1 /*
   2  * Copyright 2006-2007, Haiku.
   3  * Distributed under the terms of the MIT License.
   4  *
   5  * Authors:
   6  *              Stephan Aßmus <superstippi@gmx.de>
   7  */
   8 #ifndef NOTIFIER_H
   9 #define NOTIFIER_H
  10
  11 #include <List.h>
  12
  13 class Listener;
  14
  15 class Notifier {
  16  public:
  17                                                                 Notifier();
  18         virtual                                         ~Notifier();
  19
  20                         bool                            AddListener(Listener* listener);
  21                         bool                            RemoveListener(Listener* listener);
  22
  23                         int32                           CountListeners() const;
  24                         Listener*                       ListenerAtFast(int32 index) const;
  25
  26                         void                            Notify() const;
  27
  28                         void                            SuspendNotifications(bool suspend);
  29
  30                         bool                            HasPendingNotifications() const
  31                                                                         { return fPendingNotifications; }
  32
  33  private:
  34                         BList                           fListeners;
  35
  36                         int32                           fSuspended;
  37         mutable bool                            fPendingNotifications;
  38 };
  39
  40 class AutoNotificationSuspender {
  41  public:
  42                                                                 AutoNotificationSuspender(Notifier* object)
  43                                                                         : fObject(object)
  44                                                                 {
  45                                                                         fObject->SuspendNotifications(true);
  46                                                                 }
  47
  48         virtual                                         ~AutoNotificationSuspender()
  49                                                                 {
  50                                                                         fObject->SuspendNotifications(false);
  51                                                                 }
  52  private:
  53                         Notifier*                       fObject;
  54 };
  55
  56 #endif // NOTIFIER_H