src/apps/mediaplayer/support/Notifier.cpp

   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
   9 #include "Notifier.h"
  10
  11 #include <stdio.h>
  12 #include <typeinfo>
  13
  14 #include <OS.h>
  15
  16 #include "Listener.h"
  17
  18 // constructor
  19 Notifier::Notifier()
  20         : fListeners(2),
  21           fSuspended(0),
  22           fPendingNotifications(false)
  23 {
  24 }
  25
  26 // destructor
  27 Notifier::~Notifier()
  28 {
  29         if (fListeners.CountItems() > 0) {
  30                 char message[256];
  31                 Listener* o = (Listener*)fListeners.ItemAt(0);
  32                 sprintf(message, "Notifier::~Notifier() - %" B_PRId32
  33                                                  " listeners still watching, first: %s\n",
  34                                                  fListeners.CountItems(), typeid(*o).name());
  35                 debugger(message);
  36         }
  37 }
  38
  39 // AddListener
  40 bool
  41 Notifier::AddListener(Listener* listener)
  42 {
  43         if (listener && !fListeners.HasItem((void*)listener)) {
  44                 return fListeners.AddItem((void*)listener);
  45         }
  46         return false;
  47 }
  48
  49 // RemoveListener
  50 bool
  51 Notifier::RemoveListener(Listener* listener)
  52 {
  53         return fListeners.RemoveItem((void*)listener);
  54 }
  55
  56 // CountListeners
  57 int32
  58 Notifier::CountListeners() const
  59 {
  60         return fListeners.CountItems();
  61 }
  62
  63 // ListenerAtFast
  64 Listener*
  65 Notifier::ListenerAtFast(int32 index) const
  66 {
  67         return (Listener*)fListeners.ItemAtFast(index);
  68 }
  69
  70 // #pragma mark -
  71
  72 // Notify
  73 void
  74 Notifier::Notify() const
  75 {
  76         if (!fSuspended) {
  77                 BList observers(fListeners);
  78                 int32 count = observers.CountItems();
  79                 for (int32 i = 0; i < count; i++)
  80                         ((Listener*)observers.ItemAtFast(i))->ObjectChanged(this);
  81                 fPendingNotifications = false;
  82         } else {
  83                 fPendingNotifications = true;
  84         }
  85 }
  86
  87 // SuspendNotifications
  88 void
  89 Notifier::SuspendNotifications(bool suspend)
  90 {
  91         if (suspend)
  92                 fSuspended++;
  93         else
  94                 fSuspended--;
  95
  96         if (fSuspended < 0) {
  97                 fprintf(stderr, "Notifier::SuspendNotifications(false) - "
  98                                                 "error: suspend level below zero!\n");
  99                 fSuspended = 0;
 100         }
 101
 102         if (!fSuspended && fPendingNotifications)
 103                 Notify();
 104 }
 105