class/WindowsBase/System.Collections.Specialized/CollectionChangedEventManager.cs

   1 // Permission is hereby granted, free of charge, to any person obtaining
   2 // a copy of this software and associated documentation files (the
   3 // "Software"), to deal in the Software without restriction, including
   4 // without limitation the rights to use, copy, modify, merge, publish,
   5 // distribute, sublicense, and/or sell copies of the Software, and to
   6 // permit persons to whom the Software is furnished to do so, subject to
   7 // the following conditions:
   8 //
   9 // The above copyright notice and this permission notice shall be
  10 // included in all copies or substantial portions of the Software.
  11 //
  12 // THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
  13 // EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
  14 // MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
  15 // NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
  16 // LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
  17 // OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
  18 // WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
  19 //
  20 // Copyright (c) 2007 Novell, Inc. (http://www.novell.com)
  21 //
  22 // Authors:
  23 //      Chris Toshok (toshok@ximian.com)
  24 //
  25
  26 using System;
  27 using System.Windows;
  28
  29 namespace System.Collections.Specialized {
  30
  31         public class CollectionChangedEventManager : WeakEventManager
  32         {
  33                 internal CollectionChangedEventManager ()
  34                 {
  35                 }
  36
  37                 public static void AddListener (INotifyCollectionChanged source, IWeakEventListener listener)
  38                 {
  39                         CurrentManager.ProtectedAddListener (source, listener);
  40                 }
  41
  42                 public static void RemoveListener (INotifyCollectionChanged source, IWeakEventListener listener)
  43                 {
  44                         CurrentManager.ProtectedAddListener (source, listener);
  45                 }
  46
  47                 protected override void StartListening (object source)
  48                 {
  49                         INotifyCollectionChanged inotify = (INotifyCollectionChanged) source;
  50                         inotify.CollectionChanged += OnCollectionChanged;
  51                 }
  52
  53                 protected override void StopListening (object source)
  54                 {
  55                         INotifyCollectionChanged inotify = (INotifyCollectionChanged) source;
  56                         inotify.CollectionChanged -= OnCollectionChanged;
  57                 }
  58
  59                 private void OnCollectionChanged (object sender, NotifyCollectionChangedEventArgs e)
  60                 {
  61                         DeliverEvent (sender, e);
  62                 }
  63
  64                 private static object CurrentManagerLock = new object ();
  65
  66                 private static CollectionChangedEventManager CurrentManager {
  67                         get {
  68                                 lock (CurrentManagerLock) {
  69                                         CollectionChangedEventManager manager = (CollectionChangedEventManager)GetCurrentManager (typeof (CollectionChangedEventManager));
  70                                         if (manager == null) {
  71                                                 manager = new CollectionChangedEventManager ();
  72                                                 SetCurrentManager (typeof (CollectionChangedEventManager), manager);
  73                                         }
  74                                         return manager;
  75                                 }
  76                         }
  77                 }
  78         }
  79 }
  80