CollectionChangedEventManager.cs source code in C# .NET

Source code for the .NET framework in C#

                        
Code:

                         / 4.0 / 4.0 / untmp / DEVDIV_TFS / Dev10 / Releases / RTMRel / wpf / src / Base / System / Collections / Specialized / CollectionChangedEventManager.cs / 1305600 / CollectionChangedEventManager.cs
                        

                        
                            //---------------------------------------------------------------------------- 
//
// 
//    Copyright (C) Microsoft Corporation.  All rights reserved.
//  
//
// Description: Manager for the CollectionChanged event in the "weak event listener" 
//              pattern.  See WeakEventTable.cs for an overview. 
//
//--------------------------------------------------------------------------- 

using System;
using System.Windows;       // WeakEventManager
 
namespace System.Collections.Specialized
{ 
    ///  
    /// Manager for the INotifyCollectionChanged.CollectionChanged event.
    ///  
    public class CollectionChangedEventManager : WeakEventManager
    {
        #region Constructors
 
        //
        //  Constructors 
        // 

        private CollectionChangedEventManager() 
        {
        }

        #endregion Constructors 

        #region Public Methods 
 
        //
        //  Public Methods 
        //

        /// 
        /// Add a listener to the given source's event. 
        /// 
        public static void AddListener(INotifyCollectionChanged source, IWeakEventListener listener) 
        { 
            if (source == null)
                throw new ArgumentNullException("source"); 
            if (listener == null)
                throw new ArgumentNullException("listener");

            CurrentManager.ProtectedAddListener(source, listener); 
        }
 
        ///  
        /// Remove a listener to the given source's event.
        ///  
        public static void RemoveListener(INotifyCollectionChanged source, IWeakEventListener listener)
        {
            /* for app-compat, allow RemoveListener(null, x) - it's a no-op (see Dev10 796788)
            if (source == null) 
                throw new ArgumentNullException("source");
            */ 
            if (listener == null) 
                throw new ArgumentNullException("listener");
 
            CurrentManager.ProtectedRemoveListener(source, listener);
        }

        #endregion Public Methods 

        #region Protected Methods 
 
        //
        //  Protected Methods 
        //

        /// 
        /// Listen to the given source for the event. 
        /// 
        protected override void StartListening(object source) 
        { 
            INotifyCollectionChanged typedSource = (INotifyCollectionChanged)source;
            typedSource.CollectionChanged += new NotifyCollectionChangedEventHandler(OnCollectionChanged); 
        }

        /// 
        /// Stop listening to the given source for the event. 
        /// 
        protected override void StopListening(object source) 
        { 
            INotifyCollectionChanged typedSource = (INotifyCollectionChanged)source;
            typedSource.CollectionChanged -= new NotifyCollectionChangedEventHandler(OnCollectionChanged); 
        }

        #endregion Protected Methods
 
        #region Private Properties
 
        // 
        //  Private Properties
        // 

        // get the event manager for the current thread
        private static CollectionChangedEventManager CurrentManager
        { 
            get
            { 
                Type managerType = typeof(CollectionChangedEventManager); 
                CollectionChangedEventManager manager = (CollectionChangedEventManager)GetCurrentManager(managerType);
 
                // at first use, create and register a new manager
                if (manager == null)
                {
                    manager = new CollectionChangedEventManager(); 
                    SetCurrentManager(managerType, manager);
                } 
 
                return manager;
            } 
        }

        #endregion Private Properties
 
        #region Private Methods
 
        // 
        //  Private Methods
        // 

        // event handler for CollectionChanged event
        private void OnCollectionChanged(object sender, NotifyCollectionChangedEventArgs args)
        { 
            DeliverEvent(sender, args);
        } 
 
        #endregion Private Methods
    } 
}


// File provided for Reference Use Only by Microsoft Corporation (c) 2007.
// Copyright (c) Microsoft Corporation. All rights reserved.

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