//===================================================================================

// Microsoft patterns & practices

// Composite Application Guidance for Windows Presentation Foundation and Silverlight

//===================================================================================

// Copyright (c) Microsoft Corporation.  All rights reserved.

// THIS CODE AND INFORMATION IS PROVIDED "AS IS" WITHOUT WARRANTY

// OF ANY KIND, EITHER EXPRESSED OR IMPLIED, INCLUDING BUT NOT

// LIMITED TO THE IMPLIED WARRANTIES OF MERCHANTABILITY AND

// FITNESS FOR A PARTICULAR PURPOSE.

//===================================================================================

// The example companies, organizations, products, domain names,

// e-mail addresses, logos, people, places, and events depicted

// herein are fictitious.  No association with any real company,

// organization, product, domain name, email address, logo, person,

// places, or events is intended or should be inferred.

//===================================================================================

using System;



namespace Microsoft.Practices.Composite.Events

{

    /// <summary>

    /// Subsription token returned from <see cref="EventBase"/> on subscribe.

    /// </summary>

    public class SubscriptionToken : IEquatable<SubscriptionToken>

    {

        private readonly Guid _token;



        /// <summary>

        /// Initializes a new instance of <see cref="SubscriptionToken"/>.

        /// </summary>

        public SubscriptionToken()

        {

            _token = Guid.NewGuid();

        }



        ///<summary>

        ///Indicates whether the current object is equal to another object of the same type.

        ///</summary>

        ///<returns>

        ///<see langword="true"/> if the current object is equal to the <paramref name="other" /> parameter; otherwise, <see langword="false"/>.

        ///</returns>

        ///<param name="other">An object to compare with this object.</param>

        public bool Equals(SubscriptionToken other)

        {

            if (other == null) return false;

            return Equals(_token, other._token);

        }



        ///<summary>

        ///Determines whether the specified <see cref="T:System.Object" /> is equal to the current <see cref="T:System.Object" />.

        ///</summary>

        ///<returns>

        ///true if the specified <see cref="T:System.Object" /> is equal to the current <see cref="T:System.Object" />; otherwise, false.

        ///</returns>

        ///<param name="obj">The <see cref="T:System.Object" /> to compare with the current <see cref="T:System.Object" />. </param>

        ///<exception cref="T:System.NullReferenceException">The <paramref name="obj" /> parameter is null.</exception><filterpriority>2</filterpriority>

        public override bool Equals(object obj)

        {

            if (ReferenceEquals(this, obj)) return true;

            return Equals(obj as SubscriptionToken);

        }



        ///<summary>

        ///Serves as a hash function for a particular type. 

        ///</summary>

        ///<returns>

        ///A hash code for the current <see cref="T:System.Object" />.

        ///</returns>

        ///<filterpriority>2</filterpriority>

        public override int GetHashCode()

        {

            return _token.GetHashCode();

        }

    }

}