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

// 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;

using Microsoft.Practices.Prism.ViewModel;



namespace MVVM.Client.ViewModels

{

    /// <summary>

    /// View model for a question.

    /// </summary>

    public abstract class QuestionViewModel : NotificationObject

    {

        private bool hasChanges;



        protected QuestionViewModel()

        {

        }



        public event EventHandler<EventArgs> ResponseChanged;



        public bool HasChanges

        {

            get

            {

                return this.hasChanges;

            }

        }



        public abstract bool ResponseComplete { get; }



        protected void OnResponseChanged()

        {

            var handler = this.ResponseChanged;

            if (handler != null)

            {

                handler(this, EventArgs.Empty);

            }

        }



        protected void SetHasChanges()

        {

            this.hasChanges = true;

        }

    }

}